UBC Wiki - User contributions [en]

Course:FNH200/Lessons/Lesson 12/Page 12.9

2020-06-24T03:00:33Z

YihangChen: /* 12.9 Summary of Lesson 12 */

== 12.9 Summary of Lesson 12 ==
This lesson has been a brief overview of the topic of toxicants in foods. There are hundreds of toxicants that could be found in our food supply. We are very fortunate that here in Canada, we have the food inspection systems and regulatory mechanisms that help insure that levels of toxicants in foods are kept at levels below the no-effect level.

In this lesson, you have also learned about the causes of foodborne illness in Canada. You have gained some insight into the importance of different types of microorganisms involved in foodborne disease incidents. You have learned the importance of considering different factors in assessing the hazardous nature of toxicants or foodborne illness caused by microorganisms

Through the assigned readings, you should also have become familiar with safe food handling practices, which you should employ whenever you handle food (clean, cook, separate and chill!)

You are introduced to the concept of HACCP which is a system designed to anticipate and control food safety problems before they happen. This is accomplished with the 7 steps of the HACCP system.

Remember that the risks of food poisoning and foodborne illness are dependent on the toxicant or pathogen itself, the susceptibility of the host and factors related to the environment and handling practices.

The concepts in this lesson will help you to apply what you have learned in your daily life to minimize the risks for yourself, your family and friends.

Supplemental Videos:
# [https://www.youtube.com/watch?v=50e_Ic2rPK4&feature=emb_logo Introduction to HACCP]
# [https://www.youtube.com/watch?v=53PiVRadZAY&feature=emb_logo HACCP: The Hazard Analysis and Critical Control Point System] 
==References==
<references/>

'''Authorship:'''

FNH 200 Course content on this wiki page and associated lesson pages was originally authored by Drs. [http://www.landfood.ubc.ca/person/brent-skura/ Brent Skura], [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], and [http://www.landfood.ubc.ca/person/eunice-li-chan/ Eunice Li-Chan]. Ongoing edits and updates are contributed by past and current instructors including Drs. [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], [http://www.landfood.ubc.ca/person/azita-madadi-noei/ Azita Madadi-Noei], [http://www.landfood.ubc.ca/person/nooshin-alizadeh-pasdar/ Nooshin Alizadeh-Pasdar], and [http://www.landfood.ubc.ca/person/judy-chan/ Judy Chan].
{{cc-by-nc-sa-3.0}}

<quiz display=simple>
{1. What is the legal definition of a poison?
|type="()"}
- An effect level of 50 mg
- An effect level of 50 mg per kg body weight
- A lethal dose of 50 mg
+ A lethal dose of 50 mg per kg body weight
</quiz>

<quiz display=simple>
{ 2. Type text here or a no-break space code
|type="{}"}
Which chemical before is a good indicator of poor storage practice of tuna fish? { Histamine }
</quiz>

<quiz display=simple>
{ 3. Which of the following are NOT examples of CCP?
|type="[]"}
+ Allergenic
- Biological
+ Environmental
- Chemical
- Physical
</quiz>

<quiz display=simple>
{4. If cheddar cheese stored in the refrigerator has mould present, you can simply trim it.
|type="()"}
+ TRUE.
- FALSE.
</quiz>

<quiz display=simple>
{5. All food borne disease is due to consumption of microorganisms.
|type="()"}
- TRUE.
+ FALSE.
</quiz>

Course:FNH200/Lessons/Lesson 10/Page 10.4

2020-06-24T02:58:31Z

YihangChen:

== 10.4 Effects of Ionizing Energy Absorbed by Food - Preservation principle ==
The basis of food preservation by treatment with ionizing energy is the ability of the absorbed quanta of energy to dislodge electrons from molecules with the concomitant creation of '''free radicals''' without inducing radioactivity in the food.

When ionizing energy from a permitted source for food use is absorbed by food and collides with a molecule or atom, an ion-pair is produced if the energy from the collision is sufficient to dislodge an electron from an atomic orbit. This phenomenon can lead to breaking up of one or more bonds between atoms in the molecule, leading to new molecular fragments possessing unshared electrons (free radicals). Because of the unshared electron, free radicals are ''extremely reactive'' and tend to react with other free radicals or other molecules with unshared electrons.

It is believed that only one out of every six billion chemical bonds in bacteria or food molecules are broken by irradiation. However, the formation of ion pairs and free radicals, the reaction of free radicals with one another or other molecules, and the chemical and physical phenomena that occur as a consequence of these events form the mechanisms for the inactivation of microorganisms, enzymes and alterations of food constituents during food irradiation.

The changes induced in food by absorption of ionizing energy can arise from both '''direct''' and '''indirect effects'''. Please read the required reading '''''Irradiation and Food Safety''''' for details. You will note that many of the effects observed in foods arising from the absorption of ionizing energy are due to '''indirect effects''' as explained in the optional reading. This is shown below:[[File:FNH200_Lesson10_FreeRadicals.gif|400px|frame|center|
Figure 10.3
]]
Hydrogen, hydrogen peroxide and hydroperoxy free radicals are produced when ionizing energy is absorbed by foods (fruits, vegetables, meats, fish) that contain substantial quantities of water. Figure 10.3 shows the reactions of hydrogen '''(H)''' and hydroxyl '''(OH)''' free radicals produced by gamma irradiation of water molecules. These free radicals only exist for about '''0.0001 seconds''', but generate hydrogen peroxide (H2O2) which is the antimicrobial agent that kills bacteria, yeasts, and moulds in foods. In many cases, the free radicals are formed within the microbial cells.

As mentioned earlier, microorganisms may also be killed by a "'''direct effect'''" of the ionizing energy upon genetic material within the microbial cells that leads to the death of the microorganism. As mentioned in the required reading (''Irradiation and Food Safety'') "the damage occurring from ionizing radiation can be random and extensive, making DNA repair near impossible". In some cases, even relatively small changes in the DNA can destroy bacterial cells, and the disruption of genetic material in living cells by irradiation also enables the destruction of insects, inactivation of parasites, delaying of ripening, and prevention of sprouting.

=== Are Free Radicals Unique to Irradiated Food? ===
A concern that has been expressed in regard to the use of food irradiation is the generation of free radicals during exposure of the food to ionizing energy.

It is true that free radicals are produced in foods during irradiation. However, the free radical formation is not unique to foods which have been irradiated with ionizing energy. For example, oxidative reactions in foods containing unsaturated fats also involve free radical formation, and free radicals are also formed during the course of the Maillard browning reactions. Free radicals are also produced within our bodies and other living tissues during normal metabolism. Mechanisms (chemical and enzymatic) for inactivation of free radicals exist within the human body and other living tissues.

=== Does irradiated food become radioactive? ===
Irradiation using approved sources provides enough energy to knock an electron from the outer orbit (that is why it is termed "ionizing radiation" or "irradiation"); however, it does not have sufficient energy to penetrate the nucleus and eject neutrons, which would be required to induce radioactivity. Therefore food will NOT become radioactive by irradiation conducted using approved energy sources and within the approved limit. To become radioactive, food would need to be exposed to a '''minimum of 15 MeV''' of energy. The energy output of Cobalt 60, Cesium 137, and e-beam accelerators is carefully regulated. The maximum energy outputs allowed are '''5 or 10 MeV''', which are too low to induce radioactivity in food.

You may be interested to know that all foods are naturally radioactive, although of course at a very low level. This low background level of radioactivity arises from the naturally occurring isotopes in elements such as carbon, phosphorus, potassium, and sulfur.

Course:FNH200/Lessons/Lesson 10/Page 10.0

2020-06-24T02:57:58Z

YihangChen: /* 10.0 Overview */

Course:FNH200/Lessons/Lesson 08/Page 08.6

2020-06-24T02:57:06Z

YihangChen: /* 8.6 Summary of Lesson 8 */

== 8.6 Summary of Lesson 8 ==
* Preservation of food by dehydration involves the removal of water (thus lowering the water activity) from the food to extend the food's shelf life by slowing down microbial growth and chemical/enzymatic reactions.
* Microbial growth and chemical/enzymatic reactions will resume once the food is re-constituted or re-hydrated.
* During dehydration of food, changes such as "cell shrinkage, case hardening, and different chemical changes", can take place.
* During dehydration, several factors (e.g. temperature, air velocity, humidity of the drying air, etc) must be controlled in order to prevent undesirable changes (case hardening, excessive cell shrinkage, etc)
* Packaging materials should not only impart physical protection, but also assist in preserving dehydrated foods by further protecting against moisture absorption, as well as preventing interactions with oxygen and light.
Supplemental Video: [https://www.youtube.com/watch?time_continue=1&v=3LJto1D0iPs&feature=emb_logo Extrusion Drying]<references />

'''Authorship:'''

FNH 200 Course content on this wiki page and associated lesson pages was originally authored by Drs. [http://www.landfood.ubc.ca/person/brent-skura/ Brent Skura], [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], and [http://www.landfood.ubc.ca/person/eunice-li-chan/ Eunice Li-Chan]. Ongoing edits and updates are contributed by past and current instructors including Drs. [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], [http://www.landfood.ubc.ca/person/azita-madadi-noei/ Azita Madadi-Noei], [http://www.landfood.ubc.ca/person/nooshin-alizadeh-pasdar/ Nooshin Alizadeh-Pasdar], and [http://www.landfood.ubc.ca/person/judy-chan/ Judy Chan].
{{cc-by-nc-sa-3.0}}

<quiz display=simple>
{1. The principle of dehydration is...
|type="[]"}
- Elimination of pathogenic microorganisms
- Elimination of spoilage-causing microorganisms
+ Removal of free water
+ Lowering of water activity
</quiz>

<quiz display=simple>
{2. Type text here or a no-break space code
|type="{}"}
What is the white powder seen on the surface of dried pineapple? { Sugar }
</quiz>

<quiz display=simple>
{3. Which technique below was developed at UBC?
|type="()"}
- Sun drying
- Spray drying
+ Vacuum microwave drying
- Drum drying
- Deep fat frying
- Extrusion drying
</quiz>

<quiz display=simple>
{4. Dehydration preserves food because it lowers water activity which is required for microbes to grow and both chemical and enzymatic reactions.
|type="()"}
+ TRUE.
- FALSE.
</quiz>

<quiz display=simple>
{5. Upon rehydration, both chemical and enzymatic reactions can begin again.
|type="()"}
+ TRUE.
- FALSE.
</quiz>

Course:FNH200/Lessons/Lesson 08/Page 08.4

2020-06-24T02:56:48Z

YihangChen: /* 8.4 Drying Methods */

== 8.4 Drying Methods ==

=== Sun Drying ===
Sun drying is mostly used in dry, warm climates. This is a very slow drying method (several days). It is mostly used for fruits, vegetables, and fish. An advantage of this method is the fact that it is quite inexpensive; however, disadvantages include long drying periods (up to several weeks) and the risk of invasion by insects, birds, rodents, and microorganisms.

The appearance is shrunken and has poor rehydration capacity.
[[File:L8 fig8-aa.jpg|thumb|Sun dried tomatoes|center]]

=== Spray Drying ===
Spray driers are used to produce the greatest quantities of commercially dehydrated foods. Spray driers are restricted to use with liquid foods since the principle of the operation is the introduction of the food as a spray of small droplets into a high velocity stream of warm air. Because droplet sizes are small, drying rates are very rapid and high quality dehydrated food products can be produced. Foods most commonly dehydrated by spray driers include skim milk, coffee, tea and eggs.

You will note that the equipment is designed to maximize drying rate, to produce dry particles of uniform size and to prevent sticking of partially dry food particles to the walls of the spray driers. You should also note that spray driers operate continuously, that is, the product is sprayed into the drying chamber and the dried product and moist air are separated and removed from the driers.
[[File:L8. Spray dryer Modified.png|thumb|Figure 8.2 Spray drier. Source: Food Science and Nutritional health by T.P. Labuza and J.W. Erdman. West Publishing Co., St. Paul MN. 1984.|center|500x500px]]

{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Fluid milk and egg products are commonly spray-dried into powder form. Milk and eggs are low-acid foods that are susceptible to growth of '''pathogenic''' microorganisms as well as to '''spoilage''' by microbes and enzymes.
* Since the dehydration process does not kill microorganisms nor inactivate enzymes, can you think of additional processes or approaches that can be used in conjunction with dehydration for better preservation of milk and egg powders?
|}

=== Tray (Air) Drying ===
Food placed on trays or racks is exposed to heated air at a set velocity. This type of drying can be quite fast and requires heated air with a relative humidity (%RH) lower than that of the product to be dried. Water soluble components migrate to surface of food and are deposited as water evaporates. The dried food has relatively poor re-hydration properties, is shrunken in appearance and is very dense. Products dried this way are: pasta, vegetables, fruit, spices. The diagram below shows the sequence of events that occur during dehydration of fruit tissue.[[File:FNH200_Lesson08_TrayDryer.png|433x433px|thumb|Figure 8.3 Tray Dryer as Adapted from Labuza and Erdman|center]]

=== Drum Drying ===
During the process of drum drying, food paste is applied to a heated drum in a thin layer to promote rapid drying. As the drum rotates, it picks up a thin film of food material that dries rapidly. The dried food is scraped off the drum near the end of a full rotation of the drum. Dehydrated mashed potatoes and some ready-to-eat breakfast cereals are dried this way. Some popular low fat snack foods and potato chip like products contain drum dried potato flakes as the primary ingredient.[[File:FNH200_Lesson08_DrumDryer.png|485x485px|thumb|Figure 8.4 Drium Drier. Source: Food Science and Nutritional health by T.P. Labuza and J.W. Erdman. West Publishing Co., St. Paul MN. 1984.|center]]

=== Freeze Drying ===
'''Freeze driers''' are fairly recent innovations as far as food dehydration is concerned. Freeze drying is restricted to high value foods because of the high costs associated with this dehydration method.

During freeze drying, water is removed from food in the frozen state without transition through the liquid state. This phenomenon, called '''sublimation''', is illustrated below:

'''water(solid) —> water(vapour)'''

Sublimation of water is accelerated under '''vacuum''' conditions. During freeze drying, food is frozen and then placed in the freeze dryer, the dryer is sealed and a vacuum is created and maintained. Application of heat from '''radiant heaters''' within the shelves of the freeze drier provides the energy required for sublimation to occur. During freeze drying the amount of heat applied to the food is carefully controlled to maximize the rate of drying without causing transition of water from the solid to the liquid phase. A schematic diagram of a food being freeze dried is shown in Figure 8.5.
[[File:L8 fig8。5.jpg|thumb|Figure 8.5. Schematic drawing of how food is freeze dried.Adapted from: Potter, N. and Hotchkiss, J.H. 1995. Food Science (5th ed), Ch. 10. Aspen Publishers., p. 229.|center|500x500px]][[File:L8 fig8-bcc.png|thumb|Figure 8.6 Freeze drierSource: Food Science and Nutritional health by T.P. Labuza and J.W. Erdman. West Publishing Co., St. Paul MN. 1984.|center|500x500px]]During freeze drying, because the food remains rigid during dehydration, the subliming water leaves voids where the ice crystals were located. There is no translocation of water-soluble constituents because there is no movement of liquid, allowing freeze dried foods to '''retain their shape.''' Also, freeze dried foods '''rehydrate''' almost completely because the '''voids''' left by the subliming water provide channels through which water can enter the food, and the water-soluble components of the food in their original locations provide the driving force for rehydration. Freeze dried foods do not usually exhibit the shrinkage and chemical changes noted earlier to occur in other dehydrated foods.
* If you have consumed the instant soup mixes that are prepared in a cup with the addition of boiling water, you will have noted that the vegetables have rehydrated within several minutes and that they possess a fresh flavour. Those vegetable pieces were freeze dried.
* You may wish to compare the rate and extent of rehydration of vegetable pieces in an instant soup mix (in which vegetables were freeze dried) with those vegetables from a soup mix which has to be boiled for about 10 minutes in order to rehydrate the vegetable pieces (these vegetable pieces were tray-air dried).

=== Vacuum Microwave Drying ===
'''Vacuum microwave''' or '''radiant energy vacuum (REV)''' technology is being developed for the dehydration of food, nutraceutical and pharmaceutical products by Dr. Tim Durance in the Food Science program at the University of British Columbia. The technology consists of a combination of '''vacuum''' (in order to keep the temperature low) and '''microwaves''' (for ultra-rapid energy transfer), producing high quality products with less nutrient loss, better flavour retention, and less colour change. Vacuum microwave dried (VMD) products retain a more natural appearance and have the advantage of complete re-hydration (reconstitution). VMD is a quick drying method when compared to freeze drying and air drying methods (VMD can take only a few minutes, compared to hours in freeze drying).

For more information, visit <nowiki>http://www.enwave.net/</nowiki> (Links to an external site.)

=== Deep Fat Frying ===
During deep fat frying, the high temperature of hot oil causes water in the food to evaporate rapidly, often accompanied by substantial pick up of oil by the food being dried. Dried foods such as potato chips have a low water content (as well as a low water activity) but a high oil content. Many snack foods and bakery products, such as donuts, are produced by means of deep fat frying.

Do you know how instant noodles are made? After cooking and shaping, the noodles are dried either by deep-fat frying or non-frying (hot-air) drying. Frying is usually done at 140-150°C for 1-2 minutes, while hot-air drying uses a temperature of about 80°C for 30 min. The two drying methods yield products that differ greatly in fat content.

=== Extrusion (cooking) Drying ===
Slurry of food is passed though a tube, under pressure, that is heated by steam. The moist heat causes starch gelatinization and cooking of the product. Product is forced though a narrow opening (a die which can produce a product with a variety of shapes) at the end of the tube and escaping steam causes the dehydrating product to puff. Many ready-to-eat breakfast cereals and snack foods are produced this way.
[[File:L8 extrusion.png|thumb|Figure 8.7. Extrusion (cooking) DryingSource:Understanding Food Science and Technology by P. S. Murano. Wadsworth/Thomson Learning Inc. 2003.|center|500x500px]]
'''Common food products prepared by extrusion drying'''
{| class="wikitable"
!Category
!Examples
|-
|Ready-to-eat breakfast cereals
|Puffed cereals, flaked cereals, high-fiber strands
|-
|Snacks
|Puffed snacks, Crispbreads
|-
|Confections
|Licorice, some chocolates
|-
|Texturised protein
|Soy meat-analogues, "processed" cheese
|-
|Infant foods
|Biscuits, weaning cereals
|}
{| class="wikitable"
| '''Want to learn more?'''
|-
|
* Now that you have read about the different drying methods
** Which methods would lead to the most changes, or conversely the least changes, in the resulting dehydrated foods?
** How do dehydrated foods obtained by different drying methods compare in terms of the rate and ease of rehydration?
|}
{| class="wikitable"
|}

Course:FNH200/Lessons/Lesson 08/Page 08.3

2020-06-24T02:56:28Z

YihangChen: /* 8.3 Factors Affecting Dehydration */

== 8.3 Factors Affecting Dehydration ==
Dehydration of food requires that water (mass) be transferred from the food into the dehydrating environment, and that heat (the driving force that encourages water removal) be transferred to the food to promote water removal from the food. The objectives of food dehydration operations are to dry the food as fast as possible, at the least cost, while creating the fewest changes in food quality.

The composition of the food itself can have an effect of the rate at which dehydration occurs. For example, if water is bound to solutes in the food it will have a lower vapour pressure and therefore will be more difficult to remove. The porosity of the food is also important. Efforts are made to enhance the porosity of foods to be dehydrated in order to facilitate mass transfer and speed of drying rate, thus maximizing the efficiency of dehydration. Porous (sponge-like) structures are formed by creating steam pressure within the product during the drying process. The steam will "puff" the product. Another way of creating porosity is by making a stable foam from a liquid food prior to drying.

In addition to the composition of food, the following factors can also affect heat and mass transfer within food materials undergoing dehydration, and therefore are important to consider in order to control some of the undesirable changes described previously:
* '''''Surface area'''''. It is desirable to maximize the surface-to-volume ratio of the food to be dehydrated to minimize the resistance to heat and mass transfer. Generally, the smaller the food piece, the more rapid the rate of moisture loss.
* '''''Temperature'''''.The hotter the air, the more moisture it will hold before becoming saturated. Drying systems are designed to maximize temperature differences between the product and the drying air to increase the rate of dehydration. An upper limit to drying air temperature is dictated by adverse chemical reactions that can take place in a food at high temperatures. The upper temperature limit is also dictated by the chemical and physical nature of the food.
* '''''Air velocity'''''. The faster the air velocity within a dehydrator, the more rapid the rate of moisture removal. Food dehydrators are designed to maximize the velocity of heated air moving around the food particles to be dried.
* '''''Humidity of the drying air'''''. The drier the air, the more moisture it can absorb before it becomes saturated. The relative humidity of the drying air determines the final moisture content of the food being dried. Knowledge of the equilibrium relative humidity of food is important for the proper design of dehydrators and for the design of packaging systems that will prevent moisture adsorption by the dehydrated food during storage. You may have experienced the loss of crispness of crackers in opened packages during lengthy storage in your cupboards. Crackers have a low equilibrium relative humidity and they tend to adsorb water from the air.
* '''''Atmospheric pressure and vacuum'''''. Water boils at 100°C when it is at a pressure of 1 atm (760 mm Hg). As the pressure lowers, the boiling temperature will decrease. If the temperature is maintained constant, a decrease in pressure will increase the rate of boiling. Some concentrators and dehydrators are operated at pressures below atmospheric pressure in order to increase the rate of boiling and moisture removal. This is especially important in the case of heat-sensitive food products.

Course:FNH200/Lessons/Lesson 08/Page 08.2

2020-06-24T02:56:11Z

YihangChen: /* 8.2 Changes in Food during Dehydration */

== 8.2 Changes in Food during Dehydration ==
Similar to the other preservation methods we have reviewed, dehydration will cause changes in the food that need to be controlled in order to maintain the highest quality possible. Some of these changes are:
* '''''Cell/tissue Shrinkage'''''. As water is removed from food pieces during dehydration, the cells within the tissue shrink and lose their elasticity. If you have purchased dehydrated vegetables such as carrots, onion slices, or dehydrated fruits such as apple cubes or slices you may have observed the shrinkage that has occurred. Part of the reason for shrinkage of foods that have been dehydrated is that the water migrates from the interior of the food to the surface where it finally evaporates and is carried away by the dehydrating medium. As the water migrates to the surface of the food it carries with it the water soluble substances dissolved in it. The loss of these substances from the interior of the food pieces contributes to the shrinkage observed in dehydrated foods and also contributes to the poor rehydration properties of such foods. Loss of the water soluble components from the interior portions of the food pieces decreases the driving force for attraction of water into the food pieces during rehydration.[[File:FNH200_Lesson08_Shrinkage.gif|659x659px|thumb|Cell Shrinkage during Dehydration|center]]
Sequence of events that occur during dehydration.

(A) Fresh apple cube

(B) Partially dried apple cube

(C) Dried apple surface coated with sugars, acids and salts shape distorted due to cell shrinkage and migration of water solubles to the surface
* '''''Case hardening'''''. Case hardening occurs when rapid drying causes compounds such as sugars to form a hard, fairly impermeable case around the food piece. This phenomenon can cause the rate of dehydration to decrease. Case hardening can occur in high-sugar products such as tropical fruit and many temperate fruit products. Dehydration procedures are designed to minimize the development of case hardening as much possible.

* '''''Chemical changes'''''. A number of chemical changes occur in foods during dehydration in systems employing warm air as the drying agent. The Maillard browning reactions (''Lesson 2'') cause the development of brown colours and the formation of flavours not originally associated with the fresh product. The Maillard reactions proceed most rapidly when the water content of the food is in the range of 20% down to 15% because the reactants are in very close proximity, which increases the probability of reactions occurring. Thus, drying systems are designed to remove water through the 20-15% range of moisture content as rapidly as possible. This will minimize the negative effects the Maillard reaction has on the flavour of dehydrated food products. The flavour of rehydrated skim milk powder is due largely to the products of the Maillard reaction during dehydration of the milk. Prior to dehydration of egg whites, they are treated with an enzyme, ''glucose oxidase'', which "de-sugars" the egg whites and minimizes the colour and flavour changes that could be caused by the Maillard reactions involving glucose. Poor rehydration can occur because of the loss of the ability of some hydrophilic food constituents to absorb water. Heat denaturation of proteins, starches and gums can decrease the water-holding capacity of dehydrated foods. The salts and sugars concentrated on the outside of the food pieces will dissolve in the water added to the food to rehydrate it. Since those water soluble components are not inside the food pieces, there is less attraction for water to enter the food product. As result, rehydration is less complete. You may have noticed that dehydrated fruit pieces are much sweeter than the fresh fruit. The reason for this phenomenon is that the sugars are ''concentrated'' on the outside of the fruit. Loss of volatile substances that contribute to the flavour of foods occurs during dehydration. Generally the higher the drying temperature, the larger the loss of volatiles, with the result that the dehydrated food is less flavourful than the initial product.
Dehydrated foods may show varying extents of shrinkage or chemical changes, depending on the method and conditions used to dry the food.

Course:FNH200/Lessons/Lesson 08/Page 08.1

2020-06-24T02:55:59Z

YihangChen: /* 8.1 Introduction */

== 8.1 Introduction ==
{| class="wikitable"
|
==== '''Terms to remember''' ====
|-
|
* Water activity
* Dehydration ''vs.'' Concentration
* Case hardening
* Mass transfer
* Water soluble components
* Sublimation
* Hygroscopic
* Atmospheric pressure & vacuum
* Different dehydration methods (sun drying, tray (air) drying, freeze drying, etc.)
|}

Some reasons for dehydrating foods are:
* preservation of the food (dried milk, juices, fruit);
* retention of the size and shape of the food while imparting storage stability (freeze dried steak, vegetable pieces);
* reducing weight and bulk of food for easier storage and transportation; and
* production of convenience items (instant coffee, instant mashed potatoes, vegetables that rehydrate in instant soup preparations).
'''Food preservation by dehydration is based on the principle''' that microbial growth, chemical and enzymatic reactions occur only if sufficient '''''free'' water''' is present. When the water activity of foods is lowered there is a direct impact on microbial growth as well as chemical & enzymatic reactions.

Recapping from Lesson 2:
* '''Water activity''' (aw) defines the proportion of water in a food that is in the free, unbound form
* Microbial activity, enzymatic activity and chemical reactions can occur '''only in the free water phase''' of foods
* Water activity of foods ranges from 0 to 1.0
** Water activity of '''dehydrated''' foods is in the range of '''0.2''' to '''0.6'''
** Microorganisms '''cannot grow''' at aw below '''0.6'''
** Chemical reactions (e.g. Maillard browning) can begin to occur at aw of '''0.3'''
{| class="wikitable"
<td>Want to know more?
</td>
|-
|Please visit this website from the Cole Palmer Instrument Company for an overview on water activity, including examples of water activity values for several food products

http://www.foodtechsource.com/rcenter/tech_data/td_water.htm
|}
It is important to remember that with dehydration, microorganisms are '''not readily killed'''. Once the food is '''rehydrated''', microorganisms '''resume growth''' if favourable conditions exist.

It is also important to distinguish between food dehydration and concentration, both of which involve the removal of water from foods:

'''Dehydration''' implies removal of as much water from the food as possible in order to impart a long storage life.

'''Concentration''', on the other hand, implies that some of the water is removed from the food in order to concentrate the food constituents. Concentrated foods are not inherently shelf-stable and require the use of other forms of food preservation (e.g., refrigeration, freezing, dehydration, thermal processing) to extend storage life.

Course:FNH200/Lessons/Lesson 08/Page 08.0

2020-06-24T02:55:46Z

YihangChen: /* 8.0 Overview */

Course:FNH200/Lessons/Lesson 08/Page 08.4

2020-06-24T02:54:50Z

YihangChen: /* 8.4 Drying Methods */

= 8.4 Drying Methods =

=== Sun Drying ===
Sun drying is mostly used in dry, warm climates. This is a very slow drying method (several days). It is mostly used for fruits, vegetables, and fish. An advantage of this method is the fact that it is quite inexpensive; however, disadvantages include long drying periods (up to several weeks) and the risk of invasion by insects, birds, rodents, and microorganisms.

The appearance is shrunken and has poor rehydration capacity.
[[File:L8 fig8-aa.jpg|thumb|Sun dried tomatoes|center]]

=== Spray Drying ===
Spray driers are used to produce the greatest quantities of commercially dehydrated foods. Spray driers are restricted to use with liquid foods since the principle of the operation is the introduction of the food as a spray of small droplets into a high velocity stream of warm air. Because droplet sizes are small, drying rates are very rapid and high quality dehydrated food products can be produced. Foods most commonly dehydrated by spray driers include skim milk, coffee, tea and eggs.

You will note that the equipment is designed to maximize drying rate, to produce dry particles of uniform size and to prevent sticking of partially dry food particles to the walls of the spray driers. You should also note that spray driers operate continuously, that is, the product is sprayed into the drying chamber and the dried product and moist air are separated and removed from the driers.
[[File:L8. Spray dryer Modified.png|thumb|Figure 8.2 Spray drier. Source: Food Science and Nutritional health by T.P. Labuza and J.W. Erdman. West Publishing Co., St. Paul MN. 1984.|center|500x500px]]

{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Fluid milk and egg products are commonly spray-dried into powder form. Milk and eggs are low-acid foods that are susceptible to growth of '''pathogenic''' microorganisms as well as to '''spoilage''' by microbes and enzymes.
* Since the dehydration process does not kill microorganisms nor inactivate enzymes, can you think of additional processes or approaches that can be used in conjunction with dehydration for better preservation of milk and egg powders?
|}

=== Tray (Air) Drying ===
Food placed on trays or racks is exposed to heated air at a set velocity. This type of drying can be quite fast and requires heated air with a relative humidity (%RH) lower than that of the product to be dried. Water soluble components migrate to surface of food and are deposited as water evaporates. The dried food has relatively poor re-hydration properties, is shrunken in appearance and is very dense. Products dried this way are: pasta, vegetables, fruit, spices. The diagram below shows the sequence of events that occur during dehydration of fruit tissue.[[File:FNH200_Lesson08_TrayDryer.png|433x433px|thumb|Figure 8.3 Tray Dryer as Adapted from Labuza and Erdman|center]]

=== Drum Drying ===
During the process of drum drying, food paste is applied to a heated drum in a thin layer to promote rapid drying. As the drum rotates, it picks up a thin film of food material that dries rapidly. The dried food is scraped off the drum near the end of a full rotation of the drum. Dehydrated mashed potatoes and some ready-to-eat breakfast cereals are dried this way. Some popular low fat snack foods and potato chip like products contain drum dried potato flakes as the primary ingredient.[[File:FNH200_Lesson08_DrumDryer.png|485x485px|thumb|Figure 8.4 Drium Drier. Source: Food Science and Nutritional health by T.P. Labuza and J.W. Erdman. West Publishing Co., St. Paul MN. 1984.|center]]

=== Freeze Drying ===
'''Freeze driers''' are fairly recent innovations as far as food dehydration is concerned. Freeze drying is restricted to high value foods because of the high costs associated with this dehydration method.

During freeze drying, water is removed from food in the frozen state without transition through the liquid state. This phenomenon, called '''sublimation''', is illustrated below:

'''water(solid) —> water(vapour)'''

Sublimation of water is accelerated under '''vacuum''' conditions. During freeze drying, food is frozen and then placed in the freeze dryer, the dryer is sealed and a vacuum is created and maintained. Application of heat from '''radiant heaters''' within the shelves of the freeze drier provides the energy required for sublimation to occur. During freeze drying the amount of heat applied to the food is carefully controlled to maximize the rate of drying without causing transition of water from the solid to the liquid phase. A schematic diagram of a food being freeze dried is shown in Figure 8.5.
[[File:L8 fig8。5.jpg|thumb|Figure 8.5. Schematic drawing of how food is freeze dried.Adapted from: Potter, N. and Hotchkiss, J.H. 1995. Food Science (5th ed), Ch. 10. Aspen Publishers., p. 229.|center|500x500px]][[File:L8 fig8-bcc.png|thumb|Figure 8.6 Freeze drierSource: Food Science and Nutritional health by T.P. Labuza and J.W. Erdman. West Publishing Co., St. Paul MN. 1984.|center|500x500px]]During freeze drying, because the food remains rigid during dehydration, the subliming water leaves voids where the ice crystals were located. There is no translocation of water-soluble constituents because there is no movement of liquid, allowing freeze dried foods to '''retain their shape.''' Also, freeze dried foods '''rehydrate''' almost completely because the '''voids''' left by the subliming water provide channels through which water can enter the food, and the water-soluble components of the food in their original locations provide the driving force for rehydration. Freeze dried foods do not usually exhibit the shrinkage and chemical changes noted earlier to occur in other dehydrated foods.
* If you have consumed the instant soup mixes that are prepared in a cup with the addition of boiling water, you will have noted that the vegetables have rehydrated within several minutes and that they possess a fresh flavour. Those vegetable pieces were freeze dried.
* You may wish to compare the rate and extent of rehydration of vegetable pieces in an instant soup mix (in which vegetables were freeze dried) with those vegetables from a soup mix which has to be boiled for about 10 minutes in order to rehydrate the vegetable pieces (these vegetable pieces were tray-air dried).

=== Vacuum Microwave Drying ===
'''Vacuum microwave''' or '''radiant energy vacuum (REV)''' technology is being developed for the dehydration of food, nutraceutical and pharmaceutical products by Dr. Tim Durance in the Food Science program at the University of British Columbia. The technology consists of a combination of '''vacuum''' (in order to keep the temperature low) and '''microwaves''' (for ultra-rapid energy transfer), producing high quality products with less nutrient loss, better flavour retention, and less colour change. Vacuum microwave dried (VMD) products retain a more natural appearance and have the advantage of complete re-hydration (reconstitution). VMD is a quick drying method when compared to freeze drying and air drying methods (VMD can take only a few minutes, compared to hours in freeze drying).

For more information, visit <nowiki>http://www.enwave.net/</nowiki> (Links to an external site.)

=== Deep Fat Frying ===
During deep fat frying, the high temperature of hot oil causes water in the food to evaporate rapidly, often accompanied by substantial pick up of oil by the food being dried. Dried foods such as potato chips have a low water content (as well as a low water activity) but a high oil content. Many snack foods and bakery products, such as donuts, are produced by means of deep fat frying.

Do you know how instant noodles are made? After cooking and shaping, the noodles are dried either by deep-fat frying or non-frying (hot-air) drying. Frying is usually done at 140-150°C for 1-2 minutes, while hot-air drying uses a temperature of about 80°C for 30 min. The two drying methods yield products that differ greatly in fat content.

=== Extrusion (cooking) Drying ===
Slurry of food is passed though a tube, under pressure, that is heated by steam. The moist heat causes starch gelatinization and cooking of the product. Product is forced though a narrow opening (a die which can produce a product with a variety of shapes) at the end of the tube and escaping steam causes the dehydrating product to puff. Many ready-to-eat breakfast cereals and snack foods are produced this way.
[[File:L8 extrusion.png|thumb|Figure 8.7. Extrusion (cooking) DryingSource:Understanding Food Science and Technology by P. S. Murano. Wadsworth/Thomson Learning Inc. 2003.|center|500x500px]]
'''Common food products prepared by extrusion drying'''
{| class="wikitable"
!Category
!Examples
|-
|Ready-to-eat breakfast cereals
|Puffed cereals, flaked cereals, high-fiber strands
|-
|Snacks
|Puffed snacks, Crispbreads
|-
|Confections
|Licorice, some chocolates
|-
|Texturised protein
|Soy meat-analogues, "processed" cheese
|-
|Infant foods
|Biscuits, weaning cereals
|}
{| class="wikitable"
| '''Want to learn more?'''
|-
|
* Now that you have read about the different drying methods
** Which methods would lead to the most changes, or conversely the least changes, in the resulting dehydrated foods?
** How do dehydrated foods obtained by different drying methods compare in terms of the rate and ease of rehydration?
|}
{| class="wikitable"
|}

Course:FNH200/Lessons/Lesson 07/Page 07.4

2020-06-24T02:53:30Z

YihangChen: /* 7.4 Summary of Lesson 7 */

== 7.4 Summary of Lesson 7 ==
* Low temperature processing and its packaging materials are designed to extend the food's shelf life by slowing down microbial growth and chemical/enzymatic reactions.
* Microbial growth and chemical/enzymatic reactions will resume once the food is thawed or exposed to "warmer" temperatures.
* Refrigeration (cool storage) refers to temperatures between -2°C to16°C . In particular at '''4°C'''. This provides only a short term shelf-life extension in food as '''psychrotrophic''' organisms can still grow.
* During refrigeration, the temperature, humidity and gas atmosphere composition must be monitored in order to prevent undesirable changes in the food.
* Modified atmosphere packaging (MAP) is commonly used with some refrigerated products to enhance the shelf life of the product.
* Below '''-9.5°C''', there is no significant growth of '''spoilage''' or '''pathogenic organisms'''
* Freezing refers to temperatures below the freezing point of water. In the food industry, a minimum of '''-18°C''' is required. Food is preserved by the use of lower temperatures and lower water activity.
* During freezing, several factors (e.g. freezing rate, final storage temperature, etc) must be controlled in order to prevent undesirable changes (oxidation reactions, freezer burn, ice crystal damage, etc)
* Packaging materials should assist in preventing these undesirable changes.
'''Supplemental Videos:'''
# [https://www.youtube.com/watch?v=VqMeVZT6N4Q&feature=emb_logo Individually Quick Freeze (IQF) of sardines]
# [https://www.youtube.com/watch?v=PUTOl4SE4uQ&feature=emb_logo How to Make Frozen Treats]

=== Reference ===
Potter, N. N. and J.H. Hotchkiss. 1998. Cold Preservation and Processing. Chapter 9 in ''Food Science'', 5th ed. Chapman and Hall, New York, NY.

'''Authorship:'''

FNH 200 Course content on this wiki page and associated lesson pages was originally authored by Drs. [http://www.landfood.ubc.ca/person/brent-skura/ Brent Skura], [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], and [http://www.landfood.ubc.ca/person/eunice-li-chan/ Eunice Li-Chan]. Ongoing edits and updates are contributed by past and current instructors including Drs. [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], [http://www.landfood.ubc.ca/person/azita-madadi-noei/ Azita Madadi-Noei], [http://www.landfood.ubc.ca/person/nooshin-alizadeh-pasdar/ Nooshin Alizadeh-Pasdar], and [http://www.landfood.ubc.ca/person/judy-chan/ Judy Chan].
{{cc-by-nc-sa-3.0}}

<quiz display=simple>
{1. Syneresis leads to the following change(s) in refrigerated foods:
|type="[]"}
+ Staling of bread
- Loss of crispness and flavour in fruits and vegetable
- Colour change in fresh meat
- Loss of nutrients
+ Drip loss in fish
</quiz>

<quiz display=simple>
{2. Which package material below is NOT suitable for frozen products?
|type="()"}
- Cardbox
- Foil film
+ Glass bottle
- Plastic film
- Tetra pak
</quiz>

<quiz display=simple>
{3. A slush freezer is an example of
|type="()"}
- Air Freezing
+ Indirect Contact Freezing
- Immersion Freezing
- Cryogenic Freezing
</quiz>

<quiz display=simple>
{4. Psychrotrophic organisms can grow while food is stored in the refrigerator.
|type="()"}
+ TRUE.
- FALSE.
</quiz>

<quiz display=simple>
{5. Under freezing conditions, chemical reactions can still occur.
|type="()"}
+ TRUE.
- FALSE.
</quiz>

Course:FNH200/Lessons/Lesson 07/Page 07.2

2020-06-24T02:52:57Z

YihangChen: /* 7.2 Refrigeration (Cool Storage) of Foods */

== 7.2 Refrigeration (Cool Storage) of Foods ==
Refrigeration is one of the mildest approaches to food preservation.
* Refrigeration/Cool storage of foods falls between -2°C to 16°C. However, in the food industry, the refrigeration temperatures should be in the range of '''4°C''' and below. The Food and Drug Regulations of Canada state that perishable foods that can support the growth of disease-causing microorganisms must be stored at temperatures of '''4°C and below.'''
* A drop of 10°C '''slows down''' rate of senescence by 2 to 3 times and microbial growth by 3 to 6 times.
* Refrigeration temperatures inhibit the growth of most disease-causing microorganisms but can favour the '''psychrotrophic''' microorganisms.
* Some spoilage-causing microorganisms, particularly moulds, can grow at temperatures as low as '''-8°C'''.
* You must keep in mind that refrigeration storage temperatures only provides a '''short term''' extension to the storage life of foods
* Refrigeration storage of foods '''can not''' improve the quality of a food item that is low of quality when placed into cold storage.
In addition to being a mild approach to short-term preservation, refrigeration is also sometimes applied to achieve desirable attributes of fermented food products such as cheeses, beef and wine upon cool ripening or aging.

=== What are the optimal conditions for refrigerated storage of foods? ===
Each food commodity has its optimum refrigeration conditions for maximum storage life and retention of quality and nutritional value.

The storage life of meats, fish and dairy products are maximized by temperatures that approach 0°C. During refrigerated storage of foods, maintenance of '''controlled temperatures''' are very important to ensure maximum storage life of the foods and to prevent chill injury to certain foods, especially some fruits and vegetables. For example, as reported by Potter and Hotchkiss (1995):
* Bananas will undergo a colour change in the peel from yellow to black, while sweet potatoes may show decay, pitting and internal discolorations, when stored at temperatures below 13°C.
* Apples may become soggy or show internal browning if stored below 1-2°C.
* Potatoes and avocados may also become brown if stored below 5 and 7°C, respectively.
Other factors to be controlled for products in refrigerated storage are '''humidity''' and '''gas atmosphere composition'''. A very fine humidity balance must be maintained to prevent dehydration of the food while avoiding creation of conditions that are so humid that mould growth and food spoilage are favoured. Many food products are stored under '''controlled''' and '''modified atmospheres''' in conjunction with refrigerated storage for the extension of storage life.

A '''controlled atmosphere''' refers to a condition in which the atmosphere surrounding a food product is different from that of the normal atmosphere, and the composition of the atmosphere around the product is '''constantly monitored and maintained''' at preset levels.

'''Review from Lesson 1:''' "controlled atmosphere storage"- facilities where the atmosphere (CO2, O2 and N2) and humidity are carefully controlled and temperature kept low to slow the rate of respiration and ripening of the apples, thus extending the storage life of the fresh fruit.

'''Modified atmosphere''' refers to the creation of atmospheric conditions around the product that are different from the normal atmosphere. In this type of system, food items are placed into a package. The air in the package is then removed either by drawing a vacuum, then backflushing the package with the desired gas mixture before sealing the package, or simply by flushing the package with the desired gas mixture until the air in the package is replaced by the desired gas mixture (usually a combination ofcarbon dioxide and nitrogen) before sealing the package. Examples of products with MA-packaging '''(MAP)''' are shown in Figure 7.1. [[File:FNH200_Lesson07_MAPLettuce.jpg|frame|centre|300px]]
[[File:FNH200_Lesson07_MAPPasta.jpg|frame|centre|300px|'''Figure 7.1''' Examples of modified packaging packaging (MAP).]]The composition of the atmosphere in a modified atmosphere packed food product '''changes over time''', the changes being governed by metabolic activities of the food, the microorganisms in the food, and the gas permeability of the packaging materials used.

'''Vacuum packaged''' processed or cured meats are another example of MAP, except in this case once the vacuum is applied the product is packaged, there is '''no backflushing''' with a gas mixture prior to sealing the package. These products have a much longer storage life than those stored in air. Removal of oxygen from these products through the vacuum process suppresses the growth of the aerobic spoilage-causing bacteria. This leads to the extension of the storage life of these products.
* Retail cuts of cheese are often packed under vacuum or under gas mixtures to prevent the growth of moulds which are common aerobic spoilage-causing microorganisms of cheeses.
Keep in mind the fact that although food products packed under modified atmospheres have a longer storage life, those products '''must be kept in refrigerated storage''' in order to maximize the benefits of inhibition of growth of spoilage-causing microorganisms and to prevent the growth of microorganisms that may be capable of causing illness.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Compare and contrast controlled atmosphere storage and modified atmosphere packaging.
|}

=== Changes in Food During Refrigerated Storage ===
Over prolonged storage, numerous aundesirable changes can be observed, in addition to those brought on by microbial spoilage. These include:
* staling of bread
* loss of crispness in fruits and vegetables
* change in colour of fresh meat
* loss of flavour and nutrient value (e.g. vitamins)
* oxidative changes
* drip or syneresis from fish

Course:FNH200/Lessons/Lesson 06/Page 06.0

2020-06-24T02:51:50Z

YihangChen: /* 6.0 Overview */

Course:FNH200/Lessons/Lesson 04

2020-06-24T02:50:30Z

YihangChen:

<big><big><big>'''Food Standards, Regulations and Guides - Food Additives'''</big></big></big>

== 04.0 Overview ==
This lesson will introduce you to the concept of food regulation and you will become familiar with "standards of identity", standards and quality grades for foods, as well as the major governmental agencies that have a role in regulating the safety and quality of the food supply. You will learn about the Food and Drugs Act and Regulations of Canada, and the regulations that govern labelling and advertising as they apply to food. We will also discuss regulations governing grade standards for various food commodities that are administered by the Canadian Food Inspection Agency.

At one time or another, most people have been in a conversation where food additives have been the topic of discussion. Few people know what food additives are, what their purpose is, and what regulations govern their use. In this lesson we discuss and compare the Canadian and United States definitions of a food additive. We also discuss the classes of food additives and their functions in food systems. We review Canadian labelling requirements as they pertain to food additives and discuss the concepts employed in the evaluation of safety of food additives. We end the lesson with a discussion of aspartame and nitrites as examples of food additives that have generated much controversy in the recent past.

=== Objectives ===
After completing this lesson, you will be able to:
* discuss how regulations are established, to ensure the quality and safety of the Canadian food supply
* identify which governmental agencies are responsible for regulating the safety and quality of the food supply
* define what a food additive is
* interpret the function of food additives that are listed on the labels of ingredients of food you consume
* explain the basis upon which safety of food additives is determined; and
* articulate your set of values as they pertain to the use of food additives in foods
* compare and contrast the definition of a food additive in Canada and United States
* demonstrate the ability to do research and extract information about the Canadian food acts and regulations

=== Optional Readings ===
* Hotchkiss, J.H. and Cassens, R.G. 1987 [April]. Nitrate, nitrite and nitroso compounds in foods (A scientific status summary). ''Food Technology'', ''41''(4):127-136.
* Kroger, M, Meister, K. and Kava, R. 2006. Low-calorie sweeteners and other sugar substitutes: A review of the safety issues. Please see this link INSTEAD; Comprehensive Reviews in Food Science and Food Safety 5: (read only pp. 37-39). NOTE: this is the same article as required in lesson 3.
Resources
* Health Canada, Food program: Safety of Aspartame. https://www.canada.ca/en/health-canada/services/food-nutrition/food-safety/food-additives/sugar-substitutes/aspartame-artificial-sweeteners.html
* Health Canada. 2006. ''Food Additive Dictionary''. Publication H49-10/1996E. Ottawa: Health Canada. https://www.canada.ca/en/health-canada/services/food-nutrition/food-safety/food-additives/dictionary.html

== 04.1 Food Standards, Regulations and Guides ==
{| class="wikitable"
|
==== '''Terms to remember''' ====
|-
|
* Health Canada
* Canadian Food Inspection Agency
* Food and Drugs Act and Regulations
* Standards of identity and composition
* Food Grades
* No Effect Level (NOEL)
* Acceptable Daily Intake (ADI)
* Probable Daily Intake (PDI)
* Diketopiperazine (DKP)
* Phenylketonuria (PKU)
* Clostridium botulinum
* Nitrosamines
|}
In order to ensure that the food we purchase and consume is '''safe''' and within certain preset limits of '''quality''', there are government standards, regulations and grades in place to protect the consumer.

The Department of '''Justice Canada''' is responsible for maintaining the Consolidated Statutes and Regulations for the Government of Canada, including the '''Food and Drugs Act and Food and Drug Regulations'''.

The Food and Drugs Act of Canada is administered by the '''Health Products and Food Branch''' of '''Health Canada''', whereas inspections for compliance are enforced by the '''Canadian Food Inspection Agency'''. Several other government agencies work together to ensure the safety and quality of foods produced and/or consumed in Canada.

The government agencies and their regulatory functions are listed below.

Table 4.1 ''Government agencies and their regulatory functions''
{| class="wikitable"
|
=== Agency ===
|
=== Regulatory Function ===
|-
|Health Canada

(Health Products & Food Branch)

https://www.canada.ca/en/health-canada/services/food-nutrition.html
|
* setting food and drug regulation standards of identity and composition for foods
* Food and Drugs Act (<nowiki>http://laws-lois.justice.gc.ca/eng/acts/F-27/</nowiki>)
* food additive regulations
|-
|Canadian Food Inspection Agency (CFIA)

http://www.inspection.gc.ca/english/toce.shtml
|
* provides inspection services related to the food
* responsible for administration and enforcement of different Acts including:

* Food and Drugs Act (<nowiki>http://laws-lois.justice.gc.ca/eng/acts/F-27/</nowiki>)
* Agriculture and Agri-Food Administrative Monetary Penalties Act (http://laws-lois.justice.gc.ca/eng/acts/A-8.8/)
* Food Labeling for industry (http://www.inspection.gc.ca/food/requirements/labelling/industry/eng/1383607266489/1383607344939
|-
|Measurement Canada
|Agency of Innovation, Science and Economic Development Canada.

responsible for ensuring accuracy in the selling of measured goods,

developing and enforcing the laws related to measurement accuracy,

approving and inspecting measuring devices and investigating complaints of suspected inaccurate measurement.
* https://www.ic.gc.ca/eic/site/mc-mc.nsf/eng/Home
|-
|British Columbia Ministry of Health
|public health inspection of retail stores and food service establishments

inspection of provincially inspected meat processing plants and dairy processing plants
|-
|Municipal
|public health inspection of retail stores and food service establishments
|}

=== The Food and Drugs Act ===
Sections 3, 4, 5, and 7 of the '''Food and Drugs Act''' form the foundation of the consumer protection laws. Excerpts of the Act are shown in Box 4.1 to give you an idea of the nature of the regulations.

It is interesting to note that Section 3 of the Food and Drugs Act prohibits the advertising to the general public of any food, drug, cosmetic or device for the treatment, prevention or cure of any of the diseases listed on Schedule A of the Food and Drugs Act. This section of the Act also prohibits the sale of a food, drug, cosmetic or device that is labeled in this manner.

In the light of recent trends and the demand for natural health products, the House of Commons Standing Committee on Health mandated an External Working Group which is overseeing the revisions may be needed to this section of the Act.

{| class="wikitable"
| colspan="2" |
=== Excerpts from The Food and Drugs Act of Canada ===
http://laws-lois.justice.gc.ca/eng/acts/F%2D27/page-1.html#docCont
|-
|
==== '''Section 3''' ====
(1) no person shall advertise any food, drug, cosmetic or device to the general public as a treatment, preventative or cure for any of the diseases, disorders or abnormal physical states referred to in Schedule A.

(2) No person shall sell any food, drug, cosmetic or device

(a)that is represented by label, or:

(b) that is represented to the general public as a treatment, preventative or cure for any of the diseases, disorder or abnormal physical states referred to in Schedule A.

Some of the diseases mentioned in schedule A include alcoholism, appendicitis, arthritis, cancer, depression, diabetes, heart disease, hypertension, liver diseases, obesity, sexual impotence, tumours, venereal disease.
|
==== '''Section''' 5 ====
(1) No person shall label, package, treat, process, sell or advertise any food in manner that is false, misleading or deceptive or is likely to create an erroneous impression regarding its character, value, quantity, composition, merit or safety;

(2) An article of food that is not labelled or packaged as required by the regulations, or is labelled or packaged contrary to the regulations, shall be deemed to be labelled or packaged contrary to subsection (1).
|-
|
==== '''Section 4''' ====
No person shall sell an article of food that:

(a) has in or upon it any poisonous or harmful substance;

(b) is unfit for human consumption;

(c) consists in whole or in part of any filthy, putrid, disgusting, rotten decomposed or diseased animal or vegetable substance;

(d) is adulterated;

(e) was manufactured, prepared, preserved, packaged or stored under unsanitary conditions.
|
==== '''Section 7''' ====
(a) No person shall manufacture, prepare, preserve, package or store for sale any food under unsanitary conditions.
|}
Box 4.1 ''Sections 3, 4, 5 and 7 of The Food and Drugs Act of Canada, that are the foundation of consumer protection laws.''

== 04.2 How are Regulations established? ==
* The Food protection laws, in Canada, are wide in scope and major changes in the regulations embodied within the ''Food and Drugs Act'' are made after extensive consultation. We will discuss this consultation process when we deal with the section on ''Food Irradiation''.
* Rapid changes can also be made to the ''Food and Drugs Act'' such as in the case of delisting a food additive or other substance permitted in food when new evidence arises concerning issues of safety of a particular substance. Such was the case when the non-caloric sweeteners cyclamate and saccharin were banned.
* The regulations can be amended by authority of the Governor in Council.
As noted on Table 4.1, regulations about labelling, advertising and claims about food are administered by the '''Canadian Food Inspection Agency''' (CFIA):
* CFIA deals with food labelling, advertising and claims about food.
* Administers the labelling, packaging and advertising regulations under the Consumer Packaging and Labelling Act and Regulations and the Food and Drugs Act and Regulations.
* The CFIA also reviews all advertisements, on Canadian radio and television, making claims about foods.
'''Weights and measures''' are regulated by "Innovation, Science and Development Canada" specifically by an agency known as "Measurement Canada". This agency is responsible for inspection of measurement devices and providing the accuracy certification stickers

https://www.ic.gc.ca/eic/site/mc-mc.nsf/eng/lm04710.html

Please note that packaged retail products are subjected to ''Consumer Packaging and Labelling Act'' and Canadian Food Inspection Agency ( CFIA) is responsible for overseeing their measurement accuracy.

== 04. 3 Food Labelling Requirements ==
Labelling information required on pre-packaged food products, from domestic food processors or imported products, is based on the '''Consumer Packaging and Labelling Act and Regulations''' and can be found in theat the CFIA website: http://www.inspection.gc.ca/food/labelling/food-labelling-for-industry/eng/1383607266489/1383607344939

Summarizing the core labelling requirement, a label should include the following:
* '''Bilingual labelling'''- All mandatory information on food labels must be shown in both official languages, i.e., French and English.
* '''Common name of the food'''. The common name is the name prescribed in the Food and Drugs Regulations. In the absence of a prescribed name, the name by which the food is commonly known is used.
* Country of Origin- Declaring of Country of Origin is required for some specific food. Some companies may choose to voluntarily name the country of origin as advertising. For a complete list of foods requiring mandatory declaration please see the link below

* http://www.inspection.gc.ca/food/labelling/food-labelling-for-industry/label/country-of-origin/eng/1334599362133/1334601061354
* '''Date marking''' and '''storage instructions''' as required. This is required for foods with a storage life of '''90 days or less'''.
** '''Durable life''' is the period of time, beginning on the day on which the pre-packaged product is packaged for retail sale, during which a product stored under prescribed conditions will retain, without appreciable deterioration, its normal wholesomeness, palatability and nutritional value and any other qualities claimed for it by the manufacturer. Products that have passed the durable life date and that have been stored under prescribed conditions are still safe to eat but the quality (appearance, flavour, nutritional value) may have deteriorated.
* '''Identity and Principal Place of Business'''
* '''Irradiated foods'''
* '''Legibility and location'''
* '''List of ingredients''' in descending order of proportion
* The '''Nutrition Facts table''' will show the Calories, the amount of fat, saturated and trans fats, cholesterol, sodium, carbohydrate, fiber, sugars, protein, calcium, iron and Vitamins A and C in a specified amount of food.Nutrition facts regulations apply to all pre-packaged foods with some exemptions (e.g fresh fruit and vegetables, raw single ingredient meat and poultry that are not ground, raw fish or seafood, alcoholic beverages).
* '''Net quantity of the food'''
* '''Sweeteners'''
* '''Other mandatory information''' may be required for certain foods: eg. % alcohol for alcoholic beverages, % milk fat for some dairy products
'''Nutrient content claims''' and '''diet-related health claims''', if made, must adhere to the stated criteria (see below)

Currently, there are '''5 disease reduction claims''' allowed in Canada:
# Disease Risk Reduction Claims with Respect to Sodium and Potassium
# Disease Risk Reduction Claims with Respect to Calcium and Vitamin D
# Disease Risk Reduction Claims with Respect to Saturated and ''Trans'' Fats
# Disease Risk Reduction Claims with Respect to Cancer Risk Reduction
# Disease Risk Reduction Claims with Respect to Dental Caries
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Do you know what it means when a food is labeled '''''"fat-free"''''' or '''''"light"''?'''
** Check out these links for the answer:
*** http://www.inspection.gc.ca/food/labelling/food-labelling-for-industry/nutrient-content/specific-claim-requirements/eng/1389907770176/1389907817577?chap=4
*** http://www.inspection.gc.ca/food/labelling/food-labelling-for-industry/nutrient-content/specific-claim-requirements/eng/1389907770176/1389907817577?chap=4<nowiki/>http://healthycanadians.gc.ca/eating-nutrition/label-etiquetage/label-etiquette-eng.php
|}
{| class="wikitable"
| '''Want to learn more?'''
|-
|
* Look at labels on a number of food products in your refrigerator and in your cupboards. Is the required information present?
* Look for the ''durable life date'' on packaged perishable food products (e.g. pasteurized milk, yogurt, cottage cheese, bread, refrigerated cured meats-frankfurters bacon, etc).
* Look for "health claims" in food products (breakfast cereals, orange juice, etc). Do these claims comply with Canadian regulations?
|}

== 04.4 Standards of Food Identity and Composition ==
The Food and Drug Regulations contain descriptions of certain foods that specify, for example, '''what is allowed in those foods as ingredients'''. These descriptions are standards of identity and composition that have to be met for a food to be legally called by the name in the standard. The foods are referred to as "standardized foods". Examples of standardized foods include bread, milk, cheese, orange juice, sausage, jam, wine, beer, vinegar and salt. Foods that do not have a standard of identity are referred to as "'''unstandardized foods'''". Snack foods like potato chips, various bakery items such as rolls, donuts and cakes, yogurt, and pizza are examples of unstandardized foods.

Standards of food identity and composition are defined in the '''''Food Regulations of the Food and Drugs Act of Canada'''''
* Please '''bookmark''' the link for the '''Food and Drug Regulations''' of '''The Food and Drugs Act of Canada''':
* <nowiki>http://laws-lois.justice.gc.ca/eng/regulations/C.R.C.,_c._870/index.html</nowiki>
Note the following:
* An '''''identity''' standard'' is one that states what the food shall be and defines a food or ingredient. '''''Compositional''' standards'' list the mandatory and permitted ingredients in foods.
* There are standards of identity or composition for over '''300 foods''' in the Food Regulations in Canada. They are classified within '''28 divisions'''. ''For example'', '''Division 13''' regulates "Grain and Bakery products". In this division, the standards of identity and composition for white wheat flour and bread can be found. A fragment of this division is shown below in Box 4.2 (click on the Box to read its contents).
** The dates on the left hand side of the identity and compositional standards (Box 4.2) indicate the date of the last revision of a particular section of the standard.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Visit the Food and Drug Regulations (<nowiki>http://laws-lois.justice.gc.ca/eng/regulations/C.R.C.,_c._870/index.html</nowiki>) and answer the following questions. Can you identify the division number that regulates:
** Dairy products
** Food additives
** Cocoa & chocolate products
|}
[[File:4.2.gif|thumb|Box 4.2 Identity and Composition Standards.|center]]
 

== 04.5 Food Grades Standards ==
Food grades standards are administered by the CFIA.

Here is a list of some of the regulations:
* [https://inspection.gc.ca/about-the-cfia/acts-and-regulations/list-of-acts-and-regulations/documents-incorporated-by-reference/canadian-grade-compendium-volume-1/eng/1520878338783/1520878339422 Volume 1, Ovine carcasses and poultry carcasses]
* [https://inspection.gc.ca/about-the-cfia/acts-and-regulations/list-of-acts-and-regulations/documents-incorporated-by-reference/canadian-grade-compendium-volume-2/eng/1519996239002/1519996303947 Volume 2, Fresh fruit or vegetables]
* [https://inspection.gc.ca/about-the-cfia/acts-and-regulations/list-of-acts-and-regulations/documents-incorporated-by-reference/canadian-grade-compendium-volume-3/eng/1522257117725/1522257118286 Volume 3, Processed fruit or vegetable products]
* [https://inspection.gc.ca/about-the-cfia/acts-and-regulations/list-of-acts-and-regulations/documents-incorporated-by-reference/canadian-grade-compendium-volume-4/eng/1521118213588/1521118214322 Volume 4, Dairy products]
* [https://inspection.gc.ca/about-the-cfia/acts-and-regulations/list-of-acts-and-regulations/documents-incorporated-by-reference/canadian-grade-compendium-volume-5/eng/1520869505643/1520869506282 Volume 5, Eggs]
* [https://inspection.gc.ca/about-the-cfia/acts-and-regulations/list-of-acts-and-regulations/documents-incorporated-by-reference/canadian-grade-compendium-volume-6/eng/1523388139064/1523388171017 Volume 6, Honey]
* [https://inspection.gc.ca/about-the-cfia/acts-and-regulations/list-of-acts-and-regulations/documents-incorporated-by-reference/canadian-grade-compendium-volume-7/eng/1521118355767/1521118356469 Volume 7, Maple syrup]
* [https://inspection.gc.ca/about-the-cfia/acts-and-regulations/list-of-acts-and-regulations/documents-incorporated-by-reference/canadian-grade-compendium-volume-8/eng/1521472457185/1521472457803 Volume 8, Fish]
{| class="wikitable"
| '''Critical Thinking'''
|-
|To complete the following activities visit the http://inspection.gc.ca/food/requirements/labelling/industry/grades/eng/1468508117774/1468508381597.

1) Find out more about regulations governing fresh fruits or vegetables.

* What are the names of the 7 grades for fresh apples?
* Describe the major attributes that distinguish the first (top) grade and third grade.
''Response: Grade standard descriptions for '''processed fruits or vegetables''' indicate that the grades are based on aesthetic qualities of the fruits and vegetables. Although there is not a great deal of information available, it appears that Canada Fancy and Canada Standard processed fruits and vegetables are similar in nutrient value. Thus the grades do not necessarily indicate that a better grade (fancy) is superior to a lower grade (standard) from a nutrient point of view.''

''2) Find out more about eggs.''

Select "'''Egg Regulations'''" and scan through the information to answer the following questions:
* How many grades exist for eggs? what are they named?
* What are the basic requirements for eggs to be graded?
''Response: '''Eggs''' are graded only if certain criteria are met, and then only by an inspector at a registered egg station. The eggs are evaluated for weight, cleanliness, soundness'' and ''shape of shell, shape and position of yolk in the egg during candling, size of air cell (small = fresh), abnormalities (e.g., blood spots).''
* Which grade of eggs is further designated by size?
* Which grades are shown on a label with a "maple leaf" design?
* Which grades are sent to registered processed egg stations?
* Take a look at an egg carton in your fridge or in the supermarket. Can you find the required information about the grade? size?
3) Now select "'''Ovine and Poultry Carcass Grading Regulations'''" and browse through to answer the following
* How many grades exist for beef carcasses?
* What are the names of these grades?
* What are the main criteria that are considered in grading beef carcasses? Next time you eat a piece of steak, you should have a better understanding of what the "Triple A" means!
4) Now select "Maple Product Regulations" and browse through the Maple Syrup Grade Names.
* How many grades exist?
* What are the attributes associated with the grades?
|}

=== Video ===
At this point you should watch the video on '''Egg processing''', including the grading system and processing.

'''Can you answer the following:'''
* Why are the eggs washed?
* How is the process of candling done?
* What are the main external and internal characteristics that are evaluated during candling?
* Which grade(s) of eggs are normally found in the retail market? what happens to other grades? are all eggs suitable for food use?
* What types of processed egg products are shown? what are the conditions for HTST pasteurization of liquid whole and yolk?

== 04.6 Natural Health Products ==
To deal with the uniqueness of emerging products which are neither strictly foods nor drugs, the government has established a [https://www.canada.ca/en/health-canada/corporate/about-health-canada/branches-agencies/health-products-food-branch/natural-non-prescription-health-products-directorate.html Natural Health Products Directorate], responsible for regulations and labelling guidelines for these products. We will learn about this topic in Lesson 13.

==== '''How about the international scene?''' ====
The [http://www.fao.org/fao-who-codexalimentarius/en/ Codex Alimentarius Commission] was established in 1963 by the World Health Organization and the Food and Agriculture Organization of the United Nations to develop international food standards to protect consumer health and to facilitate fair trading practices in foods. Today, there are more than 189 member countries including Canada. Canada's participation in Codex is coordinated through the Office of the Codex Contact Point for Canada, located in the Food Directorate, Health Products and Food Branch of Health Canada.

If you are interested in the regulations in the United States, you may wish to check out the website of the US Food and Drug Administration, Centre for Food Safety and Applied Nutrition: https://www.fda.gov/

The Agriculture and Agri-Food Canada website for information concerning US FDA regulations is also useful especially for import-export cases: [http://www.agr.gc.ca/eng/home/?id=1395690825741 http://www.agr.gc.ca/eng/home/?id=1395690825741 ]

== 04.7 Food Additives ==
There is probably no component of the food system that has generated so much discussion among the consuming public as food additives. Many myths and half-truths abound about food additives, their uses and the perceived dangers related to the presence of additives in foods in the Canadian food supply. Compounding this, is the prevalence of American radio, television, newspapers and magazines in Canada with articles about the positive and, in the majority of cases, negative aspects about food additives.
* As you will note shortly, the Canadian definition of a food additive is '''not''' the same as the definition of a food additive in the United States. This has led to much of the confusion in the eyes of the Canadian public, who at times may know more about the United States regulations and legislation than the Canadian regulations and legislation and the Food and Drugs Act of Canada.

==== Canadian Food additive definition ====
A food additive is any substance, the use of which results, or may reasonably be expected to result in it or its by-products becoming a part of or affecting the characteristics of a food.

'''Under the Canadian definition, the following are considered NOT to be additives:'''
* any nutritive material that is used, recognized or commonly sold as an article or ingredient of food
* amino acids, mineral nutrients and vitamins
* spices, seasonings, flavouring preparations, essential oils, oleoresins and natural extractives
* food packaging materials and components thereof
* drugs recommended for administration to animals that may be consumed as food.
The exceptions are not included in the definition of a food additive since regulations in other divisions of the food regulations of The Food and Drugs Act of Canada govern their use.

Now compare the Canadian definition of a food additive with the definition adhered to in the '''United States''' by the ''Food and Drug Administration'', the federal counterpart to the Health Products and Food Branch of Health Canada.

==== The definition of a food additive in the United States is as follows: ====
''"In its broadest sense, a food additive is any substance added to food. Legally, the term refers to 'any substance the intended use which results or may reasonably be expected to result-directly or indirectly-in'' its ''becoming a component or otherwise affecting the characteristics of any food. This definition includes any substance used in the production, processing, treatment, packaging, transportation or storage of food. If a substance is added to a food for a specific purpose in that food, it is referred to as a direct additive. For example, the low-calorie sweetener aspartame, which is used in beverages, puddings, yogurt, chewing gum and other foods, is considered a direct additive. Many direct additives are identified on the ingredient label of foods. Indirect food additives are those that become part of the food in trace amounts due to its packaging, storage or'' other handling''. For instance, minute amounts of packaging substances may find their way into foods during storage. Food packaging manufacturers must prove to the U.S. Food and Drug Administration (FDA) that all materials coming in contact with food are'' safe, ''before they are permitted for use in such a manner."''

Quoted from the answer to "What is a food additive?" in the International Food Information Council (IFIC) Foundation US Food and Drug Administration (FDA) Brochure: April 2010 from the http://www.fda.gov/downloads/Food/IngredientsPackagingLabeling/ucm094249.pdf

Although the Canadian and American definitions of food additives sound somewhat similar there are substantial differences between them as illustrated in the following table. You can clearly deduce that confusion can exist among consumers getting their information from the media from two neighbouring countries:
{| class="wikitable"
!Considered Food Additives
!Canada
!United States
|-
|Nutritive materials, vitamins, minerals and amino acids
|No
|Yes
|-
|Spices, seasonings and flavourings
|No
|Yes
|-
|Agricultural chemical residues
|No'''a'''
|Yes'''b'''
|-
|Food packaging components
|No'''a'''
|Yes'''b'''
|-
|Drugs recommended for therapeutic use and as feed additives for administration to food producing animals
|No'''a'''
|Yes'''b'''
|-
|Number of additives permitted ("on the books")
|~400
|>3000
|}
'''a''' considered as contaminants in Canada.

'''b''' considered as unintentional food additives in the United States.

=== Justified Uses for Food Additives ===
The '''Food and Agriculture Organization''' (FAO) of the United Nations has stated that the use of food additives is justified when one or more of the following conditions are met:
# additives used to maintain nutritional quality of the food. Use of additives that prevent or inhibit destruction of nutrients during processing and storage (e.g., use of antioxidants to prevent destruction of linoleic acid in oils);
# additives that function to enhance the keeping quality or stability of the food with a concomitant decrease in food wastage (e.g., use of antioxidants to delay fat oxidation; antimicrobial agents to delay microbial spoilage of food);
# additives used to make foods attractive without deception (e.g., use of orange/yellow colours in margarine to provide a pleasing appearance; colouring agents are not permitted for use in fresh meats such as ground beef because a colouring agent could disguise the colour changes that signify the onset of spoilage of the meat);
# additives used to provide essential aids to food processing (e.g., use of emulsifying agents to promote formation of stable emulsions).

=== Food additive regulations in Canada ===

==== How are Food Additives regulated in Canada? ====
Look under '''Division 16''' '''''FOOD ADDITIVES''''' of The Food and Drug Regulations (FDR) for a detailed list of food additives set out in tabular form: https://www.canada.ca/en/health-canada/services/food-nutrition/food-safety/food-additives/lists-permitted.html

https://laws-lois.justice.gc.ca/eng/regulations/C.R.C.,_c._870/index.html

As you will notice, the list provides the following information:
# The '''purpose''' of the food additives are listed (eg. anti-caking agents);
# The '''name''' of the additives that can be used for that purpose;
# Foods in which they are '''permitted''' and the '''maximum amount''' permitted.
Since the listing of food additives is a positive list, if a food is '''not listed''' in the tables the additive in question cannot legally be used in that food item. An example of a page from Division 16 is shown in Figure 4.2.
[[File:4.2 fig.png|thumb|Figure 4.2 An example of a page from Division 16|center|500x500px]]
==== What is "Good manufacturing practice"? ====
When the maximum level of use for a food additive indicates "''Good manufacturing practice''" (GMP); it basically means the '''minimum amount''' of an additive required to accomplish the specific purpose for which the additive is listed.

This minimum amount is based on technical food processing needs.

There are '''15 categories''' of food additives in Canada. The categories and examples of the additives are shown in Table 4.3 of this lesson.

Some additives are listed in more than one category since an additive can have several functions in foods. Ascorbic acid, for example, functions as a dough conditioning agent when used in bread formulations, but it is also listed as a preservative since it also has antioxidant functionality.
{| class="wikitable"
!Additive Category
!Function
|-
|Anticaking agents
|
* keep powders (salt, sugars, startches) free running.
|-
|Bleaching, maturing, and dough conditioning agents
|
* react with flour components (wheat gluten proteins with doug conditioning agents);
* bleaching agents decolourize yellow pigments in flour;
* maturing agents produce bakery products of consistent quality, texture andcolour.
|-
|Colouring agents
|
* to produce an appealing appearance, or to restore colours lost as a result of processing or storage, or to correct seasonal variation in colour, e.g., addition of orange colouring to milk used for Cheddar cheese production,
|-
|Emulsifying, gelling, stabilizing and thickening agents
|
* emulsifying agents form and stabilize emulsions (lecithin is used as an emulsifying agent on margarine);
* gelling agents promote gel formation (gelatin is a gelling agent in dessert powders);
* stabilizing agents impart stability to food systems (carrageenan is added to chocolate milk to keep cocoa particles in suspension);
* thickening agents function to impart body to foods (xanthan gum imparts body and cling to salad dressings).
|-
|Food enzymes
|
* enzymes are biological catalysts that function to promote desirable chemical reactions in foods (invertase is used to promote sucrose hydrolysis in confectionery products).
|-
|Firming agents
|
* function to maintain the texture of foods (calcium chloride is used to prevent potatoes from disintegrating during canning).
|-
|Glazing and polishing agents
|
* additives used to make food surfaces shiny and in some cases to prevent quality deterioration (beeswax is permitted for use on confectionery products).
|-
|Miscellaneous agents
|
* food additives that do not lift into other categories (caffeine is permitted for use in cola beverages; carbon dioxide is permitted for use in making carbonated beverages).
|-
|Sweeteners
|
* additive used to sweeten foods, other than conventional nutritive sweeteners. An example is aspartame.
|-
|pH adjusting agents, acid reacting materials and water correcting agents
|
* pH adjusting agents used to ensure proper acidity of foods (citric acid added as a correcting agent; water added to canned tomatoes to ensure pH 4.5);
* acid reacting materials decrease the acidity of water or foods (calcium carbonate is permitted for use in processed cheeses);
* water correcting agents function to decrease the hardness of water.
|-
|Preservatives
|
* agents that delay the onset of food spoilage. Preservatives can be antimicrobial agents (benzoic acid, sorbic acid, potassium nitrite) or antioxidants (ascorbic acid, propyl galiate gallate, a-tocopherol) to prevent fat oxidation and enzymatic browning of fruit.
|-
|Sequestering agents
|
* agents that irreversible bind undesirable metal icons in foods that could cause undesirable colour changes, flavour changes, textural changes (sodiumhexametaphosphate is used in canned seafood to bind metals that could cause discolouration of the seafood).
|-
|Starch modifying agents
|
* additives used to alter the functional properties of starches to preventsyneresis during frozen storage or to prevent starch from becoming too viscous during thermal processing (sodium acetate and hydrochloric acid are examples of starch modifying agents).
|-
|Food additives used as yeast foods
|
* additives that serve as nutrients for yeasts (calcium carbonate) and as yeast foods (calcium lactate) are permitted for use as yeast foods in bread doughs.
|-
|Carrier or extraction solvents
|
* solvents used to solubilize colours or flavours used in food (ethanol is permitted for use in spice extracts);
* solvents used to extract oils from oilseeds or marine sources, and fordecaffeination of coffee (methylene chloride and carbon dioxide are used to decaffeinate coffee).
|}

=== The Food Additive Approval Process ===
The information that companies must provide when submitting applications to the Health Products and Food Branch of Health Canada for approval of a new food additive is listed below:
# Composition, properties, method of manufacture and specifications of the substance to be used as a food additive;
# Amount and purpose of use;
# An acceptable method of analysis to determine the presence and concentration of the proposed food additive
# Data establishing that the proposed food additive will have the intended physical or other technical effect;
# Detailed reporting of tests conducted to establish the safety of the proposed food additive. Those studies must include:
#* biochemical and physiological tests;
#* subacute and chronic toxicity tests; and
#* reproduction studies
# A proposed maximum limit for residues of the food additive in or upon the finished food;
# Specimens of the labelling proposed for the food additive; and
# A sample of the food additive.
Reference: FDR, '''Division 16''', B.16.002.

'''Note''' that the information required relates to both the technological properties of the proposed additive as well as the long term safety of the additive.

This type of documentation was required when the G.D. Searle Company applied to have the low caloric sweetener, '''aspartame''', approved for use as a food additive in Canada.

When the Health Products & Food Branch obtained the information they evaluated it relative to the safety of aspartame as well as its technological properties and proposed uses in foods.

The use level permitted in specified foods was determined taking the following parameters into consideration:
* '''No effect level''' = the highest level of the chemical which caused no harmful effects in the test animals.
* '''No effect level for humans''' = no effect level in animals, divided by a safety factor. For most food additives the safety factor is generally 100.
* '''Acceptable daily intake''' = daily dosage of a chemical which during an entire lifetime appears to be without appreciable risk on the basis of all facts known at that time. The acceptable daily intake is expressed as mg intake per kg body weight.
* '''Without appreciable risk''' = the practical certainty that injury will not result even after a lifetime of exposure.
* The '''probable daily intake''' of a food additive is determined to ensure that this value would not exceed the acceptable daily intake. Food consumption estimates of particular food commodities are used to determine the probable daily intake of the food additive in question. Data from food consumption surveys as well as information from Statistics Canada and the published scientific literature are used to estimate consumption of particular food items by various groups in Canada (e.g., children, teenagers, the elderly, etc.). If the probable daily intake of the food additive in question were to exceed the acceptable daily intake, the additive would not be approved for use or it would be approved for very restricted use.
The dose-response curve below depicts the above-mentioned concepts. These parameters will be discussed again in Lesson 12.[[File:FNH 200 Lesson 12 DoseResponse.gif|thumb|400px|Dose Response Curve|center]]

'''Examples of Food Additive Approval Process'''

Two additives, aspartame and nitrites, will now be described in order to give you some insight into the controversies which surrounded those additives and also into the decision-making processes with regard to risk/benefit issues.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Kroger, M., Meister, K., and Kava, R. 2006. Low-calories sweeteners and other sugar substitutes: A review of the safety issues. Comprehensive Reviews in Food Science and Food Safety 5: 35-47 (read esp pp.37-39).
** https://onlinelibrary.wiley.com/doi/epdf/10.1111/j.1541-4337.2006.tb00081.x
* Health Canada, Food Program: Safety of Aspartame.
** https://www.canada.ca/en/health-canada/services/food-nutrition/food-safety/food-additives/sugar-substitutes/aspartame-artificial-sweeteners.html
|}
Example 1: ''Aspartame''

'''Aspartame''' is a ''low-calorie'' sweetener yielding 4 Cal/g when metabolized. On a weight basis, aspartame yields the same caloric value as an equivalent weight of sucrose. Since aspartame is intensely sweet, it can be used in very small quantities and thus can be added to sweeten "low-calorie" foods (review Lesson 3).

Aspartame was approved for use in Canada in 1981. Since its introduction as an approved sweetener, aspartame has received much attention in the media with respect to the alleged risks related to the presence of aspartame in foods.

You will note in the article that aspartame is digested in the human body to its constituent components (aspartic acid, phenylalanine and methanol) which are metabolized by normal metabolic routes. The safety aspects of aspartic acid, phenylalanine, and methanol are discussed in the article. Aspartame also has not demonstrated carcinogenicity in animal studies. Aspartame in foods can undergo degradation to diketopiperazine (DKP) during long-term storage and when it is exposed to high temperatures for extended periods of time. Studies indicate that DKP does not appear to cause any deleterious effects when ingested.
{| class="wikitable"
|'''Critical Thinking'''
|-
|
* On the basis of current knowledge of the chemistry of aspartame and on the way in which it is metabolized in the human body, in Canada, aspartame is considered to be safe for consumption at or below the '''acceptable daily intake (ADI) of 40 mg/kg body weight per day.''' What is the ADI for aspartame in the United States?
** ''How does this translate to our daily diet?''Let us assume that an individual weighs 60 kg (132 lb). The '''total acceptable daily intake''' of aspartame per day for that individual would be:
*** 40 mg aspartame/kg body weight '''x''' 60 kg body weight '''=''' 2400 mg aspartame/day.
* A typical non-caloric soft drink in Canada contains 49 mg aspartame/100 ml soft drink (490 mg/L).
* The amount of soft drink that person could consume per day that would contribute 2400 mg of aspartame is:
** 2400 mg aspartame/day '''÷''' 490 mg aspartame/ L soft drink '''=4.9 L soft drink/day.''' That is a significant amount of soft drink!
|}
* If you consume aspartame-sweetened foods you may find it interesting to calculate your daily intake of aspartame.
* The information you would require is your weight in kilograms, the quantity of each aspartame-containing food consumed daily, as well as the concentration of aspartame in each food item (in mg aspartame/ 100 ml or 100 g, as stated on the list of ingredients for each food item).
* Note that most "''diet''" soft drinks in Canada now contain a blend of aspartame with Acesulfame-K.
* The risks, to metabolically normal individuals, relating to consumption of aspartame are very small while the benefits relating to use of aspartame are high, particularly for individuals wishing to decrease their caloric intake while still enjoying sweet tasting foods.
* The benefits of aspartame to diabetics are obvious. However, there is a small segment of the population for which aspartame in foods poses a substantial risk. Those individuals suffer from '''phenylketonuria'''
Consequently, according to the Canadian labelling regulations, foods to which aspartame is added must
# contain a statement on the label saying "contains Aspartame" either individually or conjunction with other sweeteners;
# list aspartame in the list of ingredients; and
# must also indicate the aspartame content expressed in milligrams per serving of the stated size.
# stating " Aspartame contains phenylalanine
This information is placed on the label of aspartame containing foods to warn '''phenylketonurics''' that they should avoid the product or consume it in very limited quantities because of their impaired ability to metabolize phenylalanine. Please read the information on PKU and aspartame in the reading (Kroger, M, Meister, K. and Kava, R. 2006).

Example 2: ''Nitrites''

The other food additive that we will review is nitrite.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* The article by Hotchkiss and Cassens provides an overview of the history of the use of nitrites and nitrates in foods and also a history of meat curing and regulation of the curing process.
** Hotchkiss, J.H., and Cassens, R.G. 1987 [April]. Nitrate, nitrite, and nitroso compounds in foods (A scientific status summary). ''Food Technology'', 41(4):127-136.
|}
'''Why use nitrites?'''

The reactions of myoglobin, the red pigment in meat, with nitric oxide (formed from nitrites) in cured meats leads to the formation of nitrosohemochrome, the pink colour typical of cured meat products.

As shown in Figure 4.5 below, nitrite has several functions in cured meats. By far, the most important role of nitrite is to act as an '''antimicrobial agent''', particularly towards '''''Clostridium botulinum''''' which produces the toxin responsible for botulism (you can find out more about ''Clostridium botulinum'' in Lesson 6).[[File:FNH200 Lesson04 Nitrites.gif|thumb|500px|Figure 4.5 Functions of nitrites in cured meats|center]]
* The fact that the exact mechanism by which nitrites inhibit growth and toxin production by ''Clostridium botulinum'' are not fully understood makes the search for an alternative very difficult.
* To this date an acceptable alternative to nitrite as an antimicrobial agent in cured meats has '''not been found''' even though many years and millions of dollars, in numerous countries, have been spent in the search for an alternative for nitrite and also to gain an understanding of the mechanism(s) by which nitrite functions as an '''anti-botulinal agent.'''
'''What are some of the risks associated with nitrites?'''

There is a possibility that nitrites (naturally occurring, or added as an additive, or produced by reduction of nitrates), can react with amines to produce '''nitrosamines''' - some of which are potent carcinogens. The discovery in the 1960s of nitrosamines in foods, especially in cured meats, led to many studies and reviews on the risk/benefit situation relating to the use of nitrite and nitrate as food additives, particularly in cured meats. Much research has been conducted on the nitrosation reactions that can occur in foods as well as factors in foods that lead to nitrosamine formation.

Data indicate that foods are not a major source of nitrosamine exposure in humans, and that the greatest exposure comes from use of tobacco products. In foods, beer and fried bacon contribute more nitrosamine to the diet than all other foods combined (see the scientific status summary by Hotchkiss and Cassens). Nevertheless, whenever possible, the exposure to nitrosamines should be minimized.

In 1972, levels of nitrosopyrrolidine in excess of 100 parts per billion (ppb) were detected in fried bacon. [Oneppb is an extremely small quantity; if you were to travel one foot on a trip to the Moon, it would represent one part in one billion, since the distance to the Moon is about one billion feet.] By 1982, the level of N-nitrosopyrrolidine in fried bacon produced in the United States was in the range of 10 ppb, about ten-fold lower than the level in 1972. Bacon in the raw stage, has been found to be generally free of nitrosamines which develop during high-heat frying.

You might ask why this dramatic decrease occurred. Research into meat curing operations demonstrated several instances where nitrosation reactions were favoured during the production of cured meats. Changes in the curing process led to decreases in nitrosamine formation. In addition, it was found that compounds such as ascorbic acid, sodium erythorbate (isoascorbate) and alpha-tocopherol (vitamin E) would interfere with the nitrosation reactions. The next time you have an opportunity to read a label on a package of cured meat you will notice that ascorbic acid or sodium erythorbate are listed as one of the ingredients.
* Regulatory agencies have been faced with a dilemma as far as nitrite in foods, particularly cured meats, is concerned.
* It is known that under certain circumstances, particularly during frying of bacon, that nitrosamines can be formed.
* Some nitrosamines are potent carcinogens while others are non-carcinogenic.
* The type and quantity of nitrosamines that are formed depend on the reactants and the conditions present in the food.
The article "''Nitrates, nitrites, and nitroso compounds in foods''" reviews the conditions that favour as well as those that impede nitrosamine formation. It also presents the risk/benefit situation with regard to nitrates '''(NO-3)''' and nitrites '''(NO-2)''' in the diet.

'''What are some important facts in assessing the risks and benefits of allowing nitrates as a food additive in cured meats?'''

'''The following information may help to put the issue into a clearer perspective:'''
* Our major intake of '''nitrate''' is from that naturally found in vegetables (86%), with cured meats contributing only 9% and other food commodities the remaining 5% of the nitrate in food.
* '''Nitrite''' formed from nitrate in the secretions from the salivary glands (in our saliva) represents the greatest intake of nitrite (77%). Cured meats and other food commodities represent 21% and 2 %, respectively of our nitrite intake.
* Even if nitrite was de-listed as a food additive, we would still be exposed to a substantial intake of nitrite due to its presence in saliva.
* It has also been shown that '''nitrosamines''' are formed in the human stomach even when the diet does not contain any nitrite because of the conversion of salivary nitrate to nitrite by bacteria in our mouths.
* The pH and temperature of the human stomach are in the optimum range for nitrosation reactions.
* Consequently, humans have been exposed to nitrosamines for eons of time.
* It is extremely difficult to quantify the risk posed to our health by the use of nitrites as a food additive. The risks appear to be very low.
* On the other hand, the risk of botulism from cured meats if nitrites were banned appear to be high, based on information on the incidence of occurrence of ''Clostridium botulinum'' spores in raw meats.
The risk/benefit situation related to the use of nitrites in cured meats as follows:

'''If nitrite is used:'''

'''''Risks''':''
* Potential of increased nitrosamine content in the diet. Although some nitrosamines have shown carcinogenicity at higher doses, this does not appear to be a significant risk with moderate consumption.
'''''Benefits:'''''
* Production of cured meat products at a reasonable cost with adequate control of ''Clostridium botulinum''.
'''If nitrite is not used:'''

'''''Risks''''':
* Increased potential for growth and toxin production by ''Clostridium botulinum'' in perishable cured meat products under abusive conditions.
* Shelf-stable canned cured meat products would probably not be available because the increased heat treatment required would produce a product with an undesirable texture.
'''''Benefits:'''''
* Decreased risks due to a decreased load of nitrosamines in the diet. The magnitude of this benefit may not be measurable due to the current load of nitrosamines in the diet from other sources and from nitrosamines formed ''in vivo''.

=== ''Outcome'' ===
''Based on the current evidence the benefits of using Nitrites outweighs the risk. However precautionary measures are in place to ensure the safety of the consumers. These precautionary measures include limiting the usage to specific products in which the risk of Clostridium botulinum is greater. The amount of use is regulated and industries are encouraged to use methods to reduce the risk of nitrosamine formation''

== 04.8 Summary of Lesson 4 ==
* There are various Acts and Regulations that apply to food in Canada, to ensure that Canadian consumers have access to a safe, high quality food supply.
* The Health Products and Food Branch (HPFB) of Health Canada establishes regulations and standards (within the Food and Drugs Act and Regulations-FDR)
* The Canadian Food Inspection Agency (CFIA) enforces these regulations and standards (e.g. Consumer Packaging and Labelling Act & Regulations)
* There are 28 divisions within the FDR. For example, ''Food additives'' are regulated (found) in Division 16.
* There are more than 400 approved food additives in Canada. Aspartame and nitrites are two examples of food additives; however, ''aspartame'' is classified as a "sweetener", whereas ''nitrites'' are classified as "preservatives".
* Generally, risk/benefit issues are not black and white; often they are shrouded in shades of gray. However, with the information you have gained in this course, you should be able to determine objectively the validity of reports that you may encounter in the media about food additives and about food safety issues.

'''Authorship:'''

FNH 200 Course content on this wiki page and associated lesson pages was originally authored by Drs. [http://www.landfood.ubc.ca/person/brent-skura/ Brent Skura], [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], and [http://www.landfood.ubc.ca/person/eunice-li-chan/ Eunice Li-Chan]. Ongoing edits and updates are contributed by past and current instructors including Drs. [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], [http://www.landfood.ubc.ca/person/azita-madadi-noei/ Azita Madadi-Noei], [http://www.landfood.ubc.ca/person/nooshin-alizadeh-pasdar/ Nooshin Alizadeh-Pasdar], and [http://www.landfood.ubc.ca/person/judy-chan/ Judy Chan].
{{cc-by-nc-sa-3.0}}

<quiz display=simple>
{1. Which agency below is responsible for accurate labeling of foods.
|type="()"}
- Health Canada: HPFB
+ CFIA
- Industry Canada
- BC Ministry of Health
- City of Vancouver
</quiz>

<quiz display=simple>
{2. Which food below is NOT a standardized food?
|type="()"}
- Enriched white bread
- Raisin bread
+ Pizza dough
- Whole wheat bread
- Bread
</quiz>

<quiz display=simple>
{3. Why do we use nitrites in cured meats?
|type="()"}
- To enhance the pink colour in finished products
- To enhance flavours
- To act as an antimicrobial agent
+ All of the above
- None of the above as nitrites are not approved to be added to cured meats in Canada.
</quiz>

<quiz display=simple>
{4. Match the agency with their role.
|type="{}"}
Sets new food regulations. { Health Canada }
Inspections of restaurants. { Municipal Agencies(BC Ministry of Health) }
Reviews food related advertisements for claims. { Canadian Food Inspection Agency }
</quiz>

<quiz display=simple>
{5. In order to qualify as Canada Grade A, which qualities must maple syrup have?
|type="()"}
- Undergone at least some fermentation
+ Be free of sediment and turbidity
- Be categorized in the amber color class
- Produced only in Canada
</quiz>

Course:FNH200/Lessons/Lesson 04/Page 04.8

2020-06-24T02:49:33Z

YihangChen: /* 4.8 Summary of Lesson 4 */

== 04.8 Summary of Lesson 4 ==
* There are various Acts and Regulations that apply to food in Canada, to ensure that Canadian consumers have access to a safe, high quality food supply.
* The Health Products and Food Branch (HPFB) of Health Canada establishes regulations and standards (within the Food and Drugs Act and Regulations-FDR)
* The Canadian Food Inspection Agency (CFIA) enforces these regulations and standards (e.g. Consumer Packaging and Labelling Act & Regulations)
* There are 28 divisions within the FDR. For example, ''Food additives'' are regulated (found) in Division 16.
* There are more than 400 approved food additives in Canada. Aspartame and nitrites are two examples of food additives; however, ''aspartame'' is classified as a "sweetener", whereas ''nitrites'' are classified as "preservatives".
* Generally, risk/benefit issues are not black and white; often they are shrouded in shades of gray. However, with the information you have gained in this course, you should be able to determine objectively the validity of reports that you may encounter in the media about food additives and about food safety issues.

'''Authorship:'''

FNH 200 Course content on this wiki page and associated lesson pages was originally authored by Drs. [http://www.landfood.ubc.ca/person/brent-skura/ Brent Skura], [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], and [http://www.landfood.ubc.ca/person/eunice-li-chan/ Eunice Li-Chan]. Ongoing edits and updates are contributed by past and current instructors including Drs. [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], [http://www.landfood.ubc.ca/person/azita-madadi-noei/ Azita Madadi-Noei], [http://www.landfood.ubc.ca/person/nooshin-alizadeh-pasdar/ Nooshin Alizadeh-Pasdar], and [http://www.landfood.ubc.ca/person/judy-chan/ Judy Chan].
{{cc-by-nc-sa-3.0}}

<quiz display=simple>
{1. Which agency below is responsible for accurate labeling of foods.
|type="()"}
- Health Canada: HPFB
+ CFIA
- Industry Canada
- BC Ministry of Health
- City of Vancouver
</quiz>

<quiz display=simple>
{2. Which food below is NOT a standardized food?
|type="()"}
- Enriched white bread
- Raisin bread
+ Pizza dough
- Whole wheat bread
- Bread
</quiz>

<quiz display=simple>
{3. Why do we use nitrites in cured meats?
|type="()"}
- To enhance the pink colour in finished products
- To enhance flavours
- To act as an antimicrobial agent
+ All of the above
- None of the above as nitrites are not approved to be added to cured meats in Canada.
</quiz>

<quiz display=simple>
{4. Match the agency with their role.
|type="{}"}
Sets new food regulations. { Health Canada }
Inspections of restaurants. { Municipal Agencies(BC Ministry of Health) }
Reviews food related advertisements for claims. { Canadian Food Inspection Agency }
</quiz>

<quiz display=simple>
{5. In order to qualify as Canada Grade A, which qualities must maple syrup have?
|type="()"}
- Undergone at least some fermentation
+ Be free of sediment and turbidity
- Be categorized in the amber color class
- Produced only in Canada
</quiz>

Course:FNH200/Lessons/Lesson 04/Page 04.6

2020-06-24T02:49:26Z

YihangChen: /* 4.6 Natural Health Products */

== 04.6 Natural Health Products ==
To deal with the uniqueness of emerging products which are neither strictly foods nor drugs, the government has established a [https://www.canada.ca/en/health-canada/corporate/about-health-canada/branches-agencies/health-products-food-branch/natural-non-prescription-health-products-directorate.html Natural Health Products Directorate], responsible for regulations and labelling guidelines for these products. We will learn about this topic in Lesson 13.

==== '''How about the international scene?''' ====
The [http://www.fao.org/fao-who-codexalimentarius/en/ Codex Alimentarius Commission] was established in 1963 by the World Health Organization and the Food and Agriculture Organization of the United Nations to develop international food standards to protect consumer health and to facilitate fair trading practices in foods. Today, there are more than 189 member countries including Canada. Canada's participation in Codex is coordinated through the Office of the Codex Contact Point for Canada, located in the Food Directorate, Health Products and Food Branch of Health Canada.

If you are interested in the regulations in the United States, you may wish to check out the website of the US Food and Drug Administration, Centre for Food Safety and Applied Nutrition: https://www.fda.gov/

The Agriculture and Agri-Food Canada website for information concerning US FDA regulations is also useful especially for import-export cases: [http://www.agr.gc.ca/eng/home/?id=1395690825741 http://www.agr.gc.ca/eng/home/?id=1395690825741 ]

Course:FNH200/Lessons/Lesson 04/Page 04.5

2020-06-24T02:49:21Z

YihangChen: /* 4.5 Food Grades Standards */

== 04.5 Food Grades Standards ==
Food grades standards are administered by the CFIA.

Here is a list of some of the regulations:
* [https://inspection.gc.ca/about-the-cfia/acts-and-regulations/list-of-acts-and-regulations/documents-incorporated-by-reference/canadian-grade-compendium-volume-1/eng/1520878338783/1520878339422 Volume 1, Ovine carcasses and poultry carcasses]
* [https://inspection.gc.ca/about-the-cfia/acts-and-regulations/list-of-acts-and-regulations/documents-incorporated-by-reference/canadian-grade-compendium-volume-2/eng/1519996239002/1519996303947 Volume 2, Fresh fruit or vegetables]
* [https://inspection.gc.ca/about-the-cfia/acts-and-regulations/list-of-acts-and-regulations/documents-incorporated-by-reference/canadian-grade-compendium-volume-3/eng/1522257117725/1522257118286 Volume 3, Processed fruit or vegetable products]
* [https://inspection.gc.ca/about-the-cfia/acts-and-regulations/list-of-acts-and-regulations/documents-incorporated-by-reference/canadian-grade-compendium-volume-4/eng/1521118213588/1521118214322 Volume 4, Dairy products]
* [https://inspection.gc.ca/about-the-cfia/acts-and-regulations/list-of-acts-and-regulations/documents-incorporated-by-reference/canadian-grade-compendium-volume-5/eng/1520869505643/1520869506282 Volume 5, Eggs]
* [https://inspection.gc.ca/about-the-cfia/acts-and-regulations/list-of-acts-and-regulations/documents-incorporated-by-reference/canadian-grade-compendium-volume-6/eng/1523388139064/1523388171017 Volume 6, Honey]
* [https://inspection.gc.ca/about-the-cfia/acts-and-regulations/list-of-acts-and-regulations/documents-incorporated-by-reference/canadian-grade-compendium-volume-7/eng/1521118355767/1521118356469 Volume 7, Maple syrup]
* [https://inspection.gc.ca/about-the-cfia/acts-and-regulations/list-of-acts-and-regulations/documents-incorporated-by-reference/canadian-grade-compendium-volume-8/eng/1521472457185/1521472457803 Volume 8, Fish]
{| class="wikitable"
| '''Critical Thinking'''
|-
|To complete the following activities visit the http://inspection.gc.ca/food/requirements/labelling/industry/grades/eng/1468508117774/1468508381597.

1) Find out more about regulations governing fresh fruits or vegetables.

* What are the names of the 7 grades for fresh apples?
* Describe the major attributes that distinguish the first (top) grade and third grade.
''Response: Grade standard descriptions for '''processed fruits or vegetables''' indicate that the grades are based on aesthetic qualities of the fruits and vegetables. Although there is not a great deal of information available, it appears that Canada Fancy and Canada Standard processed fruits and vegetables are similar in nutrient value. Thus the grades do not necessarily indicate that a better grade (fancy) is superior to a lower grade (standard) from a nutrient point of view.''

''2) Find out more about eggs.''

Select "'''Egg Regulations'''" and scan through the information to answer the following questions:
* How many grades exist for eggs? what are they named?
* What are the basic requirements for eggs to be graded?
''Response: '''Eggs''' are graded only if certain criteria are met, and then only by an inspector at a registered egg station. The eggs are evaluated for weight, cleanliness, soundness'' and ''shape of shell, shape and position of yolk in the egg during candling, size of air cell (small = fresh), abnormalities (e.g., blood spots).''
* Which grade of eggs is further designated by size?
* Which grades are shown on a label with a "maple leaf" design?
* Which grades are sent to registered processed egg stations?
* Take a look at an egg carton in your fridge or in the supermarket. Can you find the required information about the grade? size?
3) Now select "'''Ovine and Poultry Carcass Grading Regulations'''" and browse through to answer the following
* How many grades exist for beef carcasses?
* What are the names of these grades?
* What are the main criteria that are considered in grading beef carcasses? Next time you eat a piece of steak, you should have a better understanding of what the "Triple A" means!
4) Now select "Maple Product Regulations" and browse through the Maple Syrup Grade Names.
* How many grades exist?
* What are the attributes associated with the grades?
|}

=== Video ===
At this point you should watch the video on '''Egg processing''', including the grading system and processing.

'''Can you answer the following:'''
* Why are the eggs washed?
* How is the process of candling done?
* What are the main external and internal characteristics that are evaluated during candling?
* Which grade(s) of eggs are normally found in the retail market? what happens to other grades? are all eggs suitable for food use?
* What types of processed egg products are shown? what are the conditions for HTST pasteurization of liquid whole and yolk?

Course:FNH200/Lessons/Lesson 04/Page 04.4

2020-06-24T02:49:17Z

YihangChen: /* 4.4 Standards of Food Identity and Composition */

== 04.4 Standards of Food Identity and Composition ==
The Food and Drug Regulations contain descriptions of certain foods that specify, for example, '''what is allowed in those foods as ingredients'''. These descriptions are standards of identity and composition that have to be met for a food to be legally called by the name in the standard. The foods are referred to as "standardized foods". Examples of standardized foods include bread, milk, cheese, orange juice, sausage, jam, wine, beer, vinegar and salt. Foods that do not have a standard of identity are referred to as "'''unstandardized foods'''". Snack foods like potato chips, various bakery items such as rolls, donuts and cakes, yogurt, and pizza are examples of unstandardized foods.

Standards of food identity and composition are defined in the '''''Food Regulations of the Food and Drugs Act of Canada'''''
* Please '''bookmark''' the link for the '''Food and Drug Regulations''' of '''The Food and Drugs Act of Canada''':
* <nowiki>http://laws-lois.justice.gc.ca/eng/regulations/C.R.C.,_c._870/index.html</nowiki>
Note the following:
* An '''''identity''' standard'' is one that states what the food shall be and defines a food or ingredient. '''''Compositional''' standards'' list the mandatory and permitted ingredients in foods.
* There are standards of identity or composition for over '''300 foods''' in the Food Regulations in Canada. They are classified within '''28 divisions'''. ''For example'', '''Division 13''' regulates "Grain and Bakery products". In this division, the standards of identity and composition for white wheat flour and bread can be found. A fragment of this division is shown below in Box 4.2 (click on the Box to read its contents).
** The dates on the left hand side of the identity and compositional standards (Box 4.2) indicate the date of the last revision of a particular section of the standard.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Visit the Food and Drug Regulations (<nowiki>http://laws-lois.justice.gc.ca/eng/regulations/C.R.C.,_c._870/index.html</nowiki>) and answer the following questions. Can you identify the division number that regulates:
** Dairy products
** Food additives
** Cocoa & chocolate products
|}
[[File:4.2.gif|thumb|Box 4.2 Identity and Composition Standards.|center]]

Course:FNH200/Lessons/Lesson 04/Page 04.7

2020-06-24T02:49:05Z

YihangChen: /* 4.7 Food Additives */

== 04.7 Food Additives ==
There is probably no component of the food system that has generated so much discussion among the consuming public as food additives. Many myths and half-truths abound about food additives, their uses and the perceived dangers related to the presence of additives in foods in the Canadian food supply. Compounding this, is the prevalence of American radio, television, newspapers and magazines in Canada with articles about the positive and, in the majority of cases, negative aspects about food additives.
* As you will note shortly, the Canadian definition of a food additive is '''not''' the same as the definition of a food additive in the United States. This has led to much of the confusion in the eyes of the Canadian public, who at times may know more about the United States regulations and legislation than the Canadian regulations and legislation and the Food and Drugs Act of Canada.

==== Canadian Food additive definition ====
A food additive is any substance, the use of which results, or may reasonably be expected to result in it or its by-products becoming a part of or affecting the characteristics of a food.

'''Under the Canadian definition, the following are considered NOT to be additives:'''
* any nutritive material that is used, recognized or commonly sold as an article or ingredient of food
* amino acids, mineral nutrients and vitamins
* spices, seasonings, flavouring preparations, essential oils, oleoresins and natural extractives
* food packaging materials and components thereof
* drugs recommended for administration to animals that may be consumed as food.
The exceptions are not included in the definition of a food additive since regulations in other divisions of the food regulations of The Food and Drugs Act of Canada govern their use.

Now compare the Canadian definition of a food additive with the definition adhered to in the '''United States''' by the ''Food and Drug Administration'', the federal counterpart to the Health Products and Food Branch of Health Canada.

==== The definition of a food additive in the United States is as follows: ====
''"In its broadest sense, a food additive is any substance added to food. Legally, the term refers to 'any substance the intended use which results or may reasonably be expected to result-directly or indirectly-in'' its ''becoming a component or otherwise affecting the characteristics of any food. This definition includes any substance used in the production, processing, treatment, packaging, transportation or storage of food. If a substance is added to a food for a specific purpose in that food, it is referred to as a direct additive. For example, the low-calorie sweetener aspartame, which is used in beverages, puddings, yogurt, chewing gum and other foods, is considered a direct additive. Many direct additives are identified on the ingredient label of foods. Indirect food additives are those that become part of the food in trace amounts due to its packaging, storage or'' other handling''. For instance, minute amounts of packaging substances may find their way into foods during storage. Food packaging manufacturers must prove to the U.S. Food and Drug Administration (FDA) that all materials coming in contact with food are'' safe, ''before they are permitted for use in such a manner."''

Quoted from the answer to "What is a food additive?" in the International Food Information Council (IFIC) Foundation US Food and Drug Administration (FDA) Brochure: April 2010 from the http://www.fda.gov/downloads/Food/IngredientsPackagingLabeling/ucm094249.pdf

Although the Canadian and American definitions of food additives sound somewhat similar there are substantial differences between them as illustrated in the following table. You can clearly deduce that confusion can exist among consumers getting their information from the media from two neighbouring countries:
{| class="wikitable"
!Considered Food Additives
!Canada
!United States
|-
|Nutritive materials, vitamins, minerals and amino acids
|No
|Yes
|-
|Spices, seasonings and flavourings
|No
|Yes
|-
|Agricultural chemical residues
|No'''a'''
|Yes'''b'''
|-
|Food packaging components
|No'''a'''
|Yes'''b'''
|-
|Drugs recommended for therapeutic use and as feed additives for administration to food producing animals
|No'''a'''
|Yes'''b'''
|-
|Number of additives permitted ("on the books")
|~400
|>3000
|}
'''a''' considered as contaminants in Canada.

'''b''' considered as unintentional food additives in the United States.

=== Justified Uses for Food Additives ===
The '''Food and Agriculture Organization''' (FAO) of the United Nations has stated that the use of food additives is justified when one or more of the following conditions are met:
# additives used to maintain nutritional quality of the food. Use of additives that prevent or inhibit destruction of nutrients during processing and storage (e.g., use of antioxidants to prevent destruction of linoleic acid in oils);
# additives that function to enhance the keeping quality or stability of the food with a concomitant decrease in food wastage (e.g., use of antioxidants to delay fat oxidation; antimicrobial agents to delay microbial spoilage of food);
# additives used to make foods attractive without deception (e.g., use of orange/yellow colours in margarine to provide a pleasing appearance; colouring agents are not permitted for use in fresh meats such as ground beef because a colouring agent could disguise the colour changes that signify the onset of spoilage of the meat);
# additives used to provide essential aids to food processing (e.g., use of emulsifying agents to promote formation of stable emulsions).

=== Food additive regulations in Canada ===

==== How are Food Additives regulated in Canada? ====
Look under '''Division 16''' '''''FOOD ADDITIVES''''' of The Food and Drug Regulations (FDR) for a detailed list of food additives set out in tabular form: https://www.canada.ca/en/health-canada/services/food-nutrition/food-safety/food-additives/lists-permitted.html

https://laws-lois.justice.gc.ca/eng/regulations/C.R.C.,_c._870/index.html

As you will notice, the list provides the following information:
# The '''purpose''' of the food additives are listed (eg. anti-caking agents);
# The '''name''' of the additives that can be used for that purpose;
# Foods in which they are '''permitted''' and the '''maximum amount''' permitted.
Since the listing of food additives is a positive list, if a food is '''not listed''' in the tables the additive in question cannot legally be used in that food item. An example of a page from Division 16 is shown in Figure 4.2.
[[File:4.2 fig.png|thumb|Figure 4.2 An example of a page from Division 16|center|500x500px]]
==== What is "Good manufacturing practice"? ====
When the maximum level of use for a food additive indicates "''Good manufacturing practice''" (GMP); it basically means the '''minimum amount''' of an additive required to accomplish the specific purpose for which the additive is listed.

This minimum amount is based on technical food processing needs.

There are '''15 categories''' of food additives in Canada. The categories and examples of the additives are shown in Table 4.3 of this lesson.

Some additives are listed in more than one category since an additive can have several functions in foods. Ascorbic acid, for example, functions as a dough conditioning agent when used in bread formulations, but it is also listed as a preservative since it also has antioxidant functionality.
{| class="wikitable"
!Additive Category
!Function
|-
|Anticaking agents
|
* keep powders (salt, sugars, startches) free running.
|-
|Bleaching, maturing, and dough conditioning agents
|
* react with flour components (wheat gluten proteins with doug conditioning agents);
* bleaching agents decolourize yellow pigments in flour;
* maturing agents produce bakery products of consistent quality, texture andcolour.
|-
|Colouring agents
|
* to produce an appealing appearance, or to restore colours lost as a result of processing or storage, or to correct seasonal variation in colour, e.g., addition of orange colouring to milk used for Cheddar cheese production,
|-
|Emulsifying, gelling, stabilizing and thickening agents
|
* emulsifying agents form and stabilize emulsions (lecithin is used as an emulsifying agent on margarine);
* gelling agents promote gel formation (gelatin is a gelling agent in dessert powders);
* stabilizing agents impart stability to food systems (carrageenan is added to chocolate milk to keep cocoa particles in suspension);
* thickening agents function to impart body to foods (xanthan gum imparts body and cling to salad dressings).
|-
|Food enzymes
|
* enzymes are biological catalysts that function to promote desirable chemical reactions in foods (invertase is used to promote sucrose hydrolysis in confectionery products).
|-
|Firming agents
|
* function to maintain the texture of foods (calcium chloride is used to prevent potatoes from disintegrating during canning).
|-
|Glazing and polishing agents
|
* additives used to make food surfaces shiny and in some cases to prevent quality deterioration (beeswax is permitted for use on confectionery products).
|-
|Miscellaneous agents
|
* food additives that do not lift into other categories (caffeine is permitted for use in cola beverages; carbon dioxide is permitted for use in making carbonated beverages).
|-
|Sweeteners
|
* additive used to sweeten foods, other than conventional nutritive sweeteners. An example is aspartame.
|-
|pH adjusting agents, acid reacting materials and water correcting agents
|
* pH adjusting agents used to ensure proper acidity of foods (citric acid added as a correcting agent; water added to canned tomatoes to ensure pH 4.5);
* acid reacting materials decrease the acidity of water or foods (calcium carbonate is permitted for use in processed cheeses);
* water correcting agents function to decrease the hardness of water.
|-
|Preservatives
|
* agents that delay the onset of food spoilage. Preservatives can be antimicrobial agents (benzoic acid, sorbic acid, potassium nitrite) or antioxidants (ascorbic acid, propyl galiate gallate, a-tocopherol) to prevent fat oxidation and enzymatic browning of fruit.
|-
|Sequestering agents
|
* agents that irreversible bind undesirable metal icons in foods that could cause undesirable colour changes, flavour changes, textural changes (sodiumhexametaphosphate is used in canned seafood to bind metals that could cause discolouration of the seafood).
|-
|Starch modifying agents
|
* additives used to alter the functional properties of starches to preventsyneresis during frozen storage or to prevent starch from becoming too viscous during thermal processing (sodium acetate and hydrochloric acid are examples of starch modifying agents).
|-
|Food additives used as yeast foods
|
* additives that serve as nutrients for yeasts (calcium carbonate) and as yeast foods (calcium lactate) are permitted for use as yeast foods in bread doughs.
|-
|Carrier or extraction solvents
|
* solvents used to solubilize colours or flavours used in food (ethanol is permitted for use in spice extracts);
* solvents used to extract oils from oilseeds or marine sources, and fordecaffeination of coffee (methylene chloride and carbon dioxide are used to decaffeinate coffee).
|}

=== The Food Additive Approval Process ===
The information that companies must provide when submitting applications to the Health Products and Food Branch of Health Canada for approval of a new food additive is listed below:
# Composition, properties, method of manufacture and specifications of the substance to be used as a food additive;
# Amount and purpose of use;
# An acceptable method of analysis to determine the presence and concentration of the proposed food additive
# Data establishing that the proposed food additive will have the intended physical or other technical effect;
# Detailed reporting of tests conducted to establish the safety of the proposed food additive. Those studies must include:
#* biochemical and physiological tests;
#* subacute and chronic toxicity tests; and
#* reproduction studies
# A proposed maximum limit for residues of the food additive in or upon the finished food;
# Specimens of the labelling proposed for the food additive; and
# A sample of the food additive.
Reference: FDR, '''Division 16''', B.16.002.

'''Note''' that the information required relates to both the technological properties of the proposed additive as well as the long term safety of the additive.

This type of documentation was required when the G.D. Searle Company applied to have the low caloric sweetener, '''aspartame''', approved for use as a food additive in Canada.

When the Health Products & Food Branch obtained the information they evaluated it relative to the safety of aspartame as well as its technological properties and proposed uses in foods.

The use level permitted in specified foods was determined taking the following parameters into consideration:
* '''No effect level''' = the highest level of the chemical which caused no harmful effects in the test animals.
* '''No effect level for humans''' = no effect level in animals, divided by a safety factor. For most food additives the safety factor is generally 100.
* '''Acceptable daily intake''' = daily dosage of a chemical which during an entire lifetime appears to be without appreciable risk on the basis of all facts known at that time. The acceptable daily intake is expressed as mg intake per kg body weight.
* '''Without appreciable risk''' = the practical certainty that injury will not result even after a lifetime of exposure.
* The '''probable daily intake''' of a food additive is determined to ensure that this value would not exceed the acceptable daily intake. Food consumption estimates of particular food commodities are used to determine the probable daily intake of the food additive in question. Data from food consumption surveys as well as information from Statistics Canada and the published scientific literature are used to estimate consumption of particular food items by various groups in Canada (e.g., children, teenagers, the elderly, etc.). If the probable daily intake of the food additive in question were to exceed the acceptable daily intake, the additive would not be approved for use or it would be approved for very restricted use.
The dose-response curve below depicts the above-mentioned concepts. These parameters will be discussed again in Lesson 12.[[File:FNH 200 Lesson 12 DoseResponse.gif|thumb|400px|Dose Response Curve|center]]

'''Examples of Food Additive Approval Process'''

Two additives, aspartame and nitrites, will now be described in order to give you some insight into the controversies which surrounded those additives and also into the decision-making processes with regard to risk/benefit issues.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Kroger, M., Meister, K., and Kava, R. 2006. Low-calories sweeteners and other sugar substitutes: A review of the safety issues. Comprehensive Reviews in Food Science and Food Safety 5: 35-47 (read esp pp.37-39).
** https://onlinelibrary.wiley.com/doi/epdf/10.1111/j.1541-4337.2006.tb00081.x
* Health Canada, Food Program: Safety of Aspartame.
** https://www.canada.ca/en/health-canada/services/food-nutrition/food-safety/food-additives/sugar-substitutes/aspartame-artificial-sweeteners.html
|}
Example 1: ''Aspartame''

'''Aspartame''' is a ''low-calorie'' sweetener yielding 4 Cal/g when metabolized. On a weight basis, aspartame yields the same caloric value as an equivalent weight of sucrose. Since aspartame is intensely sweet, it can be used in very small quantities and thus can be added to sweeten "low-calorie" foods (review Lesson 3).

Aspartame was approved for use in Canada in 1981. Since its introduction as an approved sweetener, aspartame has received much attention in the media with respect to the alleged risks related to the presence of aspartame in foods.

You will note in the article that aspartame is digested in the human body to its constituent components (aspartic acid, phenylalanine and methanol) which are metabolized by normal metabolic routes. The safety aspects of aspartic acid, phenylalanine, and methanol are discussed in the article. Aspartame also has not demonstrated carcinogenicity in animal studies. Aspartame in foods can undergo degradation to diketopiperazine (DKP) during long-term storage and when it is exposed to high temperatures for extended periods of time. Studies indicate that DKP does not appear to cause any deleterious effects when ingested.
{| class="wikitable"
|'''Critical Thinking'''
|-
|
* On the basis of current knowledge of the chemistry of aspartame and on the way in which it is metabolized in the human body, in Canada, aspartame is considered to be safe for consumption at or below the '''acceptable daily intake (ADI) of 40 mg/kg body weight per day.''' What is the ADI for aspartame in the United States?
** ''How does this translate to our daily diet?''Let us assume that an individual weighs 60 kg (132 lb). The '''total acceptable daily intake''' of aspartame per day for that individual would be:
*** 40 mg aspartame/kg body weight '''x''' 60 kg body weight '''=''' 2400 mg aspartame/day.
* A typical non-caloric soft drink in Canada contains 49 mg aspartame/100 ml soft drink (490 mg/L).
* The amount of soft drink that person could consume per day that would contribute 2400 mg of aspartame is:
** 2400 mg aspartame/day '''÷''' 490 mg aspartame/ L soft drink '''=4.9 L soft drink/day.''' That is a significant amount of soft drink!
|}
* If you consume aspartame-sweetened foods you may find it interesting to calculate your daily intake of aspartame.
* The information you would require is your weight in kilograms, the quantity of each aspartame-containing food consumed daily, as well as the concentration of aspartame in each food item (in mg aspartame/ 100 ml or 100 g, as stated on the list of ingredients for each food item).
* Note that most "''diet''" soft drinks in Canada now contain a blend of aspartame with Acesulfame-K.
* The risks, to metabolically normal individuals, relating to consumption of aspartame are very small while the benefits relating to use of aspartame are high, particularly for individuals wishing to decrease their caloric intake while still enjoying sweet tasting foods.
* The benefits of aspartame to diabetics are obvious. However, there is a small segment of the population for which aspartame in foods poses a substantial risk. Those individuals suffer from '''phenylketonuria'''
Consequently, according to the Canadian labelling regulations, foods to which aspartame is added must
# contain a statement on the label saying "contains Aspartame" either individually or conjunction with other sweeteners;
# list aspartame in the list of ingredients; and
# must also indicate the aspartame content expressed in milligrams per serving of the stated size.
# stating " Aspartame contains phenylalanine
This information is placed on the label of aspartame containing foods to warn '''phenylketonurics''' that they should avoid the product or consume it in very limited quantities because of their impaired ability to metabolize phenylalanine. Please read the information on PKU and aspartame in the reading (Kroger, M, Meister, K. and Kava, R. 2006).

Example 2: ''Nitrites''

The other food additive that we will review is nitrite.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* The article by Hotchkiss and Cassens provides an overview of the history of the use of nitrites and nitrates in foods and also a history of meat curing and regulation of the curing process.
** Hotchkiss, J.H., and Cassens, R.G. 1987 [April]. Nitrate, nitrite, and nitroso compounds in foods (A scientific status summary). ''Food Technology'', 41(4):127-136.
|}
'''Why use nitrites?'''

The reactions of myoglobin, the red pigment in meat, with nitric oxide (formed from nitrites) in cured meats leads to the formation of nitrosohemochrome, the pink colour typical of cured meat products.

As shown in Figure 4.5 below, nitrite has several functions in cured meats. By far, the most important role of nitrite is to act as an '''antimicrobial agent''', particularly towards '''''Clostridium botulinum''''' which produces the toxin responsible for botulism (you can find out more about ''Clostridium botulinum'' in Lesson 6).[[File:FNH200 Lesson04 Nitrites.gif|thumb|500px|Figure 4.5 Functions of nitrites in cured meats|center]]
* The fact that the exact mechanism by which nitrites inhibit growth and toxin production by ''Clostridium botulinum'' are not fully understood makes the search for an alternative very difficult.
* To this date an acceptable alternative to nitrite as an antimicrobial agent in cured meats has '''not been found''' even though many years and millions of dollars, in numerous countries, have been spent in the search for an alternative for nitrite and also to gain an understanding of the mechanism(s) by which nitrite functions as an '''anti-botulinal agent.'''
'''What are some of the risks associated with nitrites?'''

There is a possibility that nitrites (naturally occurring, or added as an additive, or produced by reduction of nitrates), can react with amines to produce '''nitrosamines''' - some of which are potent carcinogens. The discovery in the 1960s of nitrosamines in foods, especially in cured meats, led to many studies and reviews on the risk/benefit situation relating to the use of nitrite and nitrate as food additives, particularly in cured meats. Much research has been conducted on the nitrosation reactions that can occur in foods as well as factors in foods that lead to nitrosamine formation.

Data indicate that foods are not a major source of nitrosamine exposure in humans, and that the greatest exposure comes from use of tobacco products. In foods, beer and fried bacon contribute more nitrosamine to the diet than all other foods combined (see the scientific status summary by Hotchkiss and Cassens). Nevertheless, whenever possible, the exposure to nitrosamines should be minimized.

In 1972, levels of nitrosopyrrolidine in excess of 100 parts per billion (ppb) were detected in fried bacon. [Oneppb is an extremely small quantity; if you were to travel one foot on a trip to the Moon, it would represent one part in one billion, since the distance to the Moon is about one billion feet.] By 1982, the level of N-nitrosopyrrolidine in fried bacon produced in the United States was in the range of 10 ppb, about ten-fold lower than the level in 1972. Bacon in the raw stage, has been found to be generally free of nitrosamines which develop during high-heat frying.

You might ask why this dramatic decrease occurred. Research into meat curing operations demonstrated several instances where nitrosation reactions were favoured during the production of cured meats. Changes in the curing process led to decreases in nitrosamine formation. In addition, it was found that compounds such as ascorbic acid, sodium erythorbate (isoascorbate) and alpha-tocopherol (vitamin E) would interfere with the nitrosation reactions. The next time you have an opportunity to read a label on a package of cured meat you will notice that ascorbic acid or sodium erythorbate are listed as one of the ingredients.
* Regulatory agencies have been faced with a dilemma as far as nitrite in foods, particularly cured meats, is concerned.
* It is known that under certain circumstances, particularly during frying of bacon, that nitrosamines can be formed.
* Some nitrosamines are potent carcinogens while others are non-carcinogenic.
* The type and quantity of nitrosamines that are formed depend on the reactants and the conditions present in the food.
The article "''Nitrates, nitrites, and nitroso compounds in foods''" reviews the conditions that favour as well as those that impede nitrosamine formation. It also presents the risk/benefit situation with regard to nitrates '''(NO-3)''' and nitrites '''(NO-2)''' in the diet.

'''What are some important facts in assessing the risks and benefits of allowing nitrates as a food additive in cured meats?'''

'''The following information may help to put the issue into a clearer perspective:'''
* Our major intake of '''nitrate''' is from that naturally found in vegetables (86%), with cured meats contributing only 9% and other food commodities the remaining 5% of the nitrate in food.
* '''Nitrite''' formed from nitrate in the secretions from the salivary glands (in our saliva) represents the greatest intake of nitrite (77%). Cured meats and other food commodities represent 21% and 2 %, respectively of our nitrite intake.
* Even if nitrite was de-listed as a food additive, we would still be exposed to a substantial intake of nitrite due to its presence in saliva.
* It has also been shown that '''nitrosamines''' are formed in the human stomach even when the diet does not contain any nitrite because of the conversion of salivary nitrate to nitrite by bacteria in our mouths.
* The pH and temperature of the human stomach are in the optimum range for nitrosation reactions.
* Consequently, humans have been exposed to nitrosamines for eons of time.
* It is extremely difficult to quantify the risk posed to our health by the use of nitrites as a food additive. The risks appear to be very low.
* On the other hand, the risk of botulism from cured meats if nitrites were banned appear to be high, based on information on the incidence of occurrence of ''Clostridium botulinum'' spores in raw meats.
The risk/benefit situation related to the use of nitrites in cured meats as follows:

'''If nitrite is used:'''

'''''Risks''':''
* Potential of increased nitrosamine content in the diet. Although some nitrosamines have shown carcinogenicity at higher doses, this does not appear to be a significant risk with moderate consumption.
'''''Benefits:'''''
* Production of cured meat products at a reasonable cost with adequate control of ''Clostridium botulinum''.
'''If nitrite is not used:'''

'''''Risks''''':
* Increased potential for growth and toxin production by ''Clostridium botulinum'' in perishable cured meat products under abusive conditions.
* Shelf-stable canned cured meat products would probably not be available because the increased heat treatment required would produce a product with an undesirable texture.
'''''Benefits:'''''
* Decreased risks due to a decreased load of nitrosamines in the diet. The magnitude of this benefit may not be measurable due to the current load of nitrosamines in the diet from other sources and from nitrosamines formed ''in vivo''.

=== ''Outcome'' ===
''Based on the current evidence the benefits of using Nitrites outweighs the risk. However precautionary measures are in place to ensure the safety of the consumers. These precautionary measures include limiting the usage to specific products in which the risk of Clostridium botulinum is greater. The amount of use is regulated and industries are encouraged to use methods to reduce the risk of nitrosamine formation''

Course:FNH200/Lessons/Lesson 04/Page 04.3

2020-06-24T02:48:22Z

YihangChen: /* 4. 3 Food Labelling Requirements */

== 04. 3 Food Labelling Requirements ==
Labelling information required on pre-packaged food products, from domestic food processors or imported products, is based on the '''Consumer Packaging and Labelling Act and Regulations''' and can be found in theat the CFIA website: http://www.inspection.gc.ca/food/labelling/food-labelling-for-industry/eng/1383607266489/1383607344939

Summarizing the core labelling requirement, a label should include the following:
* '''Bilingual labelling'''- All mandatory information on food labels must be shown in both official languages, i.e., French and English.
* '''Common name of the food'''. The common name is the name prescribed in the Food and Drugs Regulations. In the absence of a prescribed name, the name by which the food is commonly known is used.
* Country of Origin- Declaring of Country of Origin is required for some specific food. Some companies may choose to voluntarily name the country of origin as advertising. For a complete list of foods requiring mandatory declaration please see the link below

* http://www.inspection.gc.ca/food/labelling/food-labelling-for-industry/label/country-of-origin/eng/1334599362133/1334601061354
* '''Date marking''' and '''storage instructions''' as required. This is required for foods with a storage life of '''90 days or less'''.
** '''Durable life''' is the period of time, beginning on the day on which the pre-packaged product is packaged for retail sale, during which a product stored under prescribed conditions will retain, without appreciable deterioration, its normal wholesomeness, palatability and nutritional value and any other qualities claimed for it by the manufacturer. Products that have passed the durable life date and that have been stored under prescribed conditions are still safe to eat but the quality (appearance, flavour, nutritional value) may have deteriorated.
* '''Identity and Principal Place of Business'''
* '''Irradiated foods'''
* '''Legibility and location'''
* '''List of ingredients''' in descending order of proportion
* The '''Nutrition Facts table''' will show the Calories, the amount of fat, saturated and trans fats, cholesterol, sodium, carbohydrate, fiber, sugars, protein, calcium, iron and Vitamins A and C in a specified amount of food.Nutrition facts regulations apply to all pre-packaged foods with some exemptions (e.g fresh fruit and vegetables, raw single ingredient meat and poultry that are not ground, raw fish or seafood, alcoholic beverages).
* '''Net quantity of the food'''
* '''Sweeteners'''
* '''Other mandatory information''' may be required for certain foods: eg. % alcohol for alcoholic beverages, % milk fat for some dairy products
'''Nutrient content claims''' and '''diet-related health claims''', if made, must adhere to the stated criteria (see below)

Currently, there are '''5 disease reduction claims''' allowed in Canada:
# Disease Risk Reduction Claims with Respect to Sodium and Potassium
# Disease Risk Reduction Claims with Respect to Calcium and Vitamin D
# Disease Risk Reduction Claims with Respect to Saturated and ''Trans'' Fats
# Disease Risk Reduction Claims with Respect to Cancer Risk Reduction
# Disease Risk Reduction Claims with Respect to Dental Caries
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Do you know what it means when a food is labeled '''''"fat-free"''''' or '''''"light"''?'''
** Check out these links for the answer:
*** http://www.inspection.gc.ca/food/labelling/food-labelling-for-industry/nutrient-content/specific-claim-requirements/eng/1389907770176/1389907817577?chap=4
*** http://www.inspection.gc.ca/food/labelling/food-labelling-for-industry/nutrient-content/specific-claim-requirements/eng/1389907770176/1389907817577?chap=4<nowiki/>http://healthycanadians.gc.ca/eating-nutrition/label-etiquetage/label-etiquette-eng.php
|}
{| class="wikitable"
| '''Want to learn more?'''
|-
|
* Look at labels on a number of food products in your refrigerator and in your cupboards. Is the required information present?
* Look for the ''durable life date'' on packaged perishable food products (e.g. pasteurized milk, yogurt, cottage cheese, bread, refrigerated cured meats-frankfurters bacon, etc).
* Look for "health claims" in food products (breakfast cereals, orange juice, etc). Do these claims comply with Canadian regulations?
|}

Course:FNH200/Lessons/Lesson 04/Page 04.2

2020-06-24T02:48:06Z

YihangChen: /* 4.2 How are Regulations established? */

== 04.2 How are Regulations established? ==
* The Food protection laws, in Canada, are wide in scope and major changes in the regulations embodied within the ''Food and Drugs Act'' are made after extensive consultation. We will discuss this consultation process when we deal with the section on ''Food Irradiation''.
* Rapid changes can also be made to the ''Food and Drugs Act'' such as in the case of delisting a food additive or other substance permitted in food when new evidence arises concerning issues of safety of a particular substance. Such was the case when the non-caloric sweeteners cyclamate and saccharin were banned.
* The regulations can be amended by authority of the Governor in Council.
As noted on Table 4.1, regulations about labelling, advertising and claims about food are administered by the '''Canadian Food Inspection Agency''' (CFIA):
* CFIA deals with food labelling, advertising and claims about food.
* Administers the labelling, packaging and advertising regulations under the Consumer Packaging and Labelling Act and Regulations and the Food and Drugs Act and Regulations.
* The CFIA also reviews all advertisements, on Canadian radio and television, making claims about foods.
'''Weights and measures''' are regulated by "Innovation, Science and Development Canada" specifically by an agency known as "Measurement Canada". This agency is responsible for inspection of measurement devices and providing the accuracy certification stickers

https://www.ic.gc.ca/eic/site/mc-mc.nsf/eng/lm04710.html

Please note that packaged retail products are subjected to ''Consumer Packaging and Labelling Act'' and Canadian Food Inspection Agency ( CFIA) is responsible for overseeing their measurement accuracy.

Course:FNH200/Lessons/Lesson 04/Page 04.1

2020-06-24T02:47:51Z

YihangChen: /* 4.1 Food Standards, Regulations and Guides */

== 04.1 Food Standards, Regulations and Guides ==
{| class="wikitable"
|
==== '''Terms to remember''' ====
|-
|
* Health Canada
* Canadian Food Inspection Agency
* Food and Drugs Act and Regulations
* Standards of identity and composition
* Food Grades
* No Effect Level (NOEL)
* Acceptable Daily Intake (ADI)
* Probable Daily Intake (PDI)
* Diketopiperazine (DKP)
* Phenylketonuria (PKU)
* Clostridium botulinum
* Nitrosamines
|}
In order to ensure that the food we purchase and consume is '''safe''' and within certain preset limits of '''quality''', there are government standards, regulations and grades in place to protect the consumer.

The Department of '''Justice Canada''' is responsible for maintaining the Consolidated Statutes and Regulations for the Government of Canada, including the '''Food and Drugs Act and Food and Drug Regulations'''.

The Food and Drugs Act of Canada is administered by the '''Health Products and Food Branch''' of '''Health Canada''', whereas inspections for compliance are enforced by the '''Canadian Food Inspection Agency'''. Several other government agencies work together to ensure the safety and quality of foods produced and/or consumed in Canada.

The government agencies and their regulatory functions are listed below.

Table 4.1 ''Government agencies and their regulatory functions''
{| class="wikitable"
|
=== Agency ===
|
=== Regulatory Function ===
|-
|Health Canada

(Health Products & Food Branch)

https://www.canada.ca/en/health-canada/services/food-nutrition.html
|
* setting food and drug regulation standards of identity and composition for foods
* Food and Drugs Act (<nowiki>http://laws-lois.justice.gc.ca/eng/acts/F-27/</nowiki>)
* food additive regulations
|-
|Canadian Food Inspection Agency (CFIA)

http://www.inspection.gc.ca/english/toce.shtml
|
* provides inspection services related to the food
* responsible for administration and enforcement of different Acts including:

* Food and Drugs Act (<nowiki>http://laws-lois.justice.gc.ca/eng/acts/F-27/</nowiki>)
* Agriculture and Agri-Food Administrative Monetary Penalties Act (http://laws-lois.justice.gc.ca/eng/acts/A-8.8/)
* Food Labeling for industry (http://www.inspection.gc.ca/food/requirements/labelling/industry/eng/1383607266489/1383607344939
|-
|Measurement Canada
|Agency of Innovation, Science and Economic Development Canada.

responsible for ensuring accuracy in the selling of measured goods,

developing and enforcing the laws related to measurement accuracy,

approving and inspecting measuring devices and investigating complaints of suspected inaccurate measurement.
* https://www.ic.gc.ca/eic/site/mc-mc.nsf/eng/Home
|-
|British Columbia Ministry of Health
|public health inspection of retail stores and food service establishments

inspection of provincially inspected meat processing plants and dairy processing plants
|-
|Municipal
|public health inspection of retail stores and food service establishments
|}

=== The Food and Drugs Act ===
Sections 3, 4, 5, and 7 of the '''Food and Drugs Act''' form the foundation of the consumer protection laws. Excerpts of the Act are shown in Box 4.1 to give you an idea of the nature of the regulations.

It is interesting to note that Section 3 of the Food and Drugs Act prohibits the advertising to the general public of any food, drug, cosmetic or device for the treatment, prevention or cure of any of the diseases listed on Schedule A of the Food and Drugs Act. This section of the Act also prohibits the sale of a food, drug, cosmetic or device that is labeled in this manner.

In the light of recent trends and the demand for natural health products, the House of Commons Standing Committee on Health mandated an External Working Group which is overseeing the revisions may be needed to this section of the Act.

{| class="wikitable"
| colspan="2" |
=== Excerpts from The Food and Drugs Act of Canada ===
http://laws-lois.justice.gc.ca/eng/acts/F%2D27/page-1.html#docCont
|-
|
==== '''Section 3''' ====
(1) no person shall advertise any food, drug, cosmetic or device to the general public as a treatment, preventative or cure for any of the diseases, disorders or abnormal physical states referred to in Schedule A.

(2) No person shall sell any food, drug, cosmetic or device

(a)that is represented by label, or:

(b) that is represented to the general public as a treatment, preventative or cure for any of the diseases, disorder or abnormal physical states referred to in Schedule A.

Some of the diseases mentioned in schedule A include alcoholism, appendicitis, arthritis, cancer, depression, diabetes, heart disease, hypertension, liver diseases, obesity, sexual impotence, tumours, venereal disease.
|
==== '''Section''' 5 ====
(1) No person shall label, package, treat, process, sell or advertise any food in manner that is false, misleading or deceptive or is likely to create an erroneous impression regarding its character, value, quantity, composition, merit or safety;

(2) An article of food that is not labelled or packaged as required by the regulations, or is labelled or packaged contrary to the regulations, shall be deemed to be labelled or packaged contrary to subsection (1).
|-
|
==== '''Section 4''' ====
No person shall sell an article of food that:

(a) has in or upon it any poisonous or harmful substance;

(b) is unfit for human consumption;

(c) consists in whole or in part of any filthy, putrid, disgusting, rotten decomposed or diseased animal or vegetable substance;

(d) is adulterated;

(e) was manufactured, prepared, preserved, packaged or stored under unsanitary conditions.
|
==== '''Section 7''' ====
(a) No person shall manufacture, prepare, preserve, package or store for sale any food under unsanitary conditions.
|}
Box 4.1 ''Sections 3, 4, 5 and 7 of The Food and Drugs Act of Canada, that are the foundation of consumer protection laws.''

Course:FNH200/Lessons/Lesson 04/Page 04.0

2020-06-24T02:47:21Z

YihangChen: /* Overview */

Course:FNH200/Lessons/Lesson 02/Page 02.2

2020-06-24T02:44:55Z

YihangChen: /* Water */

= 2.2 Food Component =
Foods are made of chemical components that are working together and making the food the way it is. Chemical composition is determination of these compounds. The chemical composition tables identifies the amounts of these compounds in each food.

In Canada, the Canadian Nutrient File, provides a data base of foods and their listed composition. <nowiki>https://food-nutrition.canada.ca/cnf-fce/index-eng.jsp</nowiki>

Quantifying the amount of Carbohydrate, Fat, Protein, Water and Ash is called '''proximate analysis'''.

Food components can be classified as major and minor components.The major food components of food systems are carbohydrates, fats, proteins and water. There are also minor food components, organic acids, pigments, aroma compounds, vitamins and minerals. In this section we will discuss the important functional properties of these components and how those properties influence the chemical and physical properties of foods.

== 2.2.1 Food Major Components ==
The major food components of food systems are carbohydrates, fats, proteins and water. These are the compounds are found in largest amounts in foods. Each component has variety of functional properties which affects the physical and sensory characteristics of the food during processing and storage. Understanding these properties is essential tool in product development and also quality control. Please note that, although these components may be similar to what nutritionists and dietitians call macronutrients, we are looking at them from food science perspective.

== 2.2.1.1 Carbohydrates ==
{| class="wikitable"
|
==== Terms to remember ====
|-
|
* monosaccharides (glucose, fructose, galactose)
* disaccharides (sucrose, lactose, maltose)
* sweetness index
* invert sugar
* HFCS
* invertase
* lactase
* amylase
* maltase
* glucose isomerase
* caramelization
* Maillard browning
* reducing sugar
* sugar alcohols
|}
Carbohydrates are one of the three main classes of nutrients (the other two being fats and proteins). They occur in foods as sugars and starches and are the human body's main source of energy. Digestible carbohydrates contribute 4 Calories (kilocalories) of metabolized energy per gram. Carbohydrates should contribute about 50% of our caloric intake per day; and most of the carbohydrates that we consume should be in the form of ''complex'' carbohydrates (polysaccharides) such as starch rather than as ''simple'' carbohydrates (monosaccharides and disaccharides) such as table sugar.

==== ''a. Monosaccharides'' ====
The main monosaccharides found in foods are ''glucose'', ''fructose'' and ''galactose''. These are referred to as simple carbohydrates and one of their main functions is their ability to '''impart a sweetness sensation'''; however, sugars vary in their sweetening power. The sweetness of various sugars in comparison to sucrose (table sugar) is shown in Table 2.2

==== ''b. Disaccharides'' ====
Disaccharides are formed by the union of two monosaccharide molecules. Disaccharides are also considered as "simple" carbohydrates. They can be split into their component monosaccharides by enzymes or by boiling with dilute acids. The most important disaccharides in foods are ''sucrose'', ''lactose'' and ''maltose''. These disaccharides differ from one another in solubility, sweetness, and other properties.

===== '''Sucrose''' =====
Table sugar, obtained from sugar-cane or sugar-beet, is mainly pure sucrose. It is formed from '''''glucose''''' and '''''fructose''''' linked together. Sucrose can be found in a variety of fruits, grasses and roots.

One of the recent trends in the food industry, particularly for carbonated beverages, is the use of '''''invert sugar''''' in place of sucrose because of the inherently greater sweetening power per unit weight of the fructose containing sweetening systems (see Table 2.2). Invert sugar is produced by hydrolyzing sucrose with the enzyme invertase or with acid, to produce a mixture of glucose + fructose (1:1).
[[File:Sucrose structure formula inkscape.svg|center|thumb|Sucrose ]]
[[File:【2】L2 invert-sugar.png|thumb|Sucrose conversion|center|700x700px]]

Incidentally, the primary sugars in honey are glucose and fructose in a 40:60 ratio. Most of the nectar collected by the honey bee contains sucrose which is hydrolyzed by invertase in the saliva of the honey bee. Some of the glucose is converted to gluconic acid and hydrogen peroxide by glucose oxidase, another enzyme secreted into the collected nectar by the honey bee. The gluconic acid and hydrogen peroxide act as preservatives in the nectar. Honey also contains minute quantities of disaccharides and complex sugars.

'''Table 2.2.''' Relative sweetness of carbohydrate sweeteners.
{| class="wikitable"
!Sugar
!Sweetness Index*
|-
|sucrose
|100
|-
|glucose (dextrose)
|70 - 80
|-
|fructose (levulose)
|140
|-
|invert sugar
|100 - 130
|-
|corn syrup (mixture of glucose, maltose
|50
|-
|maltose
|20
|-
|lactose
|10 - 20
|-
|galactose
|60
|-
|sorbitol
|50
|-
|xylitol
|100
|-
| colspan="2" |high fructose corn syrups:
|-
|42% fructose
|100
|-
|55% fructose
|100+
|-
|90% fructose
|120 - 160
|-
| colspan="2" |*Perceived sweetness of a sweetener compared to sucrose as a reference.
Adapted from: Desrosier, N. W. 1976.
''Elements of Food Technology.'' AVI Publishing Company. Westport, CT. Pomeranz, Y. 1985.
''Functional Properties of Food Components.'' Academic Press Inc., Orlando, Fl.
|}
It is important to note that '''sweetness has no relation to caloric contribution''' of a sweetening agent to the diet. Fructose and lactose each produce 4 Calories of metabolized energy per gram when digested and absorbed, but lactose is only one-seventh as sweet as fructose. Thus for an equivalent sweetness intensity, less fructose would be required than lactose. Conversely, a product sweetened with lactose could potentially contain seven times the caloric content compared to a product sweetened with fructose.

==== '''Lactose''' ====
Lactose, also known as milk sugar, occurs in the milk of all animals. Cow's milk contains about 4-5%, whereas human milk contains 6-8% lactose. Lactose is formed by linking '''''glucose''''' and '''''galactose''''' together. The hydrolysis of lactose found in dairy products into its component monosaccharides is catalyzed by the enzyme lactase. Breaking down lactose substantially increases the sweetness. Lactose can also be fermented by lactic acid-producing bacteria, into ''lactic acid''. This is the acidulant and preservative agent in yogurt and numerous cheeses.
[[File:Lactose(lac).png|center|thumb]]
Have you seen lactose-free products in the market or have you met someone who is "lactose intolerant"?

Lactose intolerant people are those who do not have the enzyme lactase necessary to digest (breakdown) lactose (milk sugar). People who are lactose intolerant can suffer from minor cramps to extreme intestinal discomfort. Lactose-free products have had the enzyme lactase (usually isolated from yeast) added to them. Alternatively, lactose intolerant individuals can take tablets containing the enzyme, prior to eating or drinking dairy or other food products with lactose or milk solids. 
[[File:【3】L2 lactose-free.png|thumb|center|750x750px]][[File:FNH200_Lesson02_Lactaid01.jpg|thumb|center]][[File:【4】L2 fig2-4a.jpg|thumb|lactose free milk
'''Figure 2.3.''' Some of the products available in the market for lactose-intolerant people.
|center]] 

==== '''Maltose''' ====
The sugar maltose contains '''two glucose''' units linked together. It is obtained when starch (eg corn starch) is hydrolysed by the enzyme ''amylase'' or by heating with dilute acid (Figure 2.4). Maltose can be further hydrolysed by the enzyme ''maltase'' into its component D-glucose units, which are then enzymatically isomerized by the enzyme ''glucose isomerase'' to produce a liquid syrup composed of 42% fructose, commercially known as ''high fructose corn syrup (HFCS 42)''. HFCS has 42% fructose, 52% glucose and 6% starch. Subsequent technological improvements in which the syrup is passed through an ion-exchange column that retains fructose, allow for the production of a 90% fructose syrup. Today, ''HFCS 90'' is blended with ''HFCS 42'' to create ''HFCS 55'', which has a sweetness profile similar to sucrose (Table 2.2). Many soft drinks are now sweetened with HFCS especially when cost of these syrups is lower than the cost of sucrose or even invert sugar.

 
[[File:FNH200_Lesson02_Sugars.JPG|none|thumb|left|400px|'''Fig 2.3''' Structures of monosaccharides and disaccharides in foods and the production of high fructose corn syrups (click to get a larger image)]]

==== '''''Functional Properties of Simple Sugars in Foods''''' ====
The functional properties of sugars in foods are summarized below:
* Sugars are widely used for their sweetening power. The sweetness of carbohydrates is determined by their molecular structure and interaction with sensory receptors on the tongue. Simple sugars vary in their sweetness (Table 2.2)
* Sugars produce '''body''' and '''mouth feel''' when they are incorporated into foods at concentrations high enough to affect the viscosity (resistance to flow) of the food product
* production of '''hot supersaturated sugar''' solutions with controlled crystallization during cooling is the basis of formation of many hard candy products, toffees and related products.
* sugars are readily soluble in water because they contain many hydroxyl (OH) groups, which form hydrogen bonds with water. Solubility of sugars increases as the temperature of water increases. This property is used to produce syrups of varying concentrations for various uses (e.g. pancake syrup, concentrated syrups for use in food processing, cooking or confections.)
* Sugars can be '''crystallized''' from solution when water is evaporated. This is the basis of production of table sugar (sucrose) from the juice extracted from sugar cane and sugar beets.
* Sugars, in sufficiently high concentration, can be used to '''inhibit growth''' of undesirable microorganisms. They function as a preservative by binding water needed by the microorganisms.
* sugars are '''fermented''' by microorganisms with the concomitant production of acids and/or alcohol as well as flavouring compounds. This is the basis for production of fermented foods and ingredients obtained by means of microbial fermentations.
* sugars '''caramelize''' when exposed to high temperatures. See "Browning reactions" below.
* reducing sugars react with proteins and amino compounds to produce flavours and colours in foods (Maillard browning). See "Browning reactions" below.

'''Browning reactions'''

Another important property of the simple sugars is their ability to serve as reactants in non-enzymatic browning reactions, namely '''''caramelization''''' and the '''''Maillard browning reaction'''''.

The '''caramelization''' reaction involves reaction of sugars (reducing and non-reducing sugars) when heated at high temperatures (200°C) to produce caramel and butterscotch flavours. The brown pigments formed during the heating of sugars contributes to the colour of caramel candies and toffees (Figure 2.5a). The pigments are not the same as the melanoidins formed during the Maillard reaction. [[File:FNH200_Lesson02_CaramelLiquid.jpg|thumb|200px|[[File:FNH200_Lesson02_CaramelCandy.jpg|thumb|200px|right]]Figure 2.5a Liquid caramel and caramel candy: Examples of non-enzymatic browning of sugars.
|center]]
The '''Maillard browning reaction''' occurs when reducing sugars react with nitrogenous compounds such as amino acids, proteins or amines (Figure 2.5b).
* A reducing sugar contains a free aldehyde or ketone group. Therefore, it will contain a “free” '''OH''' on the position next to the O in the ring structure
The Maillard browning reaction is responsible for the formation of the brown pigments that appear on bread slices when they are toasted in the toaster.
[[File:Figure 2.5b.png|thumb|Figure 2.5b. Glucose, Fructose, Galactose and Lactose are examples of reducing sugars. Sucrose does not have this "free" OH, therefore is not a reducing sugar.|center|750x750px]]
{| class="wikitable"
| '''Want to learn more?'''
|-
|
* Sucrose is not a reducing sugar, will ''invert sugar'' be considered as a reducing sugar?
|}
The Maillard browning reaction is responsible for the formation of the brown pigments that appear on bread slices when they are toasted in the toaster.[[File:FNH200_Lesson02_Maillard.gif|none|'''Fig 2.5''' Maillard browning reaction. Toasted bread is an example of desirable flavours and colours produced from this reaction.]]'''Figure 2.5c.''' Maillard browning reaction. Toasted bread is an example of desirable flavours and colours produced from this reaction.
{| class="wikitable"
| '''Want to learn more?'''
|-
|
* Can you think of other food products from the Maillard reaction?
|}
Many low molecular weight intermediate compounds are formed and these often are aroma and flavour compounds that contribute to the desirable or undesirable flavours produced in a food by the Maillard reaction. Examples of desirable compounds are the aroma and flavour of baked bread, toasted bread and roasted coffee, while undesirable aromas and flavours are those that form in skim milk powder during storage or during the browning of canned peaches during long-term storage. The brown colours are high molecular weight pigments, ''melanoidins'', formed as a result of polymerization of some of the low molecular weight intermediate fractions.

'''''c. Polysaccharides'''''
{| class="wikitable"
|
==== '''Terms to remember''' ====
|-
|
* amylose
* amylopectin
* gelatinization
* retrogradation
* complex carbohydrates (starch, cellulose, xanthan gum, pectin, alginates, agar, carrageenan
* invertase
* viscosity
* thickening
* stabilizer
* suspending agent
|}
Polysaccharides are high molecular weight, long chains of monosaccharide units (i.e. glucose). They are classified as the complex carbohydrates and differ from simple carbohydrates by being insoluble in water and generally tasteless. Most of the polysaccharides used in food products are derived from plant or seaweed sources; a few are from microbial origin. They contribute to the thickness or viscosity and textural properties of food products.
{| class="wikitable"
!Polysaccharide
!Characteristics and Functional Properties
|-
|pectins
|
* are structural polymers in plants
* form the cementing material between individual plant cells
* pectin affects the texture of plant tissues
* used in jams and jellies as gelling agents in the presence of sufficient sugar and acid¨
* contribute to the viscosity of tomato paste and ketchup
* contribute to the mouth feel and maintenance of particles in suspension (e.g. orange juice, unclarified apple juice)
|-
|agar
|
* extracted from seaweed (kelp)
* used as a thickener agent
|-
|alginates
|
* extracted from certain types of seaweed
* used as gelling agents
* keep solids and liquids in suspension in fruit juices
|-
|gum arabic or gum acacia
|
* is a plant exudate from the bark of the acacia trees
* used as thickener and stabilizer in products like beer, soft drinks, ice cream
|-
|carrageenan
|
* extracted from certain types of seaweed (red algae)
* used as a suspending agent to keep cocoa particles in suspension in chocolate milk
|-
|xanthan gum
|
* produced by bacteria
* first isolated from rotting cabbage, now cultured in large fermentation tanks and purified
* used in salad dressings as a thickening agent, which enables the dressing to cling to the salad components
* used as a suspending agent to maintain pieces of onion, red pepper, spices in a stable suspension.
|-
|cellulose and hemicellulose
|
* are present in many plant tissues as supporting structures (e.g. the fibres in celery)
* are polymers of glucose that are indigestible
* along with pectin and the other carbohydrate gums form the indigestible portion of our carbohydrate intake that is known as dietary fibre
|-
|starch
|
* are polymers of glucose
* digestible when cooked (e.g. rice, potatoes, etc.)
* used as thickening, suspending and gelling agents(read text below for more information on starch)
|}

==== Starch ====
Starch is made out of ''polymers of glucose'' joined by an '''alpha, 1-4''' link. A single molecule of starch can include anywhere from 400 to several hundred thousand glucose units. Therefore, although they are made of long chains of sugar molecules, starches do not elicit a sweet taste and rather taste quite "bland". The length and ''bulkiness'' of the starch molecule prevent it from interacting with our tongue receptors! In food, starch is mostly used as a thickening, suspending and gelling agent.

In foods such as cereals and tubers starch exists in the form of starch granules (Figure 2.6). Starch molecules ('''''amylose''''', a straight/linear chain starch molecule and '''''amylopectin''''', a branched starch molecule) are tightly packed within starch granules. The starch granule is not digestible, nor is it soluble in cold water unless it is heated.

==== Figure 2.7 ====
When starch is heated in water, it undergoes a phenomenon known as '''gelatinization'''. The starch granules absorb water and swell-up as the water entering the granule begins to "loosen" the bonds between the starch molecules. Hydrogen bonds form between the water and starch molecules. The starch granule eventually "bursts", becoming soft and pliable. This is the phenomenon that occurs when puddings are made or when flour is used as a thickening agent when making gravies. Starch gelatinization is the phenomenon that leads to the conversion of hard, unchewable, raw rice kernels to the soft, easily chewed, cooked rice.

Gelatinized starch can lose some of its water holding capacity upon cooling and/or during refrigerated storage. This phenomenon is known as '''''retrogradation''''', and involves the re-association of starch molecules, especially the ''amylose'' polymers, into an ordered structure. The linear ''amylose'' molecules orient themselves in crystalline regions, leading to a squeezing out ("'''syneresis'''") of water and a loss of tenderness of the food (e.g. staling of bread) or the development of a gritty texture (e.g. starch based pudding stored in the refrigerator).

It is interesting to observe that bread stales more quickly in the refrigerator than the freezer or at room temperature. ''Can you think of why this is the case?''

Retrogradation can be avoided to a certain extent through the use of dextrins and/or modified starches, thus reducing the tendency for alignment of linear amylose chains. Starches can be partially hydrolysed by acids or enzymes to produce products of intermediate chain length (dextrins) that have numerous uses in food products. Some of the dextrin products are used to create foods that provide the sensation of containing fat but that are low in fat.

Retrogradation can also be partially reversed by heating the food (e.g. heating stale bread or buns in an oven or the microwave oven); however, once the product cools the starch quickly retrogrades again.

'''Cellulose and hemicellulose'''

These polysaccharides are present in many plant tissues as supporting structures (e.g. the fibres in celery). They too are ''polymers of glucose'' but joined by a '''beta, (ß)1- 4''' link. However, humans do not have the enzyme needed to break the beta link and therefore, cellulose is indigestible. Along with pectin and the other carbohydrate gums, cellulose forms the indigestible portion of our carbohydrate intake that is known as dietary fibre.

'''Xanthan Gum'''

Xanthan gum is a polysaccharide with a ß-D-glucose backbone like cellulose, but every second glucose unit is attached to a ''trisaccharide.''

Xanthan Gum is produced by the bacterium ''Xanthomonas campestris'', which is found on cruciferous vegetables such as cabbage and cauliflower and causes black rot. Nowadays, it is cultured in large fermentation tanks and purified. Xanthan gum is used in salad dressings as a thickening agent, which enables the dressing to cling to the salad components. It is also used as a thickener for sauces, to prevent ice crystal formation in ice cream, and as a low-calorie substitute for fat.
[[File:2.7.png|thumb|Xanthan Gum|center|500x500px]]

==== '''Pectin''' ====
Pectin is a polysaccharide that acts as a cementing material in the cell walls of all plant tissues. The white portion of the rind of lemons and oranges contains approximately 30% pectin.

It is used in jams and jellies as a gelling agent. It also contributes to the viscosity of tomato paste and ketchup. Pectins will give contribute to the mouth-feel of foods, and help maintain particles in suspension (e.g. orange juice, unclarified apple juice).
[[File:Pectin .png|thumb|pectin|center|500x500px]]

==== '''Agar, Alginates & Carrageenan''' ====
These polysaccharides are extracted from different types of seaweed (kelp). In general, they are used as thickening, gelling and suspending agents.

For example, alginates keep solids and liquids in suspension in fruit juices and provide thickness to dietetic and regular salad dressings, puddings, pie fillings, ice cream, sherbet and icings. Carrageenan is used as a suspending agent to keep cocoa particles in suspension in chocolate milk, and it is also used as a stabilizer in ice cream (stabilizing the colloidal dispersions). 

===== '''Gum Arabic (Acacia Gum)''' =====
These gums are plant exudates from the bark of the acacia trees. It is used as thickener and stabilizer in products like beer, soft drinks, and ice cream.

{| class="wikitable"
| '''Want to learn more?'''
|-
|
* Look at the list of ingredients for different food products (e.g. breakfast cereal, soft drinks, chocolates, ketchup, ice cream, etc). List the thickening agent polysaccharides included among the ingredients. What conclusions can you make about the kinds, amounts, and functions of these ingredients?
|}

== 2.2.1.2 Fats ==
{| class="wikitable"
|
==== '''Terms to remember''' ====
|-
|
* fatty acids
* saturated fat
* unsaturated: mono- and poly-unsaturated
* hydrogenation
* ''cis''-, ''trans''- configuration
* tenderizing
* aeration
* emulsifiers
* hydrophilic & hydrophobic
* phospholipids
* lecithin
* oxidative rancidity
|}
You will recall from lesson 1, that consumers are demanding "healthier" foods. Many of the products we currently see in the market, have selling points such as "low-fat" or "fat-free". This general trend towards low-fat products has given fats a negative reputation. Fats and oils are part of a group called lipids. Lipids can be found in the form of triglycerides, phospholipids and sterols. However, triglycerides make the largest class of lipids as most of the fats and oils we consume from food are in the form of triglycerides.

{| class="wikitable"
|-
|'''Want to learn more?'''
|-
|
* Please read:
** American Dietetic Association (2007). Position of the American Dietetic Association and Dietitians of Canada: Dietary Fatty Acids. Journal of the AMERICAN DIETETIC ASSOCIATION 107(9), 1599-1611. [https://www.sciencedirect.com/science/article/abs/pii/S0002822307014903?via%3Dihub link]
** From the reading, please answer the following questions:
*** What are fats? What is the correct name for fat?
*** What is the nutritional value and calories of fat?
*** What is the difference between saturated, monounsaturated and polyunsaturated fatty acids?
*** What is an omega-3 fatty acid?
*** What are '''''cis''''' and '''''trans''''' unsaturated fatty acids?
*** Why are some fats solids and others liquid at room temperature?
*** What is the term of the process used to convert a liquid oil into solid or spreadable margarine?
*** What are some functions of fat in foods?
|-
|
|}
'''''Functional Properties of Fats in Foods'''''

The required reading talked about fats and the important functional properties they have by influencing the flavour and texture of foods. Fats are even necessary for the absorption of fat soluble vitamins. The functional properties of fats (and oils) in foods are summarized below:
* Fats act as a '''lubricant''' in food making the food more palatable and easier to chew and swallow.
* Fats have '''tenderizing power''' because they coat the flour particles (protein and starch) in baked goods, creating a flaky, lighter texture that makes them easy to tear apart. Fats work best as shortening when the crystals are in the beta prime form, which produces a fine texture in the baked goods. Cakes will have a crumbly texture without the moistness given by fats.
* Another function of fats in baked goods is the one called "'''aeration'''". Fats add air (gas) to batter and doughs. The fat surrounds the air molecules that are being incorporated into the batter. They contribute to the formation of the dispersion by decreasing the viscosity in the batter, thus making it easier to flow and rise.
* Fats and oils are carriers of many '''aroma constituents''' in foods that are usually fat-soluble. Thus, fats contribute to the overall flavour of food (we will review aroma and flavour in Lesson 3- Sensory perception of foods)
* Fats and oils can be heated to very '''high temperatures''' before they begin to smoke and vaporize. Foods fried in hot fats and oils (deep fat frying) cook very fast because of the temperatures that can be attained.
* Fats gradually '''soften''' when heated. This contributes to the desirable features such as chocolates that melt in your mouth and butter and margarines that are spreadable.
* Fats form part of emulsions (review colloidal dispersions) by acting as the dispersed phase or continuous phase. Some fats can also act as "'''emulsifiers'''", assisting in keeping the emulsion stable (see "'''Fats and their role in emulsions'''" below).
'''Fats and their role in emulsions'''

You will recall that there are two types of emulsions (see colloidal dispersions and Figure 2.2): '''water in oil''' [e.g. butter, margarine], and '''oil in water''' [e.g. mayonnaise, homogenized milk].

Homogenization or other high-energy mixing processes may be used to disperse one liquid phase into another. Nevertheless, after two liquid phases such as oil and water are mixed and then left to stand, the natural tendency is for the two phases to separate. '''Emulsifiers''' are compounds that promote the formation of emulsions, i.e., the dispersion of one phase in the form of small droplets, in the second continuous phase.

Certain type of fat molecules called '''phospholipids''', can function as emulsifiers. Phospholipids are structurally similar to triglycerides, except that only two fatty acids are linked to the glycerol (making it a ''diglyceride''), and a charged group (negatively charged phosphoric acid esterified with positively charged choline group) is linked to the third position of glycerol.

'''Lecithin''' is an example of a phospholipid. Lecithin is a naturally occurring emulsifier commonly found in egg yolk and soybean oil. Other naturally occurring emulsifiers include the proteins from milk, egg yolk or other foods. Sometimes, synthetic emulsifiers (e.g. "Polysorbate 60") are used to assist in forming food emulsions.

Emulsifiers are amphiphillic molecules that have a '''hydrophilic''' [water loving] portion and a '''hydrophobic''' [water hating] portion. Emulsifiers assist in formation of an emulsion by orienting themselves at the interface between the two phases, with their hydrophilic and hydrophobic portions facing water and oil, respectively, thereby reducing the interfacial tension between oil and water phases. This can also help to '''stabilize the emulsion''' by preventing the dispersed oil droplets or water droplets from coalescing together. Other factors that affect emulsion stability are droplet size, and the viscosity of the continuous phase. Droplet size must be such that, the downward pull of gravity, is balanced by the upward forces of buoyancy. This will reduce the tendency for "creaming" (floating to the top) of the less dense (oil) phase.

Note the difference between '''"Emulsifiers"''' and '''"Stabilizers". Stabilizers''' are compounds that increase the viscosity of the continuous phase, keeping the droplets suspended or dispersed and thus reducing the rate of creaming. Some of the polysaccharides discussed earlier in this lesson are commonly used as stabilizers to thicken the continuous phase (water); some examples are “xanthan gum” and “propylene glycol alginate”.[[File:FNH200_Lesson02_Emulsifier.jpg|'''Fig 2.6''' The function of an emulsifier in an oil-in-water emulsion.|center]]Figure 2.6 illustrates the function of an emulsifier in an oil-in-water emulsion.

{| class="wikitable"
|
==== Whant to learn more? ====
|-
|
* Something to think about: Are any '''emulsifiers''' or '''stabilizers''' added to assist in the formation of a stable emulsion in:
** milk
** butter
** margarine
** mayonnaise

* '''Check out the label of these foods to find the answer!'''
|}

The major function of milk '''homogenization''' is the formation of a stable '''emulsion''' to prevent fat separation, such as that which occurs in non homogenized milk.

{| class="wikitable"
|
==== Whant to learn more? ====
|-
|
* Can you imagine what a piece of pie would look and taste like without the presence of fat in the crust? What functional properties of fat are involved in the pie crust formation?

* Some people use oil in their pie crust recipe, and some use lard. Which contains more saturated fat?
|}

== 2.2.1.3 Proteins ==
[[File:FNH200_Lesson02_Leucine.png|thumb| Leucine]]
{| class="wikitable"
|
==== '''Terms to remember''' ====
|-
|
* amino acid
* amphiphillic
* denature
* solid foam
* collagen
* lipolytic rancidity
* enzymes
* allergies
|}

Protein molecules are made up of long chains of hundreds or even thousands of amino acid units joined together. Amino acids are a type of organic acid. They are made up of an amino group (NH2) and a carboxyl group (COOH) attached to the same carbon atom.

There are '''20''' different amino acids in proteins found in food systems and in the human body. Nine of the amino acids cannot be synthesized by human tissues and must be obtained via food. These '''essential''' amino acids are isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine; histidine (essential for infants only).

Adults require 0.8 grams of protein per kilogram of body weight. Protein consumed in excess of body requirements is converted to energy or is converted to fat for storage. Proteins produce 4 Calories per gram when they are digested and the amino acids are metabolized for energy.

=== Functional Properties of Proteins in Foods ===
Proteins in tissue systems such as meats and fish contribute to the '''texture''' of the products. The difference between a tender steak and a tough steak can often be related to the types and relative abundance of various types of protein molecules within the muscle structure. Proteins from various sources (cereal grains, milk, meat, fish, legumes) can be used in various states of purity as food ingredients with differing functional properties. Some of those functional properties are described below.

==== '''Emulsion formation''' ====
Many proteins are ''amphiphillic'' molecules as they contain hydrophilic and hydrophobic portions (from amino acids) allowing them to act as '''emulsifiers'''. One part of these amino acids is attracted to water, forming hydrogen bonds, while the other part avoids water and binds with oil.
* Egg yolk and mustard proteins in mayonnaise function as emulsifiers.
[[File:Mayo .png|thumb|center|600x600px]]

==== '''Foaming''' ====
* Proteins have the ability to trap air in bubbles and this leads to the formation of foams.
* Egg white proteins function as foaming agents in the making of whipped egg whites. Whipping introduces air and denatures (unfolds) the protein molecules. The protein molecules then coagulate to form a fine film around the air pockets.
** Solid foams such as meringue are formed when the whipped egg whites are heated causing the protein to denature and form a more rigid three-dimensional structure, which won't collapse when the air escapes.
* Bread and ice cream are also examples of solid foams. Ice cream is also a solid emulsion. [[File:FNH200_Lesson02_Bread.jpg|thumb|400px|Gluten, a protein in wheat flour, traps air bubbles in bread making. Bread was prepared and photo was taken by Morgan Reid, LFS, UBC. This bread was prepared using a 250-year old sourdough culture. More details on bread culture will be discussed in [http://wiki.ubc.ca/Course:FNH200/Lesson_09#Starter_Cultures Lesson 09.]|center]]
==== '''Gel formation''' ====
* Gelatin (from the animal protein: '''''collagen''''') forms a gel by trapping large volumes of water within a semi rigid three dimensional protein matrix.
* Heating of meat proteins during the manufacture of luncheon meats, such as bologna and frankfurters, leads to gelation and formation of the textures characteristic of cured meats.
** Products such as frankfurters and bologna are also emulsions.
* Milk protein also forms a gel when it is acidified, such as in making of yogurt and cheese. The gel holds water and has a smooth texture.
[[File:FNH200_Lesson02_FriedEgg.jpg|thumb|300px|Fried Egg: an example of protein gel|center]] 
<big>'''The Amazing Functionalities of Milk Proteins'''</big>
[[File:Latte.png|thumb|latte|center|600x600px]]
* '''In latte (A):''' the milk protein traps air bubbles to form the foam structure.
* '''In milk (B):''' casein, a milk protein, acts as an emulsifier preventing the fat globules to separate (cream) from the skim milk portion. ( This function can be further enhanced by homogenization-will be further discussed in ''Lesson 6'')
* '''In cheese (C):''' casein forms a gel structure in the cheese curd.
==== '''Proteins that function as enzymes''' ====
* Enzymes are proteins that function as biological catalysts.
* In some cases enzymes are added to food as an ingredient ('''invertase''' in candy making)
* Some enzymes are used to promote food-processing operations while others are causative agents in food spoilage ('''amylase''' can ruin a starch gel; '''lipases''' can cause lipolytic rancidity which is the release of free fatty acid from glycerides).
* Enzymes in living tissue food systems such as fruits and vegetables are responsible for the reactions associated with ripening. Those same enzymes will continue the ripening process after harvest and unless they are inactivated the enzymes will eventually cause spoilage of the product (e.g. loss of crispness of stored apples; loss of sweetness of apples during storage; loss of colour in the skin of apples during storage).
* Many heating processes in food processing are designed to inactivate enzymes in addition to inactivating undesirable microorganisms in order to extend storage life of foods. These processes will be discussed later in ''Lesson 6''.
* Microorganisms, when added to food systems, to produce fermented foods, are essentially sources of desirable enzymes required to catalyse the desired chemical reactions needed to produce fermented food products (yogurt, sauerkraut, soy sauce). This will be discussed in more detail in ''Lesson 9''.
* Enzymes are also extracted from a variety of sources (plants, animal by-products, microorganisms) and purified for use as aids in food processing (e.g. '''proteases''' used for milk coagulation during cheese making; '''pectinases''' to enhance juice recovery and for clarification of apple juice; '''invertase''' for conversion of sucrose to invert sugar; '''isomerase''' to produce high fructose corn syrup).
[[File:FNH200_Lesson02_Cheese.jpg|thumb|In cheese, casein form a gel structure in cheese making|center]]

=== Food Proteins and Food Allergies ===
'''What is the relation between food proteins and allergies?'''
* Intolerance to certain proteins in foods is the basis for many food allergies. You will often see statements on labels for ice cream, cereals and candy bars that warn of the possibility that the product may contain traces of peanuts or other nut products.
* Allergies to peanut protein can be very severe, such that even with proper cleaning and sanitation, all residues of peanut allergens cannot be removed from processing equipment. Thus products that do not contain nuts, but that have been processed with equipment that was used for nut containing products may contribute enough allergen to cause some problems in very sensitive individuals.
* For recent food recalls in Canada due to potential allergy risks, see <nowiki>http://www.inspection.gc.ca/english/corpaffr/recarapp/recaltoce.shtml</nowiki>
{| class="wikitable"
|
==== Whant to learn more? ====
|-
|
* Choose one of the [http://www.inspection.gc.ca/english/corpaffr/recarapp/recaltoce.shtml recent allergy recalls] and click on "Learn more about common food allergies" to answer the following questions:
** 1. What are the ten most common food allergens related to proteins?
** 2. Sulphites are listed as food allergens as well, but they are NOT proteins. Can you explain why they are listed?
|}

== 2.2.1.4 Water ==
{| class="wikitable"
|
==== '''Terms to remember''' ====
|-
|
* free water
* bound water
* water activity
* vapour pressure
* moisture content
|}

Water is an extremely important component of food systems. Water is related to all aspects of food ranging from our perception of quality, to the ability of microorganisms to be metabolically active in food systems.

Water exists in food in two forms: '''Free water''' and '''Bound water'''.

'''Free water'''
* Some water may be present within intergranular spaces, within pores of the food matrix and as a thin film of water on the surface of many foods.
* Free water can be found in tissue food systems and in dispersions.
* Water that is free and not bound by food components generally retains its usual physical properties, can also function as a dispersing agent for colloidal substances, can function as a solvent and can be used by microorganisms.
'''Bound water'''
* Some water can be adsorbed on surfaces of macromolecules such as starches, pectins, proteins through forces such as van der Waals forces and hydrogen bond formation.
* This water does not display all of its normal physical properties and it is not readily available for use by microorganisms and chemical or enzymatic reactions.
* Another form of bound water is the water that is associated with food matrices as water of hydration. That water is also not readily available for use by microorganisms and enzymatic and chemical reactions in the food matrix, whether it is a tissue based food system or a dispersion.
* Sugars and salts (sodium chloride) can bind substantial amounts of water and are often added to foods for the purpose of decreasing the amount of free water in the food system. In that context, sugars and salts can be used to control or prevent growth of certain microorganisms in foods.

==== '''What does water activity (aw) mean?''' ====
Water activity is a measurement that is frequently used in monitoring the availability of water (free water) in foods for the support of:
* microbial growth
* chemical reactions
* enzymatic reactions
Water activity can be measured as the ratio of the vapour pressure of water in the food to the vapour pressure of pure water, both measured at the same temperature.
: <big> ''Aw = (Vapour Pressure of Water in Food at X °C) / (Vapour Pressure of Pure Water at X °C) ''</big>

Please watch the following animation that depicts the effect of solutes on vapour pressure and water activity [[File:FNH200_Lesson02_AwMovie.gif|thumb|500px|Water Activity Animation (Courtesy of UBC CTLT)|left]]

Water activity can range from '''0''' (''no free water'') to '''1.0''' (''all the water is free'', such as in distilled water).

Water activity values of a number of food products are shown below. Water activity of foods can be adjusted by physically removing water from foods during concentration and dehydration processing operations, also when the water in the food is frozen (the free water is in a solid state, in the form of ice crystals), or by adding substances that bind water thus lowering the proportion of water in the free form. The most commonly used water-binding agents are sugars and salt.

'''Water activity of selected foods:'''
{| class="wikitable"
!Food
!Water activity
!Water content (%)
|-
|pure water
|1.00
|100
|-
|fresh meat
|0.97
|65
|-
|eggs
|0.97
|75
|-
|fruits, vegetables
|0.97
|90 to 95
|-
|bread
|0.96
|35
|-
|Cheddar cheese
|0.96
|40
|-
|frankfurters
|0.93
|56
|-
|salami
|0.90
|61
|-
|jams and jellies
|0.80 to 0.95
|32
|-
|honey
|0.75
|18
|-
|dried fruit
|0.60 to 0.70
|20
|-
|wheat flour
|0.70
|12
|}

==== Is water activity the same as moisture content? ====
The answer is no. Measurement of the '''moisture content''' of a variety of food systems is a frequently conducted quality assurance measurement. However, measurement of water content of foods '''does not indicate''' whether the water is bound or free.

The data in the above table shows that water content of foods cannot be used as a reliable indicator of the water activity.

== 2.2.2 Food Minor Components ==
{| class="wikitable"
|
==== '''Terms to remember''' ====
|-
|
* ''low-acid'' and ''acid'' foods
* pH 4.6
* chlorophyll
* carotenoids
* Anthocyanidins and anthocyanins
* volatile and flavour constituents
* Fat-soluble vitamins
* Water-soluble vitamins
* antioxidant
|}

A number of other food constituents are present in foods in much smaller quantities than the major constituents (carbohydrates, proteins, fats). These minor constituents are very important in their influence on our perception of the quality attributes of the food. The minor constituents are: organic acids, pigments and aroma compounds.

== 2.2.2.1 Organic Acids ==
Fruits contain natural acids which give the fruits tartness and slow down bacterial spoilage. Organic acids also impart flavour and acidity to food. Examples of organic acids and foods in which they are occur are:
{| class="wikitable"
!Organic acid
!Food
|-
|Malic acid
|apples
|-
|citric acid
|citrus fruits, tomatoes, strawberries.
|-
|Tartaric acid
|grapes
|-
|lactic acid
|yogurt, cheese, olives, cottage cheese, sauerkraut.
|}
* The major uses of organic acids are to '''adjust pH''' or to '''acidify food''', and to '''impart flavour'''. For example, acetic acid provides flavour and decreases pH; phosphoric acid provides flavour and tartness in beverages.
* A number of organic acids are also employed as antimicrobial agents.
* Organic acids have a wide range of textural effects in food systems due to their reactions with proteins, starches, pectins, and other food constituents.
* '''What is pH?'''
** pH is a measure of the acidity of a food. Foods and beverages differ in pH because of their '''content of acids''', which produce hydrogen ions (Table 2.3). We are able to detect these ions by using a hydrogen sensitive electrode in a device called a ''pH meter''.
Table 2.3. Average pH values and acidity classification of selected foods.
{| class="wikitable"
!Chemicals Contributing to Aroma of Coffee
!pH value
!Acidity classification
|-
|Meat, fish, poultry
|7.0
| rowspan="7" |Low acid
(pH > 4.6)
|-
|Milk
|6.5
|-
|Corn
|6.3
|-
|Wheat flour
|6.0
|-
|Potatoes, peas
|5.8
|-
|Carrots
|5.1
|-
|Figs
|5.0
|-
|
|
|
|-
|Apples
|3.7
| rowspan="5" |Acid
(pH 0 - 4.6)
|-
|Cherries
|3.6
|-
|Oranges, pears, tomatoes
|3.5
|-
|Pickles
|3.0
|-
|Lemon/lime juice
|2.3
|}

==== Is pH important to the Food Industry? ====
Yes. An important pH for the food industry is '''pH 4.6'''; this is the borderline between an '''acidic food''' and a '''low acid food''' (Table 2.3).
* acid foods have pH of 4.6 or less
* low-acid foods have pH greater than 4.6
Acid foods will not support growth of disease causing microorganisms. This aspect will be discussed in more detail later in the course.

== 2.2.2.2 Colours and Pigments in Foods ==
Many food systems are coloured by pigments naturally present in the food system:

'''Chlorophyll''', the green pigment in plants, is responsible for the green colour in apples, lettuce, celery and broccoli. '''Chlorophyll a''' has a blue green hue (e.g. in the florets of fresh broccoli) while '''chlorophyll b''' has a yellow green hue (stems of broccoli).

'''Carotenoids''', a diverse group of pigments, can be subclassified into carotenes and xanthophylls. Carotenoids naturally produce red, orange and orange-yellow colours in many foods (e.g. tomatoes, carrots, pineapples, shrimp)

'''Anthocyanidins''' and '''anthocyanins''' (anthocyanidin complexed with glucose or other sugars). These pigments are the predominant colour pigments in blueberries, cherries, cranberries, plums and red cabbage. The anthocyanins are particularly sensitive to changes in pH, showing marked changes in colour with pH changes in the food system. See Figure below:[[File:FNH200_Lesson02_Athocyanin.jpg|thumb|center|500px|'''Anthocyanin''': the colour of an athocyanin is most stable and most highly coloured at low pH values. The colour will be gradually lost as the pH increases. Notice that at pH 5, the anthocyanin is almost colourless. The colour loss is reversible, and the red hue will return upon acidification.]]
As you can see in the above figure, the colour of an athocyanin is most stable and most highly coloured at '''low pH values'''. The colour will be gradually lost as the pH increases. Notice that at pH 5, the anthocyanin is almost colourless. The colour loss is reversible, and the red hue will return upon acidification.

Other pigments in food systems include hemoglobin and myoglobin (the red pigments in blood and muscle).

All of the pigments noted above are sensitive to varying degrees to changes in the environment (pH, presence or absence of oxygen, presence of metal ions, enzymatic degradation) in the food system. Thus colour changes often occur in fresh fruits, vegetables, meats and fish during storage, spoilage and as a result of processing and cooking.

In addition, there are a number of pigments, either those extracted from plants or microorganisms, or '''synthetic pigments''' that are used as colouring agents in fabricated food systems. These will be discussed in more detail in the section on food additives (Lesson 4). 

== 2.2.2.3 Aroma Constituents ==
The aroma profile of foods is very complex. The aroma of food is detected when we inhale volatile constituents of foods that react with the receptors in the olfactory regions of our nasal passages.

Most of us have experienced the aroma of freshly brewed coffee; there are actually hundreds of volatile compounds that have been identified in the aroma. The table below is a list of some of the chemical components that have been identified to contribute to the aroma of coffee; '''you don't have to memorise''' any of these compounds, it is only an example to demonstrate the amount of constituents that influence the aroma we perceive on a food.
{| class="wikitable"
! colspan="2" |Chemicals Contributing to Aroma of Coffee
|-
|Acetaldehyde
|Hydrogen sulfide
|-
|Acetic acid
|Hydroquinone
|-
|Acetone
|Isovaleric acids
|-
|Acetyl methyl carbinol
|Methyl alcohol
|-
|Ammonia
|Methyl amine
|-
|Cresols
|Methyl ethyl acetic acid
|-
|Diacetyl
|N- methyl pyrrole
|-
|Diethyl ketone
|p-Vinyl guaiacol
|-
|Dimethyl sulfide
|Phenol
|-
|Esters
|Pyrazine
|-
|Ethyl alcohol
|Pyridine and homologues
|-
|Formic acid
|Resorcinol
|-
|Furane
|Sylvestrine
|-
|Furfural
|Trimethylamine
|-
|Furfuryl alcohol
|Vanillone
|-
|Guaiacol
|
|-
|Higher fatty acids
|
|}
Adapted from: Benarde, M.A. 1971. Chemicals We Eat. American Heritage Press, N.Y., pp.208.

=== Please note that: ===
* No single chemical compound can be attributed as being the sole source of the aroma of a particular food product.
* It is the specific mixture of chemicals in a particular concentration that creates the aroma that we associate with a high quality food product.
* Any change in that specific mixture of volatile compounds or their concentrations will alter the aroma that we perceive.
* The '''volatile''' constituents that contribute to the aroma of foods are present in very low concentrations but are nonetheless very important constituents of foods.
* The '''flavour''' constituents are either present as part of the food matrix (fresh strawberries) or are modified (cooking of strawberries) or created (roasting of coffee) during processing or cooking.
 

== 2.2.2.4 Vitamins and Minerals ==

Vitamins are mainly classified into '''water-soluble''' and '''fat-soluble vitamins'''. Vitamins are organic compounds that make up a small portion of food; however, vitamins are very important from a nutritional point of view because they are essential components of the human diet as they carry out some very important tasks in the body.
* '''Water-soluble''' vitamins include vitamin C (ascorbic acid), thiamin, riboflavin, niacin, pyridoxine, vitamin B12, and folacin. These vitamins are found within the water (aqueous) phase of foods.
* '''Fat-soluble''' vitamins (vitamin A, vitamin D, vitamin E) are found within the fat (oil) portion of foods
Although Vitamins do ''not'' contribute to the physical characteristics of food, some are actually used as "food additives". Below are some examples of the two most common vitamins used as food additives:
{| class="wikitable"
!Vitamin
!Food Additive category
!Function
|-
|Ascorbic acid (Vitamin C)
|Bleaching agents
|*Hasten oxidation and aging processes as in flour whitening treatment
|-
|Ascorbic acid (Vitamin C)
|Preservatives
|Act as antioxidant to slow down rancidity and browning reactions
|-
|Tocopherols (Vitamin E)
|Preservatives
|Antioxidant
|}
'''*''' Ascorbic acid converts to its oxidizing from during mixing

'''Minerals''' (calcium, magnesium, sodium, potassium, iron, zinc) are often associated with various cellular components in tissue food systems and often are active participants in chemical and biochemical reactions that affect the chemical properties and textural characteristics of food systems.

Course:FNH200/Lessons/Lesson 01/Page 01.7

2020-06-24T02:41:41Z

YihangChen: /* 01.07 Summary of Lesson 1 */

== 01.7 Summary of Lesson 1 ==
* Food science studies the production, processing, preparing, evaluating and use of food.
* Technological advancements have led to many "food science discoveries"
* Canada offers a vast and diverse food system
* The Canadian food industry has a strong impact on Canada's economy
* Consumers and consumer demands have a strong influence on the food consumption trends

=== Closing thoughts ===
In conclusion, the food industry in Canada is a large industry that provides employment for a substantial part of the workforce in Canada. The variety of food products available in grocery stores or through food service outlets is immense and is likely to grow in response to consumer demands and changes in demographics, health, animal welfare and environmental concerns.

At this point it is important to recognize that while the amount and variety of foods consumed in Canada are increasing, many people in other parts of our world are unable to even secure enough nutritious food to maintain a healthy lifestyle. It has been estimated that about 3/4 of the world population live in lesser developed countries which are found mainly in Africa, Asia and South and Central America. Most of the inhabitants of these countries cannot get enough nutritious food to eat each day. Nutrients in short supply include fat, protein, vitamins, minerals and clean, safe drinking water. It is important to keep that thought in mind as you proceed through the course.

== References ==
* Murano, P.S. (2003). Introduction to Food Science and Technology. ''Understanding Food Science and Technology'' (Chapter 1). Belmont, California: Thompson Wadsworth.
* Potter, N. N. & Hotchkiss,J. H. (1998). Characteristics of the Food Industry. ''Food Science'' (5th ed.) (Chapter 2). Gaithersburg, Maryland: Aspen Publishers, Inc.
* Potter, N. N. & Hotchkiss,J. H. (1998). Vegetables and Fruits. ''Food Science'' (5th ed.) (Chapter 18 & pp.432-434). Gaithersburg, Maryland: Aspen Publishers, Inc.
* Food Available in Canada. Statistics Canada.<nowiki>https://www150.statcan.gc.ca/t1/tbl1/en/tv.action?pid=3210005401&pickMembers%5B0%5D=1.1&pickMembers%5B1%5D=3.1</nowiki> (Links to an external site.) (Links to an external site.)
* Food Technology Magazine Editors Share Top 10 Food Trend Predictions for 2019. <nowiki>http://www.ift.org/food-technology/past-issues/2019/april/features/2019-top-10-food-trends.aspx</nowiki>

'''Authorship:'''

FNH 200 Course content on this wiki page and associated lesson pages was originally authored by Drs. [http://www.landfood.ubc.ca/person/brent-skura/ Brent Skura], [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], and [http://www.landfood.ubc.ca/person/eunice-li-chan/ Eunice Li-Chan]. Ongoing edits and updates are contributed by past and current instructors including Drs. [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], [http://www.landfood.ubc.ca/person/azita-madadi-noei/ Azita Madadi-Noei], [http://www.landfood.ubc.ca/person/nooshin-alizadeh-pasdar/ Nooshin Alizadeh-Pasdar], and [http://www.landfood.ubc.ca/person/judy-chan/ Judy Chan].

{{cc-by-nc-sa-3.0}}

<quiz display=simple>
{1. Physical locations where a consumer may purchase and enjoy carrots:
|type="()"}
- Farmer's Market.
- Grocery Stores.
- Food Services Establishments.
+ All of the above.
</quiz>

<quiz display=simple>
{2. When are apples in BC being harvested?:
|type="()"}
- April.
- July.
+ Ocotober.
- December.
</quiz>

<quiz display=simple>
{3. What percentage of the atmosphere is oxygen?:
|type="()"}
- 0.3%
- 3%
+ 21%
- 78%
- 94%
</quiz>

<quiz display=simple>
{4. What changes occurred in the USA due to the publication of a book in 1906 about the meatpacking industry?:
|type="()"}
- The start of the vegetarian movement in the US.
+ Congress passed the meat inspection act and the food and drugs act of 1906.
- Inspectors were fired and taken out of the meatpacking plants.
- Establishment of the US Department of Agriculture.
</quiz>

<quiz display=simple>
{5. A food scientist discovers new information about food through research.
|type="()"}
+ TRUE.
- FALSE.
</quiz>

Course:FNH200/Lessons/Lesson 01/Page 01.6

2020-06-24T02:40:56Z

YihangChen:

== 01.6 Trends in Food Consumption in Canada ==

Overall, many changes have occurred in food consumption patterns in Canada in the past few decades, and they continue to change as consumer demands and perceptions change. The advent of new processing technologies have brought new products on the market and this will continue. Consumer perception of those products will determine whether they succeed or fail. Undoubtedly, advertising campaigns for various food products and controversies about the health effects of various food commodities (butter vs margarine; sugar vs non-caloric or low caloric sweeteners; fats vs fat substitutes; trans-fat free products; processed vs unprocessed foods) will continue to influence consumer food buying habits.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Read the article in the link below and comment on the following points using your own experience in Canada. http://www.ift.org/food-technology/past-issues/2019/april/features/2019-top-10-food-trends.aspx
** Cannabis/CBD oil-infused drinks
** Cannabis/CBD oil-infused food
** Zero-waste cooking
** Globally inspired breakfast dishes
** Global flavors in kid’s meals
** Hyper-local
** New cuts of meat
** Veggie-centric/vegetable-forward cuisine
** Chef-driven fast-casual concepts
** Craft/artisan/locally produced spirits
|}
{| class="wikitable"
| '''Critical Thinking'''
|-
|
* Look at the most recent '''food consumption data (2014-2018)''' in the Statistics Canada website: <nowiki>http://www5.statcan.gc.ca/cansim/a26?lang=eng&retrLang=eng&id=0020011&tabMode=dataTable&srchLan=-1&p1=-1&p2=35#customizeTab</nowiki>
* Within each food category, which products have ''increased'' in consumption and which ones have ''decreased''? Can you identify what are the main reasons for these changes in consumption patterns?
** Meat
** Poultry and Eggs
** Fish
** Dairy
** Fruit and Vegetables
** Edible oils
** Beverages
* Review the highlights for 2017 and note any interesting finding: <nowiki>https://www150.statcan.gc.ca/n1/daily-quotidien/180530/dq180530c-eng.htm</nowiki> (Links to an external site.)
|}

Course:FNH200/Lessons/Lesson 01

2020-06-24T02:40:33Z

YihangChen:

<big><big><big>'''Food Science and the Canadian Food System'''</big></big></big>

== 01.0 Overview ==
In this lesson, we will define the field of food science, and discuss the size and scope of the food industry in Canada. We will take a look at food production, importation, and distribution within Canada. Apple production and processing will be discussed as an example of the conversion of an agricultural product into a variety of food products. Finally, we will monitor some food consumption patterns and trends which have occurred over the past 40 years.

'''Objectives'''

After completing this lesson, you should be able to:
*describe the field of Food Science;
*describe the breadth and relative magnitude of various sectors of the Canadian food industry;
*identify the trends in food consumption in Canada;
*illustrate the ways that foods are distributed to consumers in Canada; and
*discuss how apples are converted into a variety of food products and how they are store
'''Optional Reading'''

Top 10 Food Trends for 2019: http://www.ift.org/food-technology/past-issues/2019/april/features/2019-top-10-food-trends.aspx

== 01.1 What is the Definition of Food Science? ==
Foods, as such, are complex systems subject to many forms of changes, including biochemical, nutritional, physical and/or sensory changes. The multidisciplinary science known as food science is used to pull together the wide range of knowledge that deals with food.

'''''Food Science''''' can be defined as the application of the principles of science, engineering, and mathematics in order to study and acquire new knowledge on the physical, chemical and biochemical nature of foods. Food science is a broad field that is composed of specializations in food microbiology, food chemistry, and food engineering. Food science also involves the study of sensory properties of food, and therefore, the psychology of food choice. From the information gathered by food science, the corresponding technologies can be applied to the utilization, processing, preservation and storage of food. This is known as '''''food technology'''''.

Here is a brief explanation of the main components (sub-fields) of Food Science''(adapted from Potter and Hotchkiss, 1995):''
* ''Food Chemistry'': deals with the composition, structure and properties of food, as well as the chemistry of changes that occur during processing.
* ''Food Analysis'': covers the principles and methods for quantitative physical and chemical analyses of food products and ingredients. These analyses are related to the standards and regulations for food processing.
* ''Food Microbiology'': relates to the study of microbial ecology in relation to food, the effect of environment on food spoilage and food manufacture, the physical, chemical, and biological destruction of microorganisms in food, the microbiological examination of food stuffs, and public health and sanitation microbiology.
* ''Food Processing'': covers the principles of food preservation and the general characteristics of raw food materials, processing factors that influence quality, packaging, waste management, good manufacturing practices, and sanitation procedures.
* ''Food Engineering:'' relates to the study and application of engineering concepts and unit operations used in food processing. Engineering principles include material and energy balances, thermodynamics, fluid flow, and heat and mass transfer.

==== Are Food Science and Nutrition the same? ====
''"the difference between food science and nutrition is that nutrition deals with the effects of foods in the person who consumes them, while food science is concerned with the study of the chemical, microbiological, physical, and sensory properties of foods and their ingredients during processing, manufacture, and storage."'' Murano (2003)

== 01.2 How Old is the Discipline of Food Science? ==
[[File:FNH200_Lesson01_AncientWine.jpg|thumb|left|200px|Fig 1.1 Ancient Egyptian Wine Making Scene]]
[[File:FNH200_Lesson01_CanningJar.jpg|thumb|right|100px|Fig 1.2 Nicolas Appert's Canning Jar]]Food science as a distinct discipline is quite new. However, many aspects of "food science" have existed for many centuries. Products derived from food fermentation (''biotechnology'') have existed for thousands of years.For example, there is evidence that people were fermenting beverages in (A) Babylon circa 5000 BC, (B) ancient Egypt circa 3000 BC, and (C) pre-Hispanic Mexico circa 2000 BC. Today we know that fermentation not only contributes to a wide variety of food products, but it also involves food processing and preservation.
{| class="wikitable"
|}
Another example dates back to 1795, when Emperor Napoleon offered 12,000 francs for a new way of preserving food for its army. It was the French confectioner François Nicolas Appert who won the prize by placing food in wide-mouthed bottles, then corking and heating them in a water bath. The existence of bacteria was not known at the time, and Appert did not know the principle upon which his process depended; however, he was correct in the thought that heat could preserve food. Appert is therefore known as the discoverer of the process later known as canning.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Make a list of questions you have about the science of foods. For example; why tomatoes are red, why gravy thickens, what is used to make "sugar-free" candy? Save your questions and search for answers as you complete this course.
|}

== 01.3 Extent of Canada's Food System==
[[File:FNH200_Lesson01_CdnFoodSystem.gif|thumb|right|500px|Fig 1.3 Canadian Food System]]
In Canada, we have a diverse food system with thousands of food products available for purchase. Those products include foods produced in Canada as well as food products imported from many countries around the world.

The Canadian food system is depicted in Figure 1.1. Foodstuffs (fruit, vegetables, cereal grains, oilseeds, animals, fowl) are produced by farmers involved in primary agricultural production. Fin fish, molluscs and crustaceans are harvested from the wild or raised on fish farms. Unprocessed foodstuffs and fish are also imported for sale or processing in Canada. These products are shipped directly to farmers' markets, processors or distributors. Many agricultural and fishery products undergo some form of processing/preservation prior to distribution to the consumer market. Many foods are fabricated from the foodstuffs produced by primary agricultural and fishery harvesting. Examples of fabricated foods are bread, smoked and cured luncheon meats, soft drinks, yogurt and chewing gum, to name a few.

Food products from processors or primary producers often pass through various distributors before they reach retail stores or food service outlets. Foods are retailed through chain stores and smaller independent stores, as well as numerous convenience stores which may be part of a chain or may be owned by an independent operator, as well as food co-operatives.

* Vegetables are sold in the fresh market as well as being processed (canned, frozen, dehydrted, fermented) to increase storage life.
* Greenhouse production of vegetables is an increasingly important component of the fresh market supply (cucumbers, peppers, lettuce, tomatoes) particularly in the fall and winter seasons.
* Seafood products are harvested and processed primarily in Atlantic Canada and in British Columbia. Seafood production includes the harvesting of wild stocks as well as production of salmon, oysters, clams and lobsters, under intensive production systems ('farmed' seafood). Cultivation of fish (trout) in fresh water occurs in a number of regions of Canada.
* Some products are transferred to the consumer market with a minimum of processing (e.g., fresh fruits, fresh vegetables) while others (e.g., beef, pork, poultry, milk, wheat) go through more extensive processing before being transported to the retail market. Many agricultural products (e.g., wheat flour, corn flour, corn starch, corn syrup, fruits, vegetables, milk, and milk components) become sources of ingredients for the production of other food products.
Below are the major Provinces in Canada involved in the production of different agricultural food commodities:
{| class="wikitable"
!Food commodity production
!Province
|-
|Animal (beef, pork, poultry)
|Widespread around Canada
|-
|Dairy milk production
|Across Canada, Ontario, Quebec
|-
|Cereal grains
|Alberta, Saskatchewan, Manitoba
|-
|Tree fruit; small fruits; cranberries, blueberries, raspberries
|British Columbia; Ontario, Nova Scotia; Almost every province; British Columbia
|-
|Vegetables
|All across Canada
|-
|Seafood
|Atlantic Canada and British Columbia
|}
Many ''agricultural commodities'', ''finished food products'' and ''ingredients'' are imported into Canada as well. These imported products must meet the same standards and regulatory requirements as foods produced in Canada. This aspect is discussed in more detail in the section of the course dealing with regulatory issues and standards (Lesson 4).
{| class="wikitable"
|'''Want to learn more?'''
|-
|How does this image from a trading store (''ca. 1910'') compare to the typical grocery store (supermarket) of today?

- Food production and marketing have come a long way since the 1900s
|}

== 01.4 The Canadian Food Industry ==
The Canadian food industry is a multi-billion dollar a year industry. Foods available to us on the grocery store shelves include both domestically produced products and imported foods.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* The next time you are in a large grocery store, take some time to survey the proportion of shelf space devoted to various food commodity groups and note the vast array and variety of products that are in the grocery store.
|}
Although Canada produces large amounts of fruits and vegetables, vast quantities of fruits and vegetables are imported as fresh product and in lesser amounts as frozen, canned and dehydrated products. This is due to the seasonal nature of fruit and vegetable production in Canada, as well as the need for climates warmer than Canada to grow fruits such as oranges, grapefruit and bananas.

Canada exports meat products (raw meat and processed meat products) to other countries but also imports meat products (raw meats of specific cuts that may be in short supply in Canada, as well as processed meat products). Likewise Canada exports raw fish (fresh and frozen salmon, cod, etc.) and processed fish (canned fish, smoked fish, salmon and herring roe) to other countries, while other types of fish (such as prawns, oysters, processed fish products) are imported into Canada.

== 01.5 Apples and Apple Products ==
[[File:FNH200_Lesson01_AppleProcessing.gif|thumb|right|500px|Figure 1.4 Apple production and processing.]]
The processing of apples will be used as an example of the utilization and conversion of an agricultural commodity to various food products and ingredients (Fig. 1.2). After harvesting, apples can be routed several directions: they can be shipped directly to the fresh market; they can be processed; or they can be put into controlled atmosphere storage facilities where the atmosphere, temperature and humidity are carefully controlled to retard the rate of respiration and ripening of the apples, thus extending the storage life of the fresh fruit. Controlled atmosphere storage of apples is described at:
* <nowiki>http://www.omafra.gov.on.ca/english/crops/facts/12-045.htm</nowiki>
Apples can be processed in various ways. A large proportion of processing apples is converted to '''apple juice'''. The type of apple juice preferred by consumers in Western Canada is the clear apple juice. Apple juice can be used as the starting material for the production of '''apple cider'''. In making cider, apple juice is inoculated with specific ''yeast'' strains which ferment sugar in the juice into ethanol and produce flavours characteristic of apple cider. Apple cider can be further processed by inoculating it with a ''bacterial'' culture that will oxidize the ethanol to acetic acid to produce '''apple vinegar'''.

The apple solids remaining after juice extraction can be used as a feed material for the production of '''pectin''' (a carbohydrate used as gelling agent in the production of jams and jellies), animal feed, or as organic matter that can be returned to agricultural lands. In some cases, the residue may also be trucked to landfill sites which adds to the waste burden entering those sites.

Apples are also processed into '''apple sauce''' and pie fillings. A greater proportion of these products are used as ingredients in the bakery and food service industries than as items in retail stores.

To a lesser extent, apples are used to produce '''dehydrated apple slices, fruit leather, apple-filled snack bars''' and as '''ingredients''' for some confectionary products and breakfast cereals.
{| class="wikitable"
|
|-
|'''Figure 1.2''' Apple production and processing
|}
{| class="wikitable"
| '''Want to learn more?'''
|-
|
* Identify a food that you enjoy. How do you think a food scientist/technologist would be involved in the production, processing and marketing of that food product?
|}

== 01.6 Trends in Food Consumption in Canada ==

Overall, many changes have occurred in food consumption patterns in Canada in the past few decades, and they continue to change as consumer demands and perceptions change. The advent of new processing technologies have brought new products on the market and this will continue. Consumer perception of those products will determine whether they succeed or fail. Undoubtedly, advertising campaigns for various food products and controversies about the health effects of various food commodities (butter vs margarine; sugar vs non-caloric or low caloric sweeteners; fats vs fat substitutes; trans-fat free products; processed vs unprocessed foods) will continue to influence consumer food buying habits.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Read the article in the link below and comment on the following points using your own experience in Canada. http://www.ift.org/food-technology/past-issues/2019/april/features/2019-top-10-food-trends.aspx
** Cannabis/CBD oil-infused drinks
** Cannabis/CBD oil-infused food
** Zero-waste cooking
** Globally inspired breakfast dishes
** Global flavors in kid’s meals
** Hyper-local
** New cuts of meat
** Veggie-centric/vegetable-forward cuisine
** Chef-driven fast-casual concepts
** Craft/artisan/locally produced spirits
|}
{| class="wikitable"
| '''Critical Thinking'''
|-
|
* Look at the most recent '''food consumption data (2014-2018)''' in the Statistics Canada website: <nowiki>http://www5.statcan.gc.ca/cansim/a26?lang=eng&retrLang=eng&id=0020011&tabMode=dataTable&srchLan=-1&p1=-1&p2=35#customizeTab</nowiki>
* Within each food category, which products have ''increased'' in consumption and which ones have ''decreased''? Can you identify what are the main reasons for these changes in consumption patterns?
** Meat
** Poultry and Eggs
** Fish
** Dairy
** Fruit and Vegetables
** Edible oils
** Beverages
* Review the highlights for 2017 and note any interesting finding: <nowiki>https://www150.statcan.gc.ca/n1/daily-quotidien/180530/dq180530c-eng.htm</nowiki> (Links to an external site.)
|}

== 01.7 Summary of Lesson 1 ==
* Food science studies the production, processing, preparing, evaluating and use of food.
* Technological advancements have led to many "food science discoveries"
* Canada offers a vast and diverse food system
* The Canadian food industry has a strong impact on Canada's economy
* Consumers and consumer demands have a strong influence on the food consumption trends

=== Closing thoughts ===
In conclusion, the food industry in Canada is a large industry that provides employment for a substantial part of the workforce in Canada. The variety of food products available in grocery stores or through food service outlets is immense and is likely to grow in response to consumer demands and changes in demographics, health, animal welfare and environmental concerns.

At this point it is important to recognize that while the amount and variety of foods consumed in Canada are increasing, many people in other parts of our world are unable to even secure enough nutritious food to maintain a healthy lifestyle. It has been estimated that about 3/4 of the world population live in lesser developed countries which are found mainly in Africa, Asia and South and Central America. Most of the inhabitants of these countries cannot get enough nutritious food to eat each day. Nutrients in short supply include fat, protein, vitamins, minerals and clean, safe drinking water. It is important to keep that thought in mind as you proceed through the course.

== References ==
* Murano, P.S. (2003). Introduction to Food Science and Technology. ''Understanding Food Science and Technology'' (Chapter 1). Belmont, California: Thompson Wadsworth.
* Potter, N. N. & Hotchkiss,J. H. (1998). Characteristics of the Food Industry. ''Food Science'' (5th ed.) (Chapter 2). Gaithersburg, Maryland: Aspen Publishers, Inc.
* Potter, N. N. & Hotchkiss,J. H. (1998). Vegetables and Fruits. ''Food Science'' (5th ed.) (Chapter 18 & pp.432-434). Gaithersburg, Maryland: Aspen Publishers, Inc.
* Food Available in Canada. Statistics Canada.<nowiki>https://www150.statcan.gc.ca/t1/tbl1/en/tv.action?pid=3210005401&pickMembers%5B0%5D=1.1&pickMembers%5B1%5D=3.1</nowiki> (Links to an external site.) (Links to an external site.)
* Food Technology Magazine Editors Share Top 10 Food Trend Predictions for 2019. <nowiki>http://www.ift.org/food-technology/past-issues/2019/april/features/2019-top-10-food-trends.aspx</nowiki>

'''Authorship:'''

FNH 200 Course content on this wiki page and associated lesson pages was originally authored by Drs. [http://www.landfood.ubc.ca/person/brent-skura/ Brent Skura], [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], and [http://www.landfood.ubc.ca/person/eunice-li-chan/ Eunice Li-Chan]. Ongoing edits and updates are contributed by past and current instructors including Drs. [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], [http://www.landfood.ubc.ca/person/azita-madadi-noei/ Azita Madadi-Noei], [http://www.landfood.ubc.ca/person/nooshin-alizadeh-pasdar/ Nooshin Alizadeh-Pasdar], and [http://www.landfood.ubc.ca/person/judy-chan/ Judy Chan].

{{cc-by-nc-sa-3.0}}

<quiz display=simple>
{1. Physical locations where a consumer may purchase and enjoy carrots:
|type="()"}
- Farmer's Market.
- Grocery Stores.
- Food Services Establishments.
+ All of the above.
</quiz>

<quiz display=simple>
{2. When are apples in BC being harvested?:
|type="()"}
- April.
- July.
+ Ocotober.
- December.
</quiz>

<quiz display=simple>
{3. What percentage of the atmosphere is oxygen?:
|type="()"}
- 0.3%
- 3%
+ 21%
- 78%
- 94%
</quiz>

<quiz display=simple>
{4. What changes occurred in the USA due to the publication of a book in 1906 about the meatpacking industry?:
|type="()"}
- The start of the vegetarian movement in the US.
+ Congress passed the meat inspection act and the food and drugs act of 1906.
- Inspectors were fired and taken out of the meatpacking plants.
- Establishment of the US Department of Agriculture.
</quiz>

<quiz display=simple>
{5. A food scientist discovers new information about food through research.
|type="()"}
+ TRUE.
- FALSE.
</quiz>

Course:FNH200/Lessons/Lesson 01

2020-06-24T02:37:04Z

YihangChen: /* 01.6 Trends in Food Consumption in Canada */

<big><big><big>'''Food Science and the Canadian Food System'''</big></big></big>

== 01.0 Overview ==
In this lesson, we will define the field of food science, and discuss the size and scope of the food industry in Canada. We will take a look at food production, importation, and distribution within Canada. Apple production and processing will be discussed as an example of the conversion of an agricultural product into a variety of food products. Finally, we will monitor some food consumption patterns and trends which have occurred over the past 40 years.

'''Objectives'''

After completing this lesson, you should be able to:
*describe the field of Food Science;
*describe the breadth and relative magnitude of various sectors of the Canadian food industry;
*identify the trends in food consumption in Canada;
*illustrate the ways that foods are distributed to consumers in Canada; and
*discuss how apples are converted into a variety of food products and how they are store
'''Optional Reading'''

Top 10 Food Trends for 2019: http://www.ift.org/food-technology/past-issues/2019/april/features/2019-top-10-food-trends.aspx

== 01.1 What is the Definition of Food Science? ==
Foods, as such, are complex systems subject to many forms of changes, including biochemical, nutritional, physical and/or sensory changes. The multidisciplinary science known as food science is used to pull together the wide range of knowledge that deals with food.

'''''Food Science''''' can be defined as the application of the principles of science, engineering, and mathematics in order to study and acquire new knowledge on the physical, chemical and biochemical nature of foods. Food science is a broad field that is composed of specializations in food microbiology, food chemistry, and food engineering. Food science also involves the study of sensory properties of food, and therefore, the psychology of food choice. From the information gathered by food science, the corresponding technologies can be applied to the utilization, processing, preservation and storage of food. This is known as '''''food technology'''''.

Here is a brief explanation of the main components (sub-fields) of Food Science''(adapted from Potter and Hotchkiss, 1995):''
* ''Food Chemistry'': deals with the composition, structure and properties of food, as well as the chemistry of changes that occur during processing.
* ''Food Analysis'': covers the principles and methods for quantitative physical and chemical analyses of food products and ingredients. These analyses are related to the standards and regulations for food processing.
* ''Food Microbiology'': relates to the study of microbial ecology in relation to food, the effect of environment on food spoilage and food manufacture, the physical, chemical, and biological destruction of microorganisms in food, the microbiological examination of food stuffs, and public health and sanitation microbiology.
* ''Food Processing'': covers the principles of food preservation and the general characteristics of raw food materials, processing factors that influence quality, packaging, waste management, good manufacturing practices, and sanitation procedures.
* ''Food Engineering:'' relates to the study and application of engineering concepts and unit operations used in food processing. Engineering principles include material and energy balances, thermodynamics, fluid flow, and heat and mass transfer.

==== Are Food Science and Nutrition the same? ====
''"the difference between food science and nutrition is that nutrition deals with the effects of foods in the person who consumes them, while food science is concerned with the study of the chemical, microbiological, physical, and sensory properties of foods and their ingredients during processing, manufacture, and storage."'' Murano (2003)

== 01.2 How Old is the Discipline of Food Science? ==
[[File:FNH200_Lesson01_AncientWine.jpg|thumb|left|200px|Fig 1.1 Ancient Egyptian Wine Making Scene]]
[[File:FNH200_Lesson01_CanningJar.jpg|thumb|right|100px|Fig 1.2 Nicolas Appert's Canning Jar]]Food science as a distinct discipline is quite new. However, many aspects of "food science" have existed for many centuries. Products derived from food fermentation (''biotechnology'') have existed for thousands of years.For example, there is evidence that people were fermenting beverages in (A) Babylon circa 5000 BC, (B) ancient Egypt circa 3000 BC, and (C) pre-Hispanic Mexico circa 2000 BC. Today we know that fermentation not only contributes to a wide variety of food products, but it also involves food processing and preservation.
{| class="wikitable"
|}
Another example dates back to 1795, when Emperor Napoleon offered 12,000 francs for a new way of preserving food for its army. It was the French confectioner François Nicolas Appert who won the prize by placing food in wide-mouthed bottles, then corking and heating them in a water bath. The existence of bacteria was not known at the time, and Appert did not know the principle upon which his process depended; however, he was correct in the thought that heat could preserve food. Appert is therefore known as the discoverer of the process later known as canning.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Make a list of questions you have about the science of foods. For example; why tomatoes are red, why gravy thickens, what is used to make "sugar-free" candy? Save your questions and search for answers as you complete this course.
|}

== 01.3 Extent of Canada's Food System==
[[File:FNH200_Lesson01_CdnFoodSystem.gif|thumb|right|500px|Fig 1.3 Canadian Food System]]
In Canada, we have a diverse food system with thousands of food products available for purchase. Those products include foods produced in Canada as well as food products imported from many countries around the world.

The Canadian food system is depicted in Figure 1.1. Foodstuffs (fruit, vegetables, cereal grains, oilseeds, animals, fowl) are produced by farmers involved in primary agricultural production. Fin fish, molluscs and crustaceans are harvested from the wild or raised on fish farms. Unprocessed foodstuffs and fish are also imported for sale or processing in Canada. These products are shipped directly to farmers' markets, processors or distributors. Many agricultural and fishery products undergo some form of processing/preservation prior to distribution to the consumer market. Many foods are fabricated from the foodstuffs produced by primary agricultural and fishery harvesting. Examples of fabricated foods are bread, smoked and cured luncheon meats, soft drinks, yogurt and chewing gum, to name a few.

Food products from processors or primary producers often pass through various distributors before they reach retail stores or food service outlets. Foods are retailed through chain stores and smaller independent stores, as well as numerous convenience stores which may be part of a chain or may be owned by an independent operator, as well as food co-operatives.

* Vegetables are sold in the fresh market as well as being processed (canned, frozen, dehydrted, fermented) to increase storage life.
* Greenhouse production of vegetables is an increasingly important component of the fresh market supply (cucumbers, peppers, lettuce, tomatoes) particularly in the fall and winter seasons.
* Seafood products are harvested and processed primarily in Atlantic Canada and in British Columbia. Seafood production includes the harvesting of wild stocks as well as production of salmon, oysters, clams and lobsters, under intensive production systems ('farmed' seafood). Cultivation of fish (trout) in fresh water occurs in a number of regions of Canada.
* Some products are transferred to the consumer market with a minimum of processing (e.g., fresh fruits, fresh vegetables) while others (e.g., beef, pork, poultry, milk, wheat) go through more extensive processing before being transported to the retail market. Many agricultural products (e.g., wheat flour, corn flour, corn starch, corn syrup, fruits, vegetables, milk, and milk components) become sources of ingredients for the production of other food products.
Below are the major Provinces in Canada involved in the production of different agricultural food commodities:
{| class="wikitable"
!Food commodity production
!Province
|-
|Animal (beef, pork, poultry)
|Widespread around Canada
|-
|Dairy milk production
|Across Canada, Ontario, Quebec
|-
|Cereal grains
|Alberta, Saskatchewan, Manitoba
|-
|Tree fruit; small fruits; cranberries, blueberries, raspberries
|British Columbia; Ontario, Nova Scotia; Almost every province; British Columbia
|-
|Vegetables
|All across Canada
|-
|Seafood
|Atlantic Canada and British Columbia
|}
Many ''agricultural commodities'', ''finished food products'' and ''ingredients'' are imported into Canada as well. These imported products must meet the same standards and regulatory requirements as foods produced in Canada. This aspect is discussed in more detail in the section of the course dealing with regulatory issues and standards (Lesson 4).
{| class="wikitable"
|'''Want to learn more?'''
|-
|How does this image from a trading store (''ca. 1910'') compare to the typical grocery store (supermarket) of today?

- Food production and marketing have come a long way since the 1900s
|}

== 01.4 The Canadian Food Industry ==
The Canadian food industry is a multi-billion dollar a year industry. Foods available to us on the grocery store shelves include both domestically produced products and imported foods.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* The next time you are in a large grocery store, take some time to survey the proportion of shelf space devoted to various food commodity groups and note the vast array and variety of products that are in the grocery store.
|}
Although Canada produces large amounts of fruits and vegetables, vast quantities of fruits and vegetables are imported as fresh product and in lesser amounts as frozen, canned and dehydrated products. This is due to the seasonal nature of fruit and vegetable production in Canada, as well as the need for climates warmer than Canada to grow fruits such as oranges, grapefruit and bananas.

Canada exports meat products (raw meat and processed meat products) to other countries but also imports meat products (raw meats of specific cuts that may be in short supply in Canada, as well as processed meat products). Likewise Canada exports raw fish (fresh and frozen salmon, cod, etc.) and processed fish (canned fish, smoked fish, salmon and herring roe) to other countries, while other types of fish (such as prawns, oysters, processed fish products) are imported into Canada.

== 01.5 Apples and Apple Products ==
[[File:FNH200_Lesson01_AppleProcessing.gif|thumb|right|500px|Figure 1.4 Apple production and processing.]]
The processing of apples will be used as an example of the utilization and conversion of an agricultural commodity to various food products and ingredients (Fig. 1.2). After harvesting, apples can be routed several directions: they can be shipped directly to the fresh market; they can be processed; or they can be put into controlled atmosphere storage facilities where the atmosphere, temperature and humidity are carefully controlled to retard the rate of respiration and ripening of the apples, thus extending the storage life of the fresh fruit. Controlled atmosphere storage of apples is described at:
* <nowiki>http://www.omafra.gov.on.ca/english/crops/facts/12-045.htm</nowiki>
Apples can be processed in various ways. A large proportion of processing apples is converted to '''apple juice'''. The type of apple juice preferred by consumers in Western Canada is the clear apple juice. Apple juice can be used as the starting material for the production of '''apple cider'''. In making cider, apple juice is inoculated with specific ''yeast'' strains which ferment sugar in the juice into ethanol and produce flavours characteristic of apple cider. Apple cider can be further processed by inoculating it with a ''bacterial'' culture that will oxidize the ethanol to acetic acid to produce '''apple vinegar'''.

The apple solids remaining after juice extraction can be used as a feed material for the production of '''pectin''' (a carbohydrate used as gelling agent in the production of jams and jellies), animal feed, or as organic matter that can be returned to agricultural lands. In some cases, the residue may also be trucked to landfill sites which adds to the waste burden entering those sites.

Apples are also processed into '''apple sauce''' and pie fillings. A greater proportion of these products are used as ingredients in the bakery and food service industries than as items in retail stores.

To a lesser extent, apples are used to produce '''dehydrated apple slices, fruit leather, apple-filled snack bars''' and as '''ingredients''' for some confectionary products and breakfast cereals.
{| class="wikitable"
|
|-
|'''Figure 1.2''' Apple production and processing
|}
{| class="wikitable"
| '''Want to learn more?'''
|-
|
* Identify a food that you enjoy. How do you think a food scientist/technologist would be involved in the production, processing and marketing of that food product?
|}

== 01.6 Trends in Food Consumption in Canada ==

Overall, many changes have occurred in food consumption patterns in Canada in the past few decades, and they continue to change as consumer demands and perceptions change. The advent of new processing technologies have brought new products on the market and this will continue. Consumer perception of those products will determine whether they succeed or fail. Undoubtedly, advertising campaigns for various food products and controversies about the health effects of various food commodities (butter vs margarine; sugar vs non-caloric or low caloric sweeteners; fats vs fat substitutes; trans-fat free products; processed vs unprocessed foods) will continue to influence consumer food buying habits.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Read the article in the link below and comment on the following points using your own experience in Canada. http://www.ift.org/food-technology/past-issues/2019/april/features/2019-top-10-food-trends.aspx
**Cannabis/CBD oil-infused drink
**Cannabis/CBD oil-infused food
**Zero-waste cooking
** Globally inspired breakfast dishes
** Global flavors in kid’s meals
** Hyper-local
** New cuts of meat
** Veggie-centric/vegetable-forward cuisine
** Chef-driven fast-casual concepts
** Craft/artisan/locally produced spirits
|}
{| class="wikitable"
| '''Critical Thinking'''
|-
|
* Look at the most recent '''food consumption data (2014-2018)''' in the Statistics Canada website: <nowiki>http://www5.statcan.gc.ca/cansim/a26?lang=eng&retrLang=eng&id=0020011&tabMode=dataTable&srchLan=-1&p1=-1&p2=35#customizeTab</nowiki>
* Within each food category, which products have ''increased'' in consumption and which ones have ''decreased''? Can you identify what are the main reasons for these changes in consumption patterns?
** Meat
** Poultry and Eggs
** Fish
** Dairy
** Fruit and Vegetables
** Edible oils
** Beverages
* Review the highlights for 2017 and note any interesting finding: <nowiki>https://www150.statcan.gc.ca/n1/daily-quotidien/180530/dq180530c-eng.htm</nowiki> (Links to an external site.)
|}

== 01.7 Summary of Lesson 1 ==
* Food science studies the production, processing, preparing, evaluating and use of food.
* Technological advancements have led to many "food science discoveries"
* Canada offers a vast and diverse food system
* The Canadian food industry has a strong impact on Canada's economy
* Consumers and consumer demands have a strong influence on the food consumption trends

=== Closing thoughts ===
In conclusion, the food industry in Canada is a large industry that provides employment for a substantial part of the workforce in Canada. The variety of food products available in grocery stores or through food service outlets is immense and is likely to grow in response to consumer demands and changes in demographics, health, animal welfare and environmental concerns.

At this point it is important to recognize that while the amount and variety of foods consumed in Canada are increasing, many people in other parts of our world are unable to even secure enough nutritious food to maintain a healthy lifestyle. It has been estimated that about 3/4 of the world population live in lesser developed countries which are found mainly in Africa, Asia and South and Central America. Most of the inhabitants of these countries cannot get enough nutritious food to eat each day. Nutrients in short supply include fat, protein, vitamins, minerals and clean, safe drinking water. It is important to keep that thought in mind as you proceed through the course.

== References ==
* Murano, P.S. (2003). Introduction to Food Science and Technology. ''Understanding Food Science and Technology'' (Chapter 1). Belmont, California: Thompson Wadsworth.
* Potter, N. N. & Hotchkiss,J. H. (1998). Characteristics of the Food Industry. ''Food Science'' (5th ed.) (Chapter 2). Gaithersburg, Maryland: Aspen Publishers, Inc.
* Potter, N. N. & Hotchkiss,J. H. (1998). Vegetables and Fruits. ''Food Science'' (5th ed.) (Chapter 18 & pp.432-434). Gaithersburg, Maryland: Aspen Publishers, Inc.
* Food Available in Canada. Statistics Canada.<nowiki>https://www150.statcan.gc.ca/t1/tbl1/en/tv.action?pid=3210005401&pickMembers%5B0%5D=1.1&pickMembers%5B1%5D=3.1</nowiki> (Links to an external site.) (Links to an external site.)
* Food Technology Magazine Editors Share Top 10 Food Trend Predictions for 2019. <nowiki>http://www.ift.org/food-technology/past-issues/2019/april/features/2019-top-10-food-trends.aspx</nowiki>

'''Authorship:'''

FNH 200 Course content on this wiki page and associated lesson pages was originally authored by Drs. [http://www.landfood.ubc.ca/person/brent-skura/ Brent Skura], [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], and [http://www.landfood.ubc.ca/person/eunice-li-chan/ Eunice Li-Chan]. Ongoing edits and updates are contributed by past and current instructors including Drs. [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], [http://www.landfood.ubc.ca/person/azita-madadi-noei/ Azita Madadi-Noei], [http://www.landfood.ubc.ca/person/nooshin-alizadeh-pasdar/ Nooshin Alizadeh-Pasdar], and [http://www.landfood.ubc.ca/person/judy-chan/ Judy Chan].

{{cc-by-nc-sa-3.0}}

<quiz display=simple>
{1. Physical locations where a consumer may purchase and enjoy carrots:
|type="()"}
- Farmer's Market.
- Grocery Stores.
- Food Services Establishments.
+ All of the above.
</quiz>

<quiz display=simple>
{2. When are apples in BC being harvested?:
|type="()"}
- April.
- July.
+ Ocotober.
- December.
</quiz>

<quiz display=simple>
{3. What percentage of the atmosphere is oxygen?:
|type="()"}
- 0.3%
- 3%
+ 21%
- 78%
- 94%
</quiz>

<quiz display=simple>
{4. What changes occurred in the USA due to the publication of a book in 1906 about the meatpacking industry?:
|type="()"}
- The start of the vegetarian movement in the US.
+ Congress passed the meat inspection act and the food and drugs act of 1906.
- Inspectors were fired and taken out of the meatpacking plants.
- Establishment of the US Department of Agriculture.
</quiz>

<quiz display=simple>
{5. A food scientist discovers new information about food through research.
|type="()"}
+ TRUE.
- FALSE.
</quiz>

Course:FNH200/Lessons/Lesson 01

2020-06-24T02:36:26Z

YihangChen: /* 01.6 Trends in Food Consumption in Canada */

<big><big><big>'''Food Science and the Canadian Food System'''</big></big></big>

== 01.0 Overview ==
In this lesson, we will define the field of food science, and discuss the size and scope of the food industry in Canada. We will take a look at food production, importation, and distribution within Canada. Apple production and processing will be discussed as an example of the conversion of an agricultural product into a variety of food products. Finally, we will monitor some food consumption patterns and trends which have occurred over the past 40 years.

'''Objectives'''

After completing this lesson, you should be able to:
*describe the field of Food Science;
*describe the breadth and relative magnitude of various sectors of the Canadian food industry;
*identify the trends in food consumption in Canada;
*illustrate the ways that foods are distributed to consumers in Canada; and
*discuss how apples are converted into a variety of food products and how they are store
'''Optional Reading'''

Top 10 Food Trends for 2019: http://www.ift.org/food-technology/past-issues/2019/april/features/2019-top-10-food-trends.aspx

== 01.1 What is the Definition of Food Science? ==
Foods, as such, are complex systems subject to many forms of changes, including biochemical, nutritional, physical and/or sensory changes. The multidisciplinary science known as food science is used to pull together the wide range of knowledge that deals with food.

'''''Food Science''''' can be defined as the application of the principles of science, engineering, and mathematics in order to study and acquire new knowledge on the physical, chemical and biochemical nature of foods. Food science is a broad field that is composed of specializations in food microbiology, food chemistry, and food engineering. Food science also involves the study of sensory properties of food, and therefore, the psychology of food choice. From the information gathered by food science, the corresponding technologies can be applied to the utilization, processing, preservation and storage of food. This is known as '''''food technology'''''.

Here is a brief explanation of the main components (sub-fields) of Food Science''(adapted from Potter and Hotchkiss, 1995):''
* ''Food Chemistry'': deals with the composition, structure and properties of food, as well as the chemistry of changes that occur during processing.
* ''Food Analysis'': covers the principles and methods for quantitative physical and chemical analyses of food products and ingredients. These analyses are related to the standards and regulations for food processing.
* ''Food Microbiology'': relates to the study of microbial ecology in relation to food, the effect of environment on food spoilage and food manufacture, the physical, chemical, and biological destruction of microorganisms in food, the microbiological examination of food stuffs, and public health and sanitation microbiology.
* ''Food Processing'': covers the principles of food preservation and the general characteristics of raw food materials, processing factors that influence quality, packaging, waste management, good manufacturing practices, and sanitation procedures.
* ''Food Engineering:'' relates to the study and application of engineering concepts and unit operations used in food processing. Engineering principles include material and energy balances, thermodynamics, fluid flow, and heat and mass transfer.

==== Are Food Science and Nutrition the same? ====
''"the difference between food science and nutrition is that nutrition deals with the effects of foods in the person who consumes them, while food science is concerned with the study of the chemical, microbiological, physical, and sensory properties of foods and their ingredients during processing, manufacture, and storage."'' Murano (2003)

== 01.2 How Old is the Discipline of Food Science? ==
[[File:FNH200_Lesson01_AncientWine.jpg|thumb|left|200px|Fig 1.1 Ancient Egyptian Wine Making Scene]]
[[File:FNH200_Lesson01_CanningJar.jpg|thumb|right|100px|Fig 1.2 Nicolas Appert's Canning Jar]]Food science as a distinct discipline is quite new. However, many aspects of "food science" have existed for many centuries. Products derived from food fermentation (''biotechnology'') have existed for thousands of years.For example, there is evidence that people were fermenting beverages in (A) Babylon circa 5000 BC, (B) ancient Egypt circa 3000 BC, and (C) pre-Hispanic Mexico circa 2000 BC. Today we know that fermentation not only contributes to a wide variety of food products, but it also involves food processing and preservation.
{| class="wikitable"
|}
Another example dates back to 1795, when Emperor Napoleon offered 12,000 francs for a new way of preserving food for its army. It was the French confectioner François Nicolas Appert who won the prize by placing food in wide-mouthed bottles, then corking and heating them in a water bath. The existence of bacteria was not known at the time, and Appert did not know the principle upon which his process depended; however, he was correct in the thought that heat could preserve food. Appert is therefore known as the discoverer of the process later known as canning.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Make a list of questions you have about the science of foods. For example; why tomatoes are red, why gravy thickens, what is used to make "sugar-free" candy? Save your questions and search for answers as you complete this course.
|}

== 01.3 Extent of Canada's Food System==
[[File:FNH200_Lesson01_CdnFoodSystem.gif|thumb|right|500px|Fig 1.3 Canadian Food System]]
In Canada, we have a diverse food system with thousands of food products available for purchase. Those products include foods produced in Canada as well as food products imported from many countries around the world.

The Canadian food system is depicted in Figure 1.1. Foodstuffs (fruit, vegetables, cereal grains, oilseeds, animals, fowl) are produced by farmers involved in primary agricultural production. Fin fish, molluscs and crustaceans are harvested from the wild or raised on fish farms. Unprocessed foodstuffs and fish are also imported for sale or processing in Canada. These products are shipped directly to farmers' markets, processors or distributors. Many agricultural and fishery products undergo some form of processing/preservation prior to distribution to the consumer market. Many foods are fabricated from the foodstuffs produced by primary agricultural and fishery harvesting. Examples of fabricated foods are bread, smoked and cured luncheon meats, soft drinks, yogurt and chewing gum, to name a few.

Food products from processors or primary producers often pass through various distributors before they reach retail stores or food service outlets. Foods are retailed through chain stores and smaller independent stores, as well as numerous convenience stores which may be part of a chain or may be owned by an independent operator, as well as food co-operatives.

* Vegetables are sold in the fresh market as well as being processed (canned, frozen, dehydrted, fermented) to increase storage life.
* Greenhouse production of vegetables is an increasingly important component of the fresh market supply (cucumbers, peppers, lettuce, tomatoes) particularly in the fall and winter seasons.
* Seafood products are harvested and processed primarily in Atlantic Canada and in British Columbia. Seafood production includes the harvesting of wild stocks as well as production of salmon, oysters, clams and lobsters, under intensive production systems ('farmed' seafood). Cultivation of fish (trout) in fresh water occurs in a number of regions of Canada.
* Some products are transferred to the consumer market with a minimum of processing (e.g., fresh fruits, fresh vegetables) while others (e.g., beef, pork, poultry, milk, wheat) go through more extensive processing before being transported to the retail market. Many agricultural products (e.g., wheat flour, corn flour, corn starch, corn syrup, fruits, vegetables, milk, and milk components) become sources of ingredients for the production of other food products.
Below are the major Provinces in Canada involved in the production of different agricultural food commodities:
{| class="wikitable"
!Food commodity production
!Province
|-
|Animal (beef, pork, poultry)
|Widespread around Canada
|-
|Dairy milk production
|Across Canada, Ontario, Quebec
|-
|Cereal grains
|Alberta, Saskatchewan, Manitoba
|-
|Tree fruit; small fruits; cranberries, blueberries, raspberries
|British Columbia; Ontario, Nova Scotia; Almost every province; British Columbia
|-
|Vegetables
|All across Canada
|-
|Seafood
|Atlantic Canada and British Columbia
|}
Many ''agricultural commodities'', ''finished food products'' and ''ingredients'' are imported into Canada as well. These imported products must meet the same standards and regulatory requirements as foods produced in Canada. This aspect is discussed in more detail in the section of the course dealing with regulatory issues and standards (Lesson 4).
{| class="wikitable"
|'''Want to learn more?'''
|-
|How does this image from a trading store (''ca. 1910'') compare to the typical grocery store (supermarket) of today?

- Food production and marketing have come a long way since the 1900s
|}

== 01.4 The Canadian Food Industry ==
The Canadian food industry is a multi-billion dollar a year industry. Foods available to us on the grocery store shelves include both domestically produced products and imported foods.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* The next time you are in a large grocery store, take some time to survey the proportion of shelf space devoted to various food commodity groups and note the vast array and variety of products that are in the grocery store.
|}
Although Canada produces large amounts of fruits and vegetables, vast quantities of fruits and vegetables are imported as fresh product and in lesser amounts as frozen, canned and dehydrated products. This is due to the seasonal nature of fruit and vegetable production in Canada, as well as the need for climates warmer than Canada to grow fruits such as oranges, grapefruit and bananas.

Canada exports meat products (raw meat and processed meat products) to other countries but also imports meat products (raw meats of specific cuts that may be in short supply in Canada, as well as processed meat products). Likewise Canada exports raw fish (fresh and frozen salmon, cod, etc.) and processed fish (canned fish, smoked fish, salmon and herring roe) to other countries, while other types of fish (such as prawns, oysters, processed fish products) are imported into Canada.

== 01.5 Apples and Apple Products ==
[[File:FNH200_Lesson01_AppleProcessing.gif|thumb|right|500px|Figure 1.4 Apple production and processing.]]
The processing of apples will be used as an example of the utilization and conversion of an agricultural commodity to various food products and ingredients (Fig. 1.2). After harvesting, apples can be routed several directions: they can be shipped directly to the fresh market; they can be processed; or they can be put into controlled atmosphere storage facilities where the atmosphere, temperature and humidity are carefully controlled to retard the rate of respiration and ripening of the apples, thus extending the storage life of the fresh fruit. Controlled atmosphere storage of apples is described at:
* <nowiki>http://www.omafra.gov.on.ca/english/crops/facts/12-045.htm</nowiki>
Apples can be processed in various ways. A large proportion of processing apples is converted to '''apple juice'''. The type of apple juice preferred by consumers in Western Canada is the clear apple juice. Apple juice can be used as the starting material for the production of '''apple cider'''. In making cider, apple juice is inoculated with specific ''yeast'' strains which ferment sugar in the juice into ethanol and produce flavours characteristic of apple cider. Apple cider can be further processed by inoculating it with a ''bacterial'' culture that will oxidize the ethanol to acetic acid to produce '''apple vinegar'''.

The apple solids remaining after juice extraction can be used as a feed material for the production of '''pectin''' (a carbohydrate used as gelling agent in the production of jams and jellies), animal feed, or as organic matter that can be returned to agricultural lands. In some cases, the residue may also be trucked to landfill sites which adds to the waste burden entering those sites.

Apples are also processed into '''apple sauce''' and pie fillings. A greater proportion of these products are used as ingredients in the bakery and food service industries than as items in retail stores.

To a lesser extent, apples are used to produce '''dehydrated apple slices, fruit leather, apple-filled snack bars''' and as '''ingredients''' for some confectionary products and breakfast cereals.
{| class="wikitable"
|
|-
|'''Figure 1.2''' Apple production and processing
|}
{| class="wikitable"
| '''Want to learn more?'''
|-
|
* Identify a food that you enjoy. How do you think a food scientist/technologist would be involved in the production, processing and marketing of that food product?
|}

== 01.6 Trends in Food Consumption in Canada ==

Overall, many changes have occurred in food consumption patterns in Canada in the past few decades, and they continue to change as consumer demands and perceptions change. The advent of new processing technologies have brought new products on the market and this will continue. Consumer perception of those products will determine whether they succeed or fail. Undoubtedly, advertising campaigns for various food products and controversies about the health effects of various food commodities (butter vs margarine; sugar vs non-caloric or low caloric sweeteners; fats vs fat substitutes; trans-fat free products; processed vs unprocessed foods) will continue to influence consumer food buying habits.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Read the article in the link below and comment on the following points using your own experience in Canada. http://www.ift.org/food-technology/past-issues/2019/april/features/2019-top-10-food-trends.aspx
**Cannabis/CBD oil-infused drinks
** Cannabis/CBD oil-infused food
** Zero-waste cooking
** Globally inspired breakfast dishes
** Global flavors in kid’s meals
** Hyper-local
** New cuts of meat
** Veggie-centric/vegetable-forward cuisine
** Chef-driven fast-casual concepts
** Craft/artisan/locally produced spirits
|}
{| class="wikitable"
| '''Critical Thinking'''
|-
|
* Look at the most recent '''food consumption data (2014-2018)''' in the Statistics Canada website: <nowiki>http://www5.statcan.gc.ca/cansim/a26?lang=eng&retrLang=eng&id=0020011&tabMode=dataTable&srchLan=-1&p1=-1&p2=35#customizeTab</nowiki>
* Within each food category, which products have ''increased'' in consumption and which ones have ''decreased''? Can you identify what are the main reasons for these changes in consumption patterns?
** Meat
** Poultry and Eggs
** Fish
** Dairy
** Fruit and Vegetables
** Edible oils
** Beverages
* Review the highlights for 2017 and note any interesting finding: <nowiki>https://www150.statcan.gc.ca/n1/daily-quotidien/180530/dq180530c-eng.htm</nowiki> (Links to an external site.)
|}

== 01.7 Summary of Lesson 1 ==
* Food science studies the production, processing, preparing, evaluating and use of food.
* Technological advancements have led to many "food science discoveries"
* Canada offers a vast and diverse food system
* The Canadian food industry has a strong impact on Canada's economy
* Consumers and consumer demands have a strong influence on the food consumption trends

=== Closing thoughts ===
In conclusion, the food industry in Canada is a large industry that provides employment for a substantial part of the workforce in Canada. The variety of food products available in grocery stores or through food service outlets is immense and is likely to grow in response to consumer demands and changes in demographics, health, animal welfare and environmental concerns.

At this point it is important to recognize that while the amount and variety of foods consumed in Canada are increasing, many people in other parts of our world are unable to even secure enough nutritious food to maintain a healthy lifestyle. It has been estimated that about 3/4 of the world population live in lesser developed countries which are found mainly in Africa, Asia and South and Central America. Most of the inhabitants of these countries cannot get enough nutritious food to eat each day. Nutrients in short supply include fat, protein, vitamins, minerals and clean, safe drinking water. It is important to keep that thought in mind as you proceed through the course.

== References ==
* Murano, P.S. (2003). Introduction to Food Science and Technology. ''Understanding Food Science and Technology'' (Chapter 1). Belmont, California: Thompson Wadsworth.
* Potter, N. N. & Hotchkiss,J. H. (1998). Characteristics of the Food Industry. ''Food Science'' (5th ed.) (Chapter 2). Gaithersburg, Maryland: Aspen Publishers, Inc.
* Potter, N. N. & Hotchkiss,J. H. (1998). Vegetables and Fruits. ''Food Science'' (5th ed.) (Chapter 18 & pp.432-434). Gaithersburg, Maryland: Aspen Publishers, Inc.
* Food Available in Canada. Statistics Canada.<nowiki>https://www150.statcan.gc.ca/t1/tbl1/en/tv.action?pid=3210005401&pickMembers%5B0%5D=1.1&pickMembers%5B1%5D=3.1</nowiki> (Links to an external site.) (Links to an external site.)
* Food Technology Magazine Editors Share Top 10 Food Trend Predictions for 2019. <nowiki>http://www.ift.org/food-technology/past-issues/2019/april/features/2019-top-10-food-trends.aspx</nowiki>

'''Authorship:'''

FNH 200 Course content on this wiki page and associated lesson pages was originally authored by Drs. [http://www.landfood.ubc.ca/person/brent-skura/ Brent Skura], [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], and [http://www.landfood.ubc.ca/person/eunice-li-chan/ Eunice Li-Chan]. Ongoing edits and updates are contributed by past and current instructors including Drs. [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], [http://www.landfood.ubc.ca/person/azita-madadi-noei/ Azita Madadi-Noei], [http://www.landfood.ubc.ca/person/nooshin-alizadeh-pasdar/ Nooshin Alizadeh-Pasdar], and [http://www.landfood.ubc.ca/person/judy-chan/ Judy Chan].

{{cc-by-nc-sa-3.0}}

<quiz display=simple>
{1. Physical locations where a consumer may purchase and enjoy carrots:
|type="()"}
- Farmer's Market.
- Grocery Stores.
- Food Services Establishments.
+ All of the above.
</quiz>

<quiz display=simple>
{2. When are apples in BC being harvested?:
|type="()"}
- April.
- July.
+ Ocotober.
- December.
</quiz>

<quiz display=simple>
{3. What percentage of the atmosphere is oxygen?:
|type="()"}
- 0.3%
- 3%
+ 21%
- 78%
- 94%
</quiz>

<quiz display=simple>
{4. What changes occurred in the USA due to the publication of a book in 1906 about the meatpacking industry?:
|type="()"}
- The start of the vegetarian movement in the US.
+ Congress passed the meat inspection act and the food and drugs act of 1906.
- Inspectors were fired and taken out of the meatpacking plants.
- Establishment of the US Department of Agriculture.
</quiz>

<quiz display=simple>
{5. A food scientist discovers new information about food through research.
|type="()"}
+ TRUE.
- FALSE.
</quiz>

Course:FNH200/Lessons/Lesson 01

2020-06-24T02:35:24Z

YihangChen: /* 01.6 Trends in Food Consumption in Canada */

<big><big><big>'''Food Science and the Canadian Food System'''</big></big></big>

== 01.0 Overview ==
In this lesson, we will define the field of food science, and discuss the size and scope of the food industry in Canada. We will take a look at food production, importation, and distribution within Canada. Apple production and processing will be discussed as an example of the conversion of an agricultural product into a variety of food products. Finally, we will monitor some food consumption patterns and trends which have occurred over the past 40 years.

'''Objectives'''

After completing this lesson, you should be able to:
*describe the field of Food Science;
*describe the breadth and relative magnitude of various sectors of the Canadian food industry;
*identify the trends in food consumption in Canada;
*illustrate the ways that foods are distributed to consumers in Canada; and
*discuss how apples are converted into a variety of food products and how they are store
'''Optional Reading'''

Top 10 Food Trends for 2019: http://www.ift.org/food-technology/past-issues/2019/april/features/2019-top-10-food-trends.aspx

== 01.1 What is the Definition of Food Science? ==
Foods, as such, are complex systems subject to many forms of changes, including biochemical, nutritional, physical and/or sensory changes. The multidisciplinary science known as food science is used to pull together the wide range of knowledge that deals with food.

'''''Food Science''''' can be defined as the application of the principles of science, engineering, and mathematics in order to study and acquire new knowledge on the physical, chemical and biochemical nature of foods. Food science is a broad field that is composed of specializations in food microbiology, food chemistry, and food engineering. Food science also involves the study of sensory properties of food, and therefore, the psychology of food choice. From the information gathered by food science, the corresponding technologies can be applied to the utilization, processing, preservation and storage of food. This is known as '''''food technology'''''.

Here is a brief explanation of the main components (sub-fields) of Food Science''(adapted from Potter and Hotchkiss, 1995):''
* ''Food Chemistry'': deals with the composition, structure and properties of food, as well as the chemistry of changes that occur during processing.
* ''Food Analysis'': covers the principles and methods for quantitative physical and chemical analyses of food products and ingredients. These analyses are related to the standards and regulations for food processing.
* ''Food Microbiology'': relates to the study of microbial ecology in relation to food, the effect of environment on food spoilage and food manufacture, the physical, chemical, and biological destruction of microorganisms in food, the microbiological examination of food stuffs, and public health and sanitation microbiology.
* ''Food Processing'': covers the principles of food preservation and the general characteristics of raw food materials, processing factors that influence quality, packaging, waste management, good manufacturing practices, and sanitation procedures.
* ''Food Engineering:'' relates to the study and application of engineering concepts and unit operations used in food processing. Engineering principles include material and energy balances, thermodynamics, fluid flow, and heat and mass transfer.

==== Are Food Science and Nutrition the same? ====
''"the difference between food science and nutrition is that nutrition deals with the effects of foods in the person who consumes them, while food science is concerned with the study of the chemical, microbiological, physical, and sensory properties of foods and their ingredients during processing, manufacture, and storage."'' Murano (2003)

== 01.2 How Old is the Discipline of Food Science? ==
[[File:FNH200_Lesson01_AncientWine.jpg|thumb|left|200px|Fig 1.1 Ancient Egyptian Wine Making Scene]]
[[File:FNH200_Lesson01_CanningJar.jpg|thumb|right|100px|Fig 1.2 Nicolas Appert's Canning Jar]]Food science as a distinct discipline is quite new. However, many aspects of "food science" have existed for many centuries. Products derived from food fermentation (''biotechnology'') have existed for thousands of years.For example, there is evidence that people were fermenting beverages in (A) Babylon circa 5000 BC, (B) ancient Egypt circa 3000 BC, and (C) pre-Hispanic Mexico circa 2000 BC. Today we know that fermentation not only contributes to a wide variety of food products, but it also involves food processing and preservation.
{| class="wikitable"
|}
Another example dates back to 1795, when Emperor Napoleon offered 12,000 francs for a new way of preserving food for its army. It was the French confectioner François Nicolas Appert who won the prize by placing food in wide-mouthed bottles, then corking and heating them in a water bath. The existence of bacteria was not known at the time, and Appert did not know the principle upon which his process depended; however, he was correct in the thought that heat could preserve food. Appert is therefore known as the discoverer of the process later known as canning.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Make a list of questions you have about the science of foods. For example; why tomatoes are red, why gravy thickens, what is used to make "sugar-free" candy? Save your questions and search for answers as you complete this course.
|}

== 01.3 Extent of Canada's Food System==
[[File:FNH200_Lesson01_CdnFoodSystem.gif|thumb|right|500px|Fig 1.3 Canadian Food System]]
In Canada, we have a diverse food system with thousands of food products available for purchase. Those products include foods produced in Canada as well as food products imported from many countries around the world.

The Canadian food system is depicted in Figure 1.1. Foodstuffs (fruit, vegetables, cereal grains, oilseeds, animals, fowl) are produced by farmers involved in primary agricultural production. Fin fish, molluscs and crustaceans are harvested from the wild or raised on fish farms. Unprocessed foodstuffs and fish are also imported for sale or processing in Canada. These products are shipped directly to farmers' markets, processors or distributors. Many agricultural and fishery products undergo some form of processing/preservation prior to distribution to the consumer market. Many foods are fabricated from the foodstuffs produced by primary agricultural and fishery harvesting. Examples of fabricated foods are bread, smoked and cured luncheon meats, soft drinks, yogurt and chewing gum, to name a few.

Food products from processors or primary producers often pass through various distributors before they reach retail stores or food service outlets. Foods are retailed through chain stores and smaller independent stores, as well as numerous convenience stores which may be part of a chain or may be owned by an independent operator, as well as food co-operatives.

* Vegetables are sold in the fresh market as well as being processed (canned, frozen, dehydrted, fermented) to increase storage life.
* Greenhouse production of vegetables is an increasingly important component of the fresh market supply (cucumbers, peppers, lettuce, tomatoes) particularly in the fall and winter seasons.
* Seafood products are harvested and processed primarily in Atlantic Canada and in British Columbia. Seafood production includes the harvesting of wild stocks as well as production of salmon, oysters, clams and lobsters, under intensive production systems ('farmed' seafood). Cultivation of fish (trout) in fresh water occurs in a number of regions of Canada.
* Some products are transferred to the consumer market with a minimum of processing (e.g., fresh fruits, fresh vegetables) while others (e.g., beef, pork, poultry, milk, wheat) go through more extensive processing before being transported to the retail market. Many agricultural products (e.g., wheat flour, corn flour, corn starch, corn syrup, fruits, vegetables, milk, and milk components) become sources of ingredients for the production of other food products.
Below are the major Provinces in Canada involved in the production of different agricultural food commodities:
{| class="wikitable"
!Food commodity production
!Province
|-
|Animal (beef, pork, poultry)
|Widespread around Canada
|-
|Dairy milk production
|Across Canada, Ontario, Quebec
|-
|Cereal grains
|Alberta, Saskatchewan, Manitoba
|-
|Tree fruit; small fruits; cranberries, blueberries, raspberries
|British Columbia; Ontario, Nova Scotia; Almost every province; British Columbia
|-
|Vegetables
|All across Canada
|-
|Seafood
|Atlantic Canada and British Columbia
|}
Many ''agricultural commodities'', ''finished food products'' and ''ingredients'' are imported into Canada as well. These imported products must meet the same standards and regulatory requirements as foods produced in Canada. This aspect is discussed in more detail in the section of the course dealing with regulatory issues and standards (Lesson 4).
{| class="wikitable"
|'''Want to learn more?'''
|-
|How does this image from a trading store (''ca. 1910'') compare to the typical grocery store (supermarket) of today?

- Food production and marketing have come a long way since the 1900s
|}

== 01.4 The Canadian Food Industry ==
The Canadian food industry is a multi-billion dollar a year industry. Foods available to us on the grocery store shelves include both domestically produced products and imported foods.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* The next time you are in a large grocery store, take some time to survey the proportion of shelf space devoted to various food commodity groups and note the vast array and variety of products that are in the grocery store.
|}
Although Canada produces large amounts of fruits and vegetables, vast quantities of fruits and vegetables are imported as fresh product and in lesser amounts as frozen, canned and dehydrated products. This is due to the seasonal nature of fruit and vegetable production in Canada, as well as the need for climates warmer than Canada to grow fruits such as oranges, grapefruit and bananas.

Canada exports meat products (raw meat and processed meat products) to other countries but also imports meat products (raw meats of specific cuts that may be in short supply in Canada, as well as processed meat products). Likewise Canada exports raw fish (fresh and frozen salmon, cod, etc.) and processed fish (canned fish, smoked fish, salmon and herring roe) to other countries, while other types of fish (such as prawns, oysters, processed fish products) are imported into Canada.

== 01.5 Apples and Apple Products ==
[[File:FNH200_Lesson01_AppleProcessing.gif|thumb|right|500px|Figure 1.4 Apple production and processing.]]
The processing of apples will be used as an example of the utilization and conversion of an agricultural commodity to various food products and ingredients (Fig. 1.2). After harvesting, apples can be routed several directions: they can be shipped directly to the fresh market; they can be processed; or they can be put into controlled atmosphere storage facilities where the atmosphere, temperature and humidity are carefully controlled to retard the rate of respiration and ripening of the apples, thus extending the storage life of the fresh fruit. Controlled atmosphere storage of apples is described at:
* <nowiki>http://www.omafra.gov.on.ca/english/crops/facts/12-045.htm</nowiki>
Apples can be processed in various ways. A large proportion of processing apples is converted to '''apple juice'''. The type of apple juice preferred by consumers in Western Canada is the clear apple juice. Apple juice can be used as the starting material for the production of '''apple cider'''. In making cider, apple juice is inoculated with specific ''yeast'' strains which ferment sugar in the juice into ethanol and produce flavours characteristic of apple cider. Apple cider can be further processed by inoculating it with a ''bacterial'' culture that will oxidize the ethanol to acetic acid to produce '''apple vinegar'''.

The apple solids remaining after juice extraction can be used as a feed material for the production of '''pectin''' (a carbohydrate used as gelling agent in the production of jams and jellies), animal feed, or as organic matter that can be returned to agricultural lands. In some cases, the residue may also be trucked to landfill sites which adds to the waste burden entering those sites.

Apples are also processed into '''apple sauce''' and pie fillings. A greater proportion of these products are used as ingredients in the bakery and food service industries than as items in retail stores.

To a lesser extent, apples are used to produce '''dehydrated apple slices, fruit leather, apple-filled snack bars''' and as '''ingredients''' for some confectionary products and breakfast cereals.
{| class="wikitable"
|
|-
|'''Figure 1.2''' Apple production and processing
|}
{| class="wikitable"
| '''Want to learn more?'''
|-
|
* Identify a food that you enjoy. How do you think a food scientist/technologist would be involved in the production, processing and marketing of that food product?
|}

== 01.6 Trends in Food Consumption in Canada ==

Overall, many changes have occurred in food consumption patterns in Canada in the past few decades, and they continue to change as consumer demands and perceptions change. The advent of new processing technologies have brought new products on the market and this will continue. Consumer perception of those products will determine whether they succeed or fail. Undoubtedly, advertising campaigns for various food products and controversies about the health effects of various food commodities (butter vs margarine; sugar vs non-caloric or low caloric sweeteners; fats vs fat substitutes; trans-fat free products; processed vs unprocessed foods) will continue to influence consumer food buying habits.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Read the article in the link below and comment on the following points using your own experience in Canada. http://www.ift.org/food-technology/past-issues/2019/april/features/2019-top-10-food-trends.aspx

*
** Cannabis/CBD oil-infused drinks
** Cannabis/CBD oil-infused food
** Zero-waste cooking
** Globally inspired breakfast dishes
** Global flavors in kid’s meals
** Hyper-local
** New cuts of meat
** Veggie-centric/vegetable-forward cuisine
** Chef-driven fast-casual concepts
** Craft/artisan/locally produced spirits
|}
{| class="wikitable"
| '''Critical Thinking'''
|-
|
* Look at the most recent '''food consumption data (2014-2018)''' in the Statistics Canada website: <nowiki>http://www5.statcan.gc.ca/cansim/a26?lang=eng&retrLang=eng&id=0020011&tabMode=dataTable&srchLan=-1&p1=-1&p2=35#customizeTab</nowiki>
* Within each food category, which products have ''increased'' in consumption and which ones have ''decreased''? Can you identify what are the main reasons for these changes in consumption patterns?
** Meat
** Poultry and Eggs
** Fish
** Dairy
** Fruit and Vegetables
** Edible oils
** Beverages
* Review the highlights for 2017 and note any interesting finding: <nowiki>https://www150.statcan.gc.ca/n1/daily-quotidien/180530/dq180530c-eng.htm</nowiki> (Links to an external site.)
|}

== 01.7 Summary of Lesson 1 ==
* Food science studies the production, processing, preparing, evaluating and use of food.
* Technological advancements have led to many "food science discoveries"
* Canada offers a vast and diverse food system
* The Canadian food industry has a strong impact on Canada's economy
* Consumers and consumer demands have a strong influence on the food consumption trends

=== Closing thoughts ===
In conclusion, the food industry in Canada is a large industry that provides employment for a substantial part of the workforce in Canada. The variety of food products available in grocery stores or through food service outlets is immense and is likely to grow in response to consumer demands and changes in demographics, health, animal welfare and environmental concerns.

At this point it is important to recognize that while the amount and variety of foods consumed in Canada are increasing, many people in other parts of our world are unable to even secure enough nutritious food to maintain a healthy lifestyle. It has been estimated that about 3/4 of the world population live in lesser developed countries which are found mainly in Africa, Asia and South and Central America. Most of the inhabitants of these countries cannot get enough nutritious food to eat each day. Nutrients in short supply include fat, protein, vitamins, minerals and clean, safe drinking water. It is important to keep that thought in mind as you proceed through the course.

== References ==
* Murano, P.S. (2003). Introduction to Food Science and Technology. ''Understanding Food Science and Technology'' (Chapter 1). Belmont, California: Thompson Wadsworth.
* Potter, N. N. & Hotchkiss,J. H. (1998). Characteristics of the Food Industry. ''Food Science'' (5th ed.) (Chapter 2). Gaithersburg, Maryland: Aspen Publishers, Inc.
* Potter, N. N. & Hotchkiss,J. H. (1998). Vegetables and Fruits. ''Food Science'' (5th ed.) (Chapter 18 & pp.432-434). Gaithersburg, Maryland: Aspen Publishers, Inc.
* Food Available in Canada. Statistics Canada.<nowiki>https://www150.statcan.gc.ca/t1/tbl1/en/tv.action?pid=3210005401&pickMembers%5B0%5D=1.1&pickMembers%5B1%5D=3.1</nowiki> (Links to an external site.) (Links to an external site.)
* Food Technology Magazine Editors Share Top 10 Food Trend Predictions for 2019. <nowiki>http://www.ift.org/food-technology/past-issues/2019/april/features/2019-top-10-food-trends.aspx</nowiki>

'''Authorship:'''

FNH 200 Course content on this wiki page and associated lesson pages was originally authored by Drs. [http://www.landfood.ubc.ca/person/brent-skura/ Brent Skura], [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], and [http://www.landfood.ubc.ca/person/eunice-li-chan/ Eunice Li-Chan]. Ongoing edits and updates are contributed by past and current instructors including Drs. [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], [http://www.landfood.ubc.ca/person/azita-madadi-noei/ Azita Madadi-Noei], [http://www.landfood.ubc.ca/person/nooshin-alizadeh-pasdar/ Nooshin Alizadeh-Pasdar], and [http://www.landfood.ubc.ca/person/judy-chan/ Judy Chan].

{{cc-by-nc-sa-3.0}}

<quiz display=simple>
{1. Physical locations where a consumer may purchase and enjoy carrots:
|type="()"}
- Farmer's Market.
- Grocery Stores.
- Food Services Establishments.
+ All of the above.
</quiz>

<quiz display=simple>
{2. When are apples in BC being harvested?:
|type="()"}
- April.
- July.
+ Ocotober.
- December.
</quiz>

<quiz display=simple>
{3. What percentage of the atmosphere is oxygen?:
|type="()"}
- 0.3%
- 3%
+ 21%
- 78%
- 94%
</quiz>

<quiz display=simple>
{4. What changes occurred in the USA due to the publication of a book in 1906 about the meatpacking industry?:
|type="()"}
- The start of the vegetarian movement in the US.
+ Congress passed the meat inspection act and the food and drugs act of 1906.
- Inspectors were fired and taken out of the meatpacking plants.
- Establishment of the US Department of Agriculture.
</quiz>

<quiz display=simple>
{5. A food scientist discovers new information about food through research.
|type="()"}
+ TRUE.
- FALSE.
</quiz>

Course:FNH200/Lessons/Lesson 01/Page 01.6

2020-06-24T02:34:24Z

YihangChen:

== 01.6 Trends in Food Consumption in Canada ==

Overall, many changes have occurred in food consumption patterns in Canada in the past few decades, and they continue to change as consumer demands and perceptions change. The advent of new processing technologies have brought new products on the market and this will continue. Consumer perception of those products will determine whether they succeed or fail. Undoubtedly, advertising campaigns for various food products and controversies about the health effects of various food commodities (butter vs margarine; sugar vs non-caloric or low caloric sweeteners; fats vs fat substitutes; trans-fat free products; processed vs unprocessed foods) will continue to influence consumer food buying habits.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Read the article in the link below and comment on the following points using your own experience in Canada.
<nowiki>http://www.ift.org/food-technology/past-issues/2019/april/features/2019-top-10-food-trends.aspx</nowiki>
*
** Cannabis/CBD oil-infused drinks
** Cannabis/CBD oil-infused food
** Zero-waste cooking
** Globally inspired breakfast dishes
** Global flavors in kid’s meals
** Hyper-local
** New cuts of meat
** Veggie-centric/vegetable-forward cuisine
** Chef-driven fast-casual concepts
** Craft/artisan/locally produced spirits
|}
{| class="wikitable"
| '''Critical Thinking'''
|-
|
* Look at the most recent '''food consumption data (2014-2018)''' in the Statistics Canada website: <nowiki>http://www5.statcan.gc.ca/cansim/a26?lang=eng&retrLang=eng&id=0020011&tabMode=dataTable&srchLan=-1&p1=-1&p2=35#customizeTab</nowiki>
* Within each food category, which products have ''increased'' in consumption and which ones have ''decreased''? Can you identify what are the main reasons for these changes in consumption patterns?
** Meat
** Poultry and Eggs
** Fish
** Dairy
** Fruit and Vegetables
** Edible oils
** Beverages
* Review the highlights for 2017 and note any interesting finding: <nowiki>https://www150.statcan.gc.ca/n1/daily-quotidien/180530/dq180530c-eng.htm</nowiki> (Links to an external site.)
|}

Course:FNH200/Lessons/Lesson 01/Page 01.6

2020-06-24T02:33:59Z

YihangChen: /* 01.06 Trends in Food Consumption in Canada */

== 01.6 Trends in Food Consumption in Canada ==

Overall, many changes have occurred in food consumption patterns in Canada in the past few decades, and they continue to change as consumer demands and perceptions change. The advent of new processing technologies have brought new products on the market and this will continue. Consumer perception of those products will determine whether they succeed or fail. Undoubtedly, advertising campaigns for various food products and controversies about the health effects of various food commodities (butter vs margarine; sugar vs non-caloric or low caloric sweeteners; fats vs fat substitutes; trans-fat free products; processed vs unprocessed foods) will continue to influence consumer food buying habits.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Read the article in the link below and comment on the following points using your own experience in Canada.
<nowiki>http://www.ift.org/food-technology/past-issues/2019/april/features/2019-top-10-food-trends.aspx</nowiki>
* Insert paragraph
** Cannabis/CBD oil-infused drinks
** Cannabis/CBD oil-infused food
** Zero-waste cooking
** Globally inspired breakfast dishes
** Global flavors in kid’s meals
** Hyper-local
** New cuts of meat
** Veggie-centric/vegetable-forward cuisine
** Chef-driven fast-casual concepts
** Craft/artisan/locally produced spirits
|}
{| class="wikitable"
| '''Critical Thinking'''
|-
|
* Look at the most recent '''food consumption data (2014-2018)''' in the Statistics Canada website: <nowiki>http://www5.statcan.gc.ca/cansim/a26?lang=eng&retrLang=eng&id=0020011&tabMode=dataTable&srchLan=-1&p1=-1&p2=35#customizeTab</nowiki>
* Within each food category, which products have ''increased'' in consumption and which ones have ''decreased''? Can you identify what are the main reasons for these changes in consumption patterns?
** Meat
** Poultry and Eggs
** Fish
** Dairy
** Fruit and Vegetables
** Edible oils
** Beverages
* Review the highlights for 2017 and note any interesting finding: <nowiki>https://www150.statcan.gc.ca/n1/daily-quotidien/180530/dq180530c-eng.htm</nowiki> (Links to an external site.)
|}

Course:FNH200/Lessons/Lesson 01/Page 01.5

2020-06-24T02:33:06Z

YihangChen: /* 01.05 Apples and Apple Products */

== 01.5 Apples and Apple Products ==
[[File:FNH200_Lesson01_AppleProcessing.gif|thumb|right|500px|Figure 1.4 Apple production and processing.]]
The processing of apples will be used as an example of the utilization and conversion of an agricultural commodity to various food products and ingredients (Fig. 1.2). After harvesting, apples can be routed several directions: they can be shipped directly to the fresh market; they can be processed; or they can be put into controlled atmosphere storage facilities where the atmosphere, temperature and humidity are carefully controlled to retard the rate of respiration and ripening of the apples, thus extending the storage life of the fresh fruit. Controlled atmosphere storage of apples is described at:
* <nowiki>http://www.omafra.gov.on.ca/english/crops/facts/12-045.htm</nowiki>
Apples can be processed in various ways. A large proportion of processing apples is converted to '''apple juice'''. The type of apple juice preferred by consumers in Western Canada is the clear apple juice. Apple juice can be used as the starting material for the production of '''apple cider'''. In making cider, apple juice is inoculated with specific ''yeast'' strains which ferment sugar in the juice into ethanol and produce flavours characteristic of apple cider. Apple cider can be further processed by inoculating it with a ''bacterial'' culture that will oxidize the ethanol to acetic acid to produce '''apple vinegar'''.

The apple solids remaining after juice extraction can be used as a feed material for the production of '''pectin''' (a carbohydrate used as gelling agent in the production of jams and jellies), animal feed, or as organic matter that can be returned to agricultural lands. In some cases, the residue may also be trucked to landfill sites which adds to the waste burden entering those sites.

Apples are also processed into '''apple sauce''' and pie fillings. A greater proportion of these products are used as ingredients in the bakery and food service industries than as items in retail stores.

To a lesser extent, apples are used to produce '''dehydrated apple slices, fruit leather, apple-filled snack bars''' and as '''ingredients''' for some confectionary products and breakfast cereals.
{| class="wikitable"
|
|-
|'''Figure 1.2''' Apple production and processing
|}
{| class="wikitable"
| '''Want to learn more?'''
|-
|
* Identify a food that you enjoy. How do you think a food scientist/technologist would be involved in the production, processing and marketing of that food product?
|}

Course:FNH200/Lessons/Lesson 01/Page 01.4

2020-06-24T02:32:53Z

YihangChen: /* 01.04 The Canadian Food Industry */

== 01.4 The Canadian Food Industry ==
The Canadian food industry is a multi-billion dollar a year industry. Foods available to us on the grocery store shelves include both domestically produced products and imported foods.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* The next time you are in a large grocery store, take some time to survey the proportion of shelf space devoted to various food commodity groups and note the vast array and variety of products that are in the grocery store.
|}
Although Canada produces large amounts of fruits and vegetables, vast quantities of fruits and vegetables are imported as fresh product and in lesser amounts as frozen, canned and dehydrated products. This is due to the seasonal nature of fruit and vegetable production in Canada, as well as the need for climates warmer than Canada to grow fruits such as oranges, grapefruit and bananas.

Canada exports meat products (raw meat and processed meat products) to other countries but also imports meat products (raw meats of specific cuts that may be in short supply in Canada, as well as processed meat products). Likewise Canada exports raw fish (fresh and frozen salmon, cod, etc.) and processed fish (canned fish, smoked fish, salmon and herring roe) to other countries, while other types of fish (such as prawns, oysters, processed fish products) are imported into Canada.

Course:FNH200/Lessons/Lesson 01/Page 01.3

2020-06-24T02:32:39Z

YihangChen: /* 01.03 Extent of Canada's Food System */

== 01.3 Extent of Canada's Food System==
[[File:FNH200_Lesson01_CdnFoodSystem.gif|thumb|right|500px|Fig 1.3 Canadian Food System]]
In Canada, we have a diverse food system with thousands of food products available for purchase. Those products include foods produced in Canada as well as food products imported from many countries around the world.

The Canadian food system is depicted in Figure 1.1. Foodstuffs (fruit, vegetables, cereal grains, oilseeds, animals, fowl) are produced by farmers involved in primary agricultural production. Fin fish, molluscs and crustaceans are harvested from the wild or raised on fish farms. Unprocessed foodstuffs and fish are also imported for sale or processing in Canada. These products are shipped directly to farmers' markets, processors or distributors. Many agricultural and fishery products undergo some form of processing/preservation prior to distribution to the consumer market. Many foods are fabricated from the foodstuffs produced by primary agricultural and fishery harvesting. Examples of fabricated foods are bread, smoked and cured luncheon meats, soft drinks, yogurt and chewing gum, to name a few.

Food products from processors or primary producers often pass through various distributors before they reach retail stores or food service outlets. Foods are retailed through chain stores and smaller independent stores, as well as numerous convenience stores which may be part of a chain or may be owned by an independent operator, as well as food co-operatives.

* Vegetables are sold in the fresh market as well as being processed (canned, frozen, dehydrted, fermented) to increase storage life.
* Greenhouse production of vegetables is an increasingly important component of the fresh market supply (cucumbers, peppers, lettuce, tomatoes) particularly in the fall and winter seasons.
* Seafood products are harvested and processed primarily in Atlantic Canada and in British Columbia. Seafood production includes the harvesting of wild stocks as well as production of salmon, oysters, clams and lobsters, under intensive production systems ('farmed' seafood). Cultivation of fish (trout) in fresh water occurs in a number of regions of Canada.
* Some products are transferred to the consumer market with a minimum of processing (e.g., fresh fruits, fresh vegetables) while others (e.g., beef, pork, poultry, milk, wheat) go through more extensive processing before being transported to the retail market. Many agricultural products (e.g., wheat flour, corn flour, corn starch, corn syrup, fruits, vegetables, milk, and milk components) become sources of ingredients for the production of other food products.
Below are the major Provinces in Canada involved in the production of different agricultural food commodities:
{| class="wikitable"
!Food commodity production
!Province
|-
|Animal (beef, pork, poultry)
|Widespread around Canada
|-
|Dairy milk production
|Across Canada, Ontario, Quebec
|-
|Cereal grains
|Alberta, Saskatchewan, Manitoba
|-
|Tree fruit; small fruits; cranberries, blueberries, raspberries
|British Columbia; Ontario, Nova Scotia; Almost every province; British Columbia
|-
|Vegetables
|All across Canada
|-
|Seafood
|Atlantic Canada and British Columbia
|}
Many ''agricultural commodities'', ''finished food products'' and ''ingredients'' are imported into Canada as well. These imported products must meet the same standards and regulatory requirements as foods produced in Canada. This aspect is discussed in more detail in the section of the course dealing with regulatory issues and standards (Lesson 4).
{| class="wikitable"
|'''Want to learn more?'''
|-
|How does this image from a trading store (''ca. 1910'') compare to the typical grocery store (supermarket) of today?

- Food production and marketing have come a long way since the 1900s
|}

Course:FNH200/Lessons/Lesson 01/Page 01.2

2020-06-24T02:32:25Z

YihangChen:

== 01.2 How Old is the Discipline of Food Science? ==
[[File:FNH200_Lesson01_AncientWine.jpg|thumb|left|200px|Fig 1.1 Ancient Egyptian Wine Making Scene]]
[[File:FNH200_Lesson01_CanningJar.jpg|thumb|right|100px|Fig 1.2 Nicolas Appert's Canning Jar]]Food science as a distinct discipline is quite new. However, many aspects of "food science" have existed for many centuries. Products derived from food fermentation (''biotechnology'') have existed for thousands of years.For example, there is evidence that people were fermenting beverages in (A) Babylon circa 5000 BC, (B) ancient Egypt circa 3000 BC, and (C) pre-Hispanic Mexico circa 2000 BC. Today we know that fermentation not only contributes to a wide variety of food products, but it also involves food processing and preservation.
{| class="wikitable"
|}
Another example dates back to 1795, when Emperor Napoleon offered 12,000 francs for a new way of preserving food for its army. It was the French confectioner François Nicolas Appert who won the prize by placing food in wide-mouthed bottles, then corking and heating them in a water bath. The existence of bacteria was not known at the time, and Appert did not know the principle upon which his process depended; however, he was correct in the thought that heat could preserve food. Appert is therefore known as the discoverer of the process later known as canning.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Make a list of questions you have about the science of foods. For example; why tomatoes are red, why gravy thickens, what is used to make "sugar-free" candy? Save your questions and search for answers as you complete this course.
|}

Course:FNH200/Lessons/Lesson 01/Page 01.1

2020-06-24T02:32:13Z

YihangChen: /* 01.01 What is the Definition of Food Science? */

== 01.1 What is the Definition of Food Science? ==
Foods, as such, are complex systems subject to many forms of changes, including biochemical, nutritional, physical and/or sensory changes. The multidisciplinary science known as food science is used to pull together the wide range of knowledge that deals with food.

'''''Food Science''''' can be defined as the application of the principles of science, engineering, and mathematics in order to study and acquire new knowledge on the physical, chemical and biochemical nature of foods. Food science is a broad field that is composed of specializations in food microbiology, food chemistry, and food engineering. Food science also involves the study of sensory properties of food, and therefore, the psychology of food choice. From the information gathered by food science, the corresponding technologies can be applied to the utilization, processing, preservation and storage of food. This is known as '''''food technology'''''.

Here is a brief explanation of the main components (sub-fields) of Food Science''(adapted from Potter and Hotchkiss, 1995):''
* ''Food Chemistry'': deals with the composition, structure and properties of food, as well as the chemistry of changes that occur during processing.
* ''Food Analysis'': covers the principles and methods for quantitative physical and chemical analyses of food products and ingredients. These analyses are related to the standards and regulations for food processing.
* ''Food Microbiology'': relates to the study of microbial ecology in relation to food, the effect of environment on food spoilage and food manufacture, the physical, chemical, and biological destruction of microorganisms in food, the microbiological examination of food stuffs, and public health and sanitation microbiology.
* ''Food Processing'': covers the principles of food preservation and the general characteristics of raw food materials, processing factors that influence quality, packaging, waste management, good manufacturing practices, and sanitation procedures.
* ''Food Engineering:'' relates to the study and application of engineering concepts and unit operations used in food processing. Engineering principles include material and energy balances, thermodynamics, fluid flow, and heat and mass transfer.

==== Are Food Science and Nutrition the same? ====
''"the difference between food science and nutrition is that nutrition deals with the effects of foods in the person who consumes them, while food science is concerned with the study of the chemical, microbiological, physical, and sensory properties of foods and their ingredients during processing, manufacture, and storage."'' Murano (2003)

Course:FNH200/Lessons/Lesson 01/Page 01.0

2020-06-24T02:32:00Z

YihangChen:

Course:FNH200/Lessons/Lesson 01

2020-06-24T02:31:10Z

YihangChen:

<big><big><big>'''Food Science and the Canadian Food System'''</big></big></big>

== 01.0 Overview ==
In this lesson, we will define the field of food science, and discuss the size and scope of the food industry in Canada. We will take a look at food production, importation, and distribution within Canada. Apple production and processing will be discussed as an example of the conversion of an agricultural product into a variety of food products. Finally, we will monitor some food consumption patterns and trends which have occurred over the past 40 years.

'''Objectives'''

After completing this lesson, you should be able to:
*describe the field of Food Science;
*describe the breadth and relative magnitude of various sectors of the Canadian food industry;
*identify the trends in food consumption in Canada;
*illustrate the ways that foods are distributed to consumers in Canada; and
*discuss how apples are converted into a variety of food products and how they are store
'''Optional Reading'''

Top 10 Food Trends for 2019: http://www.ift.org/food-technology/past-issues/2019/april/features/2019-top-10-food-trends.aspx

== 01.1 What is the Definition of Food Science? ==
Foods, as such, are complex systems subject to many forms of changes, including biochemical, nutritional, physical and/or sensory changes. The multidisciplinary science known as food science is used to pull together the wide range of knowledge that deals with food.

'''''Food Science''''' can be defined as the application of the principles of science, engineering, and mathematics in order to study and acquire new knowledge on the physical, chemical and biochemical nature of foods. Food science is a broad field that is composed of specializations in food microbiology, food chemistry, and food engineering. Food science also involves the study of sensory properties of food, and therefore, the psychology of food choice. From the information gathered by food science, the corresponding technologies can be applied to the utilization, processing, preservation and storage of food. This is known as '''''food technology'''''.

Here is a brief explanation of the main components (sub-fields) of Food Science''(adapted from Potter and Hotchkiss, 1995):''
* ''Food Chemistry'': deals with the composition, structure and properties of food, as well as the chemistry of changes that occur during processing.
* ''Food Analysis'': covers the principles and methods for quantitative physical and chemical analyses of food products and ingredients. These analyses are related to the standards and regulations for food processing.
* ''Food Microbiology'': relates to the study of microbial ecology in relation to food, the effect of environment on food spoilage and food manufacture, the physical, chemical, and biological destruction of microorganisms in food, the microbiological examination of food stuffs, and public health and sanitation microbiology.
* ''Food Processing'': covers the principles of food preservation and the general characteristics of raw food materials, processing factors that influence quality, packaging, waste management, good manufacturing practices, and sanitation procedures.
* ''Food Engineering:'' relates to the study and application of engineering concepts and unit operations used in food processing. Engineering principles include material and energy balances, thermodynamics, fluid flow, and heat and mass transfer.

==== Are Food Science and Nutrition the same? ====
''"the difference between food science and nutrition is that nutrition deals with the effects of foods in the person who consumes them, while food science is concerned with the study of the chemical, microbiological, physical, and sensory properties of foods and their ingredients during processing, manufacture, and storage."'' Murano (2003)

== 01.2 How Old is the Discipline of Food Science? ==
[[File:FNH200_Lesson01_AncientWine.jpg|thumb|left|200px|Fig 1.1 Ancient Egyptian Wine Making Scene]]
[[File:FNH200_Lesson01_CanningJar.jpg|thumb|right|100px|Fig 1.2 Nicolas Appert's Canning Jar]]Food science as a distinct discipline is quite new. However, many aspects of "food science" have existed for many centuries. Products derived from food fermentation (''biotechnology'') have existed for thousands of years.For example, there is evidence that people were fermenting beverages in (A) Babylon circa 5000 BC, (B) ancient Egypt circa 3000 BC, and (C) pre-Hispanic Mexico circa 2000 BC. Today we know that fermentation not only contributes to a wide variety of food products, but it also involves food processing and preservation.
{| class="wikitable"
|}
Another example dates back to 1795, when Emperor Napoleon offered 12,000 francs for a new way of preserving food for its army. It was the French confectioner François Nicolas Appert who won the prize by placing food in wide-mouthed bottles, then corking and heating them in a water bath. The existence of bacteria was not known at the time, and Appert did not know the principle upon which his process depended; however, he was correct in the thought that heat could preserve food. Appert is therefore known as the discoverer of the process later known as canning.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Make a list of questions you have about the science of foods. For example; why tomatoes are red, why gravy thickens, what is used to make "sugar-free" candy? Save your questions and search for answers as you complete this course.
|}

== 01.3 Extent of Canada's Food System==
[[File:FNH200_Lesson01_CdnFoodSystem.gif|thumb|right|500px|Fig 1.3 Canadian Food System]]
In Canada, we have a diverse food system with thousands of food products available for purchase. Those products include foods produced in Canada as well as food products imported from many countries around the world.

The Canadian food system is depicted in Figure 1.1. Foodstuffs (fruit, vegetables, cereal grains, oilseeds, animals, fowl) are produced by farmers involved in primary agricultural production. Fin fish, molluscs and crustaceans are harvested from the wild or raised on fish farms. Unprocessed foodstuffs and fish are also imported for sale or processing in Canada. These products are shipped directly to farmers' markets, processors or distributors. Many agricultural and fishery products undergo some form of processing/preservation prior to distribution to the consumer market. Many foods are fabricated from the foodstuffs produced by primary agricultural and fishery harvesting. Examples of fabricated foods are bread, smoked and cured luncheon meats, soft drinks, yogurt and chewing gum, to name a few.

Food products from processors or primary producers often pass through various distributors before they reach retail stores or food service outlets. Foods are retailed through chain stores and smaller independent stores, as well as numerous convenience stores which may be part of a chain or may be owned by an independent operator, as well as food co-operatives.

* Vegetables are sold in the fresh market as well as being processed (canned, frozen, dehydrted, fermented) to increase storage life.
* Greenhouse production of vegetables is an increasingly important component of the fresh market supply (cucumbers, peppers, lettuce, tomatoes) particularly in the fall and winter seasons.
* Seafood products are harvested and processed primarily in Atlantic Canada and in British Columbia. Seafood production includes the harvesting of wild stocks as well as production of salmon, oysters, clams and lobsters, under intensive production systems ('farmed' seafood). Cultivation of fish (trout) in fresh water occurs in a number of regions of Canada.
* Some products are transferred to the consumer market with a minimum of processing (e.g., fresh fruits, fresh vegetables) while others (e.g., beef, pork, poultry, milk, wheat) go through more extensive processing before being transported to the retail market. Many agricultural products (e.g., wheat flour, corn flour, corn starch, corn syrup, fruits, vegetables, milk, and milk components) become sources of ingredients for the production of other food products.
Below are the major Provinces in Canada involved in the production of different agricultural food commodities:
{| class="wikitable"
!Food commodity production
!Province
|-
|Animal (beef, pork, poultry)
|Widespread around Canada
|-
|Dairy milk production
|Across Canada, Ontario, Quebec
|-
|Cereal grains
|Alberta, Saskatchewan, Manitoba
|-
|Tree fruit; small fruits; cranberries, blueberries, raspberries
|British Columbia; Ontario, Nova Scotia; Almost every province; British Columbia
|-
|Vegetables
|All across Canada
|-
|Seafood
|Atlantic Canada and British Columbia
|}
Many ''agricultural commodities'', ''finished food products'' and ''ingredients'' are imported into Canada as well. These imported products must meet the same standards and regulatory requirements as foods produced in Canada. This aspect is discussed in more detail in the section of the course dealing with regulatory issues and standards (Lesson 4).
{| class="wikitable"
|'''Want to learn more?'''
|-
|How does this image from a trading store (''ca. 1910'') compare to the typical grocery store (supermarket) of today?

- Food production and marketing have come a long way since the 1900s
|}

== 01.4 The Canadian Food Industry ==
The Canadian food industry is a multi-billion dollar a year industry. Foods available to us on the grocery store shelves include both domestically produced products and imported foods.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* The next time you are in a large grocery store, take some time to survey the proportion of shelf space devoted to various food commodity groups and note the vast array and variety of products that are in the grocery store.
|}
Although Canada produces large amounts of fruits and vegetables, vast quantities of fruits and vegetables are imported as fresh product and in lesser amounts as frozen, canned and dehydrated products. This is due to the seasonal nature of fruit and vegetable production in Canada, as well as the need for climates warmer than Canada to grow fruits such as oranges, grapefruit and bananas.

Canada exports meat products (raw meat and processed meat products) to other countries but also imports meat products (raw meats of specific cuts that may be in short supply in Canada, as well as processed meat products). Likewise Canada exports raw fish (fresh and frozen salmon, cod, etc.) and processed fish (canned fish, smoked fish, salmon and herring roe) to other countries, while other types of fish (such as prawns, oysters, processed fish products) are imported into Canada.

== 01.5 Apples and Apple Products ==
[[File:FNH200_Lesson01_AppleProcessing.gif|thumb|right|500px|Figure 1.4 Apple production and processing.]]
The processing of apples will be used as an example of the utilization and conversion of an agricultural commodity to various food products and ingredients (Fig. 1.2). After harvesting, apples can be routed several directions: they can be shipped directly to the fresh market; they can be processed; or they can be put into controlled atmosphere storage facilities where the atmosphere, temperature and humidity are carefully controlled to retard the rate of respiration and ripening of the apples, thus extending the storage life of the fresh fruit. Controlled atmosphere storage of apples is described at:
* <nowiki>http://www.omafra.gov.on.ca/english/crops/facts/12-045.htm</nowiki>
Apples can be processed in various ways. A large proportion of processing apples is converted to '''apple juice'''. The type of apple juice preferred by consumers in Western Canada is the clear apple juice. Apple juice can be used as the starting material for the production of '''apple cider'''. In making cider, apple juice is inoculated with specific ''yeast'' strains which ferment sugar in the juice into ethanol and produce flavours characteristic of apple cider. Apple cider can be further processed by inoculating it with a ''bacterial'' culture that will oxidize the ethanol to acetic acid to produce '''apple vinegar'''.

The apple solids remaining after juice extraction can be used as a feed material for the production of '''pectin''' (a carbohydrate used as gelling agent in the production of jams and jellies), animal feed, or as organic matter that can be returned to agricultural lands. In some cases, the residue may also be trucked to landfill sites which adds to the waste burden entering those sites.

Apples are also processed into '''apple sauce''' and pie fillings. A greater proportion of these products are used as ingredients in the bakery and food service industries than as items in retail stores.

To a lesser extent, apples are used to produce '''dehydrated apple slices, fruit leather, apple-filled snack bars''' and as '''ingredients''' for some confectionary products and breakfast cereals.
{| class="wikitable"
|
|-
|'''Figure 1.2''' Apple production and processing
|}
{| class="wikitable"
| '''Want to learn more?'''
|-
|
* Identify a food that you enjoy. How do you think a food scientist/technologist would be involved in the production, processing and marketing of that food product?
|}

== 01.6 Trends in Food Consumption in Canada ==

Overall, many changes have occurred in food consumption patterns in Canada in the past few decades, and they continue to change as consumer demands and perceptions change. The advent of new processing technologies have brought new products on the market and this will continue. Consumer perception of those products will determine whether they succeed or fail. Undoubtedly, advertising campaigns for various food products and controversies about the health effects of various food commodities (butter vs margarine; sugar vs non-caloric or low caloric sweeteners; fats vs fat substitutes; trans-fat free products; processed vs unprocessed foods) will continue to influence consumer food buying habits.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Read the article in the link below and comment on the following points using your own experience in Canada.
<nowiki>http://www.ift.org/food-technology/past-issues/2019/april/features/2019-top-10-food-trends.aspx</nowiki>
* Insert paragraph
** Cannabis/CBD oil-infused drinks
** Cannabis/CBD oil-infused food
** Zero-waste cooking
** Globally inspired breakfast dishes
** Global flavors in kid’s meals
** Hyper-local
** New cuts of meat
** Veggie-centric/vegetable-forward cuisine
** Chef-driven fast-casual concepts
** Craft/artisan/locally produced spirits
|}
{| class="wikitable"
| '''Critical Thinking'''
|-
|
* Look at the most recent '''food consumption data (2014-2018)''' in the Statistics Canada website: <nowiki>http://www5.statcan.gc.ca/cansim/a26?lang=eng&retrLang=eng&id=0020011&tabMode=dataTable&srchLan=-1&p1=-1&p2=35#customizeTab</nowiki>
* Within each food category, which products have ''increased'' in consumption and which ones have ''decreased''? Can you identify what are the main reasons for these changes in consumption patterns?
** Meat
** Poultry and Eggs
** Fish
** Dairy
** Fruit and Vegetables
** Edible oils
** Beverages
* Review the highlights for 2017 and note any interesting finding: <nowiki>https://www150.statcan.gc.ca/n1/daily-quotidien/180530/dq180530c-eng.htm</nowiki> (Links to an external site.)
|}

== 01.7 Summary of Lesson 1 ==
* Food science studies the production, processing, preparing, evaluating and use of food.
* Technological advancements have led to many "food science discoveries"
* Canada offers a vast and diverse food system
* The Canadian food industry has a strong impact on Canada's economy
* Consumers and consumer demands have a strong influence on the food consumption trends

=== Closing thoughts ===
In conclusion, the food industry in Canada is a large industry that provides employment for a substantial part of the workforce in Canada. The variety of food products available in grocery stores or through food service outlets is immense and is likely to grow in response to consumer demands and changes in demographics, health, animal welfare and environmental concerns.

At this point it is important to recognize that while the amount and variety of foods consumed in Canada are increasing, many people in other parts of our world are unable to even secure enough nutritious food to maintain a healthy lifestyle. It has been estimated that about 3/4 of the world population live in lesser developed countries which are found mainly in Africa, Asia and South and Central America. Most of the inhabitants of these countries cannot get enough nutritious food to eat each day. Nutrients in short supply include fat, protein, vitamins, minerals and clean, safe drinking water. It is important to keep that thought in mind as you proceed through the course.

== References ==
* Murano, P.S. (2003). Introduction to Food Science and Technology. ''Understanding Food Science and Technology'' (Chapter 1). Belmont, California: Thompson Wadsworth.
* Potter, N. N. & Hotchkiss,J. H. (1998). Characteristics of the Food Industry. ''Food Science'' (5th ed.) (Chapter 2). Gaithersburg, Maryland: Aspen Publishers, Inc.
* Potter, N. N. & Hotchkiss,J. H. (1998). Vegetables and Fruits. ''Food Science'' (5th ed.) (Chapter 18 & pp.432-434). Gaithersburg, Maryland: Aspen Publishers, Inc.
* Food Available in Canada. Statistics Canada.<nowiki>https://www150.statcan.gc.ca/t1/tbl1/en/tv.action?pid=3210005401&pickMembers%5B0%5D=1.1&pickMembers%5B1%5D=3.1</nowiki> (Links to an external site.) (Links to an external site.)
* Food Technology Magazine Editors Share Top 10 Food Trend Predictions for 2019. <nowiki>http://www.ift.org/food-technology/past-issues/2019/april/features/2019-top-10-food-trends.aspx</nowiki>

'''Authorship:'''

FNH 200 Course content on this wiki page and associated lesson pages was originally authored by Drs. [http://www.landfood.ubc.ca/person/brent-skura/ Brent Skura], [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], and [http://www.landfood.ubc.ca/person/eunice-li-chan/ Eunice Li-Chan]. Ongoing edits and updates are contributed by past and current instructors including Drs. [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], [http://www.landfood.ubc.ca/person/azita-madadi-noei/ Azita Madadi-Noei], [http://www.landfood.ubc.ca/person/nooshin-alizadeh-pasdar/ Nooshin Alizadeh-Pasdar], and [http://www.landfood.ubc.ca/person/judy-chan/ Judy Chan].

{{cc-by-nc-sa-3.0}}

<quiz display=simple>
{1. Physical locations where a consumer may purchase and enjoy carrots:
|type="()"}
- Farmer's Market.
- Grocery Stores.
- Food Services Establishments.
+ All of the above.
</quiz>

<quiz display=simple>
{2. When are apples in BC being harvested?:
|type="()"}
- April.
- July.
+ Ocotober.
- December.
</quiz>

<quiz display=simple>
{3. What percentage of the atmosphere is oxygen?:
|type="()"}
- 0.3%
- 3%
+ 21%
- 78%
- 94%
</quiz>

<quiz display=simple>
{4. What changes occurred in the USA due to the publication of a book in 1906 about the meatpacking industry?:
|type="()"}
- The start of the vegetarian movement in the US.
+ Congress passed the meat inspection act and the food and drugs act of 1906.
- Inspectors were fired and taken out of the meatpacking plants.
- Establishment of the US Department of Agriculture.
</quiz>

<quiz display=simple>
{5. A food scientist discovers new information about food through research.
|type="()"}
+ TRUE.
- FALSE.
</quiz>

Course:FNH200/Lessons/Lesson 12

2020-06-24T00:42:13Z

YihangChen: /* 12.3 Types of Toxicants */

<big><big><big>'''Toxicants in Food and Foodborne Disease'''</big></big></big>

== 12.0 Overview ==
Foodborne disease affects a substantial portion of the Canadian population each year. The causes of food borne disease (etiolgy) includes agents with microbiological, parasitic, plant, animal and chemical origins.

In this lesson, we explore some examples of toxicants in foods, including naturally occurring constituents, naturally occurring contaminants and environmental contaminants. In order to understand the significance of toxicant presence and the regulations pertaining to them, the concepts of risk/benefit analysis toxicity, hazard, and acceptable daily intakes are discussed.

We also examine the relevant statistics to determine the major causes of foodborne disease and to gain an insight into factors that lead to foodborne disease outbreaks. We will also learn about safe food handling and preparation practices.

=== Objectives ===
After completing this lesson, you should be able to:
* define toxicity, hazard and risk, in the context of toxicants in our food supply
* explain the importance of considering the dose-response relationship
* outline the process for risk assessment in regard to food safety risks
* list and describe examples of naturally occurring (constituent or contaminant) and environmental toxicants in the food supply
* assess your risk of food intoxication by each of these toxicants and ways to minimize this risk
* explain the relative importance of various factors as contributors to the incidence of food borne disease in Canada;
* gain some insight into the major foodborne disease causing microorganims, in terms of conditions and foods implicated in outbreaks, and means of preventing their growth or toxin production in foods
* assess the potential risk of contracting food borne disease and describe safe food handling practices to minimize this risk at home

=== Optional Reading ===
* Murphy, P. A., Hendrich, S. and Landgre, C. 2006.Understanding Mycotoxins. IFT Scientific Summary
* http://www.ift.org/Knowledge-Center/Read-IFT-Publications/Science-Reports/Scientific-Status-Summaries/Editorial/Understanding-Mycotoxins.aspx
* Murphy, P. A., Hendrich, S., Landgre, C. and Bryant, C. 2006. Food Mycotoxins. An update. IFT Scientific Summary
* http://www.ift.org/~/media/Knowledge%20Center/Science%20Reports/Scientific%20Status%20Summaries/mycotoxins_0606.pdf

=== Recommended websites ===
* The Kidney Foundation of Canada B.C. branch: ''E. coli'' bacteria: What You need to Know
* Canadian Food Inspection Agency Food Facts. "Causes of Foodborne Illness". http://www.inspection.gc.ca/english/fssa/concen/causee.shtml

== 12.1 What are Toxicants? ==
{| class="wikitable"
|
==== '''Terms to remember''' ====
|-
|
* Toxicants
* Toxicity
* Hazard
* Risk
* Cholinesterase inhibitors & solanine
* Cyanogenic glycosides & amygdalin
* Mycotoxins & aflatoxins
* Histamine & "scombroid poisoning"
* Saxitoxin and "paralytic shellfish poisoning"
* Domoic acid & "amnesic shellfish poisoning'
* Tetrodotoxin & "puffer fish poisoning"
* Food infection, food intoxication
* Incident & Outbreak
* Pathogens: ''Escherichia coli'' O157:H7'', Clostridium botulinum, Salmonella, Listeria monocytogenes''
* Temperature danger Zone (TDZ)
* HACCP
|}
In earlier lessons, we discussed the chemical nature of foods. The chemical constituents together are responsible for the structure, texture or consistency, colour, flavour, smell and nutritional value of a food. Food may also contain other chemical entities which are less useful to us or might even pose a health risk to us. These chemicals often have a very important role in the metabolism or function of the plant or animal tissues which make up our food. It must be remembered that while we consume various plants and animal products, their structure and composition is not primarily to serve as human food, but to exist as growing and living biological entities. Some potentially harmful chemicals in these plant and animal products are said to be environmental toxicants or even contaminants. They are not normally part of the chemical mix of food for humans, but by various means have found their way into our food supply.

In order to appreciate better the role of toxicants in the safety of our food supply, it is necessary to discuss a number of concepts and define some of the terms.
* '''Toxicant''' - a poison or a poisonous agent.
** The term toxicant is derived from the Latin toxicum (meaning "poison") and the Greek toxikon ("arrow poison"). The term toxic conveys the meaning that something is harmful, destructive or deadly.
** Poisons are chemicals that, in very small quantities, produce illness or death. Legally, a '''poison''' is defined as a chemical that has a lethal dose of 50 milligrams or less of chemical per kilogram of body weight.
** Fifty mg/kg is equal to approximately three-fourths of a teaspoon for an average adult and about one-eighth of a teaspoon for an average two-year-old child (Reference: M.A. Ottoboni. 1997.The Dose Makes the Poison: A Plain Language Guide to Toxicology. 2nd edition. NewYork: Wiley)
** When we refer to toxicants in food, we are generally referring to substances responsible for a ''whole spectrum'' of possible results, ranging from relatively minor discomfort or sickness to poisoning that can lead to death.
* '''Toxicity''' - the intrinsic or ''inherent capacity'' of a substance to damage a biological system (produce injury) when tested by itself.
** Substances vary in their toxicity, as reflected in their dose-response curves.
** A toxicant can have an effect on several different functions within an individual. The individuals can vary among themselves with regard to the sensitivity of their different functions.
* '''Hazard''' - A thing or action that can cause adverse health effects in animals (including fish), plants or humans. The capacity to produce injury ''under the circumstances of exposure.''
** Hazard is a much more complex concept than toxicity because it includes a consideration of conditions of use; in other words, two components are involved in assessing a hazard:
*** 1. the inherent capacity to cause harm (toxicity), and
*** 2. the ease or probability of contact between the substance and the target object.
** These two components together describe the chance or probability that a substance will do harm. Dr. Ottoboni (cited below) provides two examples to make this clear.
''"An extremely toxic chemical, such as '''[https://emergency.cdc.gov/agent/strychnine/basics/facts.asp strychnine]''', when sealed in an unopenable vial, can be handled freely by people with no chance that a poisoning will occur. Its toxicity has not changed, but it presents no hazard because no contact can be established between the chemical and people. Conversely, a chemical that is not highly toxic, such as boric acid, can be very hazardous when used in a manner that makes it readily available for accidental ingestion." Dr. Ottoboni''

'''Risk''' - a function of the probability of an adverse health effect and the magnitude of that effect, consequential to a hazard; the likelihood of the occurrence and the magnitude of the consequences of an adverse event.

== 12.2 Dose Response and Risk Analysis ==
''"'''All substances are poisons; there is none which is not a poison. The right dose differentiates a poison and a remedy'''"'' is a statement attributed to the 16th-century Swiss physician Paracelsus, leading to the basis of toxicology as we now know it. (Winter and Francis, 1997. Food Technol., 51:85).

In other words, every chemical and, more specifically in the context of this lesson, every toxicant has some set of exposure conditions in which it is toxic. Conversely, every chemical has some set of exposure conditions in which it is nontoxic.

This can be described by the generalized '''dose-response curve''' shown in Figure 12.1.[[File:FNH_200_Lesson_12_DoseResponse.gif|frame|400px|'''Figure 12.1''' A generalized dose-response curve.|center]]The dose at which a substance begins to have an undesirable effect, that is, the upper limit of its "no effect" dose, is its '''threshold'''. This value is unique for each substance.

Furthermore, the '''slope''' or steepness of the increasing dose-increasing effect portion of the curve is also characteristic of the particular substance. A chemical with a very steep '''dose-response''' curve offers very little flexibility in trying to avoid a harmful exposure. A one- or two-fold difference in the amount of chemical consumed might be the difference between no-effect and serious consequences.

Both toxicity (capacity for injury as indicated by the threshold and dose-response curve) and hazard (toxicity under the conditions of exposure) are important in evaluating risks of toxicants in food. When considering toxicants we are in fact identifying a risk associated with eating. However, toxicants are only one such risk. To counter the risks are all the benefits associated with food consumption, such as provision of nutrients, pleasurable sensations, and so forth. We must weigh the risks and benefits associated with any activity, including eating food and make our decisions accordingly.

Review what we learned in Lesson 4 regarding the concepts of '''ADI, PDI,''' the '''"no-effect level"''' and the '''safety factor''', as applied to the assessment of food additives. Similar considerations are involved in the assessment of the relative danger or safety of toxicants in our food supply.

The use of a safety factor is necessitated by our inability to account for all possible differences between human and animal, and among different humans, with absolute certainty. It should be pointed out, that proper toxicological evaluation of a chemical, attempts are made to take into consideration factors such as species differences and the influence of age, gender and environment of the animals used.

== 12.3 Types of Toxicants ==
Food toxicants can be classified in a variety of ways. The scheme in Table 12.1 is based on origin or occurrence of the toxicants, namely as naturally occurring toxicants (either constituents or contaminants), or environmental toxicants.

Table 12.1.Classification of some possible food toxicants
{| class="wikitable"
!Naturally Occurring Toxicants:

''Constituents''
!Naturally Occurring Toxicants:

''Contaminants''
!Environmental Toxicants
|-
|'''Cholinesterase inhibitors:'''
* solanine in potatoes
'''Cyanogenic glycosides:'''
* amygdalin in apple seeds
'''Glucosinates:'''
* Sinigrin in cabbage
'''Protease inhibitors:'''
* protease inhibitors in soy beans
'''Nitrites:'''
* Green leafy plants
'''Allergens:'''
* beta-lactoglobulin in milk, peanut proteins, soy proteins
|'''Mycotoxins:'''
* Aflatoxin
* Patulin
* Ochratoxin A
* Vomitoxin
* Zearalenone
Examples: aflatoxin in mouldy peanuts, vomitoxin in wheat

'''Bacterial toxins:'''
* ''botulinum'' toxin
* Staphylococcal toxin
'''Seafood Toxins:'''
* Histamine
* Saxitoxin
* Domoic acid
* Tetrodotoxin
|'''Food packaging residues:'''
* Monomers of plastic resins
'''Pesticide residues:'''
* Herbicides
* Insecticides
* Fungicides
Example: malathion residues on fruit

'''Heavy metals:'''
* Lead
* Mercury
* Cadmium
Examples: lead in vegetables; mercury in large ocean fish (eg. swordfish)

'''Animal drugs:'''
* Antibiotics
* Hormones
Examples: penicillin in milk

'''Radioisotopes:'''
* from soil or
* from radioactive fallout
|}

== 12.4 Natural Constituents and Natural Contaminants ==

=== What is the basis for distinction between ''Natural Constituents'' and ''Natural Contaminants''? ===
'''Constituents''' are chemical entities that are part of the normal composition of a food material - they are not the result of some external organism or activity. '''Contaminants''', on the other hand, are present because of the presence of moulds or bacteria, or because the plant or animal was grown in a condition which permitted the toxicant to become part of the food.

The distinction between '''natural''' and '''environmental''' toxicants is a little bit less clear cut, but may be generally determined by their origin. For example, we might be able to prevent the growth of moulds, but moulds are nevertheless naturally present in the environment. Pesticides, however, are introduced into the environment by us and while not intended to become part of the food, some do to a certain extent. Mercury and lead can enter the food supply because of heavy natural deposits in the soil, but in fact are found in food predominantly because we use these metals in a wide variety of ways.

It is difficult to be definitive about the relative importance of these different food toxicants to human health. Much of what has been written on this subject can be summarized by the information in Table 12.2.[[File:FNH200_Lesson12_Perceptions.jpg|thumb|500px|'''Table 12.2''' Perceptions of hazards in the food supply held by popular belief compared to regulatory agencies.|center]]
This table attempts to illustrate the ''perceived'' importance of hazards in food. It is interesting to note that what is perceived by popular opinion to be the greatest hazard is in fact considered to be the least important by regulatory agencies, and vice-versa! Regulatory agencies base their ratings on a much broader information base (including statistical or epidemiological evidence) than does the general public.

An extensive discussion of each of the toxicants identified in Table 12.1 is not possible. Several will be discussed in some detail below, followed by a brief comment on the remaining ones.

== 12.5 Examples of Natural Constituents as Toxicants ==

=== Glycoalkaloid-Cholinesterase Inhibitors ===
* The name "cholinesterase inhibitors" refers to a variety of chemicals which are able to inhibit the activity of the enzyme '''cholinesterase'''. This enzyme is found in nerve tissues and plays an important role in the transmission of nerve impulses. When its function is inhibited, nerve function is affected.
* '''Solanine''' is an example of such inhibitors. Solanine can is found in potatoes, normally at levels of 2-13 mg/100 g fresh weight,
** the bulk of market potatoes probably contain only 3-6 mg/100 g.
** Levels as high as 80-100 mg/100 g, have been reported particularly if the potatoes have undergone '''''greening''''' (reaction of potato tubers on exposure to sunlight).
** Solanine is insoluble in water and is not lost or destroyed when potatoes are cooked. Because it is found primarily in the skin of potatoes, the peeling of potatoes reduces the concentration markedly.
Clinical symptoms of solanine poisoning: gastrointestinal disturbances and certain neurological disorders. Solanine poisoning can result in death. However, ingested solanine is less likely to cause toxic symptoms than an injected dose because it is not readily absorbed and is fairly rapidly excreted by way of the feces and the urine. Humans display drowsiness, increased sensory sensitivity, and difficulty in breathing after an oral dose of 100 mg (approximately 2-8 mg/kg body weight). Higher doses may cause vomiting and diarrhea.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* To emphasize the potential problem which this toxicant poses, it is of interest to relate a well-documented case of poisoning:
* The Canadian Disease Weekly Reports 10-18 (1984) indicated that 61 of 109 individuals (students and staff) consuming baked potatoes with margarine, as part of a school lunch program in Alberta, experienced a sudden onset of nausea, vomiting, cramps, fever, and diarrhea. Just over one-half were affected within five minutes of eating. About 40% noticed a bitter taste and 18% noticed a burning sensation in their throat while eating. Most of them recovered within three hours. Investigation of this incident revealed that the potatoes had a green tinge and in fact were found to contain 494 ppm solanine (49.4 mg/100 g).
|}
* Although the chemical solanine itself is quite a '''potent toxicant''', the '''hazard''' of solanine poisoning by consumption of potatoes is quite low.
* Potato growing and handling practices minimize the opportunity for greening, and hence minimize the production of abnormally high levels of solanine.
* Seed potatoes which are genetically low in solanine content are used, and during the growing season the potato plants are hilled, thereby decreasing exposure of the potato to light.
* After harvesting, potatoes are put into storage facilities which minimize exposure to light.
* Consumers who ignore the hazards of consuming potatoes that have '''turned green''' during improper storage at home would face a '''high risk''' of poisoning by solanine!
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Review the information provided in the following link and explore what other foods may have glycoalkaloid with cholinesterase inhibition activity.
* http://www.hc-sc.gc.ca/fn-an/pubs/securit/2010-glycoalkaloids-glycoalcaloides/index-eng.php
* [https://www.canada.ca/en/health-canada/services/food-nutrition/reports-publications/food-safety/glycoalkaloids-foods.html http://www.hc-sc.gc.ca/fn-an/pubs/securit/2010-glycoalkaloids-glycoalcaloides/index-eng.php]What can be done to minimize the exposure to this compound
|}

=== Cyanogenic Glycosides ===
* Cyanogenic glycosides yield '''hydrogen cyanide''' (HCN) upon treatment with acid or particular hydrolytic enzymes.
** They are found widely in higher plants, and also occur in ferns, moths and insects. Among the plants used as food which contain one or more of these toxicants are: cassava, sweet potato, yam, maize, bamboo, sugar cane, peas, lima beans, almonds, lime, apple, pear, cherry, apricot and plum.
* Cyanide is very rapidly absorbed from the gastrointestinal tract and produces recognizable symptoms at both fatal and non-fatal levels.
*
With fatal doses of HCN, death results from the general anoxic condition caused by the inhibition of cytochrome oxidase, with which the HCN complexes. Cytochrome oxidase is an important component of the oxidative phosphorylation cycle which occurs in the mitochondria of cells. Inhibition of the enzyme system causes the death of the cells.

Since the HCN binds reversibly to the cytochrome oxidase, non-fatal doses permit recovery by means of respiratory exchange and metabolic detoxification processes.

For humans, the minimum lethal dose of HCN taken orally has been estimated to be between 0.5-3.5 mg/kg of body weight. It is obvious from the data in Table 12.3 that consumption of 100 g of bitter almonds by a 70 kg man could produce a dose of 3.57 mg/kg of body weight, a fatal dose even for the least sensitive individual.
* '''Amygdalin''' is an example of a cyanogenic glycoside. It is found in bitter almonds and a number of fruit pits.
* Amygdalin, having a carbohydrate component ("glycoside") and '''hydrogen cyanide''' is hydrolyzed to form HCN, glucose and benzaldehyde ( Figure 12.2).
{| class="wikitable"
|}

[[File:L12 figure12。2.png|thumb|Figure 12.2 The structure of amygdalin and its hydrolysis products. Adapted from: Liener, I.E. (ed.) 1980. Toxic constituents of plant foodstuffs. New York: Academic Press.|center|620x620px]]
The enzymes responsible for the hydrolysis of cyanogenic glycosides are generically called '''ß-glycosidases'''. They are highly specific for the ß-glycosidic linkage that is characteristic of the cyanogenic glycosides.

These plant enzymes differ from the a-glycosidases (amylases) of the mammalian digestive tract that hydrolyze only a-glycosidic bonds such as those found in starch.
* Hydrolysis of cyanogenic glycosides can occur during the cutting, crushing, bruising or maceration of tissue prior to consumption, or can be initiated upon the maceration of the tissue during eating.
* Cyanide poisoning can therefore occur when enough of a plant material that is rich in cyanogenic glycosides and enzymes is consumed, or when such a material has been prepared with insufficient care to remove the HCN accumulated during preparation.
The scientific literature records numerous incidents of accidental poisonings by bitter almonds, cassava, and lima beans. Table 12.3 gives some indication of the amount of cyanide that may be produced from various plant foodstuffs.

'''Table 12.3''' Data showing the potential yield of cyanide in some plant foodstuffs. Adapted from: Liener, I.E. (ed.). 1980. Toxic constituents of plant foodstuffs. New York: Academic Press.
{| class="wikitable"
!Plant
!HCN Yield
(mg/100 g material)
|-
|Bitter almonds
|250
|-
|Bitter cassava root
|53
|-
|Bitter cassava root cortex (dried)
|245
|-
|Lima bean, American white
|10
|-
|Lima bean, Java coloured
|312
|}
* In parts of the world where some of these cyanide producing plants are used extensively for food, means of preparation have been developed to remove or hydrolyze the glycosides and to destroy the ß-glucosidase that is present. While these steps '''minimize the hazard''', they do not completely eliminate it.
It is important, however, that while the cyanide-producing capacity of a plant is important in determining its toxicity, there are other factors which must also be considered. These factors include the size and kind of subject, the speed of ingestion, the type of food ingested simultaneously with the cyanogen, the presence of active degradative enzymes both in the plant and in the subject's digestive tract, and the subject's ability to detoxify the HCN.

The hazard associated with the presence of cyanogenic glycosides in food for those individuals who consume '''large quantities''' of the affected plant foodstuff, is much more significant than those who accidentally eat the occasional apple seed or apricot kernel.

==== '''Other Natural Toxicants''' ====
There are a number of other natural toxicants listed in Table 12.1 for which only a very brief comment will be made in this course.

===== '''Protease inhibitors''' =====
* Proteinaceous compounds found in many of the legume species.
* have the ability to complex to, and thereby interfere with, certain proteolytic enzymes.
* Proteins need to be hydrolyzed into their constituent amino acids by digestive enzymes such as trypsin and chymotrypsin. If these enzymes are rendered inactive by complexing inhibitors, the body cannot fully hydrolyze the proteins, thereby creating the possibility of amino acid deficiencies.

===== '''Nitrates''' =====
* Widely found ''constituents'' of plant materials, especially green leafy plants.
* Nitrates themselves are not very toxic; however, bacteria can reduce them to '''nitrites'''.
* A primary concern about nitrites is their ability to interact chemically with hemoglobin, interfering with the blood's ability to transport the required oxygen to the body's cells. By a rather complex series of reactions, not only bacteria but also metabolic pathways within the digestive system of humans can utilize nitrate/nitrite as a precursor for the formation of '''nitrosamines''', potent carcinogens.

===== '''Allergens''' =====
* Have the ability to induce ''allergic reactions'' in sensitive individuals. Foods that are most frequently reported to cause allergic responses are: cereals such as wheat, rye and rice; legumes such as peas, peanuts and soybeans; tree nuts; milk; eggs; and seafoods such as shrimp, crab and lobster.
* The case of allergens provides a good example of the need to consider individual (genetic) differences in '''assessing risk and hazards'''. For most of us, consumption of the foods listed above does not pose any significant risk. However, for someone who is severely allergic to a particular food or food component, accidental ingestion may lead to a life-or-death situation!

== 12.6 Examples of Natural Contaminant as Toxicants ==

=== Mycotoxins ===
Mycotoxins are substances produced by moulds, which may be toxic. Mycotoxins may occur by direct contamination (due to mould growth on the food) or by indirect contamination (by using a food ingredient that was contaminated). Mycotoxins can be highly toxic to the body, some have been known to cause cancer in animal tests, others are mutagenic and able to cause mutation, and others are teratogenic and capable of causing deformities in embryos. Mycotoxins are '''invisible to the eye''', are often '''unchanged by heat''' and can potentially spread throughout a product. As a result, any sign of visible mould could indicate that the product contains mycotoxins and should be thrown away.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* '''READ:''' Understanding Mycotoxin and Mycotoxins in Food; An Update.
* The article provides an excellent overview of the various mycotoxins that might contaminate foods as well as the known pathological effects. It should make you aware that proper handling of foods, which minimizes the occurrence of mycotoxins, is extremely important.
|}
Of the many known mycotoxins (aflatoxins, sterigmatocystin, ochratoxin A, citrinin and patulin), the '''aflatoxins''' are of greatest concern because they are potent liver toxins in all animals in which they have been tested and carcinogens in some species. The different aflatoxins (B1, B2, G1, G2, M1and M2) may be found in various commodities including peanuts, corn, wheat, rice, cottonseed, copra, nuts, milk, eggs, and cheese.

One additional comment needs to be made in connection with the regulation of mycotoxins. Aflatoxins are not directly regulated in The Food and Drugs Act. In Canada, this has caused some problems in the past. A challenge of the contention that aflatoxin was injurious to human health caused a court to dismiss a charge of selling contaminated peanut butter that contained greater than 20 ppb of aflatoxin. To get around that problem, the act and regulations were changed to state that '''peanut butter''' would be considered '''contaminated''', and therefore not fit for sale, if it contained aflatoxins in excess of '''15 ppb'''.

Generally, any food which contains mould should be thrown out however because the risk of mycotoxins is fairly low in some instances, the benefit of saving the product may outweigh the potential risks involved.

==== The following should be considered when we encounter a mouldy food: ====
* Was the food refrigerated? Did the mould grow on the product while it was refrigerated? If it has, it is likely that the product does not contain aflatoxins (these are not normally produced under refrigerated conditions).
* The amount of mould on the product should also be considered, for example, if there is a tiny green mould colony on a large block of cheese, the benefits of cutting that portion off (about 2.5 cm around and beneath the cheese) are much greater than the risks involved, especially relative to the benefits of trimming extensive mould growth on a tiny piece of cheese.
* The type of food the mould is growing on should also be considered; “trimming” mould should not be done on soft, semi-solid, or liquid foods, or foods likes jams/jellies and baked products. In these products, the ability for the mould toxins to spread (via the mould mycelia) are much greater. In these cases, the risks outweigh the benefits of saving the product.
* To ensure that mould growth does not occur at home, consumers can try to prevent mould growth by minimizing contact of food with air as well as package (wrap) and refrigerate products appropriately.
{| class="wikitable"
|'''Critical Thinking'''
|-
|
* Potential toxicants in your kitchen!
* After reading the above section, consider what you would decide to do in each of the following situations for food that was stored in your home refrigerator:
** green mould colonies appearing on the surface of Cheddar cheese
** blue mould streaks in the interior of Roquefort cheese
** white mould growing on the surface of a previously opened jar of strawberry jam

* Would you eat these foods, or throw them out?
*
|}

=== Bacterial Toxins ===
The two most important bacterial toxins are those produced by ''Clostridium botulinum'' and ''Staphylococcus aureus'', which are ubiquitous microorganisms in our environment. Food poisoning caused by these two types of bacteria can be considered as due to food intoxications, because it is the chemical toxin produced by the bacteria, as opposed to the bacteria themselves (in the case of foodborne infections), that produces the toxicity. The toxins can produce illness even if the bacteria producing them have been killed. We will explore these in further detail later in this lesson (under "foodborne diseases").

Check out the recent Health Hazard Alerts regarding possible ''Clostridium botulinum'' contamination.

<nowiki>http://www.inspection.gc.ca/about-the-cfia/newsroom/food-recall-warnings/complete-listing/2019-03-15/eng/1552702897100/1552702899415</nowiki>

=== Seafood Toxins ===
Most of the natural toxicants that we encounter in our food supply are in products of plant origin. Animal tissues are much less frequently contaminated with natural toxicants. Part of the reason for this might be the fact that animals are very similar in their make-up and metabolism to humans. Animals would react similarly to toxins in their environment as humans and consequently we are not confronted with animal tissues that are from diseased or poisoned animals. For this reason, while it is a somewhat broad generalization, most natural toxicants in foods categorized as animal origin are found in seafoods rather than other animal products, and in fact, in many of these cases, the source of the toxicants originate from marine algae or through the action of microorganisms.

There are many types of seafood toxins; here we will review some of the most common ones: Histamine, Saxitoxin, Domoic acid, and Tetrodotoxin.

==== ''Histamine'' ====
Poisoning is known to result from eating scombroid fishes, i.e. fish of the Scombrida and Scomberesocidae families, including tuna, bonito and mackerel. The poisoning results in nausea, vomiting, facial flushing, headache, epigastric pain, thirst, itching of the skin and hives. The effects usually subside within 12 hours but in some severe cases death has resulted.

'''Scombroid poisoning''' is due to an allergic-type reaction to high levels of histamine or a histamine-like substance. Histidine, a naturally occurring ''amino acid'' which is particularly high in scombroid fish, is converted to histamine by bacterial action on the dead flesh of the fish. Histamine has strong vaso-active properties and in sufficient quantities will cause blood pressure changes resulting in symptoms as indicated above. It should be noted that toxic amounts of histamine may be formed before the fish starts to smell or taste bad ("spoil"). Histamine formation is dependent on the holding time and temperature of the fish during transportation and storage.

It is also important to note that histamine and other vaso-active amines may be found in many fermented foods such as cheese, wine and pickled herring.

==== ''Saxitoxin'' ====
Saxitoxin and a group of 18-24 marine biotoxins derived from saxitoxin are thought to be responsible for the condition known as '''paralytic shellfish poisoning (PSP)'''. This condition is the result of consuming shellfish, such as mussels, oysters, and clams, containing the toxin. The toxins can also accumulate in the liver of crustaceans such as crabs and lobsters.

The toxin is ineffective against the shellfish, which are able to absorb the toxin, concentrate it in their tissues and pass it onto the species feeding on them (in this case, humans).

Symptoms of saxitoxin include: tingling in the mouth, lips and finger tips. Sight and hearing are modified in much the same way as caused by alcohol intoxication. Speech becomes incoherent.

Saxitoxin is a contaminant which the shellfish consume as part of their occasional food supply. The shellfish feed on a variety of microscopic plankton among which are certain toxic dinoflagellates. At certain times of the year, under certain conditions, these dinoflagellates increase greatly in number and concentration in the oceans. This is often referred to as a bloom or "'''red tide'''."[[File:FNH200 Lesson12 RedTide.JPG|thumb|400px|'''Figure A'''. At certain times of the year, some species of dinoflagellates will increase in astronomical numbers. This phenomenon is referred to as a bloom or "red tide".|center]]During periods of bloom or red tide, the shellfish are exposed to and concentrate large amounts of saxitoxin. Saxitoxin is extremely stable and takes a long time to be flushed from the tissues of the shellfish. It is for this reason that during red tide season and for a considerable time afterwards, harvesting of shellfish is prohibited.

Saxitoxin is considered one of the potent toxins, the minimum lethal dose being about 1.0-4.0 mg/kg of body weight. However, because of the variability in the concentration of toxin in the shellfish, it is very difficult to indicate a maximum amount of shellfish tissue that can be consumed. This is obviously a situation which is not at all hazardous to anyone who rarely harvests and consumes shellfish. However the hazard increases significantly, for those who are uninformed and are fond of shellfish, particularly those harvested in areas known to be subject to red tide situations.

==== ''Domoic Acid'' ====
Domoic acid is ''(''an analog of the amino acid ''glutamic acid''), is found in some marine algae (dinoflagellate ''Nitschia''), which can accumulate in filter feeding shellfish such as clams, mussels, scallops and oysters. Consumption of shellfish with this naturally occurring marine biotoxin can lead to '''amnesic shellfish poisoning (ASP)'''.

Domoic acid, a neurotoxin, is capable of causing lesions in the central nervous system. It was first discovered in 1987 in Canada, when an outbreak occurred in individuals consuming mussels in Prince Edward Island. Of 107 individuals who were affected, four died. Most experienced gastroenteritis, and many older persons, or others with underlying chronic illnesses, developed neurological symptoms including memory loss. In this case, enough toxin was absorbed through the gastrointestinal system to cause the effects. The most severely affected cases still had significant memory loss five years after the incident.

Routine testing for the toxin is conducted, and areas in which the toxin occurs in the shellfish are closed to harvesting. Thus, the risk of amnesic shellfish poisoning is high only for individuals who choose to ignore signs indicating closure of areas to shellfish harvesting.

If you regularly harvest your own shell fish for consumption, remember to check for both PSP (and other marine toxins) and '''Sanitary Contamination Closures''' at this '''Fisheries and Oceans Canada'''website - [http://www.pac.dfo-mpo.gc.ca/fm-gp/contamination/index-eng.html Shellfish Contamination Closures - Pacific Region] (Links to an external site.)

http://www.pac.dfo-mpo.gc.ca/fm-gp/contamination/biotox/index-eng.html (Links to an external site.)

==== ''Tetrodotoxin'' ====
This toxin is the chemical of interest in '''puffer-fish''' or '''fugu poisoning'''. In Asian countries this hazard has been known for thousands of years. Although pufferfish have been known to be poisonous, many deaths still occur from eating these fish. Tetrodotoxin is found mainly in the ovaries, liver, intestine, skin and spawn of the various species of pufferfish. Although tetrodotoxin (TTX) was discovered in these fish, it is thought to be synthesized by a bacterial species such as '''''Pseudoalteromonas tetraodonis''''' associated with the puffer fish.

The meat of these fish species is considered a delicacy by the Japanese and Chinese, and the choice edible species are those that are most poisonous. The amount of poison in the fish is lowest in the summer months and increases during winter, with a peak just before spawning, in the spring. 

[[File:L12.fig12putterfish.gif|thumb|Figure B. Examples of pufferfish that can cause 'fugu poisoning' (tetradotoxin).|center|500x500px]]
Symptoms of pufferfish poisoning usually begin with a tingling sensation of the fingers, toes, lips and tongue a few minutes after eating the fish. Nausea, vomiting, diarrhea and epigastric pain appears in some cases. As the poisoning progresses, reflexes of the pupil and cornea are lost and the patient increasingly experiences paralysis and respiratory distress. If the dose is sufficiently large, death will result, caused by respiratory paralysis. The mode of action of tetrodotoxin is considered to be essentially the same as saxitoxin. As with saxitoxin, a lethal dose for humans is thought to be about 1.0 - 4.0 mg/kg.

Preventive measures are almost entirely restricted to diligence during preparation of the fish. When gutting and cleaning the fish, care must be exercised so as not to contaminate the flesh with even the minutest amount of viscera, ovaries or spawn.

Pufferfish poisoning continues to be a problem in Japan, affecting '''30 -100 persons per year,''' and primarily as a result of home preparation and consumption, not from commercial sources of the pufferfish. Again we have an example of an extremely toxic chemical but one whose hazard is quite variable. Lovers of fugu are at considerable risk, while those who do not consume this food are at absolutely no risk.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* In 2004, researchers in Japan reported success in raising poisonless pufferfish through use of a special diet including mackerel. One of the researchers, Dr. Arakawa from Nagasaki University, was quoted as stating that "We believed that pufferfish acquire poison by eating poisonous bait, such as starfish and shellfish, rather than producing it themselves. So we fed them non-poisonous bait," (source: Mari Yamaguchi, Associated Press, [http://archive.boston.com/news/world/articles/2004/06/10/nontoxic_blowfish_developed_but_some_in_japan_wont_bite/ The Boston Globe].)
* From a different perspective, Canadian scientists have suggested the potential for using puffer fish poison to relieve pain in cancer patients for whom traditional methods such as morphine don’t work - yet another example that "the right dose differentiates a poison and a remedy"!
|}

== 12.7 Examples of Environmental Toxicants ==
Table 12.1 lists a rather wide range of environmental toxicants, but this list is not comprehensive. They include:
* products of industrial activity (e.g. mercury, lead, dioxins, polychlorinated biphenyls, radioisotopes)
* products of agricultural activity (e.g. pesticide and herbicide residues, antibiotic residues)
* products of food processing (e.g. packaging residues)
* naturally occurring environmental toxicants (e.g. mercury, radioisotopes)
You may have heard about the tragic news in 2005 of the death of 27 children in Manila (the Philippines), after eating deep-fried caramelized '''cassava''' sold by vendors as recess snacks to the children. More than 100 other children, as well as one of the two vendors, were admitted to hospitals, suffering from severe stomach pain, vomiting and diarrhea. Although early reports suspected ''cyanide'' poisoning from improperly cooked cassava, subsequent laboratory tests on the cassava snack samples as well as analysis of the patients indicated that contamination by carbamate pesticide was the likely cause of the poisoning.

''"Carbamate pesticide is commonly used in farms and households on Bohol, and may have already been in the environment."'' Source: The Vancouver Sun, March 10, 2005 and March 14, 2005.

Some environmental toxicants display their toxicity at concentrations many, many times greater than we are likely to find in food; others are toxic at concentrations not far removed from those found in foods. All of them are of concern because they inhabit the environment and hence can enter our food supply. But, more important, all of them are present in the environment because they have some property that makes them useful to us. As a consequence, we must examine all environmental toxicants from a risk/benefit perspective. The decision to continue to use them should be made because their benefit outweighs their risk. Their continuing presence in the environment may also happen to a time in the past when their benefit outweighed their risk, but that may no longer be the case; a current review of risk/benefit would be in order.

Due to time constraints, we will not explore the environmental toxicants in more detail in this course.

{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Using Your Knowledge Food Recalls and Allergy Alerts
* Browse through the Canadian Food Inspection Agency (CFIA) [https://www.inspection.gc.ca/about-the-cfia/newsroom/food-recall-warnings/eng/1299076382077/1299076493846 Food Recalls/Health Hazard or Allergy Alerts website,] to obtain some insight into food recalls and alerts about potential allergens or health hazards in the food that we purchase.
** Can you find examples of naturally occurring toxicants as constituents? as contaminants
** How about examples of environmental toxicants?
** What is the most common type of recall or alert?
|}

== 12.8 Foodborne Diseases ==
You may have suffered from a bout of foodborne disease or you may know of someone who has been a victim of foodborne disease. We often hear the term food poisoning but foodborne disease is the correct term.

According to the most recent estimate from the Public Health Agency of Canada the number of cases of Foodborne illness that occur in Canada is approximately [https://www.canada.ca/en/public-health/services/food-borne-illness-canada/yearly-food-borne-illness-estimates-canada.html#wb-cont 4 million cases each year.]

A foodborne illness is caused by eating food that has been contaminated in some way. Contamination can be from different causes (etiology): '''microbiological, parasitic, plant, animal, and chemical.'''
* '''Microbiological''' agents are responsible for the majority of foodborne disease outbreaks. The specific microbiological agents are discussed in forthcoming sections of this lesson.
* '''Parasitic''' agents refer to parasites such as ''Trichinella spiralis'', ''Anisakis'' ''simplex'', tapeworm, and so forth, that are acquired from consumption of infested foods:
** ''Trichinella spiralis'', associated with consumption of undercooked pork, contaminated water or produce.
** Anisakiasis caused by ''Anisakis simplex''. Anisakiasis is associated with eating raw fish (sushi, sashimi, lomi lomi, ceviche, sunomono, Dutch green herring, marinated fish and cold-smoked fish) or undercooked fish.
* Foodborne diseases arising from consumption of '''plants''' included consumption of amanita mushrooms, taro leaves, green potatoes, and toxic algae in spirulina (an algae) protein supplement tablets.
* Illness arising from '''poisonous animals''' usually occurred as a result of consumption of shellfish containing paralytic toxins.
* '''Chemicals''' in contaminated foods that cause foodborne disease have included tin in canned foods arising from corrosion inside the metal can, residues of cleaning and sanitizing agents in food, products of rancid fats in foods, and excesses of some ingredients such as monosodium glutamate.
Here are some terms that you need to be familiar with:
* An '''incident''' refers to the occurrence of foodborne illness
* An '''outbreak''' is an incident in which two or more people experience a similar illness after ingestion of the same food and where epidemiological evidence implicates the food as the source of the illness.
* A single '''case''' is a person who has been ill following consumption of food considered to be contaminated on the basis of epidemiological evidence.
* An outbreak or single cases of '''unknown etiology''' refer to situations where epidemiological evidence implicates a common food source but where laboratory analysis fails to identify the etiological agent
Table 12.8 shows the number of cases reported in B.C. for certain types of microorganisms responsible for foodborne diseases.
{| class="wikitable"
! colspan="5" |Table 12.8. Number of reported cases in British Columbia
|-
|'''Microorganism'''
|'''2000'''
|'''2004'''
|'''2006'''
|'''2014'''
|-
|''E. coli'' O157:H7
|166
|193
|150
|56
|-
|''C. botulinum''
|4
|NA
|NA
|NA
|-
|''Salmonella''
|710
|707
|705
|1167
|-
|''Listeria monocytogenes''
|6
|10
|13
|19
|-
|Hepatitis A- Virus
|136
|76
|55
|25
|}
<nowiki>*</nowiki>All

''Source'': B.C. Centre for Disease Control. Annual Summary of reportable diseases. Enteric, Food and Waterborne diseases 2006. NA = Not available.

The numbers in Table 12.8 represent only the "tip of the iceberg" since epidemiological evidence suggests that '''only 1-4% of all foodborne disease outbreaks are actually reported and documented.'''

Some of the reasons why only some foodborne disease outbreaks are documented are:
* many people do not report to a physician when they suspect they are suffering from foodborne disease;
* actual cases of foodborne disease may be mistakenly diagnosed as having other sources (environmental, unknown sources);
* many people may attribute a mild case of foodborne illness as being due to the "24-hour flu," a "virus," "eating too much"'
* sometimes people report that they suspect they are suffering from foodborne illness but the physician does not report the case to local health units or, if reported, the case may not be sufficiently well researched and reported by health units to the provincial health authorities.
Most cases of foodborne illness are only recognized when at least two or more people become sick after eating a meal or food product in common ("outbreak"). Symptoms can arise hours or days following the consumption of the food. The CFIA reports that each year only about '''10,000 cases''' of foodborne illness are reported from which approximately 30 people die. The cost of salmonellosis has been estimated at '''$850 million''' per year in hospitalization costs and lost income. If one were to add the costs of foodborne disease caused by other organisms and other agents, the total costs become staggering (in excess of 1.3 billion dollars per year in Canada). Similar foodborne disease trends are reported yearly in the United States, the European Economic Community, Australia and other developed countries.

=== 12.8.1 Microorganisms and Foodborne Diseases ===
Table 12.9 shows examples of microorganisms that cause foodborne disease. Pathogenic microorganisms can take advantage of situations where safe food handling and storage practices are not followed.

'''Table 12.9.''' Examples of microorganisms responsible for foodborne diseases
{| class="wikitable"
!'''Microorganism responsible'''
!'''Foodborne disease'''
|-
|''E. coli'' O157H7
|''E. coli'' poisoning
|-
|Toxin produced by ''Clostridium perfringens''
|Clostridium food poisoning
|-
|Toxin produced by ''Clostridium botulinum''
|Botulism
|-
|''Salmonella''
|Salmonellosis
|-
|''Listeria monocytogenes''
|Listeriosis
|-
|''Staphylococcus aureus''
|Staph poisoning
|}
The following short descriptions of the microorganisms will provide you with an insight on the major foodborne disease-causing microorganisms, where they are found, conditions and foods implicated in outbreaks, and disease symptoms, as well as means of preventing their growth in foods.

For this course, you '''do not''' need to memorize all the details described here or in the readings. However, you should gain an understanding of how such detailed information about the different properties of pathogenic microorganisms can be used to provide '''''[https://www.canada.ca/en/public-health/services/food-borne-illness-canada/yearly-food-borne-illness-estimates-canada.html#wb-cont guidelines for food handling practices or preservation techniques]''''' to ensure better food safety and to decrease the incidence of foodborne illness.

As you read through the descriptions, try also to differentiate between those microorganisms which are responsible for foodborne illness through '''food intoxications''' versus those that do so through '''foodborne infections'''.
* In the case of foodborne intoxications, toxic substances are produced in the foods as by-products of the microorganisms prior to consumption, and cause the symptoms of foodborne illness upon ingestion.
* Foodborne infections result from the ingestion of viable microorganisms in the food at the time of consumption; these pathogenic microorganisms multiply and grow in the host, causing the symptoms of foodborne illness.

=== Food Intoxications: ===
{| class="wikitable"
!'''Organism'''
!'''Symptoms onset'''
!'''Common foods'''
!'''Prevention'''
|-
|'''''Clostridium botulinum'''''
|Botulinal toxins are among the '''most toxic substances''' known. Estimated LD50 for humans is 1 ng/kg body weight.

Dizziness, double vision, difficult swallowing, respiratory or cardiac paralysis, death (12-36 hrs)
|Low acid foods in anaerobic conditions. Improperly home-canned, vacuum-packed, poorly refrigerated foods

Baked potatoes wrapped in foil

Spores have been detected in vegetables such as carrots, potatoes and fruit (contamination with soil), in fresh and processed meats and in honey and corn syrup.
|Commercially sterile after processing must receive a "botulinum cook" (12 D)

Use sodium nitrite for cured meats

Properly refrigerate vegetable/fruit juice.

Honey, corn syrup and molasses must not be fed to infants < 1 year of age. Pasteurization of honey '''does not i'''nactivate the spores.
|}
{| class="wikitable"
!'''Organism'''
!'''Symptoms onset'''
!'''Common foods'''
!'''Prevention'''
|-
|'''''Escherichia coli O157:H7''(Shiga toxin)'''
|Bloody diarrhea, kidney failure and hemolytic uremic syndrome (HUS) in sever cases (12-72 hrs)
|Undercooked ground meat, raw milk, unpasteurized apple juice/cider, lettuce, spinach, alfalfa sprouts

Contaminated water supply (outbreak in Walkerton, Ontario)
|Practice good food sanitation and hand washing.

Properly handle and cook foods.''E. coli'' is killed by normal cooking and pasteurization, as well as ionizing radiation, but is able to survive in acidic conditions (e.g. apple juice). It does not grow well at temperatures below 8°C.

The Kidney Foundation of Canada B.C. branch: ''E. coli'' bacteria: What You need to Know
|}

=== Food Infections: ===
{| class="wikitable"
!'''Organism'''
!'''Symptoms onset'''
!'''Common foods'''
!'''Prevention'''
|-
|'''''Salmonella spp.'''''
|Nausea, fever, vomiting, abdominal cramps, diarrhea (6-48 hrs)
|Raw meats and poultry, eggs (about 60% of chickens sold in the retail market are contaminated with ''Salmonella''), milk, dairy products
|Salmonella are easily killed by heat (normal cooking and pasteurization processes) and ionizing energy, but survive freezing and dehydration. Consequently, frozen and thawed poultry can be just as contaminated as fresh poultry.
|}
{| class="wikitable"
!'''Organism'''
!'''Symptoms onset'''
!'''Common foods'''
!'''Prevention'''
|-
|'''''Listeria monocytogenes'''''
|Flu-like symptoms, meningitis, septicemia, or pneumonia. Birth defects, still birth (1 day- 3 weeks)
|Raw milk, dairy products, vegetables, fish and meat products
|The bacteria is capable of growing slowly on foods during storage in the refrigerator, and appears to be fairly tolerant to salt. It is easily killed by proper cooking and pasteurization techniques. Refrigerate raw materials and high-risk foods below 4°C.
|}

=== Viruses ===
Viruses are much smaller than bacteria and require a "living host" (human, animal) in which to grow and reproduce. Viruses do not multiply in food. Viruses are usually transferred from one food to another, from a food worker to a food, or from a contaminated water supply to a food.
{| class="wikitable"
!'''Organism'''
!'''Symptoms onset'''
!'''Common foods'''
!'''Prevention'''
|-
|'''Hepatitis A'''
|Fever, nausea, vomiting, abdominal pain, fatigue, swelling of the liver, jaundice (10-50 days)
|Foods prepared with human contact; contaminated water
|Wash hands and practice good personal hygiene, avoid raw seafood
|}
{| class="wikitable"
!'''Organism'''
!'''Symptoms onset'''
!'''Common foods'''
!'''Prevention'''
|-
|'''Noravirus'''
|Vomiting, diarrhea, headache, fever (24-48 hrs)
|Sewage, contaminated water, contaminated salad ingredients, raw seafood, infected food workers
|Use potable water, practice good personal hygiene, cook all seafood
|}

=== 12.8.2 Factors in Foodborne Disease ===
According to the World Health Organization (WHO), a small number of factors related to food handling are responsible for a large number of foodborne disease outbreaks worldwide. The most common factors and their reasons for contributing to foodborne disease are listed below:
{| class="wikitable"
!Factor
!Effect
|-
|'''Preparation of food several hours in advance & improper storage'''
|favors growth of pathogenic bacteria and/or formation of toxins
|-
|'''Insufficient cooking or reheating of food'''
|not sufficient heat is applied to eliminate/reduce pathogens
|-
|'''Inadequate cooling of foods'''
|permits survival of pathogens, allowing them to grow to sufficiently large numbers
|-
|'''Cross-contamination'''
|allowing un-contaminated food to become contaminated by improper handling of food
|-
|'''Poor personal hygiene'''
|can promote cross-contamination
|}

'''Why were foods implicated in foodborne disease outbreaks consumed, if they were so heavily contaminated with disease-causing microorganisms?'''

In some cases the food probably contained millions or billions of such bacteria per gram or millilitre, but the food would have appeared perfectly normal.

It is important to note that most ''pathogenic'' bacteria '''do not alter the colour, odour, flavour or texture of food''' even though they may be present in large numbers. This is the reason why perishable food must be handled in such a manner that contaminants will be destroyed during cooking or processing and that post-cooking and post-processing contamination must be avoided. In addition, perishable, low acid foods must be handled as though they were contaminated, which means that safe food handling practices must be followed at all times.

'''Which foods should we be particularly careful about?'''

Remember the principles we have learned in earlier lessons about factors affecting microbial growth and survival such as pH (acidity), moisture, time-temperature, oxygen.

Think about whether the food has been treated by some process that could decrease or inhibit microbes.

Consider possibility of post-processing contamination that may lead to an unsafe food.

For those who are at risk (e.g. the elderly, the very young, pregnant women and their unborn or newborn babies, and those who are immunocompromised) should be particularly careful about raw meat and fish, milk and eggs, and should avoid deli meats, soft cheeses, uncooked sprouts, liver pate, unpasteurized fruit juices/cider. They should take extra care in washing or peeling fresh fruits and vegetables, or may cook these before eating.

'''Top 4 places where food can be mishandled and lead to foodborne disease incidents:'''
# Food Service Establishments
# Food Processing Establishments
# Retail Food Establishments
# Homes
Clearly, the food service sector is responsible for the majority of reported foodborne disease incidents and cases. One of the problems in the food service sector is that foods are handled in large quantities. If proper handling procedures are not followed, it is easy for food to become contaminated, for cross contamination to occur, for inadequate cooling to occur, and for inadequate cooking or hot holding temperatures to occur since the food often receives much handling by many people before it reaches the consumer.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Public health inspectors conduct regular inspections of restaurants, food service establishments, food stores and processors. If you are interested, take a look at the '''[https://inspections.vcha.ca/ Vancouver/Richmond Restaurant Inspection Reports]''' website for examples of the type of information that inspectors look for.
* From this website, you can also find a list of closures of food establishments, including the dates and reasons for these closures.
|}
Although the food service sector may be responsible for many incidences of foodborne disease, such incidents were in fact attributed to all sectors of the food industry as well as in homes. It is the responsibility of the food processing industry and the regulatory agencies to ensure that changes in food technology do not lead to undue risks with respect to foodborne illness or other potential hazards. It may be worthwhile, at this point to consider how food is handled in your home.

=== What can be done to ensure food safety? ===
The World Health Organization (WHO) and the BC Health Files have developed ten rules for safe food handling, that if followed, can reduce the risk of foodborne disease.

Below are some key points that need to be considered
* Choose foods processed for safety (i.e. pasteurized products over unpasteurized)
* Cook foods thoroughly
* Eat cooked foods immediately
* Store food promptly and carefully. Perishable and "cold" foods should be kept "cold" below 4°C until ready to cook or eat.
** Avoid the '''"Temperature Danger Zone" (TDZ)''' which is from '''4°C to 60°C''' (40-140°F). Bacteria can grow and/or produce toxins in food if left in the TDZ.
* Reheat cooked foods thoroughly
* Avoid cross-contamination. Do not allow any contact between raw food or its traces and cooked food
* Wash hands repeatedly
* Keep all kitchen surfaces clean
* Do not let anyone with diarrhea or infected sores prepare food
* Wash all fruits and vegetables before eating
* Finally, '''if in doubt, throw it out!''' (Ministry of Health Services, 2001)

=== 12.8.3 The HACCP System: ''Seven steps to food safety'' ===
In the past, food safety programs run by the industry (food processors) and food service establishments, have corrected hazardous conditions after they happened. The HACCP system is designed to anticipate and control problems before they happen. The '''HACCP''' systems stands for '''Hazard Analysis and Critical Control Points'''. This system is recommended as the best method for ensuring food safety in retail establishments and food processing operations. There are 7 principles in a HACCP system:
# Identify Hazards
# Determine the critical control points (CCPs)
# Establish control measures (critical limits or thres holds)
# Establish procedures to monitor CCPs
# Establish corrective actions
# Keep records
# Verify procedures
While each principle is unique, they all work together to form the basic structure of an effective food safety program. (''Source'': McSwane, D., Rue, N., Linton, r., and Reeves, D.2003. Essentials of Food Safety and Sanitation. Pearson Education Canada Inc., p. 104-121)

==== HACCP Video ====
The food safety rules described above and the description of the seven steps for HACCP are summarized in the following '''video''':

[https://www.youtube.com/watch?v=53PiVRadZAY HACCP: The Hazard Analysis and Critical Control Point System]

'''How important is that we wash our hands?'''

The following figure dramatically illustrates the importance of washing hands thoroughly after handling raw meats. In this experiment, a previously sanitized hand was rubbed with a cube of raw pork for about 15 seconds. The hand was then pressed gently onto a 9" agar plate and labeled as "soiled hand" '''(A)'''. Hands were again washed with Hibitane hand sanitizer (4% w/v chlorhexidene gluconate) for 30 seconds and the right hand was gently pressed onto a second agar plate labeled as "washed hand" '''(B)'''. Both plates were incubated at room temperature for 2 days. The images below show the results/observations after two days:<gallery>
File:FNH200 Lesson12 SoiledHand.jpg|'''A. Soiled Hand'''
File:FNH200 Lesson12 WashedHand.jpg|'''B. Washed Hand'''
</gallery>'''The importance of washing hands.''' Right palm soiled with raw pork cubes (photograph courtesy of Eunice Yao, 2000. "Digital Image Analysis of Full-hand Touch Plates: A method of mimicking real soil encountered in food science industry to analyze the efficacy of antimicrobial hand sanitizer and alcohol-based sanitizing gels").

==== '''Microbe Video Pt.1''' ====
'''Microbe Video Pt.2'''

'''Microbe Video Pt.3'''

== 12.9 Summary of Lesson 12 ==
This lesson has been a brief overview of the topic of toxicants in foods. There are hundreds of toxicants that could be found in our food supply. We are very fortunate that here in Canada, we have the food inspection systems and regulatory mechanisms that help insure that levels of toxicants in foods are kept at levels below the no-effect level.

In this lesson, you have also learned about the causes of foodborne illness in Canada. You have gained some insight into the importance of different types of microorganisms involved in foodborne disease incidents. You have learned the importance of considering different factors in assessing the hazardous nature of toxicants or foodborne illness caused by microorganisms

Through the assigned readings, you should also have become familiar with safe food handling practices, which you should employ whenever you handle food (clean, cook, separate and chill!)

You are introduced to the concept of HACCP which is a system designed to anticipate and control food safety problems before they happen. This is accomplished with the 7 steps of the HACCP system.

Remember that the risks of food poisoning and foodborne illness are dependent on the toxicant or pathogen itself, the susceptibility of the host and factors related to the environment and handling practices.

The concepts in this lesson will help you to apply what you have learned in your daily life to minimize the risks for yourself, your family and friends.

Supplemental Videos:
# [https://www.youtube.com/watch?v=50e_Ic2rPK4&feature=emb_logo Introduction to HACCP]
# [https://www.youtube.com/watch?v=53PiVRadZAY&feature=emb_logo HACCP: The Hazard Analysis and Critical Control Point System] 
==References==
<references/>

'''Authorship:'''

FNH 200 Course content on this wiki page and associated lesson pages was originally authored by Drs. [http://www.landfood.ubc.ca/person/brent-skura/ Brent Skura], [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], and [http://www.landfood.ubc.ca/person/eunice-li-chan/ Eunice Li-Chan]. Ongoing edits and updates are contributed by past and current instructors including Drs. [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], [http://www.landfood.ubc.ca/person/azita-madadi-noei/ Azita Madadi-Noei], [http://www.landfood.ubc.ca/person/nooshin-alizadeh-pasdar/ Nooshin Alizadeh-Pasdar], and [http://www.landfood.ubc.ca/person/judy-chan/ Judy Chan].
{{cc-by-nc-sa-3.0}}

<quiz display=simple>
{1. What is the legal definition of a poison?
|type="()"}
- An effect level of 50 mg
- An effect level of 50 mg per kg body weight
- A lethal dose of 50 mg
+ A lethal dose of 50 mg per kg body weight
</quiz>

<quiz display=simple>
{ 2. Type text here or a no-break space code
|type="{}"}
Which chemical before is a good indicator of poor storage practice of tuna fish? { Histamine }
</quiz>

<quiz display=simple>
{ 3. Which of the following are NOT examples of CCP?
|type="[]"}
+ Allergenic
- Biological
+ Environmental
- Chemical
- Physical
</quiz>

<quiz display=simple>
{4. If cheddar cheese stored in the refrigerator has mould present, you can simply trim it.
|type="()"}
+ TRUE.
- FALSE.
</quiz>

<quiz display=simple>
{5. All food borne disease is due to consumption of microorganisms.
|type="()"}
- TRUE.
+ FALSE.
</quiz>

Course:FNH200/Lessons/Lesson 10

2020-06-24T00:40:27Z

YihangChen:

<big><big><big>'''Preservation of Food with Ionizing Energy'''</big></big></big>

== 10.0 Overview ==
The exposure of food to ionizing energy, more commonly known as food irradiation, is a preservation technology that has generated much public debate. In this lesson you will learn important definitions relating to this technology. The types and sources of ionizing energy and irradiator layout will be introduced. You will learn about the current regulations regarding the use of ionizing energy for food preservation in Canada and in other countries. We will explore a number of issues and controversies about the use of ionizing energy in the food industry. This lesson provides you a sound understanding of ionizing energy as a preservation technology and introduces you to the issues that have been raised in the popular press.

=== Objectives ===
Upon completion of this lesson you will be able to:
* understand the concept of food irradiation as a food preservation method;
* outline the terminologies commonly used in conjunction with preservation of food with ionizing energy
* describe the principles for determining the required irradiation dose depending on the desired outcome
* illustrate the principles for determining wholesomeness and safety of irradiated foods
* summarize the regulations, and compare the magnitude of food products that are approved for irradiation in Canada versus United States of America
* articulate a personal set of values pertaining to the use of ionizing energy in food preservation

=== Optional Reading ===
* Smith, J.S. and Pillai, S. 2004. Irradiation and Food Safety. (A scientific status summary). Food Technology, 58(11): 48-55
* Division 26, Food Irradiation. Food and Drugs Act, and the Food and Drug Regulations. Ottawa.
* http://laws-lois.justice.gc.ca/eng/regulations/C.R.C.%2C_c._870/page-84.html#h-137
* Guide to Food Labelling and Advertising. Section 2.14.1. Food Irradiation. Canadian Food Inspection Agency. http://www.inspection.gc.ca/english/fssa/labeti/guide/ch2ae.shtml#2.14
* [https://www.inspection.gc.ca/food-label-requirements/labelling/industry/eng/1383607266489/1383607344939#2.14 Food Irradiation]- by the Canadian Food Inspection Agency. 2014
* Frequently Asked Questions Regarding Food Irradiation on the Health Canada website (last updated 2002/11/25) http://www.hc-sc.gc.ca/fn-an/securit/irridation/faq_food_irradiation_aliment01-eng.php

== 10.1 Introduction ==
{| class="wikitable"
|
==== '''Terms to remember''' ====
|-
|
* Electromagnetic spectrum
* Ionizing energy
* X-rays, gamma and beta rays
* Division 26 of the Food and Drugs Act and Regulations
* MeV, kGy
* Free radicals
* Unique radiolytic products
* Radurization, Radicidation and Radappertization
* Radura symbol
|}

Aside from the use of genetically modified organisms in foods, there is perhaps no other method of food preservation that has generated as much heated debate recently as '''food irradiation'''. Although the basic concept of food irradiation as a food preservation technology is not new (a patent for food preservation by irradiation was applied for in the United States in 1921), it is nonetheless a controversial method of food preservation.

Much of the controversy about food irradiation seems to stem from a fear of the unknown and unfamiliar - we have often seen references in media reports of food irradiation associated with radioactive fallout, accidents at nuclear power plants and concerns about nuclear war and weapons testing. This has led to further confusion in the minds of the general public about food irradiation and what the process actually involves. Upon completing this lesson, you will have a good knowledge of what food irradiation is, what its potential applications are, the physical process of food irradiation, and limitations and advantages of food irradiation as a method of food preservation. 

== 10.2 What is Radiant Energy? ==
Radiation refers to the emission and propagation of '''energy''' through matter or space by electromagnetic disturbances. These forms of energy are found within the '''electromagnetic spectrum of radiation''' (Figure 10.1). This is an organized scale where we find energy ranging from radio waves, microwaves, visible light to ionizing radiation. These forms of energy vary in frequency, wavelength, energy value, penetrating power, and their effects on biological systems.
[[File:FNH200 Lesson10 ElectSpectrum.png|400px|thumb|'''Figure 10.1.''' The Electromagnetic. SpectrumAdapted from: Purves et al., 1992. Life The Science of Biology (3rd ed.), Ch. 8. Sinaur Associates, Inc., Sunderland, Mass., p. 164|alt=|center]]The '''longer''' wavelengths of electromagnetic energy that we are familiar with include visible light, infrared and ultraviolet rays. These are characterized by having low penetrating power. Microwaves and infrared radiation are two examples of the '''longer''' wavelengths in the electromagnetic spectrum.
* '''Microwaves''' are used in food for their heating properties. The microwaves travel in straight lines and pass through air, glass, paper and plastic, but reflected by metals. They are readily absorbed by water (polar molecule), causing it to vibrate. Heat is generated by the intermolecular friction generated from the vibrating water (polar) molecules in food. Microwaves are absorbed by food up to a depth of '''5''' to '''7.5 cm.'''
* '''Infrared energy''' can generate heat. They can reach temperatures above 100°C. Typical examples of infrared energy can be seen in ovens, toasters, and even those "infrared" lamps used to keep food warm.
Examples of '''short''' wavelengths include X-rays, beta rays and gamma rays, which can be employed as energy sources in food irradiation, since they have good penetrating power. These forms of energy are referred to as '''''ionizing energy'''''. 

== 10.3 What is Food Irradiation? ==
Food Irradiation is the application of radiation, in the form of '''ionizing energy''', to foods. According to Health Canada, Food Irradiation means "the treatment of food with ionizing radiation" from the following sources:
* Gamma radiation from a Cobalt-60 or Cesium 137
* X-rays generated from a machine source operated at or below ''5 MeV''
* Electrons generated from a machine source operated at or below ''10 MeV''
(read the full definition in [https://laws-lois.justice.gc.ca/eng/regulations/C.R.C.%2C_c._870/page-84.html#h-137 Division 26] (Links to an external site.) of the Food and Drug Regulations)
 
'''Important Definitions pertaining to food irradiation:'''
*'''Gamma radiation''' is electromagnetic radiation that has very short wavelengths, similar to "short" x-rays. Isotopes such as cobalt 60 and cesium 137 emit gamma radiation as they disintegrate. The energy level of the gamma radiation emitted by these isotopes will not induce radioactivity in food materials.
*'''X-rays''' are electromagnetic radiations that are highly energetic and of short wavelength. X-rays are produced by x-ray machines that emit a beam of fast electrons which hit a metal target in a vacuum. X-ray machines emit radiation only when the machines are turned on.
*'''Electrons''' with high-energy (speed) may also be generated by an electron beam accelerator. Electron Beam Accelerators need only electricity to operate and produce no waste materials
*'''The Gray''' is a unit of energy absorbed by a food irradiated with ionizing radiation. One gray (Gy) is equivalent to the absorption of 1 joule of energy by 1 kilogram of food. One thousand grays equals one kilogray (kGy). Most of the ionizing radiation processes permitted around the world involve absorbed doses of <10 kGy.
*'''The Rad''' is another unit used to express the radiation absorbed dose (rad), where 100 rads = 1 Gy. However, the preferred unit is the kGy (above)
Atomic Energy of Canada Limited (AECL) is a Canadian federal crown corporation that is a leading agency in the development of food irradiators that use cobalt 60 as the energy source. The Canadian Nuclear Safety Commission (CNSC) (formerly the Atomic Energy Control Board or AECB) regulates the use of nuclear energy and material in Canada.
* Cobalt 60 is produced in the Canadian-built Candu reactors. It is contained within the stainless steel rods that are used to control the rate of nuclear fission and as such is not extracted from spent nuclear fuel. In this context, the cobalt is housed within stainless steel rods which are transported to a facility near Ottawa where the cobalt 60 pellets within the rods are recovered and then reassembled in stainless steel rods to be used as the energy source in food irradiators and also irradiators for sterilizing medical supplies (bandages, specimen containers) and devices, or for use in irradiators utilized for cancer therapy.
[[File:FNH200_Lesson10_Facility.jpg|400px|thumb|Figure 10.2 Diagram of a food irradiation facility. In such a facility, cobalt 60 (Co 60) would be used as the source of ionizing energy.|center]]Figure 10.2 shows a typical diagram of an irradiation facility. In such a facility, the food is pre-packaged in boxes that are loaded into a pallet carrier where a conveyor system moves the food in the pallets. The pallets are carried into a chamber with irradiation source (eg. Cobalt 60). The pallet carriers travel through the irradiator room and around the Cobalt 60 source at a speed such that the required absorbed dose is attained. The absorbed dose depends on the amount of time food is exposed to the irradiation source. Dosimeters are placed with the food to measure the dose received (absorbed) in kGy. The irradiated pallets of food exit to the unloading station which is physically separated from the loading station so that treated and untreated foods do not become intermixed. A similar process is used with e-beam guns, where the food is carried through conveyor belts and passes through the electron beam. Please watch this video where they show food being irradiated using e-beam

=== Where are the (food) irradiation plants in Canada? ===
Most of the irradiation facilities in Canada process medical and personal care supplies. '''MDS Nordion''' (Laval, Quebec) and '''Iotron''' (Port Coquitlam, BC) process some dry food ingredients. The former uses gamma rays, while the latter uses electron beam technology. The Canadian Irradiation Centre (CIC) is a training centre operated as a joint venture by MDS Nordion and the Université du Québec, Institut Armand-Frappier (IAF). 

== 10.4 Effects of Ionizing Energy Absorbed by Food - Preservation principle ==
The basis of food preservation by treatment with ionizing energy is the ability of the absorbed quanta of energy to dislodge electrons from molecules with the concomitant creation of '''free radicals''' without inducing radioactivity in the food.

When ionizing energy from a permitted source for food use is absorbed by food and collides with a molecule or atom, an ion-pair is produced if the energy from the collision is sufficient to dislodge an electron from an atomic orbit. This phenomenon can lead to breaking up of one or more bonds between atoms in the molecule, leading to new molecular fragments possessing unshared electrons (free radicals). Because of the unshared electron, free radicals are ''extremely reactive'' and tend to react with other free radicals or other molecules with unshared electrons.

It is believed that only one out of every six billion chemical bonds in bacteria or food molecules are broken by irradiation. However, the formation of ion pairs and free radicals, the reaction of free radicals with one another or other molecules, and the chemical and physical phenomena that occur as a consequence of these events form the mechanisms for the inactivation of microorganisms, enzymes and alterations of food constituents during food irradiation.

The changes induced in food by absorption of ionizing energy can arise from both '''direct''' and '''indirect effects'''. Please read the required reading '''''Irradiation and Food Safety''''' for details. You will note that many of the effects observed in foods arising from the absorption of ionizing energy are due to '''indirect effects''' as explained in the optional reading. This is shown below:[[File:FNH200_Lesson10_FreeRadicals.gif|400px|frame|center|
Figure 10.3
]]
Hydrogen, hydrogen peroxide and hydroperoxy free radicals are produced when ionizing energy is absorbed by foods (fruits, vegetables, meats, fish) that contain substantial quantities of water. Figure 10.3 shows the reactions of hydrogen '''(H)''' and hydroxyl '''(OH)''' free radicals produced by gamma irradiation of water molecules. These free radicals only exist for about '''0.0001 seconds''', but generate hydrogen peroxide (H2O2) which is the antimicrobial agent that kills bacteria, yeasts, and moulds in foods. In many cases, the free radicals are formed within the microbial cells.

As mentioned earlier, microorganisms may also be killed by a "'''direct effect'''" of the ionizing energy upon genetic material within the microbial cells that leads to the death of the microorganism. As mentioned in the required reading (''Irradiation and Food Safety'') "the damage occurring from ionizing radiation can be random and extensive, making DNA repair near impossible". In some cases, even relatively small changes in the DNA can destroy bacterial cells, and the disruption of genetic material in living cells by irradiation also enables the destruction of insects, inactivation of parasites, delaying of ripening, and prevention of sprouting.

=== Are Free Radicals Unique to Irradiated Food? ===
A concern that has been expressed in regard to the use of food irradiation is the generation of free radicals during exposure of the food to ionizing energy.

It is true that free radicals are produced in foods during irradiation. However, the free radical formation is not unique to foods which have been irradiated with ionizing energy. For example, oxidative reactions in foods containing unsaturated fats also involve free radical formation, and free radicals are also formed during the course of the Maillard browning reactions. Free radicals are also produced within our bodies and other living tissues during normal metabolism. Mechanisms (chemical and enzymatic) for inactivation of free radicals exist within the human body and other living tissues.

=== Does irradiated food become radioactive? ===
Irradiation using approved sources provides enough energy to knock an electron from the outer orbit (that is why it is termed "ionizing radiation" or "irradiation"); however, it does not have sufficient energy to penetrate the nucleus and eject neutrons, which would be required to induce radioactivity. Therefore food will NOT become radioactive by irradiation conducted using approved energy sources and within the approved limit. To become radioactive, food would need to be exposed to a '''minimum of 15 MeV''' of energy. The energy output of Cobalt 60, Cesium 137, and e-beam accelerators is carefully regulated. The maximum energy outputs allowed are '''5 or 10 MeV''', which are too low to induce radioactivity in food.

You may be interested to know that all foods are naturally radioactive, although of course at a very low level. This low background level of radioactivity arises from the naturally occurring isotopes in elements such as carbon, phosphorus, potassium, and sulfur.

==10.5 Changes that can Occur in Food during Irradiation==
Another concern expressed about food irradiation is the possible formation of unique radiolytic products. However, in fact, the molecular changes in foods treated with ionizing energy are not usually unique or distinct from those found in non-irradiated foods such as those treated by thermal processing. The few unique ''radiolytic products'' that have been found are at such trace levels, that they are not considered to be of any significance, and so far toxicological studies have not found evidence of any harmful effects.

Other changes can occur in foods during irradiation with ionizing energy via indirect effects. These changes can involve the radiolysis of water molecules to produce reactive hydroxyl radicals, or reactions in foods of peroxides and peroxide free radicals with fats, leading to lipid oxidation(rancidity). Some vitamins are also sensitive to radiation. The extent of effects on both macronutrients and micronutrients are, of course, dependent on the dose of irradiation. Page 51 of ''Irradiation and Food Safety'' describes the effects of food irradiation on macro- and micro- nutrients. It also describes some of the sensory changes that have been perceived and their implications for the consumer.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* '''Read:''' the IFT Scientific Status Summary on "'''Irradiation and Food Safety'''" by Smith and Pillai.
* Try to answer the following questions (keep in mind the radiations doses being used):
** What are the two groups of compounds (radiolytic products) that have generated concern?
** Of these two groups, only one is considered as "unique radiolytic products" - ''which one?''
** What are the opinions of ''Health Canada'' and of the ''European Commission's Scientific Committee on Food'' on potential toxicity concerns based on mutagenicity/genotoxicity studies?
** What was the role of ''Health Canada'' in the mutagenic/genotoxic studies?
** Which nutrients are less sensitive to irradiation? Which are most sensitive?
** What effects could irradiation have on sensory properties?
|}
Below are three proposed methods of minimizing the "undesirable" changes during food irradiation:

==== Irradiation in the frozen state ====
* When water is frozen free radicals are produced at a lesser extent
* The frozen state will delay free radical diffusion and migration to food constituents beyond the site of free radical production.
* However, as we learned in the required reading by ''Smith and Pillai (2004)'', the '''D10 values''' also change as the water in the product freezes.

==== Irradiation in a vacuum ====
* Removing O2 from the system may minimize reactions; however,
* Removal of oxygen could also confer a protective effect on microorganisms.

==== Addition of free radical scavengers ====
* Ascorbic acid has a great affinity for free radicals.
* Addition of free radical scavengers to food systems results in consumption of the free radicals via reactions between the scavengers and the free radical(s).

== 10.6 Irradiation Methods & Doses ==
Table 10.2 shows the absorbed doses required to achieve a variety of applications ranging from inhibition of sprouting to achieving commercial sterilization of a food commodity.

'''Table 10.2'''. '''Typical applications of ionizing energy for food preservation'''

''Note: Includes examples that are not approved for use in Canada.''
{| class="wikitable"
!Dose (kGy)
!Purpose
!Examples
|-
|'''< 1'''
|inhibit sprouting of vegetables

kill insects eggs, larvae

slow ripening

inactivate parasites
|potatoes

wheat

bananas

pork
|-
|'''1 to 10'''
|eliminate disease causing bacteria (''Salmonella, E.coli'' O157:H7) and parasites

decrease or eliminate spoilage causing microorganisms (eg. mould)
|chicken, ground beef, fruit and vegetables

fresh strawberries
|-
|'''10 to 50 kGy'''
|decontaminate food ingredients and additives

commercially sterilizes food
|enzymes and spices

sterilized hospital diets, foods for use on missions in outer space
|}
'''Radiation Pasteurization (radicidation, radurization) methods'''

'''Radicidation''' is defined as a process designed to kill or inhibit '''''disease''-causing''' microorganisms (such as vegetative bacteria, yeasts, parasites) in food. Absorbed doses are often below 10 kGy. Foods that have been treated with a radicidation dose of ionizing energy must still be stored under refrigeration since all spoilage-causing microorganisms would not have been killed.

'''Radurization''', a form of radiation pasteurization, has as its objective the killing of the majority of '''''spoilage''-causing''' microorganisms and parasites so that storage life of the food can be extended during refrigerated storage. For example, treatment of fish to kill most of the spoilage-causing psychrotrophic bacteria would extend the storage life of the fish at refrigerated storage temperatures. Absorbed doses for radurization are below 10 kGy (often < 1 kGy).

'''Radiant Sterilization''' '''(radappertization) methods'''

'''Radappertization''', equivalent to thermal commercial sterilization, involves treatment of food with an absorbed dose of ionizing energy such that '''disease-causing''' microorganisms and all '''spoilage-causing''' microorganisms capable of growing at the conditions of storage (e.g., at ambient temperatures) are inactivated. Absorbed doses of ionizing radiation are greater than (>) 10 kGy (usually 20, 30 kGy).

Note that in Canada, '''doses above 10 kGy''' are NOT permitted!

== 10.7 Factors affecting Food Irradiation ==
The factors that need to be considered and controlled during food irradiation include:
# ''Safety and wholesomeness of the foods''
# ''Resistance of food to irradiation''
# ''Resistance of microorganisms to ionizing energy''
# ''Resistance of enzymes to ionizing energy''
# ''Cost''

=== 10.7.1. Safety and Wholesomeness of Irradiated Foods ===
In Canada, the '''Health Products and Food Branch''' of '''Health Canada''' considers issues about ''safety and wholesomeness'' of irradiated foods, in addition to the safety and wholesomeness of foods preserved by other food preservation methods. The Canadian Food Inspection Agency considers aspects related to labelling of irradiated foods. The issues of '''safety and wholesomeness of irradiated foods''' revolve around criteria of the following four principles:
* Radiological safety: ensuring that foods do not become radioactive during irradiation;
* Toxicological safety: ensuring that production of toxic and possibly carcinogenic substances does not occur;
* Microbiological safety: ensuring the efficacy of the radiation process with respect to the ability of the prescribed absorbed dose to kill disease-causing microorganisms that could be in the food.
* Nutritional adequacy: ensuring that undue losses of nutrients do not occur as a consequence of treatment of food with ionizing energy; and
The conclusions drawn by the Canadian and international regulatory agencies about food irradiation are that foods treated such that the absorbed dose is '''below 10 kGy''' do not contain toxicants at undesirable levels. That is, the irradiated foods which have absorbed a dose of less than 10 kGy are wholesome and safe for long-term consumption.

In 1997, a Study Group was convened by the World Health Organization (WHO), the Food and Agriculture Organization (FAO), and the International Atomic Energy Agency (IAEA), to evaluate wholesomeness of food irradiated with doses above 10 kGy. In a report published in 1999, "The Study Group concluded that food irradiated to any dose appropriate to achieve the intended technological objective is both safe to consume and nutritionally adequate ... Accordingly, irradiated foods are deemed wholesome throughout the technologically useful dose range from below 10 kGy to envisioned doses above 10 kGy" (WHO Technical Report Series 890). Applying the concept of "'''substantial equivalence'''", even high-dose irradiated foods are considered to be as safe as foods sterilized by conventional thermal processing, such as canning of low-acid foods.

=== 10.7.2. Resistance of Foods to Ionizing Energy ===
Not all foods are amenable to preservation by treatment with ionizing energy. The same can be said for thermal processing, freezing and dehydration as methods of food preservation. The quality of some foods may be adversely affected by irradiation, depending on the dose, temperature and conditions during irradiation. For example, colour, flavour or textural changes may result after exposure of food components to ionizing energy. Lipids or fats are particularly susceptible to oxidative reactions triggered by the radiolytic reactions and presence of free radicals. Losses of some vitamins may also occur; vitamins A, C, E and B1 (thiamine) are the most sensitive, particularly at higher doses and in foods packaged in air.

As mentioned above, these changes may be minimized by irradiating foods in the frozen state, in a vacuum, and/or with the addition of radical scavengers such as ascorbic acid. Additional strategies include applying the lowest effective irradiation dose and choosing appropriate packaging in terms of moisture and oxygen barriers.

=== 10.7.3. Resistance of Microorganisms to Ionizing Energy ===
As in the case of thermal processing (pasteurization, commercial sterilization), microorganisms vary in their resistance to the killing effects of ionizing energy. Analogous to thermal processing where ''Clostridium botulinum'' is the most heat resistant pathogen, ''C. botulinum'' spores are the most radiation resistant forms of pathogenic bacteria.

You may recall that we discussed the '''decimal reduction time (D-value)''' in Lesson 6 in conjunction with thermal processing of foods. Similarly, it is possible to determine the dose of ionizing energy necessary to effect a 90% destruction of the particular microorganism in question. When we calculated the D-value in the lesson on thermal processing, we referred to the length of time at a constant temperature required to create a 90% decrease in the population of the microorganisms or spores in question. In irradiation concept, the time at a constant temperature could be converted to an absorbed dose of thermal energy.

With food irradiation, we calculate the '''absorbed dose of ionizing energy that produces a 90% decrease in the microbial population (D10 values)'''. To achieve an appropriate margin of safety, a 5D or a 12D radiation treatment would have to be applied to acid and low acid foods, respectively. Although the source of the energy and the mechanisms by which microorganisms and spores are killed are different, the same concept (decimal reduction value) is applied during determination of the efficacy of thermal processing and preservation of food with ionizing energy.

==== Is it true that irradiation can mask food spoilage? ====
Irradiation cannot be effectively used to mask or cover up food spoilage since the microorganisms can be easily killed but the spoilage odours, off-flavours and colour changes caused by the spoilage microorganisms can not be changed or eliminated by ionizing radiation.

Thus, claims that ionizing radiation can be used to mask signs of poor quality in food are untrue.

==== What about Microbiological safety? ====
There has been concern about the creation of "superbugs" or mutants that are more dangerous but this is not a significant issue '''at the doses of ionizing radiation used in food processing.'''
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Take a look at D10-values of some important foodborne pathogens, listed in Table 1 of the IFT Scientific Status Summary on "'''Irradiation and Food Safety'''" by Smith and Pillai:

* The D10-values for ''E. coli'' 0157:H7 (in ground beef patties, at 5oC) and for ''Salmonella'' spp. (in turkey breast meat at 5oC) are 0.27-0.38 and 0.71 kGy, respectively.

** What dose would be required for a '''5D''' process for each of these pathogens under those conditions?
** What dose would be required for a '''12D''' process for each of these pathogens under those conditions?
|}

=== 10.7.4. Resistance of Enzymes to Ionizing Energy ===
The majority of food enzymes are '''more resistant''' to ionizing energy than spores of ''C. botulinum''. The term '''DE''' (D-enzyme) is used to determine the radiation dose that produces a 90% reduction of '''enzyme activity'''. The DE values are of the order of 5 Mrad. Four DE values (5 x 4 = 20x106 rad1 or 200 kGy) would produce nearly total enzyme destruction; however, 200 KGy would also destroy many food constituents!

1Remember that 100 rad is equivalent to 1 Gray of absorbed ionizing energy and 1000 Gray equals 1 KGy.

From this calculation, you will have noted that enzymes cannot be easily inactivated by treatment with ionizing radiation. Ionizing energy could never be used for blanching vegetables. One of the concerns expressed by groups opposed to food irradiation is that enzymes in food are destroyed by exposure to ionizing energy. Clearly, from the example above, that is not the case especially if you consider the maximum dose permitted in Division 26 of the Food Regulations of Canada is 10 kGy.

If vegetables were to be preserved with ionizing energy, they would first have to be blanched with heat followed by treatment with ionizing energy to inactivate the microorganisms of concern.

=== 10.7.5. Costs ===
After the issues of safety and wholesomeness have been satisfied, economic factors must be considered in evaluating the feasibility of an application of food irradiation. Food irradiation may be economically viable if it results in substantial increases in storage life and therefore marketing time and decreases in post-harvest or catching losses. This may be the case in terms of radicidation (discussed below) treatments of fresh fish or some fresh fruits. In cases where the process does not offer advantages (such as nutrition retention, technological advantages, economic advantages) it would not be economically viable.

== 10.8 Potential Applications of Radiant Energy ==
The following examples illustrate various potential applications of ionizing energy in food preservation:
* Much of the food consumed by American and Russian astronauts has been preserved with ionizing energy.
* Irradiation has proven effectiveness in the elimination of ''Salmonella'' from cut-up, packaged chicken. The chicken has received good consumer acceptance in test market trials in the United States.
* Use of low dose radiation was approved in the United States, in December 1997, for general use in irradiation of ground beef to eliminate the bacteria (''Escherichia coli'' O157:H7) that cause "hamburger disease".
* A similar application is under consideration by Health Canada. There was a Public Information Session held on the UBC campus on January 16, 2003, in which information was provided on proposed amendments to allow irradiation of ground beef, poultry, shrimp and prawns, and mangoes. On June 18th, 2016 Health Canada proposed regulatory amendment to include fresh and frozen raw ground beef to the list of approved food for irradiation. UPDATE: Feb 2017, Health Canada has approved irradiation of fresh and raw ground beef. Please [https://www.inspection.gc.ca/food-label-requirements/labelling/industry/irradiated-foods/eng/1334594151161/1334596074872 see table] for complete up to date list of approved foods for irradiation.
== 10.9 Consumer Acceptance ==
The ultimate factor which will determine the economic viability of preserving foods with ionizing energy is consumer acceptance. In North America, the jury is still out as to whether radiation preserved foods would be accepted by consumers. Results of recent consumer surveys, described under "'''Consumer acceptance'''" in the Scientific Status Summary by Smith and Pillai, suggest acceptability rates ranging from 45% to over 90%. However, there are lingering "'''concerns expressed by anti-irradiation groups'''", including the use of food irradiation to overcome poor sanitation practices and environmental concerns related to irradiation facilities.

== 10.10 Regulations and Use of Ionizing Energy in Canada ==
As you noticed in the required reading (''Irradiation and Food Safety''), in the U.S. food irradiation is regulated as a "food additive". This is another good example of the differences that exist in the food additive definition between Canada and the U.S. (reviewed in Lesson 4).

In Canada, the use of ionizing energy for irradiation of food is considered as a '''''process''''' and is regulated under'''Division 26''' of '''The Food and Drug Act and Regulations.''' Note that the sources and energy levels of ionizing energy that would be permitted for use in Canada are clearly defined (Section B.26.001). Specified types of information would have to be submitted to the Health Products and Food Branch of Health Canada when an application is made to treat a specific food commodity with ionizing energy (B.26.004). Specific records would have to be maintained by a food processor employing ionizing energy (B.26.005).

The various options suggested for labelling of irradiated foods are presented in Section 2.14.1 of the "'''Guide to Food Labelling and Advertising''' (Links to an external site.)" from the '''CFIA'''. Note that '''in addition to the mandatory basic labelling''' (''Lesson 4''), food treated with ionizing radiation MUST also include:
# A statement indicating that the food has been ''"treated by irradiation",'' or ''"treated with radiation",'' or''"irradiated".''
# The "radura" symbol is also used to indicate that a food has been irradiated (see below).
# If an irradiated food is used as an ingredient of another food, it must be declared as "irradiated" in the ingredients listing only if it constitutes '''10% or more''' of the final food.
[[File:Radura Symbol.png|thumb|Radura Symbol|center]]

{| class="wikitable"
|'''Critical Thinking'''
|-
|
* What are the risks and benefits of the application of ionizing radiation or irradiation as a food preservation technology?
* Conduct a quick search on the internet and view supporting and opposing views and critically evaluate their validity. What is your personal stand on irradiated foods?
* Visit the '''[https://faculty.canvas.ubc.ca/ubc-has-permanently-decommissioned-connect/ Fact Sheet on Food Irradiation]''' by the '''Canadian Food Inspection Agency'''. There is also a useful link at the end of the fact sheet to '''[https://www.canada.ca/en/health-canada/services/food-nutrition/food-safety/food-irradiation/frequently-asked-questions-regarding-food-irradiation.html Frequently Asked Questions Regarding Food Irradiation]''' on the Health Canada website.
** The list of approved products is listed in a table in [https://laws-lois.justice.gc.ca/eng/regulations/c.r.c.,_c._870/page-87.html#h-135 Division 26] '''of the Food and Drugs Act, Food and Drug Regulations'''. Note that approval does not necessarily mean that irradiation is actually being used for all of these approved products.
** Check out the website of the Food Program of Health Canada for the current and [https://www.canada.ca/en/health-canada/services/food-nutrition/food-safety/food-irradiation.html proposed regulatory amendments to food irradiation provisions]. The approval of new applications of irradiation undergoes a decision-making process similar to what we learned in Lesson 4 for approval of food additives.
** Can you answer the following questions?
*** What foods are currently approved for treatment by ionizing radiation in Canada?
*** What is the purpose for each approved use, and what is the permitted absorbed dose?
*** What amendments are currently being proposed in Canada?
*** What are the Canadian regulations regarding labeling of irradiated foods or foods containing irradiated ingredients
|}

== 10.11 Summary of Lesson 10 ==
* Food irradiation refers to the process of preserving food by using ionizing energy. In Canada, it is regulated under '''Division 26''' of the Food and Drugs Act and Regulations.
* Ionizing energy is characterized by having short wavelengths with high penetrating power. Examples of these forms of energy are X-rays, gamma and beta rays.
* The energy emitted from these sources is measured in '''MeV'''. Whereas, the amount of energy absorbed by the food is measured in '''kGy'''.
* Food will not become radioactive if the energy sources are operated at levels '''<15 MeV'''
* The preservation principle of food irradiation involves a '''direct''' and '''indirect''' effect on microorganisms.
* There are some oxidative changes as well as unique radiolytic products (ACBs, benzene, etc) that have been traced to certain irradiated food products.
* Irradiation in the frozen state, under a vacuum or using antioxidants, are examples of mechanisms available to try and minimize these undesirable changes.
* Depending on the absorbed dose, different irradiation methods can be achieved (radurization, radicidation and radappertization)
* There are several factors that affect food irradiation (safety & wholesomeness, resistance of food, microorganisms and enzymes, as well as cost)
* The safety & wholesomeness of irradiated foods is evaluated by the Health products and food Branch of Health Canada. It relies on 4 basic principles (radiological, toxicological and microbiological safety, and nutritional adequacy)
* There are only certain foods currently approved for treatment by ionizing radiation in Canada.
* There are specific labelling regulations for food treated with ionizing radiation
:

'''Authorship:'''

FNH 200 Course content on this wiki page and associated lesson pages was originally authored by Drs. [http://www.landfood.ubc.ca/person/brent-skura/ Brent Skura], [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], and [http://www.landfood.ubc.ca/person/eunice-li-chan/ Eunice Li-Chan]. Ongoing edits and updates are contributed by past and current instructors including Drs. [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], [http://www.landfood.ubc.ca/person/azita-madadi-noei/ Azita Madadi-Noei], [http://www.landfood.ubc.ca/person/nooshin-alizadeh-pasdar/ Nooshin Alizadeh-Pasdar], and [http://www.landfood.ubc.ca/person/judy-chan/ Judy Chan].
{{cc-by-nc-sa-3.0}}

<quiz display=simple>
{1. Ionizing energy preserves food indirectly by forming ... (Choose two)
|type="[]"}
+ Free radicals
- Radiative food
+ Hydrogen peroxide, H2O2
- Radiolytic products
</quiz>

<quiz display=simple>
{2. Which regulatory agency is responsible for the labeling and advertising of irradiated foods in Canada?
|type="()"}
- Atomic Energy of Canada
+ Canadian Food Inspection Agency
- Canadian Irradiation Centre
- Canadian Nuclear Safety Commission
</quiz>

<quiz display=simple>
{3. Choose the best definition of ionizing energy.
|type="()"}
- Energy that produces radioactivity in its target.
- Energy in the form of long waves with low energy.
+ Energy in the form of short waves with high energy.
- Energy propagated through matter and space including long and short waves.
</quiz>

<quiz display=simple>
{4. What is the maximum amount of ionizing energy used in food processing agreed upon internationally?
|type="()"}
- 5 MeV
+ 10 MeV
- 15 MeV
- 20 MeV
</quiz>

<quiz display=simple>
{5. Enzymes remain active after irradiation unlike the inactivation they undergo during blanching.
|type="()"}
+ TRUE.
- FALSE.
</quiz>

Course:FNH200/Lessons/Lesson 09

2020-06-24T00:39:20Z

YihangChen:

<big><big><big>'''Food Preservation with Biotechnology'''</big></big></big>

== 9.0 Overview ==
In this lesson we will consider the use of microorganisms, mainly in fermentation processes, in the production of foods in Canada and in other countries. You will learn about the wide variety of foods that are produced with the aid of microorganisms and future applications of biotechnological processes in food processing and preservation.

=== Objectives ===
Upon completion of this lesson you should be able to:
* define the term "biotechnology"
* describe the beneficial role that microorganisms have in the production of fermented foods and of food ingredients or additives
* outline the sequence of microbiological, chemical and physical changes that are involved in the conversion of milk to cheese
* compare and contrast the terms "biotechnology-derived foods" and "genetically modified foods", and describe the position of the Canadian government on these foods
* articulate a personal set of values pertaining to use of biotechnology in foods

=== Optional Reading ===
* Canadian Food Inspection Agency (biotechnology page) http://www.inspection.gc.ca/plants/plants-with-novel-traits/general-public/overview/eng/1337827503752/1337827590597 (Links to an external site<nowiki/>.)

=== Required Video ===
* ''Cheese production''. The link for this video will be indicated later in the lesson.

== 9.1 Microorganisms ==
{| class="wikitable"
|
==== '''Terms to remember''' ====
|-
|
* Biotechnology
* Genetic engineering
* Aerobic, anaerobic
* Microbial antagonism
* Antimicrobial agents
* Starter cultures
* Rennin, chymosin
* Rennet
* Cheddaring
* Curd, whey
* Lactic acid bacteria
* ''Propionibacterium shermanii''
* ''Streptococcus thermophilus''
* ''Penicillium roquefortii''
* ''Penicillium camembertii''
* ''Penicillium candidum''
|}

Microorganisms have been employed for centuries in food preservation. Early practitioners of food fermentations were not aware that preservation of food was aided by the actions of microscopic organisms growing in the agricultural or fisheries commodities and producing preservative agents such as acids, alcohols and substances with antimicrobial properties.

Within the broad classification of microorganisms as "the good, the bad, and the ugly" (as discussed in Lesson 5), the microorganisms used in the production of fermented foods are defined as "the good." These microorganisms produce beneficial effects in foods as a consequence of their growth and metabolism in the food products.

== 9.2 Biotechnology ==

=== What is the meaning of "biotechnology"? ===
"Biotechnology is an umbrella term that covers a broad spectrum of tools and techniques, ranging from '''fermentation''' (bread, wine, cheese) to '''plant and animal breeding, cell and tissue culture''', antibiotic production and '''genetic engineering'''. The traits of every organism are encoded in its genetic material (DNA or RNA) which is organized into individual units called genes. Genetic modification is achieved by changing the code or organization of the genetic material of an organism. This includes, but is not limited to, moving a gene or genes from one organism to another (this is commonly called '''genetic engineering''')" From: "[https://www.canada.ca/en/health-canada/services/food-nutrition/genetically-modified-foods-other-novel-foods.html Frequently asked questions on genetically modified foods]" Health Canada (Links to an external site.)

=== What are the desirable products of biotechnology? ===
Biotechnology is a term that began to be used in the 1980s and 90s, to describe the integrated use of biochemistry, microbiology and engineering sciences to utilize microorganisms and cultured animal and plant tissue cells and cell components in the production of desirable products. The definitions given above, from the websites of Health Canada and the Canadian Food Inspection Agency, indicate that "biotechnology-derived foods" includes food products obtained through a very broad spectrum of tools and techniques.

In the food industry the desirable products are food products, ingredients and additives as shown in the two columns in the following table:
{| class="wikitable"
|'''Fermented Food Products'''
|Beverages (e.g. wine beer, sake)

Dairy products (e.g. yogurt, specialty cheeses, cheddar cheese)

Meat products (e.g. salami, bologna, prosciuto)

Traditional foods (e.g. sauerkraut, soy sauce, tempe, miso)
|-
|'''Ingredients & Additives'''
|amino acids (e.g. methionine, glutamic acid)

biopolymers (e.g. xanthan gum, alginates)

Enzymes (e.g. Chymosin-B derived from ''Aspergillus niger)''

Vitamins
|}
* Microorganisms are used for the production of fermented food products
* Microorganisms are cultivated as sources of enzymes and flavouring ingredients used in food systems.
* Xanthan gum, a stabilizer used in a variety of food systems, is extracted from bacteria (''Xanthamonas campestris'') that in nature cause slime rot of cabbages.
** During the production of xanthan gum, specific isolates of the bacteria are grown in large fermenters under conditions designed to maximize production of the bacterial slime. Then the cells are harvested and gum is purified for use as a thickening and stabilizing agent
* Plant cell cultures are used to produce flavouring ingredients for use in foods. Cells of specific plants are cultured in fermentation vessels under conditions that favour production of specific flavour compounds. The culture is cultivated for a specific amount of time and then compounds are extracted from the culture.
* Microorganisms can be used for the production of useful enzymes:
For example, bovine rennin or chymosin used in the production of cheese is in short supply. Researchers in several countries have shown that it is possible to transfer the gene which codes for rennin in the dairy cow to a bacterial cell. The implanted gene is replicated with the bacterial genetic material each time the bacterial cells divide. The implanted rennin gene permits the bacteria to produce bovine rennin. Rennin produced by means of bacterial fermentation is used widely in cheese production in Canada, the United States, and other countries.

=== Is food fermentation the same as biotechnology? ===
Although the word ''biotechnology'' is a new term, biotechnology has in fact been practiced in the agriculture/food industries for thousands of years: Yogurt production in India, bread, and beer in Egypt. Thus, in the current vernacular, '''food fermentation''' would be referred to as food biotechnology- a new name for an old process.

== 9.3 Fermentation ==

=== 9.3.1 Definition of Fermentation ===
Fermentation, in the strictest sense, means "the breakdown of carbohydrates under anaerobic (absence of oxygen) conditions." However, in a broader sense, fermentation is often used to describe the anaerobic ''and'' aerobic breakdown of carbohydrates and carbohydrate-like materials by microorganisms. In fermented foods, proteins and lipids may be hydrolyzed and metabolized by microorganisms involved in the fermentation process.

When we speak of fermented foods, we are referring to the foods which have been '''produced with the aid of microorganisms'''. The changes that occur, may not be solely to the carbohydrate component of the foods, but will also likely involve microbial induced changes to the proteins and lipids in the foods to create the desired colours, flavours and textures characteristic of fermented foods.

Most fermented foods are ''not'' genetically engineered (see the above explanation of genetic engineering and compare it to the definition of fermented foods).

=== 9.3.2 Preservation principle ===
The basis of preservation of foods by fermentation is the encouragement of growth and metabolism of alcohol and acid-producing microorganisms to suppress the growth and metabolic activities of proteolytic and lipolytic, spoilage-causing microorganisms. This condition forms the basis of '''microbial antagonism''' that is the principle of preservation of foods by microorganisms specifically cultured for the production of fermented foods. Microorganisms, when cultured in foods, produce a variety of end products including acids and alcohols which act as '''antimicrobial agents'''.
* Fermentation of foods leads to the formation of chemicals ( e.g. acetic acid, citric acid, lactic acid) that are commonly added to foods as preservatives. In this case, preservatives are formed ''in situ''. In addition, other microorganisms, especially the bacteria that produce lactic acid, also produce as yet unidentified substances that have antimicrobial activity, particularly toward spoilage- and disease-causing microorganisms.
* Foods in which acids are produced, especially when the pH is lowered to 4.6 or lower, will not support the growth of pathogenic bacteria such as ''Clostridium botulinum''. Products such as sauerkraut, wine, yogurt and cheese are more stable forms of the low acid food materials that were used at the start of the fermentation process.

=== 9.3.3 Benefits of Fermentation ===
Fermented foods in many cases can be '''more nutritious''' than the unfermented original materials.
* This is particularly true for mould fermented foods where the moulds synthesize B-vitamins. Food products such as miso, and tempeh have higher levels of B-vitamins than the soybeans that are used to produce those fermented foods.
* Microorganisms also liberate nutrients from parts of plants that are normally undigestible in the human gastrointestinal tract. The availability of minerals and vitamins that are usually biologically unavailable is thereby increased.
* Fermentation can enhance the nutritional value of foods by microbial hydrolysis of cellulosic materials that are undigestible in the human digestive tract. This renders the fermented foods more digestible than their unfermented counterparts.
Fermented foods '''add variety''' to our food supply, which adds to our diet a group of nutritious products. When you review Table 9.1 you will note that microorganisms used in the production of fermented foods increase the variety of foods in our diet. A number of fermented foods listed in Table 9.1 may not be familiar to you as the list represents fermented foods produced throughout the world.

'''Table 9.1.''' Some examples of fermentations used in the food industry.
{| class="wikitable"
!'''Microorganism'''
!'''Food commodity'''
!'''Fermented product'''
|-
|'''Lactic acid bacteria'''
|Cucumbers
Olives
Cabbage
milk
Coffee cherries
Vanilla beans
Meat
Dairy
|Dill pickles, sour pickles
Green olives, ripe olives
Sauerkraut & Kimchi
Kishk
Coffee beans
Vanilla
Meat sausages (salami)
Sour cream, yogurt
|-
|'''Lactic acid bacteria with propionic acid bacteria'''
|Dairy products
|Swiss, Emmenthaler,
Gruyère cheeses
|-
|'''Lactic acid bacteria with mould'''
|Vegetable products
Dairy products
|Tempeh, soy sauce
Roquefort, Camembert,
Brie, Blue cheeses
|-
|'''Acetic acid bacteria'''
|grapes
|vinegar
|-
|'''Yeasts'''
|Malt
Fruit
Wines
Rice
Bread dough
|Beer, ale, stout
Wine, vermouth
Brandy
Saké
bread
|-
|'''Yeast with lactic acid bacteria'''
|Ginger plant
beans
|Ginger beer
vermicelli
|-
|'''Mould'''
|Soybeans
|Miso, soy sauce
|}
(Adapted from: Potter, N. and Hotchkiss, J.H. 1995. Food Science (5th ed), Ch. 12. Aspen Publishers., p. 265.)

You will note that several foods or food ingredients, such as dill pickles, olives, sauerkraut, coffee beans, vanilla, meat sausages and dairy products, are produced by fermentation with lactic acid bacteria. Lactic acid bacteria are used alone or in combination with other microorganisms in the production of a variety of foods.
* '''Acetic acid bacteria''' oxidize ethanol to acetic acid. This phenomenon forms the basis for the production of food grade acetic acid (vinegar). If you have attempted to produce your own alcoholic beverages, you may have had the unfortunate experience of having what you hoped would be a great wine or beer turned to a fruit or barley vinegar by acetic acid bacteria contaminants in your fermentation vessels.
* '''Yeasts''' are used widely in the production of alcoholic beverages and breads. Yeasts with lactic acid bacteria are used in the production of sourdough breads and pancakes and in the conversion of beans to vermicelli.
* '''Moulds''' are used in the production of many foods, particularly in Asia, as well as in the production of well known cheeses such as Roquefort, Brie and Camembert.

=== 9.3.4 Microbial Changes in Fermented Foods ===
Microbial changes in foods that undergo fermentation fall into certain categories as shown in Table 9.2. Conditions in the food to be fermented are controlled to favour growth and desirable metabolic activities of the microorganisms used in the fermentation process. As you can guess, control of conditions for production of fermented foods can be a complicated operation involving many variables.

'''Table 9.2 Microbial changes in foods undergoing fermentation'''
{| class="wikitable"
!Raw material
!Agent
!Product
|-
|Lactose, glucose
|Lactic acid bacteria
|Lactic acid
|-
|Glucose, other fermentable carbohydrates
|Yeasts
|Ethanol
|-
|Ethanol
|Acetic acid bacteria
|Acetic acid
|-
|Lipids
|Microbial lipases
|Free fatty acids, aldehydes, ketones
|-
|Proteins
|Microbial proteinases
|Polypeptides, peptides, free amino acids, amines (cause textural and flavour changes in food)
|-
|Cellulose
|Mould cellulases
|Oligosaccharides, glucose
|}

=== 9.3.5 Factors Affecting Fermentation in Foods ===
Factors that are controlled in the production of fermented foods include: '''''Starter cultures, Formation of Metabolites ( e.g Acids, Alcohol), Temperature, Oxygen and Salt.'''''

==== '''''Starter cultures''''' ====
Modern food fermentation (biotechnology) employs the use of microbial cultures specifically selected and maintained for desirable trait(s): e.g.acid production; alcohol production; production of flavour compounds; production of specific enzymes; rate of growth. In current food fermentation practices, the starter cultures are grown under specific conditions and the harvested cells are added in a specific proportion to the food to be fermented. Cultures may be grown within the food processing plant or may be purchased as frozen or dehydrated cultures.

You may also have used starter cultures in your home:
* If you have baked bread in your home, you may have used dehydrated yeast as your starter culture for the bread dough. The food industry uses dehydrated starter cultures in a similar manner, but on a much larger scale.
* If you maintain a sourdough culture in your refrigerator, you use some of the techniques employed in industry to maintain the vigour of the culture, although in industry the numbers and types of organisms in the starter cultures are constantly monitored.
* Similarly, if you have made yogurt in your home, you have probably used part of a previous batch of yogurt or a commercially produced yogurt as the source of the starter culture.

==== '''''Formation of Metabolites''''' ====
Metabolites are products resulted from metabolism by the organism. In fermentation, the desired microorganisms or more specifically the starter culture is grown to produce the desired metabolites. These compounds vary depending on the type and condition of growth of the microorganisms. The most common metabolites are acids and alcohols.

==== '''''Acids''''' ====
Foods can be preserved by the addition of acids to lower the pH or by the encouragement of growth of acid-producing microorganisms used in food fermentations. Milk and meat are treated in such a manner that the '''lactic acid-producing bacteria''', added as a starter culture, will grow rapidly and produce lactic acid in sufficient quantities to suppress growth and metabolism of spoilage and disease-causing microorganisms. Cheese, yogurt, and fermented sausages must be stored under refrigeration with or without vacuum packaging to delay growth of the acid-tolerant '''psychrotrophic''' yeasts and moulds.

==== '''''Alcohol''''' ====
Alcohol, like acid, in sufficient concentrations functions as a '''preservative'''. Alcohol in wines and beer is not of sufficient concentration to inhibit growth of ethanol-oxidizing bacteria. Wines and beer must be further processed by pasteurization or filtration through membranes with pore diameters smaller than the spoilage-causing microorganisms. Fortified wines with alcohol contents above 20% do not require further preservation treatments.

==== '''''Temperature''''' ====
Temperature can be a very important factor in controlling the type of microorganism that grows during food fermentation. For example, temperature is a key factor in ensuring the sequential development of the desirable lactic acid-producing microflora in shredded cabbage during the fermentation of cabbage to ''sauerkraut.'' The development of a typical sauerkraut flavour requires the proper succession of lactic acid bacteria starting with ''Leuconostoc meserenteroides'' (which requires cool temperatures of about 21°C) and followed in sequence by ''Lactobacillus cucumeris'' (32°C) and ''Lactobacillus pentoaceticus'' (37°C). If you have made sauerkraut in your home, you have created conditions favourable to growth of these bacteria which are part of the normal microflora of cabbages. You will also have noted that sauerkraut has a much longer storage life than the cabbages from which it was produced but it will eventually become spoiled by acid-tolerant yeasts and moulds, particularly if good sanitary habits are not followed and storage temperature of the finished sauerkraut is too high. This is one of the reasons why sauerkraut is bottled and pasteurized to further extend its storage life.

==== '''''Oxygen''''' ====
Oxygen may be desirable or undesirable in fermentation processes. Microorganisms used in fermentation processes have different oxygen requirements for growth and fermentation activity. An example is baker's yeast (''Saccharomyces cerevisae''). This yeast will grow better under aerobic conditions; however, the yeast ferments sugars more rapidly under anaerobic conditions. Therefore, oxygen requirement conditions may differ and may change during the different steps of the fermentation process.

==== '''''Salt''''' ====
Adding salt to cabbage, olives and some meats favours the growth of lactic acid-producing bacteria while inhibiting the growth of normal spoilage- and disease-causing microorganisms. Salt also tends to draw moisture and the water-soluble nutrients from tissues making them available for use by the fermentative microorganisms. This important function is one of the purposes of using salt in sauerkraut, olive and pickle production. Salt also acts as a means of controlling the growth of undesirable microorganisms that may not be inhibited by the acid produced during the fermentation process. The acid and salt together produce a food system more inhibitory to disease- and spoilage-causing microorganisms than the salt or acid alone at the same concentrations.

=== How does a starter culture work? ===
Starter cultures are used in the production of fermented dairy products, meats, wines, beer and other alcoholic beverages. The starter culture, upon addition to the food to be fermented, begins to grow rapidly under the favorable conditions provided by the food processor and to produce desirable products of metabolism (acid, alcohol, flavour compounds, enzymes).

Of special concern to commercial users of starter cultures is the potential presence of microbial viruses (phage) in the food that could infect the culture and inactivate it. The fermentation industry constantly evaluates and selects starter cultures for their phage resistance and vigour in producing the desirable end products of metabolism. Likewise, the purity of starter cultures is maintained through sterile handling techniques and strict attention to processing plant sanitation.

Other fermented foods, such as olives, salt stock cucumbers and sauerkraut, are produced by creation of conditions favourable to growth of desirable microorganisms which are part of the normal microbial flora of the starting plant materials (cabbage, cucumbers, olives). Environmental conditions such as salt concentration and temperature are strictly controlled to maximize the growth of the desirable microorganisms while suppressing the growth of undesirable microorganisms.

Fermented foods, such as yogurt, contain in excess of one billion lactic acid bacteria per gram of product. Many people shudder at the thought of consuming bacteria, but in the cases of "the good" microorganisms, no harmful effects occur to the human body. In fact, there is some evidence that certain microorganisms used in food fermentation may have beneficial effects on the digestive function of the human body (Lesson 13)

=== 9.3.6 The Technology of Fermentation ===
The '''production of Cheese''' will be used as example to demonstrate the technology of fermentation.
[[File:FNH200_Lesson09_CheeseMaking.gif|500px|frame|Figure 9.1 Scheme of Cheese Making Process|center]]
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Figure 9.1 shows that milk is the starting ingredient in the cheese making process. Note that '''10 kg''' of milk are needed to produce '''1 kg''' of cheese.
* The proximate composition of cow's milk & Cheddar cheese is compared in Table 9.3.
* '''Which of the milk components are recovered in the cheese?'''
* Milk is composed of 88% water and approximately 3.3 g protein/100 g milk, with 2.7g being casein, the protein fraction involved in cheese curd formation. The remainder of the protein (0.6g) is whey protein. Milk fat partitions to the curd during cheesemaking. Most cheeses are rich in protein, fat, calcium and phosphorus, but low in lactose content. Individuals who are intolerant to lactose in foods can usually consume cheeses without experiencing gastrointestinal disturbances.
|}
'''Table 9.3''' Proximate composition of Cow's Milk and Cheddar Cheese, in grams per 100 grams edible portion (source: USDA Nutrient Database)
{| class="wikitable"
!
!Milk
!Cheddar cheese
|-
|'''Water'''
|88.32
|36.75
|-
|'''Fat'''
|3.25
|33.14
|-
|'''Protein'''
|3.22
|24.90
|-
|'''Lactose'''
|5.26
|0.23
|-
|'''Ash (minerals)'''
|0.69
|3.93
|}

==== '''''Setting the milk''''' ====
The lactic acid-producing culture is added to pasteurized milk at a concentration of 1% (v/v) to ensure that the starter culture is present in much larger numbers than other microorganisms in the pasteurized milk. This is done to ensure that the starter culture becomes the dominant portion of the microbial population in the milk.

Colouring agent is also added at this point. In Canada, annatto and ß-carotene are permitted for use as colourants for Cheddar cheese (see lesson 4: '''Division 8''' and/or '''Table III''' of Division 16 in the Food and Drugs Act of Canada) <nowiki>http://laws-lois.justice.gc.ca/eng/regulations/C.R.C.,_c._870/page-160.html#docCont</nowiki> (Links to an external site.)

Once the inoculated milk becomes mildly acidic, '''rennet''' or enzyme is added. The combination of acid and rennet causes the caseins to coagulate and form a gel very much like that found in a carton of yogurt. The '''commercial rennin preparation''' is known as "'''rennet'''", which is obtained from the 4th stomach of the calf and contains rennin and other small amounts of other materials. Rennin (also called chymosin) is a pure enzyme.

The enzyme hydrolyzes a portion of the k-casein from the casein micelle, changing the micelles from a calcium-stable to a calcium-sensitive state that leads to the formation of the coagulum with the aid of the lactic acid produced by the starter culture. The whey is trapped within the three-dimensional network created by the aggregating casein micelles and forming a gel.

==== '''''Curd cutting''''' ====
The curd is cut into cubes to promote efficient removal of whey from the curd. During this phase, the lactic acid culture continues to produce lactic acid which also aids in expression of the whey from the casein curd by causing the aggregated micelles to aggregate even further.

==== '''''Cooking''''' ====
The cut curds are cooked at 38°C to accelerate lactic acid production and further expulsion of whey from the curd.

==== '''''Draining whey and curd matting''''' ====
The curd cubes settle and the whey is drained from the cheese vat. Matting of the curd leads to fusion of the curd pieces to form a rubbery slab. This fusion is promoted by attractive interactions between the casein micelles along the curd edges.

During matting and Cheddaring'''2''', the lactic acid bacteria continue to produce lactic acid which aids in curd fusion and shrinkage, leading to further expulsion of the whey.

'''2''' '''Cheddaring''' involves cutting the matted curd into blocks, turning the blocks every 15 minutes, and piling the blocks on one another. This process allows whey to be further squeezed from the curd.

==== '''''Salting and milling''''' ====
The matted, Cheddar curd is cut (milled) and salted. The functions of the salt are:
* to draw the whey out of the curd;
* to flavour the final cheese;
* to inhibit growth of proteolytic and lipolytic spoilage-causing microorganisms that may be associated with the newly formed milled curd;
* to provide conditions favourable to the proteolytic action of the rennet and of the proteinases of the lactic acid starter during ripening of the cheese.

==== '''''Pressing''''' ====
The curd is pressed and hooped before curing. During curing, the curds knit together such that the curd junctions cannot be seen in a good quality Cheddar cheese. If you have some Cheddar cheese in your refrigerator, cut a slice and see if you can see curd junctions in the slice. Gently bend the slice as you look at it.

If the curd has not completely knit together, the cheese will fracture along the junction lines. Cheese in which the junctions are clearly visible tends to have a crumbly rather than a smooth texture. During ripening, proteinases of the lactic acid bacteria and the rennet continue to hydrolyze the casein to produce peptides and free amino acids that contribute to the typical Cheddar cheese flavour.

==== '''''Curing and ripening''''' ====
Complex changes occur within the ripening of cheese that lead to desirable flavours and textures of the cheese.

After the pressing step, the cheese is placed in a cool room for 3-4 days. In order to prevent mould from growing on the surface of the cheese, the cheese is vacuum packed in flexible film or dipped in hot paraffin.

Curing and ripening takes place at 2°C and 85% RH. The ripening stage is continued for at least 60 days. However, as you will note with different kinds of Cheddar cheese, ripening may be continued for 12 months or more if peak flavour and aroma are desired.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Using the website below, find out if cheese produced from "raw milk" (referring to "unpasteurized" milk, and including heat-treated but not pasteurized milk) allowed for sale in Canada? http://healthycanadians.gc.ca/eating-nutrition/healthy-eating-saine-alimentation/safety-salubrite/milk-lait/raw-milk-lait-cru-eng.php?_ga=1.16692222.997077515.1449084569
* Can you think of another function of the flexible film or dipped hot paraffin on the cheese?
* After reading about the different steps involved in cheese making, you are now ready to watch the video on Dairy processing: '''Cheese production.''' This will also help you to think about the answers to the following questions.
** What are the main consequences of cheese making that result in preservation, i.e. longer shelf life of cheese, compared to the starting milk? (''hint: you should be able to identify '''4''' main factors that provide the basis of preservation of cheese'')
** What are some of the variables during cheese making that can influence the shelf-life as well as sensory properties of cheese?
|}

=== 9.3.7 Descriptions of Some Common Cheeses ===
Cheeses are classified as soft, semisoft, hard and very hard, process cheese, and whey cheese. Variations in the cheese making process result in different cheeses, in terms of flavour, texture, appearance, and shelf-life. In addition to the lactic acid cultures, a secondary culture may be used to develop characteristic properties of some of these cheeses. Swiss, blue-veined and Camembert processes are described below.

''Optional:'' If you are interested in more details of cheese making, follow this Link (Links to an external site.) to the ebook by Professor Arthur Hill at the University of Guelph.

==== Swiss cheese ====
The production of Swiss cheese (characterized as a hard-type cheese) begins much like that of cheddar cheese except that an extra ("secondary") bacterial culture, ''Propionibacterium shermanii'', is added to the milk along with the lactic acid starter bacteria.

Note that multiple starters are used for production of Swiss cheese and that one of the starters, ''Streptococcus thermophilus'', is heat-tolerant so that acid can still be produced at the higher cooking temperatures employed during production of Swiss cheese. Also note that another bacterium, ''Propionibacterium shermanii'', is used as part of the starter culture since this organism produces '''propionic acid''' and '''carbon dioxide''' from lactic acid. The ''P. shermanii'' also produce the amino acid '''proline''' which imparts the sweet taste characteristic of Swiss cheese. The starter cultures are very important in the production of a high quality Swiss cheese. [[File:FNH200_Lesson09_Swiss.JPG|300px|thumb|Swiss Cheese: Note the characteristic eyes|center]]The propionic acid contributes to the characteristic flavour of Swiss cheese while the carbon dioxide forms the holes (eyes) in the cheese during aging
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* The next time you are in the grocery store purchase a package of Swiss cheese and examine it for the presence of the eyes in the cheese. Look at the cheese closely to evaluate the shape and size of the eyes, and experience the odour and flavour of the cheese by putting some in your mouth. The starter cultures are very important in the production of a high quality Swiss cheese.
|}

==== Blue-veined cheese ====
The blue-veined cheeses are characterized as semi-soft cheeses.

There are 4 varieties of blue-veined cheeses; three that are made from cow's milk:
* Blue cheese (Denmark, U.S.)
* Stilton (England)
* Gorgonzola (Italy)
* And one (perhaps the most famous) made from ewes' (sheep's) milk: Roquefort (Roquefort region of France)
The production procedure for the blue veined cheeses is similar to that of Cheddar cheese except that the curd is inoculated with a '''mould''', ''Penicillium roquefortii'', which grows within the hooped curd producing the characteristic flavour and colour of the blue veined cheeses. After it is hooped and pressed, the cheese curd is pierced in order to provide channels for the oxygen, required for mould growth, to enter the cheese. [[File:FNH200_Lesson09_BlueCheeseTop.JPG|300x300px|thumb|Blue Cheese|center]]
[[File:FNH200_Lesson09_BlueCheeseSide.JPG|400x400px|thumb|Blue Cheese: Note sites of inoculation|center]]The '''blue''' colour is due to the mould spores that are formed during growth of the mould along the lines where the cheese curd was pierced. ''Penicillium roquefortii'' is an active producer of the enzyme '''lipase''' which breaks down the milk fat into free fatty acids, aldehydes and ketones that contribute to the sharp, distinctive flavour characteristic of the blue veined cheeses. You may remember from earlier lessons that in most food preservation situations, great efforts are made to impede the action of lipolytic enzymes since lipolysis is generally considered to be a sign of spoilage. In the blue veined cheeses, however, lipolysis of the milk fat is a necessary part of proper flavour development. Part of the flavour of the blue cheeses is a musty, somewhat mouldy flavour that is contributed by the mould mycelia.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* If you are a regular consumer of blue cheeses, slowly eat a piece of the cheese and savour its flavour. Is the flavour more intense in regions of the cheese where the mould growth was heaviest? Note the presence of the holes on the outer edge of the cheese where the curd was pierced to provide oxygen for the mould. If you have never tried a blue veined cheese, purchase a very small piece to evaluate the texture, odour and flavour of the cheese. You will note that part of the flavour of the blue cheeses is a musty, somewhat mouldy flavour that is contributed by the mould mycelia.
|}

==== Camembert cheese ====
You may be a regular consumer of mould-ripened cheese such as Camembert and Brie (soft-type cheeses) or, if you are not, you have undoubtedly seen these types in the cheese counters at the local delicatessen. The curd is produced through the use of a lactic fermentation much like that used for Cheddar cheese. In this case the surface of the pressed cheese curd is also inoculated with spores of ''Penicillium camembertii'' (or ''Penicillium candidum''*). Vigorous growth of the mould leads to the formation of a layer of '''mycelia''' that form the white, velvet-like coating on the outer layer of the cheese. The mould is highly proteolytic and the mould proteinases diffuse into the cheese curd, hydrolyzing the casein into long-chain peptides which do not contribute much flavour to the cheese.[[File:FNH200_Lesson09_Camembert.JPG|450x450px|thumb|'''Camambert cheese:''' ''The cheese surface is inoculated with mould spores. A layer of mycelia forms the white, velvet-like coating on the surface of the cheese''|center]]The hydrolysis of the casein leads to the formation of the '''creamy''' texture characteristic of a good quality Camembert cheese. If the ''Penicillium'' culture is too proteolytic or if curing takes place too long, bitter tasting short-chain peptides, free amino acids and ammonia are formed. A good quality Camembert cheese has a mild flavour, is not bitter, and has a characteristic creamy texture. With Camembert cheese, the mould should not contribute to a mouldy flavour to the cheese; a mouldy flavour is considered a quality defect.

<nowiki>*</nowiki>For the past few years in Normandy, France, the mould ''Penicillium candidum'' has been commonly used instead of ''P. camembertii''. The reason for replacing the 'traditional' mould was that ''P. camembertii'' was sometimes responsible for causing 'blue moisture' on the cheese.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* For a visual tour of how Camembert cheese is made in Normandy, please visit t[http://www.taste-camembert.com/en/ he Camembert website].

* If you have never eaten Camembert cheese, you should taste a small piece. Note the feel of the outer layer in your hands and in your mouth and evaluate the texture and flavour of the interior of the cheese in your mouth. With Camembert cheese, the mould should not contribute a mould flavour to the cheese; a mouldy flavour is considered a quality defect
|}

== 9.4 Genetically Modified Organisms, Novel Foods and Biotechnology-Derived Foods ==

Start this part of the lesson by completing the following activity.
{| class="wikitable"
|'''Critical Thinking'''
|-
|Look at the list of ingredients on a package of Cheddar cheese.
* You will note that '''microbial cultures and rennet and/or pepsin and/or microbial enzymes''' are listed. The supply of calf rennet falls short of the demand. Some cheese processors use a mixture of rennet and hog pepsin (extracted from the stomachs of slaughtered hogs) or microbial rennets (proteinases with rennet-like properties produced by selected microorganisms). The substitute rennets, however, do not produce Cheddar cheese of as high quality as that produced with calf rennet.
* A good deal of research worldwide is directed at finding enzymes which could replace calf rennet. This includes production of calf chymosin by genetic engineering of microorganisms.
* Once again, please note that '''rennin''' and '''chymosin''' are pure form of enzyme and '''rennet''' refers to the preparation containing the pure enzyme along with other materials.
Check out the required additional readings - excerpts from Justice Canada website: Food and Drug Regulations Part B Foods (Links to an external site.), Division 8 Dairy Products, B.08.030 to B.08.033 on cheese and Division 16, Food Additives (Table V Food Additives that may be used as Food Enzymes).
* What "shall" cheese consist of? What "may" it contain?
* What enzymes are permitted as food additives in cheese? Have a look at the below excerpt from the Food and Drug Regulations, B.08.033 (3)
** '''(3)''' No person shall use an enzyme other than '''(a)''' aminopeptidase derived from ''Lactococcus lactis'', bovine rennet derived from aqueous extracts from the fourth stomach of adult bovine animals, sheep and goats, chymosin A derived from ''Escherichia coli'' K-12, GE81 (pPFZ87A), chymosin B derived from ''Aspergillus niger'' var. ''awamori'', GCC0349 (pGAMpR) or from ''Kluyveromyces marxianus'' var. ''lactis'', DS1182 (pKS105), lipase derived from Animal pancreatic tissue; ''Aspergillus niger'' var.; ''Aspergillus oryzae'' var.; Edible forestomach tissue of calves, kids or lambs; ''Rhizopus oryzae'' var. or from ''Aspergillus oryzae'' (MLT-2) (pRML 787) (p3SR2); ''Rhizomucor miehei'' (Cooney and Emerson) (previous name: ''Mucor miehei'' (''Cooney and Emerson'')); ''Rhizopus niveus'', milk coagulating enzyme derived from ''Rhizomucor miehei'' (Cooney and Emerson) (previous name: ''Mucor miehei'' (Cooney and Emerson)), from ''Mucor pusillus Lindt'' by pure culture fermentation process or from ''Aspergillus oryzae'' RET-1 (pBoel777), pepsin derived from glandular layer of porcine stomach, phospholipase derived from ''Aspergillus oryzae'' (pPFJo142), protease derived from ''Micrococcus caseolyticus'' var. or rennet derived from aqueous extracts from the fourth stomach of calves, kids or lambs, in the manufacture of any cheese to which subsection (1) applies;
|}

=== What are GMOs and GEs? ===
Genetically Modified Organisms ("GMOs") are plants, animals and microorganisms in which there is a change to the heritable trait(s) of the organism by intentional manipulation. This intentional manipulation includes but is not limited to the use of modern gene technologies such as recombinant nucleic acid technology. Genetically engineered organisms are more specific and through this technology, a foreign piece of DNA (deoxyribonucleic acid) is inserted into the genetic material of the host organisms.

Genetic modification may enable the host organism to
* yield a desired product (e.g. bovine chymosin produced by genetically modified bacteria), or
** possess a desired characteristic (e.g. tolerance to a specific herbicide in genetically modified canola plants, insect resistance in corn genetically modified to produce the insect toxin produced by ''Bacillus thuringensis'', Bt; canola plants genetically modified to produce oil with specific compositional characteristics)

=== Genetic engineering and cheese ===

==== Recombinant chymosin ====
* Recent developments have enabled transfer of the gene from calves that encodes for the enzyme '''chymosin''' to specific microorganisms selected for enzyme production.
** The microorganisms are cultured in large fermenters and produce the chymosin which is then isolated, purified and sold to the dairy industry for cheese making.
** Microbially produced bovine chymosin is an approved '''food additive''' in Canada. Chymosin is the principle milk-clotting enzyme in bovine rennet extracts that have traditionally been used in cheese making.

==== Genetically engineered starter cultures ====
* Research is also being conducted to improve '''fermentative capabilities''' of lactic acid bacteria and other bacteria and moulds used in cheese making.
** Some of that research involved genetic engineering where genes encoding for '''increased resistance to bacterial viruses''' (bacteriophage, a potentially serious problem in cheese making which can cause starter culture failure), '''improved enzymatic activity''' (lactose utilization; production of desirable proteinases involved in cheese ripening) are transferred into bacteria used as starter cultures.
** Genetically improved starter cultures produced through genetic engineering must go through thorough '''testing''' and '''evaluation''' to demonstrate their '''safety''' prior to approval for their use in foods (they are classified as food additives).
There is a great deal of public concern and controversy about genetically modified foods and genetically modified organisms (these have been dubbed as ''Frankenfoods'' by opponents to the technology and the concept).
{| class="wikitable"
| '''Want to learn more?'''
|-
|To make an informed personal decision regarding whether or not you would accept (some or all) GM foods, please visit the following websites:
* [https://www.canada.ca/en/health-canada/services/food-nutrition/genetically-modified-foods-other-novel-foods.html Health Canada] (biotechnology page)
* "''Novel Food and Ingredients''" page at the Health Canada website: [https://www.canada.ca/en/health-canada/services/food-nutrition/genetically-modified-foods-other-novel-foods/approved-products.html Guidelines for the Safety Assessment of Novel Foods]"
|}
== 9.5 Packaging Requirements for Fermented Foods ==
In order to extend their shelf life, fermented foods require "additional" forms of preservation such as pasteurization and refrigeration.

Think about the variety of fermented products available in the market. What other forms of preservation methods are being used along with the fermented product?

Packaging also plays an important role as it should protect the food from re-contamination, oxidative reactions, etc.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Can you list and describe some examples of packaging materials used for fermented products?
* What type of packaging would be suitable for fermented products and why? (Hint: interaction from food with the packaging material)
|}

== 9.6 Summary of Lesson 9 ==
* Fermentation has a long history of use in civilization. Biotechnology is the "new" term applied for such an ancient preservation process
* When we speak of fermented foods we are referring to the foods which have been produced with the aid of microorganisms.
* Preservation of food by biotechnology involves the use of live microorganisms to produce desirable changes in the food, including acids, alcohols and other (antimicrobial) substances that inhibit the growth of other microorganisms (microbial antagonism)
* Food fermentation can be caused by bacteria, yeast, and mould
* Cheese is an example of a fermented food or a product derived from biotechnology
* Different and unique starter cultures are used in the fermentation of milk, to make different types of cheese
* Genetically Modified Organisms ("GMOs") are plants, animals and microorganisms in which there is a change to the heritable trait(s) of the organism by intentional manipulation.
* Fermented foods require additional preservation methods to enhance the shelf-life and stability of the product. Packaging materials also play an important role.
'''Supplemental Videos:'''
# [https://www.youtube.com/watch?v=txWbdnd8xL8&feature=emb_logo LARGE scale production]
# [https://www.youtube.com/watch?v=y9wLhRrj5Ug&feature=emb_logo Cheese making process]. This is a pretty easy to follow clip, a bit funny and has all necessary science content needed for FNH 200
# [https://www.youtube.com/watch?v=Pnw-XwCctYY&feature=emb_logo How is cheese made?] This video is even clearer than the one above, but I feel there is less science content.

'''Authorship:'''

FNH 200 Course content on this wiki page and associated lesson pages was originally authored by Drs. [http://www.landfood.ubc.ca/person/brent-skura/ Brent Skura], [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], and [http://www.landfood.ubc.ca/person/eunice-li-chan/ Eunice Li-Chan]. Ongoing edits and updates are contributed by past and current instructors including Drs. [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], [http://www.landfood.ubc.ca/person/azita-madadi-noei/ Azita Madadi-Noei], [http://www.landfood.ubc.ca/person/nooshin-alizadeh-pasdar/ Nooshin Alizadeh-Pasdar], and [http://www.landfood.ubc.ca/person/judy-chan/ Judy Chan].
{{cc-by-nc-sa-3.0}}

<quiz display=simple>
{1. Which two regulatory agencies are responsible for the regulations of products derived from biotechnology in Canada?
|type="[]"}
+ Health Canada
+ Canadian Food Inspection Agency
- World Health Organization
- Food and Agriculture Organization
- Codex Alimentarius Commission
- Canadian Biotechnology Advisory Committee
</quiz>

<quiz display=simple>
{ 2. Type text here or a no-break space code
|type="{}"}
Which microorganism leads to the production of alcoholic beverages? { Yeast }
</quiz>

<quiz display=simple>
{3. Which one of the following is NOT an approved novel food in Canada?
|type="()"}
- Herbicide tolerant corn
- Algal protein
- Acrylamide-reducing yeast
- Non-browning apple
- All of the above
+ None of the above
</quiz>

<quiz display=simple>
{4. Which is the best definition of a genetically modified organism?
|type="()"}
- Microorganisms that have had genetic material intentionally manipulated in order to produce enzymes or particular by products.
- A plant that has a trait that has been produced intentionally through breeding or genetic engineering.
+ A living organism (plant, animal, microorganism) that has a trait that has been produced intentionally through manipulating genetic material (DNA).
- Plants and animals that have had genetic material belonging to a different species inserted into their own genetic material to produce a desired trait.
</quiz>

<quiz display=simple>
{5. Which are two components that produce microbial antagonism seen in fermentation?
|type="()"}
- Oxygen and Alcohols
- Polysaccharides and Acids
- Salts and Acids
+ Acids and Alcohols
</quiz>

Course:FNH200/Lessons/Lesson 08

2020-06-24T00:38:06Z

YihangChen: /* 8.5 Packaging Requirements for Dehydrated Foods */

<big><big><big>'''Dehydration as a Food Preservation Method'''</big></big></big>

== 8.0 Overview ==
Dehydration of foodstuffs involves the removal of water to increase the storage stability of perishable food items. You will learn about processing parameters that affect the ultimate quality of dehydrated plant and animal tissues and fluids that are used as food. You will learn about the principles of spray drying and freeze drying of foods that are amenable to these dehydration methods. The advantages and disadvantages of various dehydration technologies will be discussed. You will learn packaging requirements for maintenance of the quality of dehydrated foods.

=== Objectives ===
Upon completion of this lesson, you will be able to:
* illustrate the underlying concepts of various methods of food dehydration
* outline the basis for extension of storage life of foods by dehydration
* compare and contrast methods for dehydrating different foods, and the consequences in terms of food quality
* explain factors affecting the rate of dehydration
* describe the packaging requirements for foods dehydrated by various dehydration methods

== 8.1 Introduction ==
{| class="wikitable"
|
==== '''Terms to remember''' ====
|-
|
* Water activity
* Dehydration ''vs.'' Concentration
* Case hardening
* Mass transfer
* Water soluble components
* Sublimation
* Hygroscopic
* Atmospheric pressure & vacuum
* Different dehydration methods (sun drying, tray (air) drying, freeze drying, etc.)
|}

Some reasons for dehydrating foods are:
* preservation of the food (dried milk, juices, fruit);
* retention of the size and shape of the food while imparting storage stability (freeze dried steak, vegetable pieces);
* reducing weight and bulk of food for easier storage and transportation; and
* production of convenience items (instant coffee, instant mashed potatoes, vegetables that rehydrate in instant soup preparations).
'''Food preservation by dehydration is based on the principle''' that microbial growth, chemical and enzymatic reactions occur only if sufficient '''''free'' water''' is present. When the water activity of foods is lowered there is a direct impact on microbial growth as well as chemical & enzymatic reactions.

Recapping from Lesson 2:
* '''Water activity''' (aw) defines the proportion of water in a food that is in the free, unbound form
* Microbial activity, enzymatic activity and chemical reactions can occur '''only in the free water phase''' of foods
* Water activity of foods ranges from 0 to 1.0
** Water activity of '''dehydrated''' foods is in the range of '''0.2''' to '''0.6'''
** Microorganisms '''cannot grow''' at aw below '''0.6'''
** Chemical reactions (e.g. Maillard browning) can begin to occur at aw of '''0.3'''
{| class="wikitable"
<td>Want to know more?
</td>
|-
|Please visit this website from the Cole Palmer Instrument Company for an overview on water activity, including examples of water activity values for several food products

http://www.foodtechsource.com/rcenter/tech_data/td_water.htm
|}
It is important to remember that with dehydration, microorganisms are '''not readily killed'''. Once the food is '''rehydrated''', microorganisms '''resume growth''' if favourable conditions exist.

It is also important to distinguish between food dehydration and concentration, both of which involve the removal of water from foods:

'''Dehydration''' implies removal of as much water from the food as possible in order to impart a long storage life.

'''Concentration''', on the other hand, implies that some of the water is removed from the food in order to concentrate the food constituents. Concentrated foods are not inherently shelf-stable and require the use of other forms of food preservation (e.g., refrigeration, freezing, dehydration, thermal processing) to extend storage life.

== 8.2 Changes in Food during Dehydration ==
Similar to the other preservation methods we have reviewed, dehydration will cause changes in the food that need to be controlled in order to maintain the highest quality possible. Some of these changes are:
* '''''Cell/tissue Shrinkage'''''. As water is removed from food pieces during dehydration, the cells within the tissue shrink and lose their elasticity. If you have purchased dehydrated vegetables such as carrots, onion slices, or dehydrated fruits such as apple cubes or slices you may have observed the shrinkage that has occurred. Part of the reason for shrinkage of foods that have been dehydrated is that the water migrates from the interior of the food to the surface where it finally evaporates and is carried away by the dehydrating medium. As the water migrates to the surface of the food it carries with it the water soluble substances dissolved in it. The loss of these substances from the interior of the food pieces contributes to the shrinkage observed in dehydrated foods and also contributes to the poor rehydration properties of such foods. Loss of the water soluble components from the interior portions of the food pieces decreases the driving force for attraction of water into the food pieces during rehydration.[[File:FNH200_Lesson08_Shrinkage.gif|659x659px|thumb|Cell Shrinkage during Dehydration|center]]
Sequence of events that occur during dehydration.

(A) Fresh apple cube

(B) Partially dried apple cube

(C) Dried apple surface coated with sugars, acids and salts shape distorted due to cell shrinkage and migration of water solubles to the surface
* '''''Case hardening'''''. Case hardening occurs when rapid drying causes compounds such as sugars to form a hard, fairly impermeable case around the food piece. This phenomenon can cause the rate of dehydration to decrease. Case hardening can occur in high-sugar products such as tropical fruit and many temperate fruit products. Dehydration procedures are designed to minimize the development of case hardening as much possible.

* '''''Chemical changes'''''. A number of chemical changes occur in foods during dehydration in systems employing warm air as the drying agent. The Maillard browning reactions (''Lesson 2'') cause the development of brown colours and the formation of flavours not originally associated with the fresh product. The Maillard reactions proceed most rapidly when the water content of the food is in the range of 20% down to 15% because the reactants are in very close proximity, which increases the probability of reactions occurring. Thus, drying systems are designed to remove water through the 20-15% range of moisture content as rapidly as possible. This will minimize the negative effects the Maillard reaction has on the flavour of dehydrated food products. The flavour of rehydrated skim milk powder is due largely to the products of the Maillard reaction during dehydration of the milk. Prior to dehydration of egg whites, they are treated with an enzyme, ''glucose oxidase'', which "de-sugars" the egg whites and minimizes the colour and flavour changes that could be caused by the Maillard reactions involving glucose. Poor rehydration can occur because of the loss of the ability of some hydrophilic food constituents to absorb water. Heat denaturation of proteins, starches and gums can decrease the water-holding capacity of dehydrated foods. The salts and sugars concentrated on the outside of the food pieces will dissolve in the water added to the food to rehydrate it. Since those water soluble components are not inside the food pieces, there is less attraction for water to enter the food product. As result, rehydration is less complete. You may have noticed that dehydrated fruit pieces are much sweeter than the fresh fruit. The reason for this phenomenon is that the sugars are ''concentrated'' on the outside of the fruit. Loss of volatile substances that contribute to the flavour of foods occurs during dehydration. Generally the higher the drying temperature, the larger the loss of volatiles, with the result that the dehydrated food is less flavourful than the initial product.
Dehydrated foods may show varying extents of shrinkage or chemical changes, depending on the method and conditions used to dry the food.

== 8.3 Factors Affecting Dehydration ==
Dehydration of food requires that water (mass) be transferred from the food into the dehydrating environment, and that heat (the driving force that encourages water removal) be transferred to the food to promote water removal from the food. The objectives of food dehydration operations are to dry the food as fast as possible, at the least cost, while creating the fewest changes in food quality.

The composition of the food itself can have an effect of the rate at which dehydration occurs. For example, if water is bound to solutes in the food it will have a lower vapour pressure and therefore will be more difficult to remove. The porosity of the food is also important. Efforts are made to enhance the porosity of foods to be dehydrated in order to facilitate mass transfer and speed of drying rate, thus maximizing the efficiency of dehydration. Porous (sponge-like) structures are formed by creating steam pressure within the product during the drying process. The steam will "puff" the product. Another way of creating porosity is by making a stable foam from a liquid food prior to drying.

In addition to the composition of food, the following factors can also affect heat and mass transfer within food materials undergoing dehydration, and therefore are important to consider in order to control some of the undesirable changes described previously:
* '''''Surface area'''''. It is desirable to maximize the surface-to-volume ratio of the food to be dehydrated to minimize the resistance to heat and mass transfer. Generally, the smaller the food piece, the more rapid the rate of moisture loss.
* '''''Temperature'''''.The hotter the air, the more moisture it will hold before becoming saturated. Drying systems are designed to maximize temperature differences between the product and the drying air to increase the rate of dehydration. An upper limit to drying air temperature is dictated by adverse chemical reactions that can take place in a food at high temperatures. The upper temperature limit is also dictated by the chemical and physical nature of the food.
* '''''Air velocity'''''. The faster the air velocity within a dehydrator, the more rapid the rate of moisture removal. Food dehydrators are designed to maximize the velocity of heated air moving around the food particles to be dried.
* '''''Humidity of the drying air'''''. The drier the air, the more moisture it can absorb before it becomes saturated. The relative humidity of the drying air determines the final moisture content of the food being dried. Knowledge of the equilibrium relative humidity of food is important for the proper design of dehydrators and for the design of packaging systems that will prevent moisture adsorption by the dehydrated food during storage. You may have experienced the loss of crispness of crackers in opened packages during lengthy storage in your cupboards. Crackers have a low equilibrium relative humidity and they tend to adsorb water from the air.
* '''''Atmospheric pressure and vacuum'''''. Water boils at 100°C when it is at a pressure of 1 atm (760 mm Hg). As the pressure lowers, the boiling temperature will decrease. If the temperature is maintained constant, a decrease in pressure will increase the rate of boiling. Some concentrators and dehydrators are operated at pressures below atmospheric pressure in order to increase the rate of boiling and moisture removal. This is especially important in the case of heat-sensitive food products.

== 8.4 Drying Methods ==

=== Sun Drying ===
Sun drying is mostly used in dry, warm climates. This is a very slow drying method (several days). It is mostly used for fruits, vegetables, and fish. An advantage of this method is the fact that it is quite inexpensive; however, disadvantages include long drying periods (up to several weeks) and the risk of invasion by insects, birds, rodents, and microorganisms.

The appearance is shrunken and has poor rehydration capacity.
[[File:L8 fig8-aa.jpg|thumb|Sun dried tomatoes|center]]

=== Spray Drying ===
Spray driers are used to produce the greatest quantities of commercially dehydrated foods. Spray driers are restricted to use with liquid foods since the principle of the operation is the introduction of the food as a spray of small droplets into a high velocity stream of warm air. Because droplet sizes are small, drying rates are very rapid and high quality dehydrated food products can be produced. Foods most commonly dehydrated by spray driers include skim milk, coffee, tea and eggs.

You will note that the equipment is designed to maximize drying rate, to produce dry particles of uniform size and to prevent sticking of partially dry food particles to the walls of the spray driers. You should also note that spray driers operate continuously, that is, the product is sprayed into the drying chamber and the dried product and moist air are separated and removed from the driers.
[[File:L8. Spray dryer Modified.png|thumb|Figure 8.2 Spray drier. Source: Food Science and Nutritional health by T.P. Labuza and J.W. Erdman. West Publishing Co., St. Paul MN. 1984.|center|500x500px]]

{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Fluid milk and egg products are commonly spray-dried into powder form. Milk and eggs are low-acid foods that are susceptible to growth of '''pathogenic''' microorganisms as well as to '''spoilage''' by microbes and enzymes.
* Since the dehydration process does not kill microorganisms nor inactivate enzymes, can you think of additional processes or approaches that can be used in conjunction with dehydration for better preservation of milk and egg powders?
|}

=== Tray (Air) Drying ===
Food placed on trays or racks is exposed to heated air at a set velocity. This type of drying can be quite fast and requires heated air with a relative humidity (%RH) lower than that of the product to be dried. Water soluble components migrate to surface of food and are deposited as water evaporates. The dried food has relatively poor re-hydration properties, is shrunken in appearance and is very dense. Products dried this way are: pasta, vegetables, fruit, spices. The diagram below shows the sequence of events that occur during dehydration of fruit tissue.[[File:FNH200_Lesson08_TrayDryer.png|433x433px|thumb|Figure 8.3 Tray Dryer as Adapted from Labuza and Erdman|center]]

=== Drum Drying ===
During the process of drum drying, food paste is applied to a heated drum in a thin layer to promote rapid drying. As the drum rotates, it picks up a thin film of food material that dries rapidly. The dried food is scraped off the drum near the end of a full rotation of the drum. Dehydrated mashed potatoes and some ready-to-eat breakfast cereals are dried this way. Some popular low fat snack foods and potato chip like products contain drum dried potato flakes as the primary ingredient.[[File:FNH200_Lesson08_DrumDryer.png|485x485px|thumb|Figure 8.4 Drium Drier. Source: Food Science and Nutritional health by T.P. Labuza and J.W. Erdman. West Publishing Co., St. Paul MN. 1984.|center]]

=== Freeze Drying ===
'''Freeze driers''' are fairly recent innovations as far as food dehydration is concerned. Freeze drying is restricted to high value foods because of the high costs associated with this dehydration method.

During freeze drying, water is removed from food in the frozen state without transition through the liquid state. This phenomenon, called '''sublimation''', is illustrated below:

'''water(solid) —> water(vapour)'''

Sublimation of water is accelerated under '''vacuum''' conditions. During freeze drying, food is frozen and then placed in the freeze dryer, the dryer is sealed and a vacuum is created and maintained. Application of heat from '''radiant heaters''' within the shelves of the freeze drier provides the energy required for sublimation to occur. During freeze drying the amount of heat applied to the food is carefully controlled to maximize the rate of drying without causing transition of water from the solid to the liquid phase. A schematic diagram of a food being freeze dried is shown in Figure 8.5.
[[File:L8 fig8。5.jpg|thumb|Figure 8.5. Schematic drawing of how food is freeze dried.Adapted from: Potter, N. and Hotchkiss, J.H. 1995. Food Science (5th ed), Ch. 10. Aspen Publishers., p. 229.|center|500x500px]][[File:L8 fig8-bcc.png|thumb|Figure 8.6 Freeze drierSource: Food Science and Nutritional health by T.P. Labuza and J.W. Erdman. West Publishing Co., St. Paul MN. 1984.|center|500x500px]]During freeze drying, because the food remains rigid during dehydration, the subliming water leaves voids where the ice crystals were located. There is no translocation of water-soluble constituents because there is no movement of liquid, allowing freeze dried foods to '''retain their shape.''' Also, freeze dried foods '''rehydrate''' almost completely because the '''voids''' left by the subliming water provide channels through which water can enter the food, and the water-soluble components of the food in their original locations provide the driving force for rehydration. Freeze dried foods do not usually exhibit the shrinkage and chemical changes noted earlier to occur in other dehydrated foods.
* If you have consumed the instant soup mixes that are prepared in a cup with the addition of boiling water, you will have noted that the vegetables have rehydrated within several minutes and that they possess a fresh flavour. Those vegetable pieces were freeze dried.
* You may wish to compare the rate and extent of rehydration of vegetable pieces in an instant soup mix (in which vegetables were freeze dried) with those vegetables from a soup mix which has to be boiled for about 10 minutes in order to rehydrate the vegetable pieces (these vegetable pieces were tray-air dried).

=== Vacuum Microwave Drying ===
'''Vacuum microwave''' or '''radiant energy vacuum (REV)''' technology is being developed for the dehydration of food, nutraceutical and pharmaceutical products by Dr. Tim Durance in the Food Science program at the University of British Columbia. The technology consists of a combination of '''vacuum''' (in order to keep the temperature low) and '''microwaves''' (for ultra-rapid energy transfer), producing high quality products with less nutrient loss, better flavour retention, and less colour change. Vacuum microwave dried (VMD) products retain a more natural appearance and have the advantage of complete re-hydration (reconstitution). VMD is a quick drying method when compared to freeze drying and air drying methods (VMD can take only a few minutes, compared to hours in freeze drying).

For more information, visit <nowiki>http://www.enwave.net/</nowiki> (Links to an external site.)

=== Deep Fat Frying ===
During deep fat frying, the high temperature of hot oil causes water in the food to evaporate rapidly, often accompanied by substantial pick up of oil by the food being dried. Dried foods such as potato chips have a low water content (as well as a low water activity) but a high oil content. Many snack foods and bakery products, such as donuts, are produced by means of deep fat frying.

Do you know how instant noodles are made? After cooking and shaping, the noodles are dried either by deep-fat frying or non-frying (hot-air) drying. Frying is usually done at 140-150°C for 1-2 minutes, while hot-air drying uses a temperature of about 80°C for 30 min. The two drying methods yield products that differ greatly in fat content.

=== Extrusion (cooking) Drying ===
Slurry of food is passed though a tube, under pressure, that is heated by steam. The moist heat causes starch gelatinization and cooking of the product. Product is forced though a narrow opening (a die which can produce a product with a variety of shapes) at the end of the tube and escaping steam causes the dehydrating product to puff. Many ready-to-eat breakfast cereals and snack foods are produced this way.
[[File:L8 extrusion.png|thumb|Figure 8.7. Extrusion (cooking) DryingSource:Understanding Food Science and Technology by P. S. Murano. Wadsworth/Thomson Learning Inc. 2003.|center|500x500px]]
'''Common food products prepared by extrusion drying'''
{| class="wikitable"
!Category
!Examples
|-
|Ready-to-eat breakfast cereals
|Puffed cereals, flaked cereals, high-fiber strands
|-
|Snacks
|Puffed snacks, Crispbreads
|-
|Confections
|Licorice, some chocolates
|-
|Texturised protein
|Soy meat-analogues, "processed" cheese
|-
|Infant foods
|Biscuits, weaning cereals
|}
{| class="wikitable"
| '''Want to learn more?'''
|-
|
* Now that you have read about the different drying methods
** Which methods would lead to the most changes, or conversely the least changes, in the resulting dehydrated foods?
** How do dehydrated foods obtained by different drying methods compare in terms of the rate and ease of rehydration?
|}
{| class="wikitable"
|}

== 8.5 Packaging Requirements for Dehydrated Foods ==
Many dried foods also require that the packaging material provide ''physical protection'' to prevent the food from becoming crushed during distribution and handling.
{| class="wikitable"
|'''Want to learn more?'''
|-
|''Take a look at dehydrated products in your kitchen cupboard or in the grocery store, and '''think about''':''
* what drying method(s) might have been used
* the effects of drying on the product properties, rate and ease of rehydration
* the type of packaging used and why?
|}

== 8.6 Summary of Lesson 8 ==
* Preservation of food by dehydration involves the removal of water (thus lowering the water activity) from the food to extend the food's shelf life by slowing down microbial growth and chemical/enzymatic reactions.
* Microbial growth and chemical/enzymatic reactions will resume once the food is re-constituted or re-hydrated.
* During dehydration of food, changes such as "cell shrinkage, case hardening, and different chemical changes", can take place.
* During dehydration, several factors (e.g. temperature, air velocity, humidity of the drying air, etc) must be controlled in order to prevent undesirable changes (case hardening, excessive cell shrinkage, etc)
* Packaging materials should not only impart physical protection, but also assist in preserving dehydrated foods by further protecting against moisture absorption, as well as preventing interactions with oxygen and light.
Supplemental Video: [https://www.youtube.com/watch?time_continue=1&v=3LJto1D0iPs&feature=emb_logo Extrusion Drying]<references />

'''Authorship:'''

FNH 200 Course content on this wiki page and associated lesson pages was originally authored by Drs. [http://www.landfood.ubc.ca/person/brent-skura/ Brent Skura], [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], and [http://www.landfood.ubc.ca/person/eunice-li-chan/ Eunice Li-Chan]. Ongoing edits and updates are contributed by past and current instructors including Drs. [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], [http://www.landfood.ubc.ca/person/azita-madadi-noei/ Azita Madadi-Noei], [http://www.landfood.ubc.ca/person/nooshin-alizadeh-pasdar/ Nooshin Alizadeh-Pasdar], and [http://www.landfood.ubc.ca/person/judy-chan/ Judy Chan].
{{cc-by-nc-sa-3.0}}

<quiz display=simple>
{1. The principle of dehydration is...
|type="[]"}
- Elimination of pathogenic microorganisms
- Elimination of spoilage-causing microorganisms
+ Removal of free water
+ Lowering of water activity
</quiz>

<quiz display=simple>
{2. Type text here or a no-break space code
|type="{}"}
What is the white powder seen on the surface of dried pineapple? { Sugar }
</quiz>

<quiz display=simple>
{3. Which technique below was developed at UBC?
|type="()"}
- Sun drying
- Spray drying
+ Vacuum microwave drying
- Drum drying
- Deep fat frying
- Extrusion drying
</quiz>

<quiz display=simple>
{4. Dehydration preserves food because it lowers water activity which is required for microbes to grow and both chemical and enzymatic reactions.
|type="()"}
+ TRUE.
- FALSE.
</quiz>

<quiz display=simple>
{5. Upon rehydration, both chemical and enzymatic reactions can begin again.
|type="()"}
+ TRUE.
- FALSE.
</quiz>

Course:FNH200/Lessons/Lesson 07

2020-06-24T00:34:55Z

YihangChen:

<big><big><big>'''Preservation of Foods by Low Temperature'''</big></big></big>

== 7.0 Overview ==
In this lesson you will learn about the principles that form the basis for extending the storage life of foods through the use of low temperatures above and below the freezing point of water. You will also learn about chilled storage of perishable foods and the use of modified and controlled atmospheres to extend the storage life of foods.

You will learn about the importance of freezing and thawing rates and their influence on the quality of frozen foods. The importance of ice crystal size and chemical reactions and physical changes that can occur in foods during freezing, frozen storage and thawing will be briefly discussed. You will learn about some of the methods of freezing foods and also about packaging requirements for foods held in chilled and frozen storage.

=== Objectives ===
Upon completion of this lesson, you will be able to:
* explain the principles that form the basis of extension of storage life of foods at low temperatures;
* outline the importance of freezing rates, temperature stability during storage of frozen foods, and thawing rates on quality maintenance in frozen foods
* describe the factors that can affect quality of foods during frozen storage

=== Required Videos ===
* Corn processing and Ice cream production
The links for these videos will be indicated later in the lesson. 

== 7.1 Use of Low Temperatures in Food Preservation ==
{| class="wikitable"
|
==== '''Terms to remember''' ====
|-
|
* Psychrotrophic
* Modified atmosphere packaging (MAP)
* Freezing point
* Latent heat
* Concentration effects
* Freezer burn
* Freezing rate
* '''IQF'''(individually quick frozen)
* Indirect contact freezers
* Cryogenic
* water vapour
|}
Refrigeration or cool storage generally refers to storage at temperatures above freezing, while freezing and frozen storage occur at temperatures below freezing. However, whereas pure water freezes at 0°C, most foods do not begin to freeze until a temperature of -2°C or lower is reached.

'''Refrigerated''' or cool storage generally will preserve most perishable foods for days or weeks, while good '''frozen''' storage conditions with proper packaging can preserve foods for months or even years.

It should be noted that some '''psychrotrophic''' pathogens (review terminology in Lesson 5) can grow, although slowly, at refrigerator temperatures, and some spoilage organisms can even grow at temperatures below 0°C providing that there is unfrozen water available.

Below '''-9.5°C''', there is no significant growth of '''spoilage''' or '''pathogenic organisms,''' and there is a gradual decrease in numbers of living organisms. However, freezing and frozen storage do not lead to complete destruction, and rapid growth and multiplication can occur during '''thawing.'''

== 7.2 Refrigeration (Cool Storage) of Foods ==
Refrigeration is one of the mildest approaches to food preservation.
* Refrigeration/Cool storage of foods falls between -2°C to 16°C. However, in the food industry, the refrigeration temperatures should be in the range of '''4°C''' and below. The Food and Drug Regulations of Canada state that perishable foods that can support the growth of disease-causing microorganisms must be stored at temperatures of '''4°C and below.'''
* A drop of 10°C '''slows down''' rate of senescence by 2 to 3 times and microbial growth by 3 to 6 times.
* Refrigeration temperatures inhibit the growth of most disease-causing microorganisms but can favour the '''psychrotrophic''' microorganisms.
* Some spoilage-causing microorganisms, particularly moulds, can grow at temperatures as low as '''-8°C'''.
* You must keep in mind that refrigeration storage temperatures only provides a '''short term''' extension to the storage life of foods
* Refrigeration storage of foods '''can not''' improve the quality of a food item that is low of quality when placed into cold storage.
In addition to being a mild approach to short-term preservation, refrigeration is also sometimes applied to achieve desirable attributes of fermented food products such as cheeses, beef and wine upon cool ripening or aging.

=== What are the optimal conditions for refrigerated storage of foods? ===
Each food commodity has its optimum refrigeration conditions for maximum storage life and retention of quality and nutritional value.

The storage life of meats, fish and dairy products are maximized by temperatures that approach 0°C. During refrigerated storage of foods, maintenance of '''controlled temperatures''' are very important to ensure maximum storage life of the foods and to prevent chill injury to certain foods, especially some fruits and vegetables. For example, as reported by Potter and Hotchkiss (1995):
* Bananas will undergo a colour change in the peel from yellow to black, while sweet potatoes may show decay, pitting and internal discolorations, when stored at temperatures below 13°C.
* Apples may become soggy or show internal browning if stored below 1-2°C.
* Potatoes and avocados may also become brown if stored below 5 and 7°C, respectively.
Other factors to be controlled for products in refrigerated storage are '''humidity''' and '''gas atmosphere composition'''. A very fine humidity balance must be maintained to prevent dehydration of the food while avoiding creation of conditions that are so humid that mould growth and food spoilage are favoured. Many food products are stored under '''controlled''' and '''modified atmospheres''' in conjunction with refrigerated storage for the extension of storage life.

A '''controlled atmosphere''' refers to a condition in which the atmosphere surrounding a food product is different from that of the normal atmosphere, and the composition of the atmosphere around the product is '''constantly monitored and maintained''' at preset levels.

'''Review from Lesson 1:''' "controlled atmosphere storage"- facilities where the atmosphere (CO2, O2 and N2) and humidity are carefully controlled and temperature kept low to slow the rate of respiration and ripening of the apples, thus extending the storage life of the fresh fruit.

'''Modified atmosphere''' refers to the creation of atmospheric conditions around the product that are different from the normal atmosphere. In this type of system, food items are placed into a package. The air in the package is then removed either by drawing a vacuum, then backflushing the package with the desired gas mixture before sealing the package, or simply by flushing the package with the desired gas mixture until the air in the package is replaced by the desired gas mixture (usually a combination ofcarbon dioxide and nitrogen) before sealing the package. Examples of products with MA-packaging '''(MAP)''' are shown in Figure 7.1. [[File:FNH200_Lesson07_MAPLettuce.jpg|frame|centre|300px]]
[[File:FNH200_Lesson07_MAPPasta.jpg|frame|centre|300px|'''Figure 7.1''' Examples of modified packaging packaging (MAP).]]The composition of the atmosphere in a modified atmosphere packed food product '''changes over time''', the changes being governed by metabolic activities of the food, the microorganisms in the food, and the gas permeability of the packaging materials used.

'''Vacuum packaged''' processed or cured meats are another example of MAP, except in this case once the vacuum is applied the product is packaged, there is '''no backflushing''' with a gas mixture prior to sealing the package. These products have a much longer storage life than those stored in air. Removal of oxygen from these products through the vacuum process suppresses the growth of the aerobic spoilage-causing bacteria. This leads to the extension of the storage life of these products.
* Retail cuts of cheese are often packed under vacuum or under gas mixtures to prevent the growth of moulds which are common aerobic spoilage-causing microorganisms of cheeses.
Keep in mind the fact that although food products packed under modified atmospheres have a longer storage life, those products '''must be kept in refrigerated storage''' in order to maximize the benefits of inhibition of growth of spoilage-causing microorganisms and to prevent the growth of microorganisms that may be capable of causing illness.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Compare and contrast controlled atmosphere storage and modified atmosphere packaging.
|}

=== Changes in Food During Refrigerated Storage ===
Over prolonged storage, numerous aundesirable changes can be observed, in addition to those brought on by microbial spoilage. These include:
* staling of bread
* loss of crispness in fruits and vegetables
* change in colour of fresh meat
* loss of flavour and nutrient value (e.g. vitamins)
* oxidative changes
* drip or syneresis from fish

== 7.3 Freezing and Frozen Storage of Foods ==
Freezing provides longer shelf life of food. It is carried out at temperatures well below 0°C. In fact, commercial freezing requires a minimum of '''-18°C'''. Household freezers only reach temperatures of -12 to -14°C

The basis for preservation by freezing/frozen storage is that freezing permits longer term storage than refrigerated storage due to:
# lower temperatures used (remember that microorganisms can not grow well at temperatures below '''-9.5°C''')
# lower water activity (by freezing the "free" water present in the food)
Both factors slow down chemical and enzymatic reactions as well as microbial growth.
* Keep in mind that physical, chemical & enzymatic changes may still take place, especially if freezing and frozen storage conditions are not optimal.
* Freezing slows/stops microbial growth. However, storage of food at freezing temperatures '''does not kill all microorganisms''' and in fact many disease-causing and spoilage-causing microorganisms can survive in frozen foods for many years (e.g. ''Listeria monocytogenes''). Once the food is '''thawed''', the surviving microorganisms can resume their growth and function, causing disease or spoilage if the proper conditions for microbial growth prevail.
* When freezing of food is properly done, it can preserve the quality of the food without causing major changes in appearance, texture and flavour.
* Frozen foods are generally of higher nutritional and aesthetic quality than thermally processed foods. The faster the rate of freezing, the better the retention of quality, both from sensory and nutritional perspectives. The effect of freezing and other preservation methods on nutrient quality will be discussed later in the course (Lesson 11).
* Whether food is frozen in your home or in a food processing plant, the same principles govern the maintenance of quality during freezing and frozen storage.
What does "freezing point" mean?

Freezing point is the temperature at which ice crystals are in equilibrium with air-saturated water at 1 atmosphere pressure. Solutes in water will depress the freezing point.

=== What is the freezing point of pure water? ...of water in foods? ===
Although the freezing point of ''pure water'' is 0oC, actually water does not begin to freeze until it is supercooled to several degrees below 0oC.

The freezing point of ''foods'' is below the freezing point of pure water, because foods contain solutes dissolved in the aqueous (water) phase. The dissolved solutes have the net effect of lowering the freezing point of foods by several degrees Celsius.

Once water starts to crystallize, there is an abrupt rise in temperature due to the evolution of the latent heat of fusion or crystallization. Only after all the water has frozen (crystallized) will the temperature approach the temperature of the freezing environment.

'''Note''' that water is frozen out as pure water. Until all of the water is frozen, there is an ever-increasing concentration of water-soluble solutes in the unfrozen phase. In fact, there is a considerable proportion of unfrozen water at temperatures below 0 C.

=== How much water remains unfrozen? ===
This depends both on the temperature as well as the food product itself. For example, for beef, 70% of the water remains in the unfrozen state at -4.0 oC, compared to 3% and only trace amounts at -9.0 and -18oC, respectively.

From this description you will begin to appreciate that many complex changes occur within food systems as the freezing operation is carried out.

'''Freezing and thawing curves''' are shown below in Figure 7.1. This figure describes the transitions that take place in a hypothetical food material during freezing and thawing, including:
* removal of heat from the product (sensible heat)
* freezing of water (liquid) into ice crystals (solid) (latent heat of fusion or crystallization)
* further cooling to the surrounding temperature
[[File:L7 fig7-1.png|thumb|center|500x500px]]
[[File:L7 fig7-1b - FNH200.gif|thumb|center|500x500px]]
'''Changes in Food During Freezing, Frozen Storage and Thawing'''

You may have had the unfortunate experience of placing a beverage or other container of liquid food in a freezer to chill it quickly, only to find the container has cracked or the lid popped off because of the expansion of the water in the food as the water froze. The same phenomenon occurs within the cells of food during freezing if the conditions are not carefully controlled.

Rupture of cell walls and membranes during freezing and thawing can lead to formation of drip when the product is thawed. The process of freezing foods has great influence on the ultimate quality of the food once it is thawed and prepared for consumption. Changes that occur in foods during freezing, storage and thawing can be both chemical and physical in nature.

Various chemical, enzymatic and physical changes are promoted as a result of the '''concentration of components''' (''concentration effects'') in the unfrozen water phase within the frozen foods.

For example:
* Chemical changes such as ''oxidative rancidity'' or ''oxidation'' of flavour components, pigments and vitamins.
* Enzymatic reactions such as enzymatic browning or lipolytic rancidity.
* Meats become tougher due to protein denaturation by ''chemical effects'' and ''cell breakage'' by ice crystals
In freezing foods, the objective is to promote the formation of tiny ice crystals rather than the formation of fewer but larger ice crystals that cause cellular damage. '''Ice crystal damage''' can lead to loss of water from the food product once it is thawed.
* The drip that is found in thawed strawberries or beef is due in part to ice crystal damage to the cells, leading to leakage of cellular fluids into extracellular spaces, and to the loss of water-holding capacity of food components as a result of concentration effects.
* Emulsions and other dispersions are destabilized by the growth of numerous small ice crystals to larger, less numerous but more damaging ice crystals; such growth in ice crystal size is usually caused by temperature fluctuations.
* You may have noted shrinkage and development of graininess in ice cream stored in the frost-free freezer section of your refrigerator. This is due to partial melting of the ice cream during temperature fluctuations that result from the defrost cycles. This leads to foam destabilization and crystallization of lactose as a consequence of concentration effects.
Other undesirable changes include formation of '''package ice''' and '''freeze dehydration''' which is popularly called '''''freezer burn''''' and can produce unsightly food surfaces and loss of nutrients. "Freezer burn" is a misnomer since the food does not "burn" in the freezer but rather takes on an appearance of having been burnt because of the moisture loss that occurs during this freeze dehydration.

''How can we minimize '''Changes in Food During Freezing, Frozen Storage and Thawing?'''''
* Blanching (lesson 6)
* Proper temperature control for freezing and frozen storage
* Appropriate packaging (discussed later in this lesson)

=== Factors affecting the quality of frozen foods ===
The type and extent of changes during freezing, frozen storage and thawing, which are directly related to the final quality of frozen foods, are affected by many factors. Here are the 4 most common ones:
* rate of freezing
* final storage temperature
* stability of storage temperature, and
* rate of thawing

==== '''Rate of freezing (freezing rate)''' ====
The rate of freezing of foods is very important, with rapid freezing rates being desirable since the formation of many '''small ice crystals''' is favoured. Freezing rates vary depending on:
# '''Food composition:''' Some food components such as proteins and fats act as insulators. Presence of these components slow down the freezing.
# '''Temperature difference''': the greater the temperature difference between the food and the refrigerant, the faster the freezing rate.
# '''Product thickness/geometry''' and '''heat transfer rate''': the thinner the food piece or greater the heat transfer rate, the faster the freezing rate.
# '''Air velocity''': the greater the velocity of refrigerated air or circulating refrigerant, the faster the freezing rate.
# '''Degree of contact''': the more contact between the food and the cooling medium, the faster the freezing rate.
These five factors are given great attention in the design of food freezing plants in order to maximize the rate of freezing so that quality attributes of the food commodity can be retained.

==== '''Final storage temperature''' ====
The final temperature for storage of frozen foods is dictated by a number of factors: texture changes, chemical reactions, etc. There are a number of reasons why the storage temperature of about -18°C is commonly used and the normal operating temperature of deep freezers sold for home use is also -18°C.

Table 7.1 shows the number of months during which high quality storage life of frozen food can be maintained at three different storage temperatures. Note how temperature has a marked influence on the storage life of frozen foods. You can see in Table 7.1 that each food commodity has its optimum storage life at -18°C. The rates of deterioration of frozen foods are governed by the chemical composition and physical structure of the foods.
[[File:L7 table 7.1.png|thumb|Table 7.1. Approximate number of months of high quality storage1.|center|900x900px]]

=== Stability of the storage temperature ===
As important as the storage temperature is the '''stability of the storage temperature'''. It is important to note that as the temperature of the frozen food increases, the amount of unfrozen water increases. Thus small fluctuations in storage temperature can cause melting of small ice crystals with subsequent refreezing of the liquid water on to other small ice crystals as the temperature drops, leading to the formation of fewer but larger ice crystals which can produce negative changes in the food quality.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Garden peas and corn kernels are frozen individually at the vegetable processing plant. When the package is picked-up the contents should feel like a bag of marbles. However, often when we purchase frozen peas in the retail store, those peas/corn are presented as a solid block.

* Why does this change in physical appearance occur?

* Response'': The intermittent thawing and refreezing that takes place in the freezer display cabinets that are commonly used in retail stores are the main cause. As the peas partially defrost, the layer of water on the outside of each pea melts and as the temperature of peas then decreases again, the melted layer of water on adjoining peas freezes, thus causing the peas to stick together. One way of telling whether frozen foods such as garden peas have been handled properly throughout the distribution and retail chains is to determine whether the peas are frozen together in a large mass. If they are, '''temperature abuse''' has occurred at some point in the handling systems.''
|}

=== '''The rate of thawing''' ===
The '''rate of thawing''' of frozen foods is as critical to quality maintenance as the rate of freezing. Maximum quality retention is achieved by rapid thawing rates. Figure 7.1 shows a thawing curve for a hypothetical food product. Since ice is a good conductor of heat (it has a high thermal diffusivity) the temperature of a frozen food rapidly approaches the melting point of ice. After the rapid initial temperature increase, subsequent increases in temperature occur very slowly because of the need to supply the '''latent heat of fusion'''1 for the conversion of water from the crystalline state to the liquid state at 0°C.

1'''Latent heat''' is the quantity of heat required to change the state or condition under which a substance exists, without changing its temperature.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* What is the impact of a long thawing period on the quality of the food?
* How should you thaw frozen foods?
* Why should you NOT re-freeze food after it has been thawed
|}

=== '''Freezing Methods''' ===
The three basic methods of freezing foods are presented below.

'''Table 7.2.''' Commercial freezing methods.
{| class="wikitable"
!Air Freezing
!Indirect Contact Freezing
!Immersion & Cryogenic Freezing
|-
|Still-air "sharp" freezer

Air blast freezer

Fluidized-bed freezer (IQF)
|Single plate

Double plate

Pressure plate

Slush freezer
|Heat Exchange fluid

Compressed gas

Refrigerant spray
|-
| colspan="3" |Adapted from: Potter, N.N. and Hotchkiss, J.H. 1995. Cold Preservation and Processing (Ch. 9). In ''Food Science'', 5th ed. Chapman and Hall, New York, NY. p.187
|}

=== Air Freezing ===
Air freezing is the oldest and most common type of freezing used. The freezer section of your household refrigerator and the deep freezer are examples of '''still air freezers''' or low air velocity systems

==== '''Air blast freezing''' ====
Air blast freezing is a moderately fast freeze because of vigorous circulation of cold air. The product is placed on trays or mesh belts and passed slowly through an insulated tunnel. In different systems the temperature may range from -18°C to -34°C, with an air velocity of 100-3500 lineal feet per minute, with a counter current air flow.

Air blast freezers operate at lower temperatures than still air freezers and rely on movement of the cold air at high velocity over the food in order to achieve rapid removal of heat and to maximize the freezing rate.

Garden peas and individually quick frozen shrimp or prawns are frozen in '''fluidized-bed freezers'''. In this type of air freezing, solid particles ranging in size from peas to strawberries are being exposed through a movement of the cold air (-20 to -34°C) at high velocity as they pass along a conveyor belt. This will impart a ''vibratory motion''to food particles, accelerating the freezing rate. The cold air being forced upward through the bed lifts and suspends the food particles, thus fluidization occurs. In this way, a rapid freezing rate is accomplished and an '''IQF (individually quick frozen)''' product is produced. In other words, food items are frozen as individual pieces and are not stuck together.

The garden peas, corn and other IQF products are packaged after freezing. If garden peas, or any other food product that is stated to be IQF on the package label, are present in the package as a solid block, this indicates that the product has undergone partial thawing and refreezing during storage, distribution, retailing, or on the way home from the retail store to your home.

Figure 7.2 illustrates the process of "'''fluidized bed freezing'''" used for some products.[[File:FNH200_Lesson07_IQF.png|565x565px|thumb|Figure 7.2. Fluidized-bed Freezer|center]]

==== Video (on canvas) ====
'''''Corn Processing'''''

Please watch the video on '''Corn processing.''' Note the following:
* How are the kernels separated from the cobs?
* Why is corn starch added in the "froth flotation washer"?
* What is the purpose of blanching? what temperature/time is used?
* What is the "IQF" process and what temperature is used for freezing?
* How long can corn be stored in a frozen state?

=== Indirect contact freezers ===
Indirect Contact freezers are used in the production of various frozen food commodities. In these freezers, food is placed on belts or trays and a refrigerant circulates through a wall beside the food. As the food comes into "contact" with the cold wall, it quickly cools down and freezes. Plate and slush freezers are some examples of indirect contact freezers.

During '''plate freezing''' food products are placed in contact with a metal surface which is cooled by a cold brine, or a vaporizer refrigerant such as ammonia. The packaged food either rests on, slides against or is pressed between the cold metal plates. These plates maintain firm contact with two major surfaces of packages to facilitate heat transfer and prevent bulging of the packages during the freezing process. Fish sticks and frozen fish fillets are commonly frozen in plate contact freezers (Figure 7.3).

[[File:FNH200_Lesson07_PlateFreezer.png|502x502px|thumb|Figure 7.3 Plate Freezer|center]] Another type of indirect contact freezer is the '''slush freezers''' or '''scraped surface heat exchangers'''. These freezers can be used only for fluid food products. A common example of a scraped surface freezer is the machine used to convert ice cream mix to soft ice cream in restaurants and ice cream shops. The same principle is used in the commercial production of ice cream that is sold as hard ice cream. In the case of ice cream, the rotator not only aids in promoting rapid freezing and the development of small ice crystals, but it also aids in the incorporation of air bubbles into the freezing mix which results in the formation of a ''solid foam'' (review definition of a solid foam from Lesson 2).

As mentioned before, shrinkage and development of graininess in ice cream stored in the frost-free freezer section of your refrigerator is due to partial melting of the ice cream during temperature fluctuations that result from the defrost cycles. This leads to foam destabilization and crystallization of lactose as a consequence of concentration effects.

=== Video (on canvas) ===
'''''Ice Cream Processing Video'''''

Please watch the video on '''Ice cream production.''' Note the following:
* Main steps followed in the production of ice cream
* What type of freezer(s) are used?
* What tests are conducted to assure safety and quality?

=== Immersion and Cryogenic freezing ===
'''Immersion freezing''' involves the immersion of packaged or un-packaged food products directly in a non-toxic refrigerant fluid. The refrigerant fluids commonly used are propylene glycol, glycerol, sodium chloride, calcium chloride, and mixtures of salt and sugar. Canned citrus juice, turkeys and chickens are often frozen in immersion freezing units. Ice cream popsicles can also be frozen using this method.

'''Cryogenic freezing''' is accomplished with cryogenic liquids, with liquid nitrogen being the most commonly used. This is a very rapid freezing method in which un-packaged or thinly packaged foods are exposed to extremely cold freezant. In contrast to the liquid immersion freezing, heat removal is accomplished during a change of state by the freezant. Products such as TV dinners, preformed hamburger patties and other high value food products are frozen in cryogenic freezers because of the excellent retention of quality imparted by the rapid rate of freezing and small ice crystal formation. Figure 7.4 illustrates a cryogenic process. [[File:FNH200_Lesson07_Cryogenic.png|492x492px|thumb|Figure 7.4 Cryogenic Freezing|center]]

How does liquid nitrogen cryogenic freezing work?

The product is first placed on a conveyor belt and is moved into the pre-cooling part of the freezing unit. Once the food is cooled, the food is sprayed by liquid nitrogen as it is being moved through the conveyor belt; here is where the freezing process takes place, by the nitrogen boiling as it contacts the food. Finally, the food is allowed to equilibrate to the desired final temperature (between -18°C to -30°C).

The following table gives a summary of some of the advantages and disadvantages of the freezing methods we have discussed:

Table 7.3. Some advantages and disadvantages of freezing methods.
{| class="wikitable"
!Freezing method
!Advantages
!Disadvantages
|-
|Air blast freezing; Fluidize-bed freezing (IQF)
|
* Economical
* Can freeze various sizes and shapes of food
* IQF has more efficient heat transfer, increased rate of freezing
|
* Possible excess dehydration (freezer burn)
* Undesirable bulging of the packages (by expansion of the product) may occur
* Non-uniform products can not be fluidized (IQF) easily
|-
|Indirect Contact Freezing
|
* Economical
* Minimal dehydration
* Minimal package bulging
|
* Slow freezing process
* Products must be of uniform thickness
|-
|Immersion/ Cryogenic freezing
|
* Rapid freezing process
* Almost no dehydration
* Oxygen is excluded, decreasing oxidative spoilage
* Individual freezing pieces have less freezing damage
|
* Difficult to find suitable freezants
* Cost of operating is high
|}
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Can you think about examples of foods that are processed using the three categories for freezing - i.e. in air, indirect contact, and immersion/cryogenic?
|}
'''Packaging Considerations for Frozen Foods''' Packaging materials to be used for frozen foods must be resistant to the transfer of water vapour from the food to the dry environment within the freezing unit. The packaging material must not shatter in the cold temperatures encountered in frozen storage. Therefore glass is not a good material for packaging frozen foods because it tends to shatter and it is not flexible. The packaging material should resist the formation of pinholes during normal handling.

Breaches in the packaging material will promote the development of ''freezer burn'' on the exposed areas of the food. Depending on the food, the packaging material may have to possess barrier properties toward '''light and/or oxygen'''.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* After completing this lesson can you answer the following:
** how long can foods be kept in the refrigerator? in the freezer?
** can microorganisms grow/survive under these conditions?
** how can we maximize the quality of refrigerated or frozen foods?
** what other approach(es) can be used in combination with low temperature to maximize shelf life and quality?
|}

== 7.4 Summary of Lesson 7 ==
* Low temperature processing and its packaging materials are designed to extend the food's shelf life by slowing down microbial growth and chemical/enzymatic reactions.
* Microbial growth and chemical/enzymatic reactions will resume once the food is thawed or exposed to "warmer" temperatures.
* Refrigeration (cool storage) refers to temperatures between -2°C to16°C . In particular at '''4°C'''. This provides only a short term shelf-life extension in food as '''psychrotrophic''' organisms can still grow.
* During refrigeration, the temperature, humidity and gas atmosphere composition must be monitored in order to prevent undesirable changes in the food.
* Modified atmosphere packaging (MAP) is commonly used with some refrigerated products to enhance the shelf life of the product.
* Below '''-9.5°C''', there is no significant growth of '''spoilage''' or '''pathogenic organisms'''
* Freezing refers to temperatures below the freezing point of water. In the food industry, a minimum of '''-18°C''' is required. Food is preserved by the use of lower temperatures and lower water activity.
* During freezing, several factors (e.g. freezing rate, final storage temperature, etc) must be controlled in order to prevent undesirable changes (oxidation reactions, freezer burn, ice crystal damage, etc)
* Packaging materials should assist in preventing these undesirable changes.
'''Supplemental Videos:'''
# [https://www.youtube.com/watch?v=VqMeVZT6N4Q&feature=emb_logo Individually Quick Freeze (IQF) of sardines]
# [https://www.youtube.com/watch?v=PUTOl4SE4uQ&feature=emb_logo How to Make Frozen Treats]

=== Reference ===
Potter, N. N. and J.H. Hotchkiss. 1998. Cold Preservation and Processing. Chapter 9 in ''Food Science'', 5th ed. Chapman and Hall, New York, NY.

'''Authorship:'''

FNH 200 Course content on this wiki page and associated lesson pages was originally authored by Drs. [http://www.landfood.ubc.ca/person/brent-skura/ Brent Skura], [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], and [http://www.landfood.ubc.ca/person/eunice-li-chan/ Eunice Li-Chan]. Ongoing edits and updates are contributed by past and current instructors including Drs. [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], [http://www.landfood.ubc.ca/person/azita-madadi-noei/ Azita Madadi-Noei], [http://www.landfood.ubc.ca/person/nooshin-alizadeh-pasdar/ Nooshin Alizadeh-Pasdar], and [http://www.landfood.ubc.ca/person/judy-chan/ Judy Chan].
{{cc-by-nc-sa-3.0}}

<quiz display=simple>
{1. Syneresis leads to the following change(s) in refrigerated foods:
|type="[]"}
+ Staling of bread
- Loss of crispness and flavour in fruits and vegetable
- Colour change in fresh meat
- Loss of nutrients
+ Drip loss in fish
</quiz>

<quiz display=simple>
{2. Which package material below is NOT suitable for frozen products?
|type="()"}
- Cardbox
- Foil film
+ Glass bottle
- Plastic film
- Tetra pak
</quiz>

<quiz display=simple>
{3. A slush freezer is an example of
|type="()"}
- Air Freezing
+ Indirect Contact Freezing
- Immersion Freezing
- Cryogenic Freezing
</quiz>

<quiz display=simple>
{4. Psychrotrophic organisms can grow while food is stored in the refrigerator.
|type="()"}
+ TRUE.
- FALSE.
</quiz>

<quiz display=simple>
{5. Under freezing conditions, chemical reactions can still occur.
|type="()"}
+ TRUE.
- FALSE.
</quiz>

Course:FNH200/Lessons/Lesson 06

2020-06-24T00:33:30Z

YihangChen: /* 6.0 Overview */

<big><big><big>'''Thermal Preservation of Foods'''</big></big></big>

== 6.0 Overview ==
To understand the concepts that form the basis of thermal preservation of foods, you must become familiar with the associated terminology. In this lesson you will learn the meaning of terms such as blanching, pasteurization, commercial sterilization, z-value, F-value, hermetically sealed containers, decimal reduction time and 12D concept of safety in the context of thermally processed foods. You will also learn about the containers that are used to package thermally processed foods.

=== Objectives ===
The overall goal of this lesson is that you gain an appreciation of how various food commodity groups are preserved through the application of thermal energy. More specifically, you will be able to:
* interpret the basis of thermal food processing
* compare and contrast thermal processing categories: blanching, pasteurization, and commercial sterilization
* discuss the thermal death curves
* apply the thermal death curves to predict the rate of death of a particular microorganism under a specified set of conditions
* differentiate between conduction and convection heating of foods during thermal processing of foods; and
* list the fundamental requirements of packaging materials used for thermally processed foods

=== Optional Reading ===
* Food safety facts on Botulism.
* https://www.canada.ca/en/public-health/services/food-poisoning/botulism-clostridium-botulinum.html or link through here: http://www.inspection.gc.ca/english/fssa/concen/cause/botulisme.shtml

=== Required Video ===
''Dairy processing'':
* '''milk''' (6:46 min)
* '''butter''' (2:50 min) The links for these videos will be indicated later in the lesson.

== 6.1 Methods Used in Thermal Preservation ==
{| class="wikitable"
|
==== '''Terms to remember''' ====
|-
|
* Blanching
* Pasteurization
* Commercial sterilization
* UHT processing
* Aseptic packaging
* Thermal Death Curves
* Margin of safety
* D-value, z-value, F-value
* Inoculated pack studies
* Tetra Pak
* Retort
* Cold point
* Conduction
* Convection
|}

=== Terms Used in Thermal Preservation ===
The safety and storage life of many perishable foods can be enhanced by the use of high temperatures to inactivate undesirable disease and spoilage-causing microorganisms and to inactivate enzymes in food that can cause spoilage.

Three categories of thermal preservation of foods are:
* blanching
* pasteurization
* commercial sterilization
In this section, we will discuss a number of terms and concepts commonly used when dealing with thermal preservation of foods on a commercial basis.

=== Blanching ===
Blanching is a form of thermal processing applied mainly to vegetables and some fruit by exposing them to heated or boiling water or even culinary steam for a short period of time. Blanching is a food processing operation designed to:
# '''Inactivate enzymes''' in plant tissues so that enzymatic degradation does not occur in the interval between packaging and thermal processing or during frozen storage or in the early stages of food dehydration and after reconstitution of dehydrated plant foods.
# '''wilt''' vegetable products to enable packing of the products into containers so that proper fill weights can be achieved.
# '''drive off''' inter- and intracellular oxygen and other gases from plant tissues so that containers are not deformed by excessively high internal pressures due to expanding gases within the container and to permit formation of a vacuum in the container after thermal processing

=== Pasteurization ===
Pasteurization is a thermal process that involves using temperatures of at least 72°C for 15 seconds ('''high temperature short time''' or '''HTST''' process), prior to packaging.

The '''basis for preservation''' by pasteurization is to inactivate '''pathogenic''' (disease causing) bacteria and viruses in '''low acid''' food products such as milk.

'''Acid''' food products (pH < 4.6) are mainly pasteurized to inactivate '''spoilage'''-causing microorganisms. Pathogenic microorganisms cannot grow and do not survive very well in acid foods such as citrus juices or apple juice (with the exception of ''Escherichia coli'' 0157:H7, which will be discussed in Lesson 12).
* In low-acid and acid foods, many '''spoilage-causing''' microorganisms can still survive typical pasteurization process conditions:
** For example, in milk, the proteolytic and lipolytic bacteria are more heat resistant and can survive the pasteurization process. This explains why the typical spoilage pattern of pasteurized milk reflects the ''proteolytic'' (protein degradation) and ''lipolytic'' (lipid degradation) action of the psychrotrophic, spoilage-causing bacteria.
Because pasteurization does not kill all the psychrotrophic spoilage-causing bacteria in milk, pasteurized milk must be '''refrigerated''' to maintain shelf life quality.

The '''durable life date''' on milk containers reflects the storage life that can be expected when milk is held at 4 °C or lower.

=== Commercial sterilization (CS) ===
This thermal process involves heating the food with a minimum treatment of 121°C moist heat for 15 minutes. The process usually involves pre-sealing the food in containers prior to heating (also known as "'''canning'''"). Other forms of CS involve heating the food before it is aseptically packaged ('''UHT-Aseptic packaging''').

The basis for preservation by CS is to destroy both spoilage and disease causing microorganisms in low-acid and acid foods, thus rendering the food "''commercially sterile''".
* '''Commercially sterile''' as described in the Food Regulations (Division 27) of the Food and Drugs Act of Canada "means the condition obtained in a food that has been processed by the application of heat, alone or in combination with other treatments, to render the food free from viable forms of microorganisms, including spores, capable of growing in the food at temperatures at which the food is designed normally to be held during distribution and storage". Therefore, commercially sterilization involves the destruction of spoilage-causing and disease-causing microorganisms'''*'''
** '''''*''' Commercially sterile foods may contain small numbers of extremely thermophilic bacteria spores; however, the spores '''cannot germinate''' and produce actively growing cells at room temperature, nor would they cause disease.''
* Canning can be traced back to the early 1800's. It is called the "''botulinum cook''".
* Today, if a can of food is being sterilized, ''each'' food particle must receive the heat treatment (e.g. 121°C for 15 min).
* When food is placed in a can, the heat treatment will change since heat transfer to the food takes place at a slower rate. Depending on the size of the can, the time to achieve sterility could be several hours.
* Most commercially sterile products have a shelf life of '''2 years or more'''.

=== Ultra-high temperature processing (UHT) and Aseptic packaging: ===
The basis of UHT and aseptic packaging is the application of "ultra high temperature" (heat) to food '''before packaging,''' then filling the food into '''pre-sterilized''' containers in a '''sterile atmosphere'''. This process will render the food '''shelf stable''' or commercially sterile without the need for refrigeration.
* UHT- Aseptic packaging is a relatively new development whereby food can be heated to 140-150°C very rapidly by direct injection of steam, held at that temperature for short period of time (e.g. 4-6 seconds) and then cooled, in a vacuum chamber to flash off the water added in the form of condensed steam. This is carried out as a continuous flow operation. The '''decrease in processing time''' due to the higher temperature, and the minimal come-up time and cool-down time leads to a higher quality product.
* The UHT processed food is '''aseptically packaged''' into pre-sterilized containers. These are usually cartons made from laminated plastic, aluminum and paper, which are chemically sterilized with a combination of hydrogen peroxide and heat, and then filled in the same piece of equipment which is housed in a sterile environment. For more information about these cartons, visit the "'''Tetra Pak'''" aseptic technology ([[www.tetrapak.com]])
** There are other forms of packaging that can also be used in aseptic UHT processing: plastic cans, flexible pouches, thermoformed plastic containers, bag-in-box, and bulk totes.

* '''UHT-aseptically packaged''' products have a shelf life of '''6 months''' '''or more,''' without refrigeration. It depends on the type of packaging being used. For example, ''Tetra Pak'' cartons can eventually be more prone to perforations in the packaging layers, whereas the newer ''plastic bottles'' are more resistant to pin hole formation allowing them to have a longer shelf life.
** Some example of food products processed with UHT are:
*** liquid products: milk, juices, cream, yogurt, wine, salad dressings
*** semi-liquid/solid products: baby foods; tomato products, fruits and vegetable juices, soups.

* Contrary to popular opinion, UHT processed milk and juices do not contain ''added agents'' to provide the long storage life at ambient temperature in the laminated cartons. The products are preserved solely through the '''application of heat'''. It is critical that the sterilized products are transferred to packaging equipment under '''aseptic conditions''', to avoid contamination after thermal processing.
Please '''note''' that many products that are UHT treated are '''not necessarily''' aseptically packaged. This gives them the "advantage" of a longer shelf life at '''refrigeration''' temperatures compared to conventional pasteurized (HTST) products. However, this does not produce a shelf-stable product at ambient temperatures due to the possibility of '''post-processing recontamination'''.

=== Video (on canvas) ===
You should now watch the '''video''' on '''milk and butter processing'''.

Note the following:
* Three major processes used- clarification, homogenization, pasteurization
* pasteurization of dairy products other than milk- the effect of other ingredients (e.g. in egg nog)
* UHT process, aseptic packaging, Tetra Pak
* salted versus unsalted butter- why does the latter have to be kept in the freezer?

{| class="wikitable"
| '''Want to learn more?'''
|-
|
* Will canned food and aseptically packaged UHT food products require a durable life date stamped on the label?
* What about products that have been UHT processed but not packaged under aspectic conditions?
|}

== 6.2 How are heat treatment selected? ==
The intensity of the heat treatment employed for a particular food preservation application depends upon a number of factors. The main considerations in selecting the required temperature-time conditions for thermal processing are:
# What is the '''objective''' or purpose? (blanching or pasteurization or commercial sterilization)
# Are there additional preservation steps? (is it combined with other preservation methods?)
# What are the physical, chemical properties of the food? (Type of food)
# What is the heat resistance of microorganisms in the food?

==== '''Here are some examples to illustrate these points:''' ====
* Foods that will be consumed within a short period of time after processing can have storage life extended by a combination of pasteurization and refrigerated storage (used for pasteurized milk and for pasteurized, vacuum packaged, cured meats).
* Longer storage times at ambient temperatures in evacuated sealed containers requires the use of commercial sterilization.
* The time-temperature combination required for pasteurization and commercial sterilization is determined by the most heat-resistant disease-causing and spoilage-causing microorganisms in the particular food commodity.
* For a particular food commodity, the type of thermal processing operation and the rate of heat penetration into the slowest heating portion of the food within a particular container are governed by the food's physical properties (solid vs. liquid, or solid particles suspended in a liquid) and chemical properties (pH, fat content, presence or absence of heat-inducible thickening agents, food components that have protective or antagonistic effects on the thermal resistance of microorganisms).
* It is imperative that thermal preservation processes be designed so that the '''slowest heating portion''' of the food commodity receives the specified '''time-temperature''' thermal treatment to minimize risks of illness and/or post-processing spoilage.
* The thermal processes applied to foods are governed by the heat resistance of the microorganisms in the food.
In '''low acid''' foods which are to be thermally processed and vacuum sealed within gas-tight containers, the microorganism of most concern is '''''Clostridium botulinum'''''.

The habitat of ''Clostridium botulinum'' can be soil (agricultural and forest), water (fresh, brackish and marine) and mud (fresh water and salt water). As a consequence, all foods of agricultural and fisheries origin must be considered as being potentially contaminated with ''Clostridium botulinum'' spores.

{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Food safety facts on Botulism [https://www.inspection.gc.ca/food-safety-for-industry/information-for-consumers/fact-sheets-and-infographics/food-poisoning/eng/1331151916451/1331152055552 link]
|}
Low acid foods which are to be packaged and stored under anaerobic condition, require a specifically designed thermal processing treatment to ensure the destruction of any ''Clostridium botulinum'' spores. This will provide a large margin of safety. Actively growing vegetative ''Clostridium botulinum'' cells produce a very potent neurotoxin.

==== How can we determine if ''C. botulinum'' spores have been destroyed? ====
* To determine the thermal resistance of heat-resistant spores in foods, '''"Inoculated pack studies"''' are carried out using a non-pathogenic spore-forming bacterium, '''''Clostridium sporogenes'' PA3679''' (a putrefactive anaerobe).
* Since '''PA3679''' spores are '''''more''''' heat resistant than those of ''Clostridium botulinum'' spores, a process designed to kill PA3679 spores will definitely kill ''Clostridium botulinum'' spores with a wide margin of safety.
** The concept of "'''margin of safety'''" is later described in this lesson. 

== 6.3 Thermal Death Curves ==
When microorganisms (bacteria, such as vegetative cells and spores, moulds, viruses and yeasts) are exposed to high temperatures capable of causing death of the organisms, one observes that the population is not killed instantaneously. We see that microbial death during thermal processing follows a '''logarithmic order'''. This means that bacteria are killed by heat at a rate that is nearly proportional to the number present in the system being heated.
[[File:FNH200 Lesson06 ThermalDeathRate.gif|center]]
The '''survivor curve''' or '''thermal death rate curve''' plotted in Figure 6.1 depicts the logarithmic order of death. You will note that the time taken to traverse one logarithmic cycle represents the time, at a constant temperature, required to kill 90% of a microbial population.

The time required to kill 90% of the microbial population exposed to a specific temperature is defined as the '''decimal reduction time''' or '''D-value'''

A sample calculation of the decimal reduction time follows:

If we were to start out with a population of 105 (=100,000) bacterial cells in a unit volume or mass of food at time 'A', only 104 (=10,000) cells would survive after one logarithmic cycle on the graph was traversed (time 'B'). The reduction in the number of survivors from 100,000 to 10,000 represents a 90% decrease in the number of survivors, as shown below: 
: '''% Reduction in survivors''' 
: = (Survivors at time 'A' - Survivors at time 'B')/Survivors at time 'A' x 100% 
: = (100,000 survivors - 10,000 survivors)/100,000 Survivors x 100% 
: = 90,000 Survivors / 100,000 Survivors x 100%
: = 90%
Assume that time 'A' is 5 minutes and that time 'B' is 10 minutes. During the time (10-5 = 5 minutes) that the survivor curve traversed one logarithmic cycle, 90% of the microorganisms were killed (10% survived) by the exposure to the constant temperature.

The time taken to kill 90% of the microbial population was 5 minutes. The D-value at that particular temperature was 5 minutes.

Note from the preceding discussion that the D-value is a useful index of the heat resistance of a particular microorganism to the killing effects of heat at a particular temperature. However, also note that D-values apply to a specific microorganism under a specified set of conditions (temperature, type of food).

==== '''What effects do different conditions have on the D-value?''' ====
* If the temperature is '''increased''', the '''D-value would decrease''' because the rate of microbial death would increase.
* The magnitude of the D-value depends on how the constituents of the food affect the sensitivity of the microorganism to the killing effects of heat. The protective effect of food constituents are discussed in more detail later in this lesson.
{| class="wikitable"
|'''Want to learn more?'''
|-
|Would increasing the microbial load (in other words, the initial number of microorganisms in the food) increase the decimal reduction time (D-value) of the microorganism at a specified temperature?
|}
Figure 6.1 is defined as a thermal death rate curve. That is, it describes the rate of death of a particular microorganism under a specified set of conditions. A '''thermal death time curve''' (Figure 6.2) can be constructed from a number of thermal death rate curves by exposing the microorganism to a variety of temperatures and determining the decimal reduction time at each temperature.[[File:FNH200_Lesson06_ThermalDeathTime.jpg|thumb|400px|'''Figure 6.2. Thermal death time curve.'''Adapted from: Potter, N. and Hotchkiss, J.H. 1995. Food Science (5th ed). Aspen Publishers., p. 142.|center]]
 The thermal death '''''time''''' curve provides information about the ''time'' required to kill a particular microorganism in a particular food at a variety of temperatures. Take a close look at Figure 6.2. For example, at a temperature of ~116°C, 10 minutes are required to kill the population of this specific microorganism.

All of the time-temperature combinations along the plotted thermal death time curve represent the same killing power, with lower temperatures requiring longer time of exposure. You should also note that any point above the line (e.g., 100 minutes at ~108°C) will ensure that the microorganism is killed, while time-temperature combinations that fall below the plotted line (e.g., 100 minutes at 104°C) represent conditions that will not kill all of the microorganisms present.

You should also note in Figure 6.2 that vegetative bacteria cells have a much lower heat resistance than spores.

'''What do the ''z''-values and ''F''-values in Figure 6.2 indicate?'''

These two terms characterize a thermal death time curve. Potter and Hotchkiss (1995) define the '''''z''-value''' as "the number of '''degrees''' required for a specific thermal death time curve to pass through one log cycle".
* Different microorganisms in a given food will have different ''z''-values.
* Similarly, a given microorganism will have different ''z''-values in different foods.
* The ''z''-value indicates the resistance of a microbial population to changing temperature.
The '''''F''-value''', is a mathematically calculated number that describes the total lethal effects of the process at the slowest heating point in a food container. The standard reference temperature is generally selected as '''121.1°C''' (250 °F)''',''' and the relative '''time''' (in minutes) required to sterilize any selected organism at 121°C is known as the '''''F''-value''' of that organism.

From Potter and Hotchkiss (1955): the F-value ''"is the number of '''minutes''' at a'' specific temperature ''required to destroy a specified number of organisms having a specific z-value".''
* The ''F''-value is the equivalent of all heat considered with respect to its capacity to destroy spores or vegetative cells of a particular microorganism. In other words, it is a measure of '''"lethality"''' or the capacity of the heat treatment to '''sterilize'''.

== 6.4 Margin of Safety ==
Inherent in the thermal processing of foods is the concept of a '''margin of safety''' which refers to the probability that a container of food could still contain a viable spore of ''Clostridium botulinum'' after the completion of the thermal processing. Obviously, the goal is to ensure that the margin of safety is as large as possible which means that the probability of survival of spore of ''Clostridium botulinum'' after thermal process is as low as possible without causing undue heat damage to the quality factors and nutrient value of the food.

Since ''Clostridium botulinum'' is ubiquitous in the environment where food materials are grown and harvested, the assumption is made that all foods to be preserved are potentially contaminated with ''Clostridium botulinum'' spores and thus must be processed accordingly.

'''As the spore population in a food system is increased, the total time required at a particular temperature to kill ALL the spores increases'''. This phenomenon is inherent in the logarithmic order of death of microbial cells and spores. During preparation of foods for processing, efforts are made to minimize the microbial population in the foods to be processed. Microbial and spore populations can be minimized by proper handling techniques, the use of extensive washing, and the use of peeling and trimming procedures to remove as many as possible of the spores that may be present on the food.
* Typically, for '''low acid''' foods (pH greater than 4.6) a margin of safety of '''12D''' is applied. This means that the low acid foods (e.g. milk, meat, poultry, fish, vegetables) are subjected to a thermal process so that the slowest heating portion of the food is exposed to an amount of thermal energy (heat) such that the microbial spores present in the food will experience the equivalent of 12 successive decimal reduction times. This has the capability of killing 1012 (one trillion) spores of ''Clostridium botulinum'' per container. Since the natural levels of contamination of foods with ''C. botulinum'' are much lower than that, a large margin of safety is introduced for thermally processed foods. The D-value is temperature dependent. Thus, the higher the temperature, the lower the D-value and the less time taken to achieve the 12D "botulinum cook" for low acid canned foods.
* Another important factor to be considered is that ''C. botulinum'' is very sensitive to acid and it will not grow in foods at pH 4.6 or below. Therefore, the 12D heat treatment would be excessive and unnecessary for '''acid foods''' (pH of 4.6 or less). With acid foods, temperatures at or below 100°C for a few minutes should be an adequate heat treatment. Typically, a '''5D''' thermal process is usually used for acid foods.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* If the spore population in a container of food were increased from 100 spores to 10,000 spores, would the margin of safety of a 12D thermal process increase or decrease?
* What is the effect of a higher initial microbial load on the margin of safety?
|}

== 6.5 Heat Transfer Characteristics of Foods ==
The rate and mechanism by which heat is transferred through a food material during thermal processing is very important in determining how long it will take the slowest heating part of the food (the '''cold point''') to reach the desired time-temperature combination required to ensure destruction of ''Clostridium botulinum'' spores with an adequate margin of safety.

Factors that affect the heat transfer characteristics of a food are
* the consistency of the food (liquid -viscous or non viscous- or solid)
* the chemical composition of the food.
* other factors that are important are the container size, shape and composition.
Foods that are thermally processed after being packed in containers (such as metal cans, glass bottles, plastic pouches) are exposed to an environment of pressurized steam within a vessel called a '''retort''' (Figure 6.3).

A retort operates very much on the same principles as the pressure cooker or pressure canner with which you may be more familiar. Packages of foods are placed in the retort after which the retort is sealed and the air within is vented by purging the retort with steam. Once the retort is properly vented, the steam pressure inside is increased to achieve the desired processing temperature. <gallery widths="360" heights="360">
File:FNH200 Lesson06 Retort.jpg|'''Figure 6.3''' Commercial retort
File:FNH200 Lesson06 RetortCanning.jpg|A worker pushing load of canned food into a retort
</gallery>
A processing temperature of 250°F (121°C) is achieved by establishing a steam pressure of 15 pounds per square inch within the retort. In comparison, the normal household pressure cooker and pressure canner operate at 10 pounds per square inch steam pressure (116°C or 214°F). The containers of food in the retort are bathed in an atmosphere of hot, high pressure steam. Heat is transferred by the hot steam condensing on the containers of food with the heat transferred through the walls of the containers (glass, metal or plastic) to the food inside the container. If the food is a '''solid''' (salmon, for example), heat energy is transferred by '''conduction''' (Figure 6.4).
[[File:FNH200_Lesson06_HeatTransfer.gif|thumb|350px|Figure 6.4. Types of heat transfer during thermal processing|center]]
Heating food by conduction is a slow process. The '''cold point''' (illustrated in Figure 6.4) is in the centre of the container if the container is cylindrical (e.g., canned salmon). Foods that are '''non-viscous liquids''' (canned evaporated milk, for example) heat by '''convection'''.

Foods that are a '''combination''' of solids and liquid components heat up by a combination of convection and conduction heating. Note the location of the cold points in relation to conduction heating (in the geometric centre of a cylindrical container) and convection heating (one third of the way up the centre axis measured from the bottom of the cylindrical container). The actual cold point need to be determined by extensive heat penetration studies using insertion of thermocouples inside the can and collecting the heating data throughout the process. The cold point of a container of food must receive the required amount of thermal energy to ensure killing of ''Clostridium botulinum'' spores that may be present and to ensure a sufficient margin of safety.

If a food formulation is changed such that the mechanism of heat transfer is altered from convection heating to conduction heating, the processing times should be altered to accommodate the change in mechanism of heat transfer, otherwise the food could be under processed and could pose a potential health hazard with respect to botulism. In the past, outbreaks of botulism have occurred due to such changes in heat transfer resulting from changes in product formulation or in the changes in product piece size which can affect the rate of heat transfer.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* What is the heat transfer mechanism for canned tomato juice, tomatoes packed in brine, and tomato paste? Other things being equal (e.g size of the can, net quantity), which would you expect to reach uniform complete heating first? last?
|}

== 6.6 Protective Effects of Food Constituents ==
Sugars, oils, fats and salt can have the effect of protecting spores and vegetative cells from the killing effects of heat, thus requiring use of longer exposure times or higher temperatures for processing those foods exhibiting these protective effects. Certain spices may have antimicrobial activity and change the resistance of microorganisms and spores to the killing effects of high temperatures (D and z values are decreased). Food processing companies must be very careful in re-evaluating the lethality of the thermal processes they used after they reformulate foods that are preserved by thermal processing (commercial sterilization, pasteurization).

== 6.7 Home Canning ==
When canning foods at home, be sure to process all low-acid products in a pressure canner following the manufacturer's instructions closely. Any deviation from those instructions could substantially decrease the margin of safety of the process being used.
 
According to the [https://www.canada.ca/en/public-health/services/diseases/botulism.html Canadian Food Inspection Agency,] "Improperly prepared home-canned, low-acid foods (e.g. corn, green beans, mushrooms, spaghetti sauce, salmon) are most likely to represent a risk for botulism. Outbreaks of botulism have also occurred in Canada's Inuit populations when people have eaten improperly prepared raw or parboiled meats from marine mammals."

== 6.8 Material Used for Packing Thermally Processed Foods ==
Some of the most common types of packaging materials are described below:
{| class="wikitable"
|Container description
|Observations
|-
|
=== '''Steel body cans "tin can"''' ===
[[File:FNH200_Lesson06_TinCan.jpg|thumb|80px|left]]
|
* Steel body cans with a thin layer of tin ('tin cans") are the most widely used containers.
* Can withstand high temperatures and pressure differentials
* Not readily breakable
* The can lids provide a good indication of the presence of a vacuum and thus a hermetic seal (a seal that is impervious to the transmission of gases, water and microorganisms)
* The steel, and very often the tin plating, must be protected with lacquers to minimize reaction of the metals with food constituents.
|-
|
=== '''Glass jars''' ===
[[File:FNH200_Lesson06_GlassJar.jpg|thumb|300px|left]]
|
* More resistant to corrosion and reaction with food constituents
* Allows the consumer to see the contents in the container.
* Glass is heavy and bulky and must be packaged with extra protection to prevent physical breakage of the glass during transportation
* Glass filled containers must also be processed in the retort with extra care to prevent breakage due to thermal shock.
|-
|
=== '''Sterile cartons (Tetra Pak)''' ===
[[File:FNH200_Lesson06_TetraPak.jpg|thumb|80px|left]]
|
* Made from laminated plastic, aluminum and paper ('''click here for a Tetra Pak carton''')Link (Links to an external site.)
* If you have an '''UHT juice or milk''' container in your home you may wish to look at the laminate film after you have used the contents. '''''Can you locate most of the layers of the laminate?'''''
** Carton laminates are first sterilized by treatment with hydrogen peroxide followed by forming and filling of the cartons under sterile conditions. A chemical sterilizing agent must be used for this type of packaging material since exposure of the laminated material to high temperatures required for heat sterilization would destroy the packaging material
|-
|
=== '''Retortable pouch''' ===
[[File:FNH200_Lesson06_Pouch.JPG|thumb|100px|left]]
|
* The retortable pouch is a relatively new form of packaging. The pouch is made of a laminate of plastic films and aluminum.
* heat penetrates these pouches faster due to their thinner profile, allowing the 12D thermal process at the cold point to take place in a much shorter period of time than the conventional metal can or glass bottle.
* Nutrient retention is superior in foods thermally processed in the retortable pouch.
* The pouch itself must be packaged in an outer protective carton to minimize physical damage to the food due to handling by the consumer and to avoid inadvertent puncture of the container
|-
|
=== '''Plastic cans/bottles''' ===
[[File:FNH200 Lesson06 PlasticCan.JPG|thumb|100px|left]]
|
* New types of plastic packaging materials that can be produced in the shape of a can or bottle
* Can be hermetically sealed and thermally processed in a steam retort to achieve the 12D process for low acid foods.
* Newer plastic bottles can be used with UHT-Aseptic packaging technologies
* Some of these containers are used for foods that are ready to eat. These containers, unlike metal cans and glass bottles can be placed in the microwave oven.
|}

== 6.9 Summary of Lesson 6 ==
* Thermal Processing (TP) and packaging materials used in TP are designed to kill microorganisms and extend the food's shelf life.
* Blanching mainly inactivates undesirable enzymes in food. It is usually used in combination with other preservation (processing) methods.
* The magnitude of the thermal process will have a different impact on the food's preservation. E.g. Pasteurization destroys pathogens and only some of the spoilage-causing microorganisms, whereas commercial sterilization destroys both pathogens and spoilage-causing microorganisms.
* Heat treatments are determined using "thermal death curves" (TDRC, TDTC). These curves provide important information of the survival and heat-resistance of different microorganisms, the effect of different temperatures, etc.
* UHT with aseptic packaging allows food to be stored at room temperature.
* A wide margin of safety is desired in order to ensure that ''Clostridium botulinum'' is destroyed.
* Conduction and convection are mechanisms of heat transfer.
* Some food constituents can have a "protective" effect on food that is being thermally processed
* Different packaging materials have a specific use for the different types of thermal processing methods.

'''Supplemental Video:''' [https://www.youtube.com/watch?v=ed14AjlBonI&feature=emb_logo Tetra Pak® A6 - Meet the filling machine for Tetra Evero® Aseptic]

=== Reference ===
* Potter, N. N. and J.H. Hotchkiss. 1995 or 1998. Heat Preservation and Processing ''in'' Food Science, 5th ed. Chapman and Hall, New York, NY. Chapter 8.

'''Authorship:'''

FNH 200 Course content on this wiki page and associated lesson pages was originally authored by Drs. [http://www.landfood.ubc.ca/person/brent-skura/ Brent Skura], [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], and [http://www.landfood.ubc.ca/person/eunice-li-chan/ Eunice Li-Chan]. Ongoing edits and updates are contributed by past and current instructors including Drs. [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], [http://www.landfood.ubc.ca/person/azita-madadi-noei/ Azita Madadi-Noei], [http://www.landfood.ubc.ca/person/nooshin-alizadeh-pasdar/ Nooshin Alizadeh-Pasdar], and [http://www.landfood.ubc.ca/person/judy-chan/ Judy Chan].
{{cc-by-nc-sa-3.0}}

<quiz display=simple>
{1. What is the main purpose to pasteurize milk?
|type="()"}
+ To eliminate pathogenic microorganisms
- To inactivate polyphenol oxidase
- To eliminate spoilage-causing microorganisms
- To eliminate psychrotrophic spoilage-causing microorganisms
</quiz>

<quiz display=simple>
{ 2. Type text here or a no-break space code
|type="{}"}
What is the most common way to sterilize Tetra Pak? { Hydrogen peroxide }
</quiz>

<quiz display=simple>
{3. If the amount of microorganisms increases in a food the D-value does NOT change, but the margin of safety decreases.
|type="()"}
+ TRUE.
- FALSE.
</quiz>

<quiz display=simple>
{4. Spores are more heat resistant than vegetative cells. The means that spores have higher D-value than vegetative cells.
|type="()"}
+ TRUE.
- FALSE.
</quiz>

<quiz display=simple>
{5. If the D-value of a species of bacteria is 2 minutes at 70˚C and there are 10,000 of these bacteria in a given food, then how many bacterial cells would be left in that food if it was heated at 70˚C for 6 minutes?
|type="()"}
+ 10
- 1000
- 100
- 50
</quiz>

Course:FNH200/Lessons/Lesson 05

2020-06-24T00:27:00Z

YihangChen: /* Oxygen requirements: */

== 5.0 Overview ==
In this lesson you will learn about the chemical, enzymatic and microbiological factors that are responsible for food deterioration and spoilage. We will discuss the important environmental factors in food that affect the growth of disease-causing and spoilage-causing microorganisms in food. You will also learn about various types of chemical spoilage, such as enzymatic browning of fruit and vegetable tissues. Finally, as an introduction to food preservation, you will learn the principles upon which food preservation techniques are based. Upon completing this lesson you will have the fundamental knowledge required to fully appreciate the concepts of food preservation to be covered in Lessons 6 through 10.

=== Objectives ===
After completing this lesson, you will be able to:
* describe the factors (chemical, enzymatic, microbiological) that commonly contribute to food deterioration and spoilage;
* summarize possible mechanisms for inhibiting the factors that promote deterioration of quality in food systems

== 5.1 Food Deterioration: the need for food preservation ==
{| class="wikitable"
|
==== '''Terms to remember''' ====
|-
|
* Bacteria, mould, yeast
* Psychrotrophs, mesophiles, thermophiles
* spores
* Vegetative cells
* Aerobic, anaerobic, facultative anaerobe
* Oxidative rancidity
* Hydrolytic or lipolytic rancidity
* Enzymatic browning
|}
* About 10-20 % of all agricultural commodities are lost each year (pre-harvest deterioration) due to: weeds, insects, microorganisms, rodents and birds.
* All foods (agricultural & aquatic products) undergo varying degrees of deterioration after harvest (post-harvest) and during storage.
* Losses occur in the nutritional value, safety, and aesthetic appeal (colour, texture, flavour).
* Food is subject to physical, chemical and biological deterioration.
* Food deterioration involves: heat, cold, light, oxygen, moisture, dryness, food enzymes, microorganisms and macroorganisms (see figure below).
The objective of food preservation technologies is to delay the onset of spoilage and to enable the creation of new food products from the resource commodities. The different factors that can lead to deterioration of food are shown in Figure 5.1 and are described in more detail in the next sections.[[File:FNH200_Lesson05_Factors.gif|frame|center|5.1 Food deterioration]]

== 5.2 Microorganisms ==
* Microorganisms are ubiquitous. Almost all food materials that arrive at food processing plants, retail stores, food service receiving docks, and even your kitchen, are contaminated with a variety of microorganisms.
* Microorganisms cause a great deal of food spoilage throughout the world. This has major economic consequences and also result in loss of potential sources of nutrients, since the spoiled food typically is discarded.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Take a moment to brace yourself before you consider the types of microbial spoilage that have transpired in your kitchen or refrigerator recently.
* Perhaps bread or cheese has become spoiled by moulds. Yogurt or fruit may have spoiled because of yeast or mould growth. Meat, fresh or processed, may have become spoiled by bacteria growing in the surface or within the product.
|}
Microorganisms can be classified into 3 general categories as shown in Figure 5.2.
[[File:L5 fig5-2.png|thumb|Figure 5.2 The good, the bad, and the ugly microorganisms|center|720x720px]]

From Fig 5.2., we note that microorganisms can be put to good use for the production of fermented foods, but that they can also be the causes of spoilage and food borne diseases. '''Bacteria, yeasts''' and '''moulds''' may contribute to production of fermented foods, as well as food spoilage and food borne disease. '''Viruses''' although not considered true microorganism they can be agents of food borne disease but do not cause food spoilage, nor are they used to produce fermented foods.

In this lesson, we will focus primarily on obtaining a general understanding of the role of microorganisms in the deterioration or spoilage of food. The importance of microorganisms in fermented foods and food borne diseases will be discussed in more depth in Lessons 9 and 12, respectively.

Some important characteristics of microorganisms in foods causing food spoilage are summarized below:

=== Bacteria ===
[[File:L5 clostridium botulinum-new.jpg|thumb|Clostridium botulinum By Content Providers: CDC[see page for license], via Wikimedia Commons|center|398x398px]]
Bacteria are the microorganisms that grow the fastest in food.

They reproduce by cell division, whereby one cell divides into two, and these two daughter cells further each divide into another two cells.

The time taken for bacterial cells to complete one complete cycle of cell division is the generation time. With a generation time of 7 minutes, a single bacterial cell could produce a population of a billion cells within 210 minutes (3 1/2 hours).

Bacteria may exist in two forms:

'''vegetative cells''', which are actively metabolizing cells, consume nutrients and produce waste products.

'''spores''', which are the dormant form of the bacterial cell. The spore is analogous to the seed of a green plant. All of the genetic material is contained within the spore. When favourable conditions are encountered, the spore '''germinates''' and produces an actively metabolizing bacterial cell capable of cell division).

=== Yeasts ===
[[File:L5 yeast buds.jpg|thumb|Yeast Buds: By Masur (Own work) [Public domain], via Wikimedia Commons|120x120px]]
Yeasts are commonly found in many foods of agricultural and aquatic origin. Yeasts reproduce by budding.

They generally grow more slowly than bacteria but can '''tolerate more severe environmental conditions''' than bacteria.
* For example yeasts are not inhibited by pH to the same extent as bacteria
* Yeasts can grow in many foods with low water activity that would normally inhibit growth of bacteria
Some yeasts are used to produce fermented foods and beverages.

=== Moulds ===
[[File:L5 moulds.jpg|thumb|Nectarines contaminated with mould(note the visible mycelia-white, and spores -green)This file is licensed under the Creative Commons (Links to an external site.) Attribution-Share Alike 3.0 Unported (Links to an external site.) license.|center]]
[[File:L5 mould-morphology.png|thumb|Mould morphology diagramBy Martin Cilenšek (Scan from Naše škodljive rastline (1892)) [Public domain], via Wikimedia Commons|center|450x450px]]
Moulds are '''filamentous''' and are also found on most foods of agricultural and aquatic origin. Most moulds produce '''spores'''.

Like yeasts, moulds can grow on foods that have a '''low pH''' and also in foods with '''low water activities''' that would inhibit growth of bacteria and yeasts.

Some moulds are used in the production of mould-fermented foods (e.g. mould ripened cheeses), but most moulds are agents of food spoilage and many also produce toxins (mycotoxins) under favourable conditions.

==== What are microbial spores? ====
* '''Mold''' and '''some bacteria''' produce spores. Microbial spores are '''very''' '''resistant''' to a variety of conditions (heat, dehydration, ionizing radiation, antimicrobial agents) that can inhibit or cause death of the ''vegetative cell''.
* In food preservation and processing, the spores of '''''Clostridium botulinum''''', an anaerobic bacterium, are of great concern because the spores are very heat resistant. ''Clostridium botulinum'' is also the group of bacteria that produces the toxin that causes the very serious illness, '''botulism'''. We will discuss ''Clostridium botulinum'' in more detail in Lessons 6 and 12

== Oxygen and temperature requirements for microorganisms: ==
Microorganisms can also be characterized on the basis of '''temperature ranges''' and '''oxygen requirements''' over which growth occurs. For example, mould are strictly aerobic (require oxygen), but different mould species can have different temperature requirements. Some bacteria are aerobic mesophiles, and some are anaerobic mesophiles.

=== Oxygen requirements: ===
* '''AEROBIC:''' grow only in the '''presence''' of dissolved oxygen (Bacteria, yeast, mould)
* '''ANAEROBIC:''' grow only in the '''absence''' of dissolved oxygen (Bacteria)
* '''FACULTATIVE ANAEROBE:''' can grow in the '''presence''' or '''absence''' of oxygen (Bacteria, yeast)
{| class="wikitable"
! colspan="3" |'''Temperature requirements'''
|-
|'''Classification'''
|'''Growth temperatures ('''°C''')'''
|'''Characteristics'''
|-
|'''''Psychrophiles'''''

'''''Psychrotrophs'''''
|0 to 18

-5 to 35
|''Psychrophiles'' grow well in cold temperatures, while ''Psychrotrophs'' have adapted to living and multiplying in cold environments. ''Psychrotrophs'' are the major cause of spoilage in refrigerated foods.
|-
|'''''Mesophiles'''''
|10 to 45
|''Mesophiles'' grow well in moderate temperatures. Many mesophiles have an optimum growth temperature of 37°C. Most spoilage and disease-causing organisms are mesophiles.
|-
|'''''Thermophiles'''''
|50 to >100
|Thermophiles grow best at high temperatures. Most thermophilic organisms are spoilage-causing.
|}

== 5.3 Insects, Rodents and Parasites ==
* Pests are major contributors to post-harvest losses
* Rodents alone ruin >30,000,000 tonnes of food each year worldwide
* Insects are believed to destroy 5-10% of the U.S. grain crop annually, and in some parts of the world this figure can be as high as 50%
* Pests will damage the food and open it to microbial contamination
* Rodent, insect and bird control are important factors in the agriculture and food industries.
You may have had first-hand experience with insects or rodents causing food deterioration in your home. These organisms are often referred to as food pests and the food industry pays a great deal of attention to '''pest management'''. If you have had problems with food pests in your pantry or cupboards, you will appreciate the damage they can cause and the fact that great efforts must be taken to control their activities and invasiveness.

'''Parasites''' can cause damage to food quality. An example is the visible appearance of parasitic cysts in fish flesh which lowers the quality and market value of infested products. Parasites such as ''Trichinella spiralis'' in pork and ''Anisakis species'' in some types of fish can also cause health problems in humans if they are ingested through inadequately cooked or improperly processed foods, infested with those parasites.

== 5.4 Enzymes Endogenous to Foods ==
Enzymes can catalyze reactions leading to chemical changes in foods. Living organisms (animal and plant) have their own enzyme balance. This enzyme balance is disrupted once the animal is killed or the plant is harvested, but the enzymes may continue to catalyze chemical reactions within foods even after slaughter or harvest.

Some examples of enzymatic deterioration in foods are described below:
* The '''softening''' of fruit tissue and the '''changes in flavour and colour''' during storage after picking are examples of deterioration of food quality by enzymes. It is enzymatic action that causes the softening of apple tissue during storage, with texture changing from that of a crisp apple to a somewhat soft and mealy apple with a concomitant loss of sweetness. Enzymes in the apple tissue degrade pectins that cement the cells together, leading to the textural change.
* You also no doubt have experienced the browning of apples, potatoes and peaches after they have been sliced and exposed to oxygen in the atmosphere. This browning phenomenon is known as '''enzymatic browning''' and is catalyzed by an enzyme known as polyphenol oxidase which catalyzes the oxidation of colorless phenols in the tissues to brown colored compounds, as shown in the following equation:
Enzymes can catalyze reactions leading to chemical changes in foods. Living organisms (animal and plant) have their own enzyme balance. This enzyme balance is disrupted once the animal is killed or the plant is harvested, but the enzymes may continue to catalyze chemical reactions within foods even after slaughter or harvest.

[[File:FNH200_Lesson05_Oxidase.gif|center]]
Enzymes can be inactivated by means of heat, chemicals (e.g. antioxidants), and by controlling the gaseous environment. 
== 5.5 Factors Affecting Microbial Growth, Enzyme Activity and Chemical Reactions in Foods ==
Temperature, moisture and oxygen as well as light may have profound influences on microbial growth, enzyme activity and chemical reactions in foods.

=== ''Temperature effects:'' ===
* Rates of reactions generally increase as the temperature increases until an optimum is achieved, after which further increases in temperature cause the rates of reaction to decrease because of inactivation of microorganisms or enzymes or because of inhibitory effects on chemical reactions.
* Excessive heat also denatures proteins, breaks emulsions, removes moisture from foods (drying out), and destroys vitamins.
* Cold temperatures can also deteriorate food. A well known example is "chill injury", the change in texture and discolouration of fruits and vegetables when they are exposed to freezing temperatures.
* Freezing temperatures can deteriorate liquid foods such as milk, causing emulsions to break and fat to separate, and denaturing protein causing it to curdle or coagulate. "Freezer burn" due to loss of moisture can occur in solid and liquid foods.

=== ''Gain or Loss of Moisture:'' ===
* Water loss during storage (e.g. wilting of lettuce in the refrigerator), or water uptake (e.g. by dehydrated foods) can lead to deterioration.
* Retrogradation of starch, resulting in staling of bread, is caused by packing of linear starch molecules leading to the exclusion of water that was previously absorbed during gelatinization. The bread becomes tough and develops a dry texture.
* Changes in water activity (free versus bound water) can influence chemical and enzymatic reactions and microbial growth.

=== ''Oxygen effects:'' ===
* Oxygen is an important factor in food quality, since many oxidative reactions lead to deterioration in the quality of food and, in some cases, to losses in nutritive value. Oxidative deterioration is often accelerated by light.
* For example, deterioration frequently occurs because of oxidation of the fats in food products. The development of rancidity in breakfast cereals, vegetable oils and oil-based products, and in deep-fried foods is due to reaction of oxygen with fats, particularly those with high unsaturated fatty acid content. This type of rancidity is known as '''oxidative rancidity'''. This is in contrast to rancidity induced in foods upon the release of free fatty acids by very high temperatures or by the action of lipase enzymes, either endogenous or produced by spoilage-causing microorganisms. The latter rancidity is known as '''hydrolytic''' or '''lipolytic rancidity'''.
* Oxidation of vitamins and colour pigments can lead to the deterioration of nutritive quality and aesthetic appeal of foods.

=== ''Physical deterioration:'' ===
* Physical abuse causes tissue disruption and release of enzymes into tissues which can lead to changes such as enzymatic browning mentioned earlier.
* Furthermore, improper packaging, for example, can cause crushing and tissue damage, making foods such as fruits and vegetables particularly susceptible to microbial invasion as well as enzymatic and chemical reactions.

=== ''Time:'' ===
* For the majority of foods, quality will decrease with time.
* Food preservation, packaging and storage practices are aimed to maintain this quality for as long as possible (shelf life); however, eventually the quality of any food will decrease with time.

== 5.6 Principles of Food Preservation ==
Food commodities are classified based on their shelf-life expectancy. Depending on the '''type of food''' and the '''type of preservation''' (processing) method used, their shelf-life can vary from a few days to several months or even years! Below is a summary of the three main classifications used: perishable, semi-perishable and shelf-stable foods:
{| class="wikitable"
!Perishable Foods
!Semi-perishable Foods
!Shelf-stable Foods
|-
|
* Perishable foods are those foods that are not processed or are only minimally processed and have a shelf life of '''less than 60 days'''.
* Spoilage of perishable foods is usually caused by microbial growth or senescence1
* Examples of perishable foods are: '''meat, leafy vegetables, soft fruits, and milk.'''
|
* Semi-perishable foods last between '''2 to 6 months''' as a result of some form of preservation method.
* Examples of semi-perishable foods are: '''ice cream, cheeses, and dry snack foods.'''
|
* Shelf-stable foods have a shelf life '''greater than 6 months.'''
* Examples of shelf-stable foods are: '''cereal grains, dehydrated pasta, some frozen foods, canned foods, and dehydrated vegetables.'''
|}
1 Fruits and vegetables '''continue to respire''' after harvest. Respiration is fueled by carbohydrate metabolism that generates adenosine triphosphate (ATP) needed to promote various reactions in the tissues. When nutrients become exhausted, the tissues begin to deteriorate (soften, change colour, rot, produce off-odours). The deterioration is called '''senescence'''.

At the beginning of this lesson we learned about the many factors that contribute to food spoilage (deterioration). The following are the main goals for food preservation. This is just a '''brief introduction''' to the actual preservation methods that we will explore in the subsequent lessons (Lessons 6 to 10).

{| class="wikitable"
!Preservation "goal"
!Preservation method(s) used
|-
| rowspan="8" |
===== '''To control of Microorganisms''' =====
Controlling microorganisms by
* keeping microorganisms out of food
* removing microorganisms from foods
* delaying the initiation of microbial growth
* killing microorganisms or spores
|
===== 1) HIGH TEMPERATURE- "HEAT" =====
Thermal processing involves the application of heat to inactivate enzymes and destory microorganisms.
* Most bacteria are killed in the range o '''82-93°C.'''
* Spores are NOT destroyed even by boiling water at 100°C for 30 min.
* To ensure sterility (total microbial destruction, including spores) a temperature of '''121°C''' must be maintained for '''15 minutes''' or longer.
There are various degrees of thermal processing:
* blanching
* pasteurization
* commercial sterilization
Thermal processing will be discussed in more detail in '''Lesson 6.'''
|-
|
===== 2) LOW TEMPERATURE- "COLD" =====
Lowering temperature of a food decreases the rate of enzymatic, chemical and microbial reactions in food thus extending storage life.

Microbial growth rates decrease as temperatures decrease towards 0°C. Low temperatures, however, favour the proliferation of ''psychrotrophic'' microorganisms which ultimately cause spoilage of cold stored foods.

There are two main categories of low temperature storage of food:
* refrigeration
* freezing
Microorganisms are not easily killed by frozen storage of foods although death will occur slowly. Consequently, freezing cannot be relied upon to rid food of microbial contamination (''Bacillus'' species and ''Clostridium'' species are virtually unaffected by low temperatures).

Some microorganisms can grow at temperatures as low as -9.5°C. Thus when food is held at improper frozen storage temperatures, microbial growth and spoilage can still occur, especially after thawing.

These preservation methods will be discussed in '''Lesson 7.'''
|-
|
===== 3) LOWERING WATER ACTIVITY (Aw) =====
Each specific organism has its own range of Aw in which it will grow. Bacteria normally need Aw of 0.90 and higher, yeast need >0.70, while moulds need 0.60-0.70 and higher. Of course, there are always some exceptions. For example, the pathogenic bacteria ''Staphylococcus aureus'' can grow at Aw as low as 0.83-0.84, while the yeast ''Saccharomyces. cerevisiae'' requires Aw of 0.90.

'''Drying'''
* Microorganisms require '''free water''' in order to survive and multiply. Therefore, controlling water activity and water content of food can enable extension of storage life.
* When free water is removed from the food and therefore from microbial cells, multiplication will stop since water will be unavailable for chemical, microbial and enzymatic reactions.
'''PLEASE REVIEW CONCEPT OF WATER ACTIVITY (AW) FROM LESSON 2.'''

Water activity in foods can be controlled (lowered) by:
* '''Freezing''' water as crystals of pure water.
* Physical removal of water from food ('''dehydration''')
* Removal of some of the water from food ('''concentration''') by addition of substances that bind water in food making it unable to participate in chemical, microbial and enzymatic reactions (e.g. addition of salt or sugar, at high concentrations, to food).
The concept of food dehydration will be explored inLesson 8.
|-
|
===== 4) ACIDS =====
As discussed in Lesson 2, the acidity of a food can be described by its pH, which is the negative logarithm (base 10) of the hydrogen ion concentration. The pH of a food is an important factor that determines rates of chemical and enzymatic reactions as well as survival and growth of microorganisms in foods during processing, distribution and storage. The pH of solutions can vary between 0 (extremely acidic) to 14 (extremely alkaline). A pH of 7 defines a food that is neither acidic nor alkaline (i.e., it is neutral).

Only a few foods have a pH above 7; an example is egg albumen (white) which has a pH of 9. Most foods fall within the pH range of 2 to 7. The acidity of a food can be adjusted by the addition of food grade acids or alkalis or by acids produced through microbial fermentations. Beyond their influence on pH per se, some acids are also antimicrobial agents.

As we first learned in Lesson 2, '''pH 4.6''' is a critical value in terms of microbial growth and stability, and we will explore in subsequent lessons, how the pH of a food is an important criterion in determining how the food should be processed or stored.
|-
|
===== 5) SUGAR and SALT =====
As discussed before, sugar and salt exert their preservative effects primarily through their effects on water activity of a food. Thus sugars and salt are employed in foods not only for their contributions to the flavour of foods but also because of their water binding properties. In addition, at very high concentrations, they may have a dehydrating effect on the microbial cells.

One of the preservatives in cured processed meats is salt, while sugars in jams and jellies prevent growth of bacteria and yeasts (except those that are tolerant to low water activities and moulds which can grow under conditions of low water activity).
|-
|
===== 6) OXYGEN =====
It is the oxygen in air or within a food that determines whether a food can support the growth of aerobic or anaerobic microorganisms.
* Thus moulds can be inhibited from growing on foods by excluding oxygen. This is the function of waxes applied to rounds of cheese during aging and also is the function of paraffin wax placed on top of jams and jellies.
* However, the removal of oxygen from low acid foods with a high water activity can pose a potential health hazard because conditions can be created whereby anaerobic disease-causing microorganisms, such as ''Clostridium botulinum'', may be able to proliferate and produce toxins that could cause disease when the toxin-containing food is consumed. Vegetables and fish can be safely stored in an oxygen-free environment only if the ''Clostridium botulinum'' spores are killed by the application of heat. This will be discussed in more detail in Lesson 6.
|-
|
===== 7) FERMENTATION =====
* Specific microorganisms (starter cultures) are cultured in certain foods to facilitate chemical changes in the foods such that the foods have a longer storage life.
* Inhibitors such as acids, alcohol and bacteriocins (antimicrobial agents) are produced by the starter cultures. The inhibitors delay or prevent growth of undesirable microorganisms.
Fermentation will be discussed in more detail in Lesson 9: Food Biotechnology.
|-
|
===== 8) CHEMICALS =====
Microorganisms that can cause deteriorative changes in foods can be controlled by the use of chemical agents that have antimicrobial properties. Only a few such agents are permitted for use in Canada and their use as preservatives is defined within The Food and Drug Regulations of Canada.
* Examples of '''antimicrobial agents''' added to some foods are:
** Sodium propionate - may be added to bread formulations as a mould inhibitor.
** Sodium benzoate - may be added to some acidic foods to delay growth of acid tolerant spoilage bacteria.
Similarly, '''antioxidants''' that are approved for specific uses may be added to delay the onset of oxidative rancidity.
* For example, VITAMINS C and E (lesson 2). Another antioxidant, Butylated hydroxyanisole (BHA), is added to the packaging material for some breakfast cereals to react with oxygen before it can enter the package and react with sensitive constituents in the breakfast cereal to cause oxidative rancidity.
|-
|
===== '''To Control of Enzymes and Oxygen''' =====
Controlling enzymes and Oxygen by:
* inactivating endogenous enzymes; and
* preventing or delaying chemical reactions in the food
|
===== 9) RADIATION (ENERGY) =====
Various forms of radiation (energy) can be used to preserve food.
* Ionizing radiation or "food irradiation" can be used to inactivate microorganisms in food, and to destroy storage pests (insects, mites, flies), thereby extending the storage life of the food.
* Microwave treatment of food can be used to inactivate enzymes and microorganisms through generation of high temperatures as a result of the interaction of the microwave energy with water in the food.
* Infrared radiation is used to toast foods, to keep foods hot and to cook foods.
* Ultraviolet energy is used to sterilize air and water used in food processing, particularly in the beverage industry.
This topic will be explored in more detail in Lesson 10.

Enzymes in foods are controlled by many of the same techniques described above to control the activity of microorganisms in foods.

As an example of controlling enzymatic activity, the enzyme system that causes browning of fruit and vegetable tissues will be used as a model for discussion.

Refer again to the example of the browning reaction caused by polyphenol oxidase given earlier in this lesson. We have all had the experience of observing apple tissue turning brown after it has been cut and exposed to oxygen in the air. The enzymatic browning reaction can be inhibited in the following ways:
* The apple slices can be dipped in hot water to cause heat denaturation of the polyphenol oxidase. This will adversely affect the physical properties of the apple but this is not of much concern during the manufacture of apple sauce or pie filling.
* Oxygen can be excluded from the surface of the apple tissue by immersing the apple slices in water. Oxygen will not be completely excluded from the tissue surface but the rate of diffusion of oxygen to the tissue is impaired by the water. The availability of oxygen becomes rate limiting and thus slows down the reaction rate. The slices will eventually turn brown but the time required for browning to occur will be much longer than the time required during exposure of the apple tissue to oxygen in the air. This practice is widely used to delay browning of fruit and of peeled and sliced potatoes in the food processing and food service industries and in the home.
* Acid conditions can be created on the apple slices by applying acids such as citric acid. Polyphenol oxidase activity is inhibited by the more acidic conditions created by adding citric acid or lemon juice (which contains citric and ascorbic acids), thus slowing down the rate of the enzyme catalyzed browning reaction.
* Chemical reducing agents can be applied to the surfaces of apple slices to remove oxygen from the surface. '''Ascorbic acid (vitamin C)''' is often employed as an '''antioxidant''', acting as an oxygen scavenger to delay the onset of enzymatic browning by reacting with oxygen before the oxygen can take part in the browning reaction.
|}

If you have ever preserved fruit such as apple slices or peaches in your home, you probably have sprinkled the sliced fruit with a commercial preparation of ascorbic acid and citric acid to delay the onset of browning before the fruit is frozen. Sulfur dioxide or metabisulfites have also been employed to inhibit the browning reaction, although the use of these substances is now severely restricted because of the sensitivity of certain segments of the population to sulfur dioxide and sulfites in foods.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* It is fairly simple to observe firsthand the relative effects on the rate of browning that result from the treatments described above.
* Slice an apple and compare the rates of browning in apple slices left exposed to the air to those that have been dipped in boiling water for several minutes, or stored under water, or treated with a commercial preparation of citric acid and ascorbic acid, or lemon juice.
|}

'''''Video (on canvas)'''''

==== '''''Food Preservation Video Pt. 1 and 2''''' ====
== 5.7 Summary ==
* Food deterioration can occur as a result of physical, chemical or biological causes.
* The primary objectives of food preservation are to minimize deterioration and eliminate potential microbiological harm to the consumer, and to maintain quality and nutritional value while producing a safe food product.
* A number of methods can be used to achieve these objectives. However, it should be noted that no method can completely eliminate spoilage phenomena indefinitely. For example, although canned foods will not undergo microbial or enzymatic spoilage as long as the physical integrity of the can is maintained, the foods may spoil as a consequence of chemical reactions such as Maillard browning which can proceed slowly even at ambient temperature.
* As mentioned in the video, "'''''old'''''" preservation technologies such as smoking or fermentation cause noticeable changes in the food (i.e. fresh salmon vs. smoked salmon, grapes vs. wine, milk vs. cheese); whereas "'''''new'''''" preservation technologies such as pasteurization or freezing change very little the starting food material. We should remember however, that without these "old" preservation methods we wouldn't have the variety of desirable food products such as: cheese, bread, wine, smoked meats, etc.

'''Authorship:'''

FNH 200 Course content on this wiki page and associated lesson pages was originally authored by Drs. [http://www.landfood.ubc.ca/person/brent-skura/ Brent Skura], [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], and [http://www.landfood.ubc.ca/person/eunice-li-chan/ Eunice Li-Chan]. Ongoing edits and updates are contributed by past and current instructors including Drs. [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], [http://www.landfood.ubc.ca/person/azita-madadi-noei/ Azita Madadi-Noei], [http://www.landfood.ubc.ca/person/nooshin-alizadeh-pasdar/ Nooshin Alizadeh-Pasdar], and [http://www.landfood.ubc.ca/person/judy-chan/ Judy Chan].
{{cc-by-nc-sa-3.0}}

<quiz display=simple>
{ Type text here or a no-break space code
|type="{}"}
1. Name of the enzyme responsible for the browning of apple after it’s cut. { Polyphenol oxidase }
</quiz>

<quiz display=simple>
{2. Choose all the correct ways to prevent apple slices from enzymatic browning:
|type="[]"}
+ Dipping apple slices in hot water.
+ Dipping apple slices in water.
+ Dipping apple slices in water with lemon juice.
+ Applying sulfur dioxide.
</quiz>

<quiz display=simple>
{3. There are factors that influence the extent of spoilage. Which of the following statement is true about heat?
|type="()"}
- Excessive heat denatures enzymes but promotes microbial growth.
- Low heat denatures enzymes but promotes microbial growth.
+ Excessive heat denatures enzymes and can destroy microbes.
- Low heat denatures enzymes and can destroy microbes.
</quiz>

<quiz display=simple>
{4. There are factors that influence the extent of spoilage. Which of the following statement is true about moisture?
|type="()"}
+ Changes in free water influences enzymatic, microbiological and chemical spoilage.
- Changes in free water only influence chemical spoilage and not enzymatic or microbiological.
- Changes in free water influences enzymatic and microbiological spoilage and not chemical.
- Changes in free water only influence enzymatic and not chemical spoilage or microbiological.
</quiz>

<quiz display=simple>
{5. What is true about enzymes and microorganisms?
|type="()"}
- Enzymes are found in plants like vegetables and in meats but not in microorganisms like bacteria.
- Both enzymes and microorganisms are considered living things.
- Enzymes present in microorganisms only cause food spoilage as none are present in food items like vegetables or meats.
+ Enzymes are found naturally in all living things including plants and microorganisms.
</quiz>

Course:FNH200/Lessons/Lesson 04

2020-06-24T00:22:57Z

YihangChen: /* Overview */

<big><big><big>'''Food Standards, Regulations and Guides - Food Additives'''</big></big></big>

== 4.0 Overview ==
This lesson will introduce you to the concept of food regulation and you will become familiar with "standards of identity", standards and quality grades for foods, as well as the major governmental agencies that have a role in regulating the safety and quality of the food supply. You will learn about the Food and Drugs Act and Regulations of Canada, and the regulations that govern labelling and advertising as they apply to food. We will also discuss regulations governing grade standards for various food commodities that are administered by the Canadian Food Inspection Agency.

At one time or another, most people have been in a conversation where food additives have been the topic of discussion. Few people know what food additives are, what their purpose is, and what regulations govern their use. In this lesson we discuss and compare the Canadian and United States definitions of a food additive. We also discuss the classes of food additives and their functions in food systems. We review Canadian labelling requirements as they pertain to food additives and discuss the concepts employed in the evaluation of safety of food additives. We end the lesson with a discussion of aspartame and nitrites as examples of food additives that have generated much controversy in the recent past.

=== Objectives ===
After completing this lesson, you will be able to:
* discuss how regulations are established, to ensure the quality and safety of the Canadian food supply
* identify which governmental agencies are responsible for regulating the safety and quality of the food supply
* define what a food additive is
* interpret the function of food additives that are listed on the labels of ingredients of food you consume
* explain the basis upon which safety of food additives is determined; and
* articulate your set of values as they pertain to the use of food additives in foods
* compare and contrast the definition of a food additive in Canada and United States
* demonstrate the ability to do research and extract information about the Canadian food acts and regulations

=== Optional Readings ===
* Hotchkiss, J.H. and Cassens, R.G. 1987 [April]. Nitrate, nitrite and nitroso compounds in foods (A scientific status summary). ''Food Technology'', ''41''(4):127-136.
* Kroger, M, Meister, K. and Kava, R. 2006. Low-calorie sweeteners and other sugar substitutes: A review of the safety issues. Please see this link INSTEAD; Comprehensive Reviews in Food Science and Food Safety 5: (read only pp. 37-39). NOTE: this is the same article as required in lesson 3.
Resources
* Health Canada, Food program: Safety of Aspartame. https://www.canada.ca/en/health-canada/services/food-nutrition/food-safety/food-additives/sugar-substitutes/aspartame-artificial-sweeteners.html
* Health Canada. 2006. ''Food Additive Dictionary''. Publication H49-10/1996E. Ottawa: Health Canada. https://www.canada.ca/en/health-canada/services/food-nutrition/food-safety/food-additives/dictionary.html

== 4.1 Food Standards, Regulations and Guides ==
{| class="wikitable"
|
==== '''Terms to remember''' ====
|-
|
* Health Canada
* Canadian Food Inspection Agency
* Food and Drugs Act and Regulations
* Standards of identity and composition
* Food Grades
* No Effect Level (NOEL)
* Acceptable Daily Intake (ADI)
* Probable Daily Intake (PDI)
* Diketopiperazine (DKP)
* Phenylketonuria (PKU)
* Clostridium botulinum
* Nitrosamines
|}
In order to ensure that the food we purchase and consume is '''safe''' and within certain preset limits of '''quality''', there are government standards, regulations and grades in place to protect the consumer.

The Department of '''Justice Canada''' is responsible for maintaining the Consolidated Statutes and Regulations for the Government of Canada, including the '''Food and Drugs Act and Food and Drug Regulations'''.

The Food and Drugs Act of Canada is administered by the '''Health Products and Food Branch''' of '''Health Canada''', whereas inspections for compliance are enforced by the '''Canadian Food Inspection Agency'''. Several other government agencies work together to ensure the safety and quality of foods produced and/or consumed in Canada.

The government agencies and their regulatory functions are listed below.

Table 4.1 ''Government agencies and their regulatory functions''
{| class="wikitable"
|
=== Agency ===
|
=== Regulatory Function ===
|-
|Health Canada

(Health Products & Food Branch)

https://www.canada.ca/en/health-canada/services/food-nutrition.html
|
* setting food and drug regulation standards of identity and composition for foods
* Food and Drugs Act (<nowiki>http://laws-lois.justice.gc.ca/eng/acts/F-27/</nowiki>)
* food additive regulations
|-
|Canadian Food Inspection Agency (CFIA)

http://www.inspection.gc.ca/english/toce.shtml
|
* provides inspection services related to the food
* responsible for administration and enforcement of different Acts including:

* Food and Drugs Act (<nowiki>http://laws-lois.justice.gc.ca/eng/acts/F-27/</nowiki>)
* Agriculture and Agri-Food Administrative Monetary Penalties Act (http://laws-lois.justice.gc.ca/eng/acts/A-8.8/)
* Food Labeling for industry (http://www.inspection.gc.ca/food/requirements/labelling/industry/eng/1383607266489/1383607344939
|-
|Measurement Canada
|Agency of Innovation, Science and Economic Development Canada.

responsible for ensuring accuracy in the selling of measured goods,

developing and enforcing the laws related to measurement accuracy,

approving and inspecting measuring devices and investigating complaints of suspected inaccurate measurement.
* https://www.ic.gc.ca/eic/site/mc-mc.nsf/eng/Home
|-
|British Columbia Ministry of Health
|public health inspection of retail stores and food service establishments

inspection of provincially inspected meat processing plants and dairy processing plants
|-
|Municipal
|public health inspection of retail stores and food service establishments
|}

=== The Food and Drugs Act ===
Sections 3, 4, 5, and 7 of the '''Food and Drugs Act''' form the foundation of the consumer protection laws. Excerpts of the Act are shown in Box 4.1 to give you an idea of the nature of the regulations.

It is interesting to note that Section 3 of the Food and Drugs Act prohibits the advertising to the general public of any food, drug, cosmetic or device for the treatment, prevention or cure of any of the diseases listed on Schedule A of the Food and Drugs Act. This section of the Act also prohibits the sale of a food, drug, cosmetic or device that is labeled in this manner.

In the light of recent trends and the demand for natural health products, the House of Commons Standing Committee on Health mandated an External Working Group which is overseeing the revisions may be needed to this section of the Act.

{| class="wikitable"
| colspan="2" |
=== Excerpts from The Food and Drugs Act of Canada ===
http://laws-lois.justice.gc.ca/eng/acts/F%2D27/page-1.html#docCont
|-
|
==== '''Section 3''' ====
(1) no person shall advertise any food, drug, cosmetic or device to the general public as a treatment, preventative or cure for any of the diseases, disorders or abnormal physical states referred to in Schedule A.

(2) No person shall sell any food, drug, cosmetic or device

(a)that is represented by label, or:

(b) that is represented to the general public as a treatment, preventative or cure for any of the diseases, disorder or abnormal physical states referred to in Schedule A.

Some of the diseases mentioned in schedule A include alcoholism, appendicitis, arthritis, cancer, depression, diabetes, heart disease, hypertension, liver diseases, obesity, sexual impotence, tumours, venereal disease.
|
==== '''Section''' 5 ====
(1) No person shall label, package, treat, process, sell or advertise any food in manner that is false, misleading or deceptive or is likely to create an erroneous impression regarding its character, value, quantity, composition, merit or safety;

(2) An article of food that is not labelled or packaged as required by the regulations, or is labelled or packaged contrary to the regulations, shall be deemed to be labelled or packaged contrary to subsection (1).
|-
|
==== '''Section 4''' ====
No person shall sell an article of food that:

(a) has in or upon it any poisonous or harmful substance;

(b) is unfit for human consumption;

(c) consists in whole or in part of any filthy, putrid, disgusting, rotten decomposed or diseased animal or vegetable substance;

(d) is adulterated;

(e) was manufactured, prepared, preserved, packaged or stored under unsanitary conditions.
|
==== '''Section 7''' ====
(a) No person shall manufacture, prepare, preserve, package or store for sale any food under unsanitary conditions.
|}
Box 4.1 ''Sections 3, 4, 5 and 7 of The Food and Drugs Act of Canada, that are the foundation of consumer protection laws.''

== 4.2 How are Regulations established? ==
* The Food protection laws, in Canada, are wide in scope and major changes in the regulations embodied within the ''Food and Drugs Act'' are made after extensive consultation. We will discuss this consultation process when we deal with the section on ''Food Irradiation''.
* Rapid changes can also be made to the ''Food and Drugs Act'' such as in the case of delisting a food additive or other substance permitted in food when new evidence arises concerning issues of safety of a particular substance. Such was the case when the non-caloric sweeteners cyclamate and saccharin were banned.
* The regulations can be amended by authority of the Governor in Council.
As noted on Table 4.1, regulations about labelling, advertising and claims about food are administered by the '''Canadian Food Inspection Agency''' (CFIA):
* CFIA deals with food labelling, advertising and claims about food.
* Administers the labelling, packaging and advertising regulations under the Consumer Packaging and Labelling Act and Regulations and the Food and Drugs Act and Regulations.
* The CFIA also reviews all advertisements, on Canadian radio and television, making claims about foods.
'''Weights and measures''' are regulated by "Innovation, Science and Development Canada" specifically by an agency known as "Measurement Canada". This agency is responsible for inspection of measurement devices and providing the accuracy certification stickers

https://www.ic.gc.ca/eic/site/mc-mc.nsf/eng/lm04710.html

Please note that packaged retail products are subjected to ''Consumer Packaging and Labelling Act'' and Canadian Food Inspection Agency ( CFIA) is responsible for overseeing their measurement accuracy.

== 4. 3 Food Labelling Requirements ==
Labelling information required on pre-packaged food products, from domestic food processors or imported products, is based on the '''Consumer Packaging and Labelling Act and Regulations''' and can be found in theat the CFIA website: http://www.inspection.gc.ca/food/labelling/food-labelling-for-industry/eng/1383607266489/1383607344939

Summarizing the core labelling requirement, a label should include the following:
* '''Bilingual labelling'''- All mandatory information on food labels must be shown in both official languages, i.e., French and English.
* '''Common name of the food'''. The common name is the name prescribed in the Food and Drugs Regulations. In the absence of a prescribed name, the name by which the food is commonly known is used.
* Country of Origin- Declaring of Country of Origin is required for some specific food. Some companies may choose to voluntarily name the country of origin as advertising. For a complete list of foods requiring mandatory declaration please see the link below

* http://www.inspection.gc.ca/food/labelling/food-labelling-for-industry/label/country-of-origin/eng/1334599362133/1334601061354
* '''Date marking''' and '''storage instructions''' as required. This is required for foods with a storage life of '''90 days or less'''.
** '''Durable life''' is the period of time, beginning on the day on which the pre-packaged product is packaged for retail sale, during which a product stored under prescribed conditions will retain, without appreciable deterioration, its normal wholesomeness, palatability and nutritional value and any other qualities claimed for it by the manufacturer. Products that have passed the durable life date and that have been stored under prescribed conditions are still safe to eat but the quality (appearance, flavour, nutritional value) may have deteriorated.
* '''Identity and Principal Place of Business'''
* '''Irradiated foods'''
* '''Legibility and location'''
* '''List of ingredients''' in descending order of proportion
* The '''Nutrition Facts table''' will show the Calories, the amount of fat, saturated and trans fats, cholesterol, sodium, carbohydrate, fiber, sugars, protein, calcium, iron and Vitamins A and C in a specified amount of food.Nutrition facts regulations apply to all pre-packaged foods with some exemptions (e.g fresh fruit and vegetables, raw single ingredient meat and poultry that are not ground, raw fish or seafood, alcoholic beverages).
* '''Net quantity of the food'''
* '''Sweeteners'''
* '''Other mandatory information''' may be required for certain foods: eg. % alcohol for alcoholic beverages, % milk fat for some dairy products
'''Nutrient content claims''' and '''diet-related health claims''', if made, must adhere to the stated criteria (see below)

Currently, there are '''5 disease reduction claims''' allowed in Canada:
# Disease Risk Reduction Claims with Respect to Sodium and Potassium
# Disease Risk Reduction Claims with Respect to Calcium and Vitamin D
# Disease Risk Reduction Claims with Respect to Saturated and ''Trans'' Fats
# Disease Risk Reduction Claims with Respect to Cancer Risk Reduction
# Disease Risk Reduction Claims with Respect to Dental Caries
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Do you know what it means when a food is labeled '''''"fat-free"''''' or '''''"light"''?'''
** Check out these links for the answer:
*** http://www.inspection.gc.ca/food/labelling/food-labelling-for-industry/nutrient-content/specific-claim-requirements/eng/1389907770176/1389907817577?chap=4
*** http://www.inspection.gc.ca/food/labelling/food-labelling-for-industry/nutrient-content/specific-claim-requirements/eng/1389907770176/1389907817577?chap=4<nowiki/>http://healthycanadians.gc.ca/eating-nutrition/label-etiquetage/label-etiquette-eng.php
|}
{| class="wikitable"
| '''Want to learn more?'''
|-
|
* Look at labels on a number of food products in your refrigerator and in your cupboards. Is the required information present?
* Look for the ''durable life date'' on packaged perishable food products (e.g. pasteurized milk, yogurt, cottage cheese, bread, refrigerated cured meats-frankfurters bacon, etc).
* Look for "health claims" in food products (breakfast cereals, orange juice, etc). Do these claims comply with Canadian regulations?
|}

== 4.4 Standards of Food Identity and Composition ==
The Food and Drug Regulations contain descriptions of certain foods that specify, for example, '''what is allowed in those foods as ingredients'''. These descriptions are standards of identity and composition that have to be met for a food to be legally called by the name in the standard. The foods are referred to as "standardized foods". Examples of standardized foods include bread, milk, cheese, orange juice, sausage, jam, wine, beer, vinegar and salt. Foods that do not have a standard of identity are referred to as "'''unstandardized foods'''". Snack foods like potato chips, various bakery items such as rolls, donuts and cakes, yogurt, and pizza are examples of unstandardized foods.

Standards of food identity and composition are defined in the '''''Food Regulations of the Food and Drugs Act of Canada'''''
* Please '''bookmark''' the link for the '''Food and Drug Regulations''' of '''The Food and Drugs Act of Canada''':
* <nowiki>http://laws-lois.justice.gc.ca/eng/regulations/C.R.C.,_c._870/index.html</nowiki>
Note the following:
* An '''''identity''' standard'' is one that states what the food shall be and defines a food or ingredient. '''''Compositional''' standards'' list the mandatory and permitted ingredients in foods.
* There are standards of identity or composition for over '''300 foods''' in the Food Regulations in Canada. They are classified within '''28 divisions'''. ''For example'', '''Division 13''' regulates "Grain and Bakery products". In this division, the standards of identity and composition for white wheat flour and bread can be found. A fragment of this division is shown below in Box 4.2 (click on the Box to read its contents).
** The dates on the left hand side of the identity and compositional standards (Box 4.2) indicate the date of the last revision of a particular section of the standard.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Visit the Food and Drug Regulations (<nowiki>http://laws-lois.justice.gc.ca/eng/regulations/C.R.C.,_c._870/index.html</nowiki>) and answer the following questions. Can you identify the division number that regulates:
** Dairy products
** Food additives
** Cocoa & chocolate products
|}
[[File:4.2.gif|thumb|Box 4.2 Identity and Composition Standards.|center]]
 

== 4.5 Food Grades Standards ==
Food grades standards are administered by the CFIA.

Here is a list of some of the regulations:
* [https://inspection.gc.ca/about-the-cfia/acts-and-regulations/list-of-acts-and-regulations/documents-incorporated-by-reference/canadian-grade-compendium-volume-1/eng/1520878338783/1520878339422 Volume 1, Ovine carcasses and poultry carcasses]
* [https://inspection.gc.ca/about-the-cfia/acts-and-regulations/list-of-acts-and-regulations/documents-incorporated-by-reference/canadian-grade-compendium-volume-2/eng/1519996239002/1519996303947 Volume 2, Fresh fruit or vegetables]
* [https://inspection.gc.ca/about-the-cfia/acts-and-regulations/list-of-acts-and-regulations/documents-incorporated-by-reference/canadian-grade-compendium-volume-3/eng/1522257117725/1522257118286 Volume 3, Processed fruit or vegetable products]
* [https://inspection.gc.ca/about-the-cfia/acts-and-regulations/list-of-acts-and-regulations/documents-incorporated-by-reference/canadian-grade-compendium-volume-4/eng/1521118213588/1521118214322 Volume 4, Dairy products]
* [https://inspection.gc.ca/about-the-cfia/acts-and-regulations/list-of-acts-and-regulations/documents-incorporated-by-reference/canadian-grade-compendium-volume-5/eng/1520869505643/1520869506282 Volume 5, Eggs]
* [https://inspection.gc.ca/about-the-cfia/acts-and-regulations/list-of-acts-and-regulations/documents-incorporated-by-reference/canadian-grade-compendium-volume-6/eng/1523388139064/1523388171017 Volume 6, Honey]
* [https://inspection.gc.ca/about-the-cfia/acts-and-regulations/list-of-acts-and-regulations/documents-incorporated-by-reference/canadian-grade-compendium-volume-7/eng/1521118355767/1521118356469 Volume 7, Maple syrup]
* [https://inspection.gc.ca/about-the-cfia/acts-and-regulations/list-of-acts-and-regulations/documents-incorporated-by-reference/canadian-grade-compendium-volume-8/eng/1521472457185/1521472457803 Volume 8, Fish]
{| class="wikitable"
| '''Critical Thinking'''
|-
|To complete the following activities visit the http://inspection.gc.ca/food/requirements/labelling/industry/grades/eng/1468508117774/1468508381597.

1) Find out more about regulations governing fresh fruits or vegetables.

* What are the names of the 7 grades for fresh apples?
* Describe the major attributes that distinguish the first (top) grade and third grade.
''Response: Grade standard descriptions for '''processed fruits or vegetables''' indicate that the grades are based on aesthetic qualities of the fruits and vegetables. Although there is not a great deal of information available, it appears that Canada Fancy and Canada Standard processed fruits and vegetables are similar in nutrient value. Thus the grades do not necessarily indicate that a better grade (fancy) is superior to a lower grade (standard) from a nutrient point of view.''

''2) Find out more about eggs.''

Select "'''Egg Regulations'''" and scan through the information to answer the following questions:
* How many grades exist for eggs? what are they named?
* What are the basic requirements for eggs to be graded?
''Response: '''Eggs''' are graded only if certain criteria are met, and then only by an inspector at a registered egg station. The eggs are evaluated for weight, cleanliness, soundness'' and ''shape of shell, shape and position of yolk in the egg during candling, size of air cell (small = fresh), abnormalities (e.g., blood spots).''
* Which grade of eggs is further designated by size?
* Which grades are shown on a label with a "maple leaf" design?
* Which grades are sent to registered processed egg stations?
* Take a look at an egg carton in your fridge or in the supermarket. Can you find the required information about the grade? size?
3) Now select "'''Ovine and Poultry Carcass Grading Regulations'''" and browse through to answer the following
* How many grades exist for beef carcasses?
* What are the names of these grades?
* What are the main criteria that are considered in grading beef carcasses? Next time you eat a piece of steak, you should have a better understanding of what the "Triple A" means!
4) Now select "Maple Product Regulations" and browse through the Maple Syrup Grade Names.
* How many grades exist?
* What are the attributes associated with the grades?
|}

=== Video ===
At this point you should watch the video on '''Egg processing''', including the grading system and processing.

'''Can you answer the following:'''
* Why are the eggs washed?
* How is the process of candling done?
* What are the main external and internal characteristics that are evaluated during candling?
* Which grade(s) of eggs are normally found in the retail market? what happens to other grades? are all eggs suitable for food use?
* What types of processed egg products are shown? what are the conditions for HTST pasteurization of liquid whole and yolk?

== 4.6 Natural Health Products ==
To deal with the uniqueness of emerging products which are neither strictly foods nor drugs, the government has established a [https://www.canada.ca/en/health-canada/corporate/about-health-canada/branches-agencies/health-products-food-branch/natural-non-prescription-health-products-directorate.html Natural Health Products Directorate], responsible for regulations and labelling guidelines for these products. We will learn about this topic in Lesson 13.

==== '''How about the international scene?''' ====
The [http://www.fao.org/fao-who-codexalimentarius/en/ Codex Alimentarius Commission] was established in 1963 by the World Health Organization and the Food and Agriculture Organization of the United Nations to develop international food standards to protect consumer health and to facilitate fair trading practices in foods. Today, there are more than 189 member countries including Canada. Canada's participation in Codex is coordinated through the Office of the Codex Contact Point for Canada, located in the Food Directorate, Health Products and Food Branch of Health Canada.

If you are interested in the regulations in the United States, you may wish to check out the website of the US Food and Drug Administration, Centre for Food Safety and Applied Nutrition: https://www.fda.gov/

The Agriculture and Agri-Food Canada website for information concerning US FDA regulations is also useful especially for import-export cases: [http://www.agr.gc.ca/eng/home/?id=1395690825741 http://www.agr.gc.ca/eng/home/?id=1395690825741 ]

== 4.7 Food Additives ==
There is probably no component of the food system that has generated so much discussion among the consuming public as food additives. Many myths and half-truths abound about food additives, their uses and the perceived dangers related to the presence of additives in foods in the Canadian food supply. Compounding this, is the prevalence of American radio, television, newspapers and magazines in Canada with articles about the positive and, in the majority of cases, negative aspects about food additives.
* As you will note shortly, the Canadian definition of a food additive is '''not''' the same as the definition of a food additive in the United States. This has led to much of the confusion in the eyes of the Canadian public, who at times may know more about the United States regulations and legislation than the Canadian regulations and legislation and the Food and Drugs Act of Canada.

==== Canadian Food additive definition ====
A food additive is any substance, the use of which results, or may reasonably be expected to result in it or its by-products becoming a part of or affecting the characteristics of a food.

'''Under the Canadian definition, the following are considered NOT to be additives:'''
* any nutritive material that is used, recognized or commonly sold as an article or ingredient of food
* amino acids, mineral nutrients and vitamins
* spices, seasonings, flavouring preparations, essential oils, oleoresins and natural extractives
* food packaging materials and components thereof
* drugs recommended for administration to animals that may be consumed as food.
The exceptions are not included in the definition of a food additive since regulations in other divisions of the food regulations of The Food and Drugs Act of Canada govern their use.

Now compare the Canadian definition of a food additive with the definition adhered to in the '''United States''' by the ''Food and Drug Administration'', the federal counterpart to the Health Products and Food Branch of Health Canada.

==== The definition of a food additive in the United States is as follows: ====
''"In its broadest sense, a food additive is any substance added to food. Legally, the term refers to 'any substance the intended use which results or may reasonably be expected to result-directly or indirectly-in'' its ''becoming a component or otherwise affecting the characteristics of any food. This definition includes any substance used in the production, processing, treatment, packaging, transportation or storage of food. If a substance is added to a food for a specific purpose in that food, it is referred to as a direct additive. For example, the low-calorie sweetener aspartame, which is used in beverages, puddings, yogurt, chewing gum and other foods, is considered a direct additive. Many direct additives are identified on the ingredient label of foods. Indirect food additives are those that become part of the food in trace amounts due to its packaging, storage or'' other handling''. For instance, minute amounts of packaging substances may find their way into foods during storage. Food packaging manufacturers must prove to the U.S. Food and Drug Administration (FDA) that all materials coming in contact with food are'' safe, ''before they are permitted for use in such a manner."''

Quoted from the answer to "What is a food additive?" in the International Food Information Council (IFIC) Foundation US Food and Drug Administration (FDA) Brochure: April 2010 from the http://www.fda.gov/downloads/Food/IngredientsPackagingLabeling/ucm094249.pdf

Although the Canadian and American definitions of food additives sound somewhat similar there are substantial differences between them as illustrated in the following table. You can clearly deduce that confusion can exist among consumers getting their information from the media from two neighbouring countries:
{| class="wikitable"
!Considered Food Additives
!Canada
!United States
|-
|Nutritive materials, vitamins, minerals and amino acids
|No
|Yes
|-
|Spices, seasonings and flavourings
|No
|Yes
|-
|Agricultural chemical residues
|No'''a'''
|Yes'''b'''
|-
|Food packaging components
|No'''a'''
|Yes'''b'''
|-
|Drugs recommended for therapeutic use and as feed additives for administration to food producing animals
|No'''a'''
|Yes'''b'''
|-
|Number of additives permitted ("on the books")
|~400
|>3000
|}
'''a''' considered as contaminants in Canada.

'''b''' considered as unintentional food additives in the United States.

=== Justified Uses for Food Additives ===
The '''Food and Agriculture Organization''' (FAO) of the United Nations has stated that the use of food additives is justified when one or more of the following conditions are met:
# additives used to maintain nutritional quality of the food. Use of additives that prevent or inhibit destruction of nutrients during processing and storage (e.g., use of antioxidants to prevent destruction of linoleic acid in oils);
# additives that function to enhance the keeping quality or stability of the food with a concomitant decrease in food wastage (e.g., use of antioxidants to delay fat oxidation; antimicrobial agents to delay microbial spoilage of food);
# additives used to make foods attractive without deception (e.g., use of orange/yellow colours in margarine to provide a pleasing appearance; colouring agents are not permitted for use in fresh meats such as ground beef because a colouring agent could disguise the colour changes that signify the onset of spoilage of the meat);
# additives used to provide essential aids to food processing (e.g., use of emulsifying agents to promote formation of stable emulsions).

=== Food additive regulations in Canada ===

==== How are Food Additives regulated in Canada? ====
Look under '''Division 16''' '''''FOOD ADDITIVES''''' of The Food and Drug Regulations (FDR) for a detailed list of food additives set out in tabular form: https://www.canada.ca/en/health-canada/services/food-nutrition/food-safety/food-additives/lists-permitted.html

https://laws-lois.justice.gc.ca/eng/regulations/C.R.C.,_c._870/index.html

As you will notice, the list provides the following information:
# The '''purpose''' of the food additives are listed (eg. anti-caking agents);
# The '''name''' of the additives that can be used for that purpose;
# Foods in which they are '''permitted''' and the '''maximum amount''' permitted.
Since the listing of food additives is a positive list, if a food is '''not listed''' in the tables the additive in question cannot legally be used in that food item. An example of a page from Division 16 is shown in Figure 4.2.
[[File:4.2 fig.png|thumb|Figure 4.2 An example of a page from Division 16|center|500x500px]]
==== What is "Good manufacturing practice"? ====
When the maximum level of use for a food additive indicates "''Good manufacturing practice''" (GMP); it basically means the '''minimum amount''' of an additive required to accomplish the specific purpose for which the additive is listed.

This minimum amount is based on technical food processing needs.

There are '''15 categories''' of food additives in Canada. The categories and examples of the additives are shown in Table 4.3 of this lesson.

Some additives are listed in more than one category since an additive can have several functions in foods. Ascorbic acid, for example, functions as a dough conditioning agent when used in bread formulations, but it is also listed as a preservative since it also has antioxidant functionality.
{| class="wikitable"
!Additive Category
!Function
|-
|Anticaking agents
|
* keep powders (salt, sugars, startches) free running.
|-
|Bleaching, maturing, and dough conditioning agents
|
* react with flour components (wheat gluten proteins with doug conditioning agents);
* bleaching agents decolourize yellow pigments in flour;
* maturing agents produce bakery products of consistent quality, texture andcolour.
|-
|Colouring agents
|
* to produce an appealing appearance, or to restore colours lost as a result of processing or storage, or to correct seasonal variation in colour, e.g., addition of orange colouring to milk used for Cheddar cheese production,
|-
|Emulsifying, gelling, stabilizing and thickening agents
|
* emulsifying agents form and stabilize emulsions (lecithin is used as an emulsifying agent on margarine);
* gelling agents promote gel formation (gelatin is a gelling agent in dessert powders);
* stabilizing agents impart stability to food systems (carrageenan is added to chocolate milk to keep cocoa particles in suspension);
* thickening agents function to impart body to foods (xanthan gum imparts body and cling to salad dressings).
|-
|Food enzymes
|
* enzymes are biological catalysts that function to promote desirable chemical reactions in foods (invertase is used to promote sucrose hydrolysis in confectionery products).
|-
|Firming agents
|
* function to maintain the texture of foods (calcium chloride is used to prevent potatoes from disintegrating during canning).
|-
|Glazing and polishing agents
|
* additives used to make food surfaces shiny and in some cases to prevent quality deterioration (beeswax is permitted for use on confectionery products).
|-
|Miscellaneous agents
|
* food additives that do not lift into other categories (caffeine is permitted for use in cola beverages; carbon dioxide is permitted for use in making carbonated beverages).
|-
|Sweeteners
|
* additive used to sweeten foods, other than conventional nutritive sweeteners. An example is aspartame.
|-
|pH adjusting agents, acid reacting materials and water correcting agents
|
* pH adjusting agents used to ensure proper acidity of foods (citric acid added as a correcting agent; water added to canned tomatoes to ensure pH 4.5);
* acid reacting materials decrease the acidity of water or foods (calcium carbonate is permitted for use in processed cheeses);
* water correcting agents function to decrease the hardness of water.
|-
|Preservatives
|
* agents that delay the onset of food spoilage. Preservatives can be antimicrobial agents (benzoic acid, sorbic acid, potassium nitrite) or antioxidants (ascorbic acid, propyl galiate gallate, a-tocopherol) to prevent fat oxidation and enzymatic browning of fruit.
|-
|Sequestering agents
|
* agents that irreversible bind undesirable metal icons in foods that could cause undesirable colour changes, flavour changes, textural changes (sodiumhexametaphosphate is used in canned seafood to bind metals that could cause discolouration of the seafood).
|-
|Starch modifying agents
|
* additives used to alter the functional properties of starches to preventsyneresis during frozen storage or to prevent starch from becoming too viscous during thermal processing (sodium acetate and hydrochloric acid are examples of starch modifying agents).
|-
|Food additives used as yeast foods
|
* additives that serve as nutrients for yeasts (calcium carbonate) and as yeast foods (calcium lactate) are permitted for use as yeast foods in bread doughs.
|-
|Carrier or extraction solvents
|
* solvents used to solubilize colours or flavours used in food (ethanol is permitted for use in spice extracts);
* solvents used to extract oils from oilseeds or marine sources, and fordecaffeination of coffee (methylene chloride and carbon dioxide are used to decaffeinate coffee).
|}

=== The Food Additive Approval Process ===
The information that companies must provide when submitting applications to the Health Products and Food Branch of Health Canada for approval of a new food additive is listed below:
# Composition, properties, method of manufacture and specifications of the substance to be used as a food additive;
# Amount and purpose of use;
# An acceptable method of analysis to determine the presence and concentration of the proposed food additive
# Data establishing that the proposed food additive will have the intended physical or other technical effect;
# Detailed reporting of tests conducted to establish the safety of the proposed food additive. Those studies must include:
#* biochemical and physiological tests;
#* subacute and chronic toxicity tests; and
#* reproduction studies
# A proposed maximum limit for residues of the food additive in or upon the finished food;
# Specimens of the labelling proposed for the food additive; and
# A sample of the food additive.
Reference: FDR, '''Division 16''', B.16.002.

'''Note''' that the information required relates to both the technological properties of the proposed additive as well as the long term safety of the additive.

This type of documentation was required when the G.D. Searle Company applied to have the low caloric sweetener, '''aspartame''', approved for use as a food additive in Canada.

When the Health Products & Food Branch obtained the information they evaluated it relative to the safety of aspartame as well as its technological properties and proposed uses in foods.

The use level permitted in specified foods was determined taking the following parameters into consideration:
* '''No effect level''' = the highest level of the chemical which caused no harmful effects in the test animals.
* '''No effect level for humans''' = no effect level in animals, divided by a safety factor. For most food additives the safety factor is generally 100.
* '''Acceptable daily intake''' = daily dosage of a chemical which during an entire lifetime appears to be without appreciable risk on the basis of all facts known at that time. The acceptable daily intake is expressed as mg intake per kg body weight.
* '''Without appreciable risk''' = the practical certainty that injury will not result even after a lifetime of exposure.
* The '''probable daily intake''' of a food additive is determined to ensure that this value would not exceed the acceptable daily intake. Food consumption estimates of particular food commodities are used to determine the probable daily intake of the food additive in question. Data from food consumption surveys as well as information from Statistics Canada and the published scientific literature are used to estimate consumption of particular food items by various groups in Canada (e.g., children, teenagers, the elderly, etc.). If the probable daily intake of the food additive in question were to exceed the acceptable daily intake, the additive would not be approved for use or it would be approved for very restricted use.
The dose-response curve below depicts the above-mentioned concepts. These parameters will be discussed again in Lesson 12.[[File:FNH 200 Lesson 12 DoseResponse.gif|thumb|400px|Dose Response Curve|center]]

'''Examples of Food Additive Approval Process'''

Two additives, aspartame and nitrites, will now be described in order to give you some insight into the controversies which surrounded those additives and also into the decision-making processes with regard to risk/benefit issues.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Kroger, M., Meister, K., and Kava, R. 2006. Low-calories sweeteners and other sugar substitutes: A review of the safety issues. Comprehensive Reviews in Food Science and Food Safety 5: 35-47 (read esp pp.37-39).
** https://onlinelibrary.wiley.com/doi/epdf/10.1111/j.1541-4337.2006.tb00081.x
* Health Canada, Food Program: Safety of Aspartame.
** https://www.canada.ca/en/health-canada/services/food-nutrition/food-safety/food-additives/sugar-substitutes/aspartame-artificial-sweeteners.html
|}
Example 1: ''Aspartame''

'''Aspartame''' is a ''low-calorie'' sweetener yielding 4 Cal/g when metabolized. On a weight basis, aspartame yields the same caloric value as an equivalent weight of sucrose. Since aspartame is intensely sweet, it can be used in very small quantities and thus can be added to sweeten "low-calorie" foods (review Lesson 3).

Aspartame was approved for use in Canada in 1981. Since its introduction as an approved sweetener, aspartame has received much attention in the media with respect to the alleged risks related to the presence of aspartame in foods.

You will note in the article that aspartame is digested in the human body to its constituent components (aspartic acid, phenylalanine and methanol) which are metabolized by normal metabolic routes. The safety aspects of aspartic acid, phenylalanine, and methanol are discussed in the article. Aspartame also has not demonstrated carcinogenicity in animal studies. Aspartame in foods can undergo degradation to diketopiperazine (DKP) during long-term storage and when it is exposed to high temperatures for extended periods of time. Studies indicate that DKP does not appear to cause any deleterious effects when ingested.
{| class="wikitable"
|'''Critical Thinking'''
|-
|
* On the basis of current knowledge of the chemistry of aspartame and on the way in which it is metabolized in the human body, in Canada, aspartame is considered to be safe for consumption at or below the '''acceptable daily intake (ADI) of 40 mg/kg body weight per day.''' What is the ADI for aspartame in the United States?
** ''How does this translate to our daily diet?''Let us assume that an individual weighs 60 kg (132 lb). The '''total acceptable daily intake''' of aspartame per day for that individual would be:
*** 40 mg aspartame/kg body weight '''x''' 60 kg body weight '''=''' 2400 mg aspartame/day.
* A typical non-caloric soft drink in Canada contains 49 mg aspartame/100 ml soft drink (490 mg/L).
* The amount of soft drink that person could consume per day that would contribute 2400 mg of aspartame is:
** 2400 mg aspartame/day '''÷''' 490 mg aspartame/ L soft drink '''=4.9 L soft drink/day.''' That is a significant amount of soft drink!
|}
* If you consume aspartame-sweetened foods you may find it interesting to calculate your daily intake of aspartame.
* The information you would require is your weight in kilograms, the quantity of each aspartame-containing food consumed daily, as well as the concentration of aspartame in each food item (in mg aspartame/ 100 ml or 100 g, as stated on the list of ingredients for each food item).
* Note that most "''diet''" soft drinks in Canada now contain a blend of aspartame with Acesulfame-K.
* The risks, to metabolically normal individuals, relating to consumption of aspartame are very small while the benefits relating to use of aspartame are high, particularly for individuals wishing to decrease their caloric intake while still enjoying sweet tasting foods.
* The benefits of aspartame to diabetics are obvious. However, there is a small segment of the population for which aspartame in foods poses a substantial risk. Those individuals suffer from '''phenylketonuria'''
Consequently, according to the Canadian labelling regulations, foods to which aspartame is added must
# contain a statement on the label saying "contains Aspartame" either individually or conjunction with other sweeteners;
# list aspartame in the list of ingredients; and
# must also indicate the aspartame content expressed in milligrams per serving of the stated size.
# stating " Aspartame contains phenylalanine
This information is placed on the label of aspartame containing foods to warn '''phenylketonurics''' that they should avoid the product or consume it in very limited quantities because of their impaired ability to metabolize phenylalanine. Please read the information on PKU and aspartame in the reading (Kroger, M, Meister, K. and Kava, R. 2006).

Example 2: ''Nitrites''

The other food additive that we will review is nitrite.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* The article by Hotchkiss and Cassens provides an overview of the history of the use of nitrites and nitrates in foods and also a history of meat curing and regulation of the curing process.
** Hotchkiss, J.H., and Cassens, R.G. 1987 [April]. Nitrate, nitrite, and nitroso compounds in foods (A scientific status summary). ''Food Technology'', 41(4):127-136.
|}
'''Why use nitrites?'''

The reactions of myoglobin, the red pigment in meat, with nitric oxide (formed from nitrites) in cured meats leads to the formation of nitrosohemochrome, the pink colour typical of cured meat products.

As shown in Figure 4.5 below, nitrite has several functions in cured meats. By far, the most important role of nitrite is to act as an '''antimicrobial agent''', particularly towards '''''Clostridium botulinum''''' which produces the toxin responsible for botulism (you can find out more about ''Clostridium botulinum'' in Lesson 6).[[File:FNH200 Lesson04 Nitrites.gif|thumb|500px|Figure 4.5 Functions of nitrites in cured meats|center]]
* The fact that the exact mechanism by which nitrites inhibit growth and toxin production by ''Clostridium botulinum'' are not fully understood makes the search for an alternative very difficult.
* To this date an acceptable alternative to nitrite as an antimicrobial agent in cured meats has '''not been found''' even though many years and millions of dollars, in numerous countries, have been spent in the search for an alternative for nitrite and also to gain an understanding of the mechanism(s) by which nitrite functions as an '''anti-botulinal agent.'''
'''What are some of the risks associated with nitrites?'''

There is a possibility that nitrites (naturally occurring, or added as an additive, or produced by reduction of nitrates), can react with amines to produce '''nitrosamines''' - some of which are potent carcinogens. The discovery in the 1960s of nitrosamines in foods, especially in cured meats, led to many studies and reviews on the risk/benefit situation relating to the use of nitrite and nitrate as food additives, particularly in cured meats. Much research has been conducted on the nitrosation reactions that can occur in foods as well as factors in foods that lead to nitrosamine formation.

Data indicate that foods are not a major source of nitrosamine exposure in humans, and that the greatest exposure comes from use of tobacco products. In foods, beer and fried bacon contribute more nitrosamine to the diet than all other foods combined (see the scientific status summary by Hotchkiss and Cassens). Nevertheless, whenever possible, the exposure to nitrosamines should be minimized.

In 1972, levels of nitrosopyrrolidine in excess of 100 parts per billion (ppb) were detected in fried bacon. [Oneppb is an extremely small quantity; if you were to travel one foot on a trip to the Moon, it would represent one part in one billion, since the distance to the Moon is about one billion feet.] By 1982, the level of N-nitrosopyrrolidine in fried bacon produced in the United States was in the range of 10 ppb, about ten-fold lower than the level in 1972. Bacon in the raw stage, has been found to be generally free of nitrosamines which develop during high-heat frying.

You might ask why this dramatic decrease occurred. Research into meat curing operations demonstrated several instances where nitrosation reactions were favoured during the production of cured meats. Changes in the curing process led to decreases in nitrosamine formation. In addition, it was found that compounds such as ascorbic acid, sodium erythorbate (isoascorbate) and alpha-tocopherol (vitamin E) would interfere with the nitrosation reactions. The next time you have an opportunity to read a label on a package of cured meat you will notice that ascorbic acid or sodium erythorbate are listed as one of the ingredients.
* Regulatory agencies have been faced with a dilemma as far as nitrite in foods, particularly cured meats, is concerned.
* It is known that under certain circumstances, particularly during frying of bacon, that nitrosamines can be formed.
* Some nitrosamines are potent carcinogens while others are non-carcinogenic.
* The type and quantity of nitrosamines that are formed depend on the reactants and the conditions present in the food.
The article "''Nitrates, nitrites, and nitroso compounds in foods''" reviews the conditions that favour as well as those that impede nitrosamine formation. It also presents the risk/benefit situation with regard to nitrates '''(NO-3)''' and nitrites '''(NO-2)''' in the diet.

'''What are some important facts in assessing the risks and benefits of allowing nitrates as a food additive in cured meats?'''

'''The following information may help to put the issue into a clearer perspective:'''
* Our major intake of '''nitrate''' is from that naturally found in vegetables (86%), with cured meats contributing only 9% and other food commodities the remaining 5% of the nitrate in food.
* '''Nitrite''' formed from nitrate in the secretions from the salivary glands (in our saliva) represents the greatest intake of nitrite (77%). Cured meats and other food commodities represent 21% and 2 %, respectively of our nitrite intake.
* Even if nitrite was de-listed as a food additive, we would still be exposed to a substantial intake of nitrite due to its presence in saliva.
* It has also been shown that '''nitrosamines''' are formed in the human stomach even when the diet does not contain any nitrite because of the conversion of salivary nitrate to nitrite by bacteria in our mouths.
* The pH and temperature of the human stomach are in the optimum range for nitrosation reactions.
* Consequently, humans have been exposed to nitrosamines for eons of time.
* It is extremely difficult to quantify the risk posed to our health by the use of nitrites as a food additive. The risks appear to be very low.
* On the other hand, the risk of botulism from cured meats if nitrites were banned appear to be high, based on information on the incidence of occurrence of ''Clostridium botulinum'' spores in raw meats.
The risk/benefit situation related to the use of nitrites in cured meats as follows:

'''If nitrite is used:'''

'''''Risks''':''
* Potential of increased nitrosamine content in the diet. Although some nitrosamines have shown carcinogenicity at higher doses, this does not appear to be a significant risk with moderate consumption.
'''''Benefits:'''''
* Production of cured meat products at a reasonable cost with adequate control of ''Clostridium botulinum''.
'''If nitrite is not used:'''

'''''Risks''''':
* Increased potential for growth and toxin production by ''Clostridium botulinum'' in perishable cured meat products under abusive conditions.
* Shelf-stable canned cured meat products would probably not be available because the increased heat treatment required would produce a product with an undesirable texture.
'''''Benefits:'''''
* Decreased risks due to a decreased load of nitrosamines in the diet. The magnitude of this benefit may not be measurable due to the current load of nitrosamines in the diet from other sources and from nitrosamines formed ''in vivo''.

=== ''Outcome'' ===
''Based on the current evidence the benefits of using Nitrites outweighs the risk. However precautionary measures are in place to ensure the safety of the consumers. These precautionary measures include limiting the usage to specific products in which the risk of Clostridium botulinum is greater. The amount of use is regulated and industries are encouraged to use methods to reduce the risk of nitrosamine formation''

== 4.8 Summary of Lesson 4 ==
* There are various Acts and Regulations that apply to food in Canada, to ensure that Canadian consumers have access to a safe, high quality food supply.
* The Health Products and Food Branch (HPFB) of Health Canada establishes regulations and standards (within the Food and Drugs Act and Regulations-FDR)
* The Canadian Food Inspection Agency (CFIA) enforces these regulations and standards (e.g. Consumer Packaging and Labelling Act & Regulations)
* There are 28 divisions within the FDR. For example, ''Food additives'' are regulated (found) in Division 16.
* There are more than 400 approved food additives in Canada. Aspartame and nitrites are two examples of food additives; however, ''aspartame'' is classified as a "sweetener", whereas ''nitrites'' are classified as "preservatives".
* Generally, risk/benefit issues are not black and white; often they are shrouded in shades of gray. However, with the information you have gained in this course, you should be able to determine objectively the validity of reports that you may encounter in the media about food additives and about food safety issues.

'''Authorship:'''

FNH 200 Course content on this wiki page and associated lesson pages was originally authored by Drs. [http://www.landfood.ubc.ca/person/brent-skura/ Brent Skura], [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], and [http://www.landfood.ubc.ca/person/eunice-li-chan/ Eunice Li-Chan]. Ongoing edits and updates are contributed by past and current instructors including Drs. [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], [http://www.landfood.ubc.ca/person/azita-madadi-noei/ Azita Madadi-Noei], [http://www.landfood.ubc.ca/person/nooshin-alizadeh-pasdar/ Nooshin Alizadeh-Pasdar], and [http://www.landfood.ubc.ca/person/judy-chan/ Judy Chan].
{{cc-by-nc-sa-3.0}}

<quiz display=simple>
{1. Which agency below is responsible for accurate labeling of foods.
|type="()"}
- Health Canada: HPFB
+ CFIA
- Industry Canada
- BC Ministry of Health
- City of Vancouver
</quiz>

<quiz display=simple>
{2. Which food below is NOT a standardized food?
|type="()"}
- Enriched white bread
- Raisin bread
+ Pizza dough
- Whole wheat bread
- Bread
</quiz>

<quiz display=simple>
{3. Why do we use nitrites in cured meats?
|type="()"}
- To enhance the pink colour in finished products
- To enhance flavours
- To act as an antimicrobial agent
+ All of the above
- None of the above as nitrites are not approved to be added to cured meats in Canada.
</quiz>

<quiz display=simple>
{4. Match the agency with their role.
|type="{}"}
Sets new food regulations. { Health Canada }
Inspections of restaurants. { Municipal Agencies(BC Ministry of Health) }
Reviews food related advertisements for claims. { Canadian Food Inspection Agency }
</quiz>

<quiz display=simple>
{5. In order to qualify as Canada Grade A, which qualities must maple syrup have?
|type="()"}
- Undergone at least some fermentation
+ Be free of sediment and turbidity
- Be categorized in the amber color class
- Produced only in Canada
</quiz>

Course:FNH200/Lessons/Lesson 02

2020-06-24T00:19:16Z

YihangChen: /* Chemical and Physical Properties of Food */

=== <big><big><big>Chemical and Physical Properties of Food</big></big></big> ===

== 2.0 Overview ==
In this lesson we will discuss the chemical properties of food constituents and how those constituents affect the physical properties of foods. You will learn about the various classes of carbohydrates, ranging from monosaccharides to polysaccharides, and their functional properties important to food science and technology. You will learn about the caramelization and Maillard browning reactions and their importance as a determinant of food quality.

Important properties of proteins such as foaming, emulsion stabilization and gelation will be explored. The importance of proteins in the production of selected food commodities will be explained, and you will learn about enzymes, which are proteins that function as biological catalysts, and their importance in food technology.

We will discuss the basic properties of fats and differentiate between saturated and unsaturated fats. You will learn about triacylglycerols or triglycerides and their functional properties, and about emulsions and emulsifiers and the many foods that are created through the formation of emulsions.

The importance of organic acids, pigments and water in foods and their role in determining the properties of foods will be described.

Through a discussion of the production of flour from wheat and the production of bread, you will begin to appreciate how various constituents interact to produce the desirable physical and flavourcharacteristics of bakery products.

=== Objectives ===
The overall objective of this lesson is to give you an appreciation that foods are mixtures of chemicals that interact to produce the particular characteristics of the food from sensory, chemical and physical stimuli. At the conclusion of this lesson, you will be able to:
* compare and contrast food- colloidal dispersions;
* summarize the functional properties of carbohydrates, proteins and fats in foods;
* distinguish between caramelization and the Maillard browning reaction and state the importance of these reactions in food;
* explain the function of emulsifiers and stabilizers in emulsions;
* interpret the importance of water, pH, and minor constituents in quality and safety of foods
* outline the minor constituents of foods

=== Optional Readings ===
* Position of the Academy of Nutrition and Dietetics: Use of Nutritive and Nonnutritive Sweeteners. (2012). J Acad Nutr Diet.112:739-758. [https://www.sciencedirect.com/science/article/pii/S2212267212003255 Link]
* American Dietetic Association (2007). Position of the American Dietetic Association and Dietitians of Canada: Dietary Fatty Acids. Journal of the AMERICAN DIETETIC ASSOCIATION 107(9), 1599-1611. [https://www.sciencedirect.com/science/article/pii/S0002822307014903?via%3Dihub click here]
 
== 2.1 Food-Colloidial Dispersions ==
{| class="wikitable"
|
==== '''Terms to remember''' ====
|-
|
* Emulsions
* Foams
* Gels
* Continuous phase; dispersed phase
* ''More terms to be found throughout this lesson.''
|}
Foods are essentially mixtures of chemical compounds arranged in specific organizations that give rise to the particular chemical, physical and sensory properties of each food system. A knowledge of the chemical and physical properties of the constituents of foods is important to your understanding of how food systems behave under the various conditions encountered in preservation, storage and preparation for consumption. Food systems vary in their chemical composition and physical properties, ranging from chemically simple systems such as sugar syrups to the chemically complex food systems such as milk, muscle food systems, and plant tissue systems.

In '''Colloidal Dispersions''', the particles of one substance are distributed, dispersed, in another substance '''without dissolving'''.
* The substance that is dispersed within another is called the '''dispersed phase'''.
* The substance that extends throughout the system and surrounds the dispersed phase is called the '''continuous phase'''.
[[File:FNH200_Lesson02_DispersionA.jpg|thumb|(A) Oil in water [[File:FNH200_Lesson02_DispersionB.jpg|thumb|center]](B) Water in oil emulsion

'''Figure 2.2''' Examples of emulsions
]]Table 2.1 shows the dispersed and continuous phases of some typical Colloidal dispersions.

'''Table 2.1.''' Colloidal dispersions
{| class="wikitable"
!Dispersed Phase
!Continuous Phase
!Name of Dispersion
!Examples
|-
|solid
|liquid
|'''sol'''
|starches, proteins and some plant polysaccharides in water
|-
|liquid
|liquid
|'''emulsion'''
|milk, mayonnaise
|-
|liquid
|solid
|'''solid emulsion'''
|butter, margarine
|-
|[liquid]
|solid
|'''gel'''
|starch, pectin or gelatin gels
|-
|gas
|liquid
|'''foam'''
|beaten egg white, whipped cake frostings
|-
|gas
|solid
|'''solid foam'''
|meringue, ice cream, bread
|}
For example, a '''sol''' is a suspension of large molecules dispersed in a liquid, generally water.

An '''emulsion''' is a suspension of liquid droplets (fat or water) within a liquid medium (fat or water). Food '''emulsions''' can be either oil in water (o/w) or water in oil (w/o). Homogenized milk is a dispersion of milk fat droplets in a liquid medium (skim milk portion of milk), while skim milk itself is a suspension of milk protein particles, the casein micelles, within a water-based medium. A '''solid emulsion''' is a dispersion of liquid droplets within a solid phase. Margarine and butter are examples of water in oil emulsions, in which the continuous phase is solid under refrigerator or low ambient temperatures.

A '''gel''' is a dispersion of water held within a continuous matrix of polysaccharides (starch gels) or proteins (gelatin gels). Some scientists consider the water in gels to be a second continuous phase rather than a dispersed phase. 

== 2.2 Food Component ==
Foods are made of chemical components that are working together and making the food the way it is. Chemical composition is determination of these compounds. The chemical composition tables identifies the amounts of these compounds in each food.

In Canada, the Canadian Nutrient File, provides a data base of foods and their listed composition. <nowiki>https://food-nutrition.canada.ca/cnf-fce/index-eng.jsp</nowiki>

Quantifying the amount of Carbohydrate, Fat, Protein, Water and Ash is called '''proximate analysis'''.

Food components can be classified as major and minor components.The major food components of food systems are carbohydrates, fats, proteins and water. There are also minor food components, organic acids, pigments, aroma compounds, vitamins and minerals. In this section we will discuss the important functional properties of these components and how those properties influence the chemical and physical properties of foods.

== 2.2.1 Food Major Components ==
The major food components of food systems are carbohydrates, fats, proteins and water. These are the compounds are found in largest amounts in foods. Each component has variety of functional properties which affects the physical and sensory characteristics of the food during processing and storage. Understanding these properties is essential tool in product development and also quality control. Please note that, although these components may be similar to what nutritionists and dietitians call macronutrients, we are looking at them from food science perspective.

== 2.2.1.1 Carbohydrates ==
{| class="wikitable"
|
==== Terms to remember ====
|-
|
* monosaccharides (glucose, fructose, galactose)
* disaccharides (sucrose, lactose, maltose)
* sweetness index
* invert sugar
* HFCS
* invertase
* lactase
* amylase
* maltase
* glucose isomerase
* caramelization
* Maillard browning
* reducing sugar
* sugar alcohols
|}
Carbohydrates are one of the three main classes of nutrients (the other two being fats and proteins). They occur in foods as sugars and starches and are the human body's main source of energy. Digestible carbohydrates contribute 4 Calories (kilocalories) of metabolized energy per gram. Carbohydrates should contribute about 50% of our caloric intake per day; and most of the carbohydrates that we consume should be in the form of ''complex'' carbohydrates (polysaccharides) such as starch rather than as ''simple'' carbohydrates (monosaccharides and disaccharides) such as table sugar.

==== ''a. Monosaccharides'' ====
The main monosaccharides found in foods are ''glucose'', ''fructose'' and ''galactose''. These are referred to as simple carbohydrates and one of their main functions is their ability to '''impart a sweetness sensation'''; however, sugars vary in their sweetening power. The sweetness of various sugars in comparison to sucrose (table sugar) is shown in Table 2.2

==== ''b. Disaccharides'' ====
Disaccharides are formed by the union of two monosaccharide molecules. Disaccharides are also considered as "simple" carbohydrates. They can be split into their component monosaccharides by enzymes or by boiling with dilute acids. The most important disaccharides in foods are ''sucrose'', ''lactose'' and ''maltose''. These disaccharides differ from one another in solubility, sweetness, and other properties.

===== '''Sucrose''' =====
Table sugar, obtained from sugar-cane or sugar-beet, is mainly pure sucrose. It is formed from '''''glucose''''' and '''''fructose''''' linked together. Sucrose can be found in a variety of fruits, grasses and roots.

One of the recent trends in the food industry, particularly for carbonated beverages, is the use of '''''invert sugar''''' in place of sucrose because of the inherently greater sweetening power per unit weight of the fructose containing sweetening systems (see Table 2.2). Invert sugar is produced by hydrolyzing sucrose with the enzyme invertase or with acid, to produce a mixture of glucose + fructose (1:1).
[[File:Sucrose structure formula inkscape.svg|center|thumb|Sucrose ]]
[[File:【2】L2 invert-sugar.png|thumb|Sucrose conversion|center|700x700px]]

Incidentally, the primary sugars in honey are glucose and fructose in a 40:60 ratio. Most of the nectar collected by the honey bee contains sucrose which is hydrolyzed by invertase in the saliva of the honey bee. Some of the glucose is converted to gluconic acid and hydrogen peroxide by glucose oxidase, another enzyme secreted into the collected nectar by the honey bee. The gluconic acid and hydrogen peroxide act as preservatives in the nectar. Honey also contains minute quantities of disaccharides and complex sugars.

'''Table 2.2.''' Relative sweetness of carbohydrate sweeteners.
{| class="wikitable"
!Sugar
!Sweetness Index*
|-
|sucrose
|100
|-
|glucose (dextrose)
|70 - 80
|-
|fructose (levulose)
|140
|-
|invert sugar
|100 - 130
|-
|corn syrup (mixture of glucose, maltose
|50
|-
|maltose
|20
|-
|lactose
|10 - 20
|-
|galactose
|60
|-
|sorbitol
|50
|-
|xylitol
|100
|-
| colspan="2" |high fructose corn syrups:
|-
|42% fructose
|100
|-
|55% fructose
|100+
|-
|90% fructose
|120 - 160
|-
| colspan="2" |*Perceived sweetness of a sweetener compared to sucrose as a reference.
Adapted from: Desrosier, N. W. 1976.
''Elements of Food Technology.'' AVI Publishing Company. Westport, CT. Pomeranz, Y. 1985.
''Functional Properties of Food Components.'' Academic Press Inc., Orlando, Fl.
|}
It is important to note that '''sweetness has no relation to caloric contribution''' of a sweetening agent to the diet. Fructose and lactose each produce 4 Calories of metabolized energy per gram when digested and absorbed, but lactose is only one-seventh as sweet as fructose. Thus for an equivalent sweetness intensity, less fructose would be required than lactose. Conversely, a product sweetened with lactose could potentially contain seven times the caloric content compared to a product sweetened with fructose.

==== '''Lactose''' ====
Lactose, also known as milk sugar, occurs in the milk of all animals. Cow's milk contains about 4-5%, whereas human milk contains 6-8% lactose. Lactose is formed by linking '''''glucose''''' and '''''galactose''''' together. The hydrolysis of lactose found in dairy products into its component monosaccharides is catalyzed by the enzyme lactase. Breaking down lactose substantially increases the sweetness. Lactose can also be fermented by lactic acid-producing bacteria, into ''lactic acid''. This is the acidulant and preservative agent in yogurt and numerous cheeses.
[[File:Lactose(lac).png|center|thumb]]
Have you seen lactose-free products in the market or have you met someone who is "lactose intolerant"?

Lactose intolerant people are those who do not have the enzyme lactase necessary to digest (breakdown) lactose (milk sugar). People who are lactose intolerant can suffer from minor cramps to extreme intestinal discomfort. Lactose-free products have had the enzyme lactase (usually isolated from yeast) added to them. Alternatively, lactose intolerant individuals can take tablets containing the enzyme, prior to eating or drinking dairy or other food products with lactose or milk solids. 
[[File:【3】L2 lactose-free.png|thumb|center|750x750px]][[File:FNH200_Lesson02_Lactaid01.jpg|thumb|center]][[File:【4】L2 fig2-4a.jpg|thumb|lactose free milk
'''Figure 2.3.''' Some of the products available in the market for lactose-intolerant people.
|center]]

==== '''Maltose''' ====
The sugar maltose contains '''two glucose''' units linked together. It is obtained when starch (eg corn starch) is hydrolysed by the enzyme ''amylase'' or by heating with dilute acid (Figure 2.4). Maltose can be further hydrolysed by the enzyme ''maltase'' into its component D-glucose units, which are then enzymatically isomerized by the enzyme ''glucose isomerase'' to produce a liquid syrup composed of 42% fructose, commercially known as ''high fructose corn syrup (HFCS 42)''. HFCS has 42% fructose, 52% glucose and 6% starch. Subsequent technological improvements in which the syrup is passed through an ion-exchange column that retains fructose, allow for the production of a 90% fructose syrup. Today, ''HFCS 90'' is blended with ''HFCS 42'' to create ''HFCS 55'', which has a sweetness profile similar to sucrose (Table 2.2). Many soft drinks are now sweetened with HFCS especially when cost of these syrups is lower than the cost of sucrose or even invert sugar. [[File:FNH200_Lesson02_Sugars.JPG|thumb|400px|'''Fig 2.3''' Structures of monosaccharides and disaccharides in foods and the production of high fructose corn syrups (click to get a larger image)|center]]

==== '''''Functional Properties of Simple Sugars in Foods''''' ====
The functional properties of sugars in foods are summarized below:
* Sugars are widely used for their sweetening power. The sweetness of carbohydrates is determined by their molecular structure and interaction with sensory receptors on the tongue. Simple sugars vary in their sweetness (Table 2.2)
* Sugars produce '''body''' and '''mouth feel''' when they are incorporated into foods at concentrations high enough to affect the viscosity (resistance to flow) of the food product
* production of '''hot supersaturated sugar''' solutions with controlled crystallization during cooling is the basis of formation of many hard candy products, toffees and related products.
* sugars are readily soluble in water because they contain many hydroxyl (OH) groups, which form hydrogen bonds with water. Solubility of sugars increases as the temperature of water increases. This property is used to produce syrups of varying concentrations for various uses (e.g. pancake syrup, concentrated syrups for use in food processing, cooking or confections.)
* Sugars can be '''crystallized''' from solution when water is evaporated. This is the basis of production of table sugar (sucrose) from the juice extracted from sugar cane and sugar beets.
* Sugars, in sufficiently high concentration, can be used to '''inhibit growth''' of undesirable microorganisms. They function as a preservative by binding water needed by the microorganisms.
* sugars are '''fermented''' by microorganisms with the concomitant production of acids and/or alcohol as well as flavouring compounds. This is the basis for production of fermented foods and ingredients obtained by means of microbial fermentations.
* sugars '''caramelize''' when exposed to high temperatures. See "Browning reactions" below.
* reducing sugars react with proteins and amino compounds to produce flavours and colours in foods (Maillard browning). See "Browning reactions" below.

'''Browning reactions'''

Another important property of the simple sugars is their ability to serve as reactants in non-enzymatic browning reactions, namely '''''caramelization''''' and the '''''Maillard browning reaction'''''.

The '''caramelization''' reaction involves reaction of sugars (reducing and non-reducing sugars) when heated at high temperatures (200°C) to produce caramel and butterscotch flavours. The brown pigments formed during the heating of sugars contributes to the colour of caramel candies and toffees (Figure 2.5a). The pigments are not the same as the melanoidins formed during the Maillard reaction. [[File:FNH200_Lesson02_CaramelLiquid.jpg|thumb|200px|[[File:FNH200_Lesson02_CaramelCandy.jpg|thumb|200px|right]]Figure 2.5a Liquid caramel and caramel candy: Examples of non-enzymatic browning of sugars.
|center]]
The '''Maillard browning reaction''' occurs when reducing sugars react with nitrogenous compounds such as amino acids, proteins or amines (Figure 2.5b).
* A reducing sugar contains a free aldehyde or ketone group. Therefore, it will contain a “free” '''OH''' on the position next to the O in the ring structure
The Maillard browning reaction is responsible for the formation of the brown pigments that appear on bread slices when they are toasted in the toaster.
[[File:Figure 2.5b.png|thumb|Figure 2.5b. Glucose, Fructose, Galactose and Lactose are examples of reducing sugars. Sucrose does not have this "free" OH, therefore is not a reducing sugar.|center|750x750px]]
{| class="wikitable"
| '''Want to learn more?'''
|-
|
* Sucrose is not a reducing sugar, will ''invert sugar'' be considered as a reducing sugar?
|}
The Maillard browning reaction is responsible for the formation of the brown pigments that appear on bread slices when they are toasted in the toaster.[[File:FNH200_Lesson02_Maillard.gif|'''Fig 2.5''' Maillard browning reaction. Toasted bread is an example of desirable flavours and colours produced from this reaction.|center]] '''Figure 2.5c.''' Maillard browning reaction. Toasted bread is an example of desirable flavours and colours produced from this reaction.
{| class="wikitable"
| '''Want to learn more?'''
|-
|
* Can you think of other food products from the Maillard reaction?
|}
Many low molecular weight intermediate compounds are formed and these often are aroma and flavour compounds that contribute to the desirable or undesirable flavours produced in a food by the Maillard reaction. Examples of desirable compounds are the aroma and flavour of baked bread, toasted bread and roasted coffee, while undesirable aromas and flavours are those that form in skim milk powder during storage or during the browning of canned peaches during long-term storage. The brown colours are high molecular weight pigments, ''melanoidins'', formed as a result of polymerization of some of the low molecular weight intermediate fractions.

'''''c. Polysaccharides'''''
{| class="wikitable"
|
==== '''Terms to remember''' ====
|-
|
* amylose
* amylopectin
* gelatinization
* retrogradation
* complex carbohydrates (starch, cellulose, xanthan gum, pectin, alginates, agar, carrageenan
* invertase
* viscosity
* thickening
* stabilizer
* suspending agent
|}
Polysaccharides are high molecular weight, long chains of monosaccharide units (i.e. glucose). They are classified as the complex carbohydrates and differ from simple carbohydrates by being insoluble in water and generally tasteless. Most of the polysaccharides used in food products are derived from plant or seaweed sources; a few are from microbial origin. They contribute to the thickness or viscosity and textural properties of food products.
{| class="wikitable"
!Polysaccharide
!Characteristics and Functional Properties
|-
|pectins
|
* are structural polymers in plants
* form the cementing material between individual plant cells
* pectin affects the texture of plant tissues
* used in jams and jellies as gelling agents in the presence of sufficient sugar and acid¨
* contribute to the viscosity of tomato paste and ketchup
* contribute to the mouth feel and maintenance of particles in suspension (e.g. orange juice, unclarified apple juice)
|-
|agar
|
* extracted from seaweed (kelp)
* used as a thickener agent
|-
|alginates
|
* extracted from certain types of seaweed
* used as gelling agents
* keep solids and liquids in suspension in fruit juices
|-
|gum arabic or gum acacia
|
* is a plant exudate from the bark of the acacia trees
* used as thickener and stabilizer in products like beer, soft drinks, ice cream
|-
|carrageenan
|
* extracted from certain types of seaweed (red algae)
* used as a suspending agent to keep cocoa particles in suspension in chocolate milk
|-
|xanthan gum
|
* produced by bacteria
* first isolated from rotting cabbage, now cultured in large fermentation tanks and purified
* used in salad dressings as a thickening agent, which enables the dressing to cling to the salad components
* used as a suspending agent to maintain pieces of onion, red pepper, spices in a stable suspension.
|-
|cellulose and hemicellulose
|
* are present in many plant tissues as supporting structures (e.g. the fibres in celery)
* are polymers of glucose that are indigestible
* along with pectin and the other carbohydrate gums form the indigestible portion of our carbohydrate intake that is known as dietary fibre
|-
|starch
|
* are polymers of glucose
* digestible when cooked (e.g. rice, potatoes, etc.)
* used as thickening, suspending and gelling agents(read text below for more information on starch)
|}

==== Starch ====
Starch is made out of ''polymers of glucose'' joined by an '''alpha, 1-4''' link. A single molecule of starch can include anywhere from 400 to several hundred thousand glucose units. Therefore, although they are made of long chains of sugar molecules, starches do not elicit a sweet taste and rather taste quite "bland". The length and ''bulkiness'' of the starch molecule prevent it from interacting with our tongue receptors! In food, starch is mostly used as a thickening, suspending and gelling agent.

In foods such as cereals and tubers starch exists in the form of starch granules (Figure 2.6). Starch molecules ('''''amylose''''', a straight/linear chain starch molecule and '''''amylopectin''''', a branched starch molecule) are tightly packed within starch granules. The starch granule is not digestible, nor is it soluble in cold water unless it is heated.

==== Figure 2.7 ====
When starch is heated in water, it undergoes a phenomenon known as '''gelatinization'''. The starch granules absorb water and swell-up as the water entering the granule begins to "loosen" the bonds between the starch molecules. Hydrogen bonds form between the water and starch molecules. The starch granule eventually "bursts", becoming soft and pliable. This is the phenomenon that occurs when puddings are made or when flour is used as a thickening agent when making gravies. Starch gelatinization is the phenomenon that leads to the conversion of hard, unchewable, raw rice kernels to the soft, easily chewed, cooked rice.

Gelatinized starch can lose some of its water holding capacity upon cooling and/or during refrigerated storage. This phenomenon is known as '''''retrogradation''''', and involves the re-association of starch molecules, especially the ''amylose'' polymers, into an ordered structure. The linear ''amylose'' molecules orient themselves in crystalline regions, leading to a squeezing out ("'''syneresis'''") of water and a loss of tenderness of the food (e.g. staling of bread) or the development of a gritty texture (e.g. starch based pudding stored in the refrigerator).

It is interesting to observe that bread stales more quickly in the refrigerator than the freezer or at room temperature. ''Can you think of why this is the case?''

Retrogradation can be avoided to a certain extent through the use of dextrins and/or modified starches, thus reducing the tendency for alignment of linear amylose chains. Starches can be partially hydrolysed by acids or enzymes to produce products of intermediate chain length (dextrins) that have numerous uses in food products. Some of the dextrin products are used to create foods that provide the sensation of containing fat but that are low in fat.

Retrogradation can also be partially reversed by heating the food (e.g. heating stale bread or buns in an oven or the microwave oven); however, once the product cools the starch quickly retrogrades again.

'''Cellulose and hemicellulose'''

These polysaccharides are present in many plant tissues as supporting structures (e.g. the fibres in celery). They too are ''polymers of glucose'' but joined by a '''beta, (ß)1- 4''' link. However, humans do not have the enzyme needed to break the beta link and therefore, cellulose is indigestible. Along with pectin and the other carbohydrate gums, cellulose forms the indigestible portion of our carbohydrate intake that is known as dietary fibre.

'''Xanthan Gum'''

Xanthan gum is a polysaccharide with a ß-D-glucose backbone like cellulose, but every second glucose unit is attached to a ''trisaccharide.''

Xanthan Gum is produced by the bacterium ''Xanthomonas campestris'', which is found on cruciferous vegetables such as cabbage and cauliflower and causes black rot. Nowadays, it is cultured in large fermentation tanks and purified. Xanthan gum is used in salad dressings as a thickening agent, which enables the dressing to cling to the salad components. It is also used as a thickener for sauces, to prevent ice crystal formation in ice cream, and as a low-calorie substitute for fat.
[[File:2.7.png|thumb|Xanthan Gum|center|500x500px]]

==== '''Pectin''' ====
Pectin is a polysaccharide that acts as a cementing material in the cell walls of all plant tissues. The white portion of the rind of lemons and oranges contains approximately 30% pectin.

It is used in jams and jellies as a gelling agent. It also contributes to the viscosity of tomato paste and ketchup. Pectins will give contribute to the mouth-feel of foods, and help maintain particles in suspension (e.g. orange juice, unclarified apple juice).
[[File:Pectin .png|thumb|pectin|center|500x500px]]

==== '''Agar, Alginates & Carrageenan''' ====
These polysaccharides are extracted from different types of seaweed (kelp). In general, they are used as thickening, gelling and suspending agents.

For example, alginates keep solids and liquids in suspension in fruit juices and provide thickness to dietetic and regular salad dressings, puddings, pie fillings, ice cream, sherbet and icings. Carrageenan is used as a suspending agent to keep cocoa particles in suspension in chocolate milk, and it is also used as a stabilizer in ice cream (stabilizing the colloidal dispersions). 

===== '''Gum Arabic (Acacia Gum)''' =====
These gums are plant exudates from the bark of the acacia trees. It is used as thickener and stabilizer in products like beer, soft drinks, and ice cream.

{| class="wikitable"
| '''Want to learn more?'''
|-
|
* Look at the list of ingredients for different food products (e.g. breakfast cereal, soft drinks, chocolates, ketchup, ice cream, etc). List the thickening agent polysaccharides included among the ingredients. What conclusions can you make about the kinds, amounts, and functions of these ingredients?
|}

== 2.2.1.2 Fats ==
{| class="wikitable"
|
==== '''Terms to remember''' ====
|-
|
* fatty acids
* saturated fat
* unsaturated: mono- and poly-unsaturated
* hydrogenation
* ''cis''-, ''trans''- configuration
* tenderizing
* aeration
* emulsifiers
* hydrophilic & hydrophobic
* phospholipids
* lecithin
* oxidative rancidity
|}
You will recall from lesson 1, that consumers are demanding "healthier" foods. Many of the products we currently see in the market, have selling points such as "low-fat" or "fat-free". This general trend towards low-fat products has given fats a negative reputation. Fats and oils are part of a group called lipids. Lipids can be found in the form of triglycerides, phospholipids and sterols. However, triglycerides make the largest class of lipids as most of the fats and oils we consume from food are in the form of triglycerides.

{| class="wikitable"
|-
|'''Want to learn more?'''
|-
|
* Please read:
** American Dietetic Association (2007). Position of the American Dietetic Association and Dietitians of Canada: Dietary Fatty Acids. Journal of the AMERICAN DIETETIC ASSOCIATION 107(9), 1599-1611. [https://www.sciencedirect.com/science/article/abs/pii/S0002822307014903?via%3Dihub link]
** From the reading, please answer the following questions:
*** What are fats? What is the correct name for fat?
*** What is the nutritional value and calories of fat?
*** What is the difference between saturated, monounsaturated and polyunsaturated fatty acids?
*** What is an omega-3 fatty acid?
*** What are '''''cis''''' and '''''trans''''' unsaturated fatty acids?
*** Why are some fats solids and others liquid at room temperature?
*** What is the term of the process used to convert a liquid oil into solid or spreadable margarine?
*** What are some functions of fat in foods?
|-
|
|}
'''''Functional Properties of Fats in Foods'''''

The required reading talked about fats and the important functional properties they have by influencing the flavour and texture of foods. Fats are even necessary for the absorption of fat soluble vitamins. The functional properties of fats (and oils) in foods are summarized below:
* Fats act as a '''lubricant''' in food making the food more palatable and easier to chew and swallow.
* Fats have '''tenderizing power''' because they coat the flour particles (protein and starch) in baked goods, creating a flaky, lighter texture that makes them easy to tear apart. Fats work best as shortening when the crystals are in the beta prime form, which produces a fine texture in the baked goods. Cakes will have a crumbly texture without the moistness given by fats.
* Another function of fats in baked goods is the one called "'''aeration'''". Fats add air (gas) to batter and doughs. The fat surrounds the air molecules that are being incorporated into the batter. They contribute to the formation of the dispersion by decreasing the viscosity in the batter, thus making it easier to flow and rise.
* Fats and oils are carriers of many '''aroma constituents''' in foods that are usually fat-soluble. Thus, fats contribute to the overall flavour of food (we will review aroma and flavour in Lesson 3- Sensory perception of foods)
* Fats and oils can be heated to very '''high temperatures''' before they begin to smoke and vaporize. Foods fried in hot fats and oils (deep fat frying) cook very fast because of the temperatures that can be attained.
* Fats gradually '''soften''' when heated. This contributes to the desirable features such as chocolates that melt in your mouth and butter and margarines that are spreadable.
* Fats form part of emulsions (review colloidal dispersions) by acting as the dispersed phase or continuous phase. Some fats can also act as "'''emulsifiers'''", assisting in keeping the emulsion stable (see "'''Fats and their role in emulsions'''" below).
'''Fats and their role in emulsions'''

You will recall that there are two types of emulsions (see colloidal dispersions and Figure 2.2): '''water in oil''' [e.g. butter, margarine], and '''oil in water''' [e.g. mayonnaise, homogenized milk].

Homogenization or other high-energy mixing processes may be used to disperse one liquid phase into another. Nevertheless, after two liquid phases such as oil and water are mixed and then left to stand, the natural tendency is for the two phases to separate. '''Emulsifiers''' are compounds that promote the formation of emulsions, i.e., the dispersion of one phase in the form of small droplets, in the second continuous phase.

Certain type of fat molecules called '''phospholipids''', can function as emulsifiers. Phospholipids are structurally similar to triglycerides, except that only two fatty acids are linked to the glycerol (making it a ''diglyceride''), and a charged group (negatively charged phosphoric acid esterified with positively charged choline group) is linked to the third position of glycerol.

'''Lecithin''' is an example of a phospholipid. Lecithin is a naturally occurring emulsifier commonly found in egg yolk and soybean oil. Other naturally occurring emulsifiers include the proteins from milk, egg yolk or other foods. Sometimes, synthetic emulsifiers (e.g. "Polysorbate 60") are used to assist in forming food emulsions.

Emulsifiers are amphiphillic molecules that have a '''hydrophilic''' [water loving] portion and a '''hydrophobic''' [water hating] portion. Emulsifiers assist in formation of an emulsion by orienting themselves at the interface between the two phases, with their hydrophilic and hydrophobic portions facing water and oil, respectively, thereby reducing the interfacial tension between oil and water phases. This can also help to '''stabilize the emulsion''' by preventing the dispersed oil droplets or water droplets from coalescing together. Other factors that affect emulsion stability are droplet size, and the viscosity of the continuous phase. Droplet size must be such that, the downward pull of gravity, is balanced by the upward forces of buoyancy. This will reduce the tendency for "creaming" (floating to the top) of the less dense (oil) phase.

Note the difference between '''"Emulsifiers"''' and '''"Stabilizers". Stabilizers''' are compounds that increase the viscosity of the continuous phase, keeping the droplets suspended or dispersed and thus reducing the rate of creaming. Some of the polysaccharides discussed earlier in this lesson are commonly used as stabilizers to thicken the continuous phase (water); some examples are “xanthan gum” and “propylene glycol alginate”.[[File:FNH200_Lesson02_Emulsifier.jpg|'''Fig 2.6''' The function of an emulsifier in an oil-in-water emulsion.|center]]Figure 2.6 illustrates the function of an emulsifier in an oil-in-water emulsion.

{| class="wikitable"
|
==== Whant to learn more? ====
|-
|
* Something to think about: Are any '''emulsifiers''' or '''stabilizers''' added to assist in the formation of a stable emulsion in:
** milk
** butter
** margarine
** mayonnaise

* '''Check out the label of these foods to find the answer!'''
|}

The major function of milk '''homogenization''' is the formation of a stable '''emulsion''' to prevent fat separation, such as that which occurs in non homogenized milk.

{| class="wikitable"
|
==== Whant to learn more? ====
|-
|
* Can you imagine what a piece of pie would look and taste like without the presence of fat in the crust? What functional properties of fat are involved in the pie crust formation?

* Some people use oil in their pie crust recipe, and some use lard. Which contains more saturated fat?
|}

== 2.2.1.3 Proteins ==
[[File:FNH200_Lesson02_Leucine.png|thumb| Leucine]]
{| class="wikitable"
|
==== '''Terms to remember''' ====
|-
|
* amino acid
* amphiphillic
* denature
* solid foam
* collagen
* lipolytic rancidity
* enzymes
* allergies
|}

Protein molecules are made up of long chains of hundreds or even thousands of amino acid units joined together. Amino acids are a type of organic acid. They are made up of an amino group (NH2) and a carboxyl group (COOH) attached to the same carbon atom.

There are '''20''' different amino acids in proteins found in food systems and in the human body. Nine of the amino acids cannot be synthesized by human tissues and must be obtained via food. These '''essential''' amino acids are isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine; histidine (essential for infants only).

Adults require 0.8 grams of protein per kilogram of body weight. Protein consumed in excess of body requirements is converted to energy or is converted to fat for storage. Proteins produce 4 Calories per gram when they are digested and the amino acids are metabolized for energy.

=== Functional Properties of Proteins in Foods ===
Proteins in tissue systems such as meats and fish contribute to the '''texture''' of the products. The difference between a tender steak and a tough steak can often be related to the types and relative abundance of various types of protein molecules within the muscle structure. Proteins from various sources (cereal grains, milk, meat, fish, legumes) can be used in various states of purity as food ingredients with differing functional properties. Some of those functional properties are described below.

==== '''Emulsion formation''' ====
Many proteins are ''amphiphillic'' molecules as they contain hydrophilic and hydrophobic portions (from amino acids) allowing them to act as '''emulsifiers'''. One part of these amino acids is attracted to water, forming hydrogen bonds, while the other part avoids water and binds with oil.
* Egg yolk and mustard proteins in mayonnaise function as emulsifiers.
[[File:Mayo .png|thumb|center|600x600px]]

==== '''Foaming''' ====
* Proteins have the ability to trap air in bubbles and this leads to the formation of foams.
* Egg white proteins function as foaming agents in the making of whipped egg whites. Whipping introduces air and denatures (unfolds) the protein molecules. The protein molecules then coagulate to form a fine film around the air pockets.
** Solid foams such as meringue are formed when the whipped egg whites are heated causing the protein to denature and form a more rigid three-dimensional structure, which won't collapse when the air escapes.
* Bread and ice cream are also examples of solid foams. Ice cream is also a solid emulsion. [[File:FNH200_Lesson02_Bread.jpg|thumb|400px|Gluten, a protein in wheat flour, traps air bubbles in bread making. Bread was prepared and photo was taken by Morgan Reid, LFS, UBC. This bread was prepared using a 250-year old sourdough culture. More details on bread culture will be discussed in [http://wiki.ubc.ca/Course:FNH200/Lesson_09#Starter_Cultures Lesson 09.]|center]]
==== '''Gel formation''' ====
* Gelatin (from the animal protein: '''''collagen''''') forms a gel by trapping large volumes of water within a semi rigid three dimensional protein matrix.
* Heating of meat proteins during the manufacture of luncheon meats, such as bologna and frankfurters, leads to gelation and formation of the textures characteristic of cured meats.
** Products such as frankfurters and bologna are also emulsions.
* Milk protein also forms a gel when it is acidified, such as in making of yogurt and cheese. The gel holds water and has a smooth texture.
[[File:FNH200_Lesson02_FriedEgg.jpg|thumb|300px|Fried Egg: an example of protein gel|center]] 
<big>'''The Amazing Functionalities of Milk Proteins'''</big>
[[File:Latte.png|thumb|latte|center|600x600px]]
* '''In latte (A):''' the milk protein traps air bubbles to form the foam structure.
* '''In milk (B):''' casein, a milk protein, acts as an emulsifier preventing the fat globules to separate (cream) from the skim milk portion. ( This function can be further enhanced by homogenization-will be further discussed in ''Lesson 6'')
* '''In cheese (C):''' casein forms a gel structure in the cheese curd.
==== '''Proteins that function as enzymes''' ====
* Enzymes are proteins that function as biological catalysts.
* In some cases enzymes are added to food as an ingredient ('''invertase''' in candy making)
* Some enzymes are used to promote food-processing operations while others are causative agents in food spoilage ('''amylase''' can ruin a starch gel; '''lipases''' can cause lipolytic rancidity which is the release of free fatty acid from glycerides).
* Enzymes in living tissue food systems such as fruits and vegetables are responsible for the reactions associated with ripening. Those same enzymes will continue the ripening process after harvest and unless they are inactivated the enzymes will eventually cause spoilage of the product (e.g. loss of crispness of stored apples; loss of sweetness of apples during storage; loss of colour in the skin of apples during storage).
* Many heating processes in food processing are designed to inactivate enzymes in addition to inactivating undesirable microorganisms in order to extend storage life of foods. These processes will be discussed later in ''Lesson 6''.
* Microorganisms, when added to food systems, to produce fermented foods, are essentially sources of desirable enzymes required to catalyse the desired chemical reactions needed to produce fermented food products (yogurt, sauerkraut, soy sauce). This will be discussed in more detail in ''Lesson 9''.
* Enzymes are also extracted from a variety of sources (plants, animal by-products, microorganisms) and purified for use as aids in food processing (e.g. '''proteases''' used for milk coagulation during cheese making; '''pectinases''' to enhance juice recovery and for clarification of apple juice; '''invertase''' for conversion of sucrose to invert sugar; '''isomerase''' to produce high fructose corn syrup).
[[File:FNH200_Lesson02_Cheese.jpg|thumb|In cheese, casein form a gel structure in cheese making|center]]

=== Food Proteins and Food Allergies ===
'''What is the relation between food proteins and allergies?'''
* Intolerance to certain proteins in foods is the basis for many food allergies. You will often see statements on labels for ice cream, cereals and candy bars that warn of the possibility that the product may contain traces of peanuts or other nut products.
* Allergies to peanut protein can be very severe, such that even with proper cleaning and sanitation, all residues of peanut allergens cannot be removed from processing equipment. Thus products that do not contain nuts, but that have been processed with equipment that was used for nut containing products may contribute enough allergen to cause some problems in very sensitive individuals.
* For recent food recalls in Canada due to potential allergy risks, see <nowiki>http://www.inspection.gc.ca/english/corpaffr/recarapp/recaltoce.shtml</nowiki>
{| class="wikitable"
|
==== Whant to learn more? ====
|-
|
* Choose one of the [http://www.inspection.gc.ca/english/corpaffr/recarapp/recaltoce.shtml recent allergy recalls] and click on "Learn more about common food allergies" to answer the following questions:
** 1. What are the ten most common food allergens related to proteins?
** 2. Sulphites are listed as food allergens as well, but they are NOT proteins. Can you explain why they are listed?
|}

== 2.2.1.4 Water ==
{| class="wikitable"
|
==== '''Terms to remember''' ====
|-
|
* free water
* bound water
* water activity
* vapour pressure
* moisture content
|}

Water is an extremely important component of food systems. Water is related to all aspects of food ranging from our perception of quality, to the ability of microorganisms to be metabolically active in food systems.

Water exists in food in two forms: '''Free water''' and '''Bound water'''.

'''Free water'''
* Some water may be present within intergranular spaces, within pores of the food matrix and as a thin film of water on the surface of many foods.
* Free water can be found in tissue food systems and in dispersions.
* Water that is free and not bound by food components generally retains its usual physical properties, can also function as a dispersing agent for colloidal substances, can function as a solvent and can be used by microorganisms.
'''Bound water'''
* Some water can be adsorbed on surfaces of macromolecules such as starches, pectins, proteins through forces such as van der Waals forces and hydrogen bond formation.
* This water does not display all of its normal physical properties and it is not readily available for use by microorganisms and chemical or enzymatic reactions.
* Another form of bound water is the water that is associated with food matrices as water of hydration. That water is also not readily available for use by microorganisms and enzymatic and chemical reactions in the food matrix, whether it is a tissue based food system or a dispersion.
* Sugars and salts (sodium chloride) can bind substantial amounts of water and are often added to foods for the purpose of decreasing the amount of free water in the food system. In that context, sugars and salts can be used to control or prevent growth of certain microorganisms in foods.

==== '''What does water activity (aw) mean?''' ====
Water activity is a measurement that is frequently used in monitoring the availability of water (free water) in foods for the support of:
* microbial growth
* chemical reactions
* enzymatic reactions
Water activity can be measured as the ratio of the vapour pressure of water in the food to the vapour pressure of pure water, both measured at the same temperature.
: <big> ''Aw = (Vapour Pressure of Water in Food at X °C) / (Vapour Pressure of Pure Water at X °C) ''</big>

Please watch the following animation that depicts the effect of solutes on vapour pressure and water activity [[File:FNH200_Lesson02_AwMovie.gif|thumb|500px|Water Activity Animation (Courtesy of UBC CTLT)|left]]

Water activity can range from '''0''' (''no free water'') to '''1.0''' (''all the water is free'', such as in distilled water).

Water activity values of a number of food products are shown below. Water activity of foods can be adjusted by physically removing water from foods during concentration and dehydration processing operations, also when the water in the food is frozen (the free water is in a solid state, in the form of ice crystals), or by adding substances that bind water thus lowering the proportion of water in the free form. The most commonly used water-binding agents are sugars and salt.

'''Water activity of selected foods:'''
{| class="wikitable"
!Food
!Water activity
!Water content (%)
|-
|pure water
|1.00
|100
|-
|fresh meat
|0.97
|65
|-
|eggs
|0.97
|75
|-
|fruits, vegetables
|0.97
|90 to 95
|-
|bread
|0.96
|35
|-
|Cheddar cheese
|0.96
|40
|-
|frankfurters
|0.93
|56
|-
|salami
|0.90
|61
|-
|jams and jellies
|0.80 to 0.95
|32
|-
|honey
|0.75
|18
|-
|dried fruit
|0.60 to 0.70
|20
|-
|wheat flour
|0.70
|12
|}

==== Is water activity the same as moisture content? ====
The answer is no. Measurement of the '''moisture content''' of a variety of food systems is a frequently conducted quality assurance measurement. However, measurement of water content of foods '''does not indicate''' whether the water is bound or free.

The data in the above table shows that water content of foods cannot be used as a reliable indicator of the water activity.

== 2.2.2 Food Minor Components ==
{| class="wikitable"
|
==== '''Terms to remember''' ====
|-
|
* ''low-acid'' and ''acid'' foods
* pH 4.6
* chlorophyll
* carotenoids
* Anthocyanidins and anthocyanins
* volatile and flavour constituents
* Fat-soluble vitamins
* Water-soluble vitamins
* antioxidant
|}

A number of other food constituents are present in foods in much smaller quantities than the major constituents (carbohydrates, proteins, fats). These minor constituents are very important in their influence on our perception of the quality attributes of the food. The minor constituents are: organic acids, pigments and aroma compounds.

== 2.2.2.1 Organic Acids ==
Fruits contain natural acids which give the fruits tartness and slow down bacterial spoilage. Organic acids also impart flavour and acidity to food. Examples of organic acids and foods in which they are occur are:
{| class="wikitable"
!Organic acid
!Food
|-
|Malic acid
|apples
|-
|citric acid
|citrus fruits, tomatoes, strawberries.
|-
|Tartaric acid
|grapes
|-
|lactic acid
|yogurt, cheese, olives, cottage cheese, sauerkraut.
|}
* The major uses of organic acids are to '''adjust pH''' or to '''acidify food''', and to '''impart flavour'''. For example, acetic acid provides flavour and decreases pH; phosphoric acid provides flavour and tartness in beverages.
* A number of organic acids are also employed as antimicrobial agents.
* Organic acids have a wide range of textural effects in food systems due to their reactions with proteins, starches, pectins, and other food constituents.
* '''What is pH?'''
** pH is a measure of the acidity of a food. Foods and beverages differ in pH because of their '''content of acids''', which produce hydrogen ions (Table 2.3). We are able to detect these ions by using a hydrogen sensitive electrode in a device called a ''pH meter''.
Table 2.3. Average pH values and acidity classification of selected foods.
{| class="wikitable"
!Chemicals Contributing to Aroma of Coffee
!pH value
!Acidity classification
|-
|Meat, fish, poultry
|7.0
| rowspan="7" |Low acid
(pH > 4.6)
|-
|Milk
|6.5
|-
|Corn
|6.3
|-
|Wheat flour
|6.0
|-
|Potatoes, peas
|5.8
|-
|Carrots
|5.1
|-
|Figs
|5.0
|-
|
|
|
|-
|Apples
|3.7
| rowspan="5" |Acid
(pH 0 - 4.6)
|-
|Cherries
|3.6
|-
|Oranges, pears, tomatoes
|3.5
|-
|Pickles
|3.0
|-
|Lemon/lime juice
|2.3
|}

==== Is pH important to the Food Industry? ====
Yes. An important pH for the food industry is '''pH 4.6'''; this is the borderline between an '''acidic food''' and a '''low acid food''' (Table 2.3).
* acid foods have pH of 4.6 or less
* low-acid foods have pH greater than 4.6
Acid foods will not support growth of disease causing microorganisms. This aspect will be discussed in more detail later in the course.

== 2.2.2.2 Colours and Pigments in Foods ==
Many food systems are coloured by pigments naturally present in the food system:

'''Chlorophyll''', the green pigment in plants, is responsible for the green colour in apples, lettuce, celery and broccoli. '''Chlorophyll a''' has a blue green hue (e.g. in the florets of fresh broccoli) while '''chlorophyll b''' has a yellow green hue (stems of broccoli).

'''Carotenoids''', a diverse group of pigments, can be subclassified into carotenes and xanthophylls. Carotenoids naturally produce red, orange and orange-yellow colours in many foods (e.g. tomatoes, carrots, pineapples, shrimp)

'''Anthocyanidins''' and '''anthocyanins''' (anthocyanidin complexed with glucose or other sugars). These pigments are the predominant colour pigments in blueberries, cherries, cranberries, plums and red cabbage. The anthocyanins are particularly sensitive to changes in pH, showing marked changes in colour with pH changes in the food system. See Figure below:[[File:FNH200_Lesson02_Athocyanin.jpg|thumb|center|500px|'''Anthocyanin''': the colour of an athocyanin is most stable and most highly coloured at low pH values. The colour will be gradually lost as the pH increases. Notice that at pH 5, the anthocyanin is almost colourless. The colour loss is reversible, and the red hue will return upon acidification.]]
As you can see in the above figure, the colour of an athocyanin is most stable and most highly coloured at '''low pH values'''. The colour will be gradually lost as the pH increases. Notice that at pH 5, the anthocyanin is almost colourless. The colour loss is reversible, and the red hue will return upon acidification.

Other pigments in food systems include hemoglobin and myoglobin (the red pigments in blood and muscle).

All of the pigments noted above are sensitive to varying degrees to changes in the environment (pH, presence or absence of oxygen, presence of metal ions, enzymatic degradation) in the food system. Thus colour changes often occur in fresh fruits, vegetables, meats and fish during storage, spoilage and as a result of processing and cooking.

In addition, there are a number of pigments, either those extracted from plants or microorganisms, or '''synthetic pigments''' that are used as colouring agents in fabricated food systems. These will be discussed in more detail in the section on food additives (Lesson 4). 

== 2.2.2.3 Aroma Constituents ==
The aroma profile of foods is very complex. The aroma of food is detected when we inhale volatile constituents of foods that react with the receptors in the olfactory regions of our nasal passages.

Most of us have experienced the aroma of freshly brewed coffee; there are actually hundreds of volatile compounds that have been identified in the aroma. The table below is a list of some of the chemical components that have been identified to contribute to the aroma of coffee; '''you don't have to memorise''' any of these compounds, it is only an example to demonstrate the amount of constituents that influence the aroma we perceive on a food.
{| class="wikitable"
! colspan="2" |Chemicals Contributing to Aroma of Coffee
|-
|Acetaldehyde
|Hydrogen sulfide
|-
|Acetic acid
|Hydroquinone
|-
|Acetone
|Isovaleric acids
|-
|Acetyl methyl carbinol
|Methyl alcohol
|-
|Ammonia
|Methyl amine
|-
|Cresols
|Methyl ethyl acetic acid
|-
|Diacetyl
|N- methyl pyrrole
|-
|Diethyl ketone
|p-Vinyl guaiacol
|-
|Dimethyl sulfide
|Phenol
|-
|Esters
|Pyrazine
|-
|Ethyl alcohol
|Pyridine and homologues
|-
|Formic acid
|Resorcinol
|-
|Furane
|Sylvestrine
|-
|Furfural
|Trimethylamine
|-
|Furfuryl alcohol
|Vanillone
|-
|Guaiacol
|
|-
|Higher fatty acids
|
|}
Adapted from: Benarde, M.A. 1971. Chemicals We Eat. American Heritage Press, N.Y., pp.208.

=== Please note that: ===
* No single chemical compound can be attributed as being the sole source of the aroma of a particular food product.
* It is the specific mixture of chemicals in a particular concentration that creates the aroma that we associate with a high quality food product.
* Any change in that specific mixture of volatile compounds or their concentrations will alter the aroma that we perceive.
* The '''volatile''' constituents that contribute to the aroma of foods are present in very low concentrations but are nonetheless very important constituents of foods.
* The '''flavour''' constituents are either present as part of the food matrix (fresh strawberries) or are modified (cooking of strawberries) or created (roasting of coffee) during processing or cooking.
 

== 2.2.2.4 Vitamins and Minerals ==

Vitamins are mainly classified into '''water-soluble''' and '''fat-soluble vitamins'''. Vitamins are organic compounds that make up a small portion of food; however, vitamins are very important from a nutritional point of view because they are essential components of the human diet as they carry out some very important tasks in the body.
* '''Water-soluble''' vitamins include vitamin C (ascorbic acid), thiamin, riboflavin, niacin, pyridoxine, vitamin B12, and folacin. These vitamins are found within the water (aqueous) phase of foods.
* '''Fat-soluble''' vitamins (vitamin A, vitamin D, vitamin E) are found within the fat (oil) portion of foods
Although Vitamins do ''not'' contribute to the physical characteristics of food, some are actually used as "food additives". Below are some examples of the two most common vitamins used as food additives:
{| class="wikitable"
!Vitamin
!Food Additive category
!Function
|-
|Ascorbic acid (Vitamin C)
|Bleaching agents
|*Hasten oxidation and aging processes as in flour whitening treatment
|-
|Ascorbic acid (Vitamin C)
|Preservatives
|Act as antioxidant to slow down rancidity and browning reactions
|-
|Tocopherols (Vitamin E)
|Preservatives
|Antioxidant
|}
'''*''' Ascorbic acid converts to its oxidizing from during mixing

'''Minerals''' (calcium, magnesium, sodium, potassium, iron, zinc) are often associated with various cellular components in tissue food systems and often are active participants in chemical and biochemical reactions that affect the chemical properties and textural characteristics of food systems.

== 2.3 Summary of Lesson 2 ==
* Colloidal dispersions allow particles of one substance to be distributed (dispersed) in another substance without dissolving. Foods can have many different types of colloidal dispersions.
* There are 4 major components of foods: carbohydrates, lipids, proteins and water.
* Carbohydrates include simple sugars (e.g. glucose and sucrose) and "complex" carbohydrates (e.g. starch, xanthan gum). Carbohydrates can have several functional properties in food, ranging from imparting sweetness to thickening capacity.
* Fats can be saturated or unsaturated, which affects their physical state (solid versus liquid) and functional properties in food. These functional properties range from tenderizing to emulsifying capacity.
* Proteins are made of chains of amino acids and serve many purposes in food. They not only impart texture and act as enzymes, but also have other functional properties such as gel and foam formation.
* Water in food is found in the free and bound form. Water activity is an important measurement of the amount of free water available for microbial, chemical and enzymatic reactions. Water activity can be controlled during processing of foods.
* The level of acidity in food is measured by the food's "pH". Establishing the acidity of a food is an important factor in controlling the growth of microorganisms. Food scientists use pH 4.6 as the borderline between an "Acid" and "Low acid" food.
* Pigments and aroma constituents contribute to important characteristics in food. These minor constituents can be easily modified by factors such as pH and temperature.
* Vitamins can be water or fat soluble. Some vitamins are used as food additives, primarily as "antioxidants".
Watch this video for fun and learn about properties of sugar: [https://www.youtube.com/watch?v=VY8q0hN6KwA&feature=emb_logo Hard Candy Chemistry]<references />

'''Authorship:'''

FNH 200 Course content on this wiki page and associated lesson pages was originally authored by Drs. [http://www.landfood.ubc.ca/person/brent-skura/ Brent Skura], [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], and [http://www.landfood.ubc.ca/person/eunice-li-chan/ Eunice Li-Chan]. Ongoing edits and updates are contributed by past and current instructors including Drs. [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], [http://www.landfood.ubc.ca/person/azita-madadi-noei/ Azita Madadi-Noei], [http://www.landfood.ubc.ca/person/nooshin-alizadeh-pasdar/ Nooshin Alizadeh-Pasdar], and [http://www.landfood.ubc.ca/person/judy-chan/ Judy Chan].
{{cc-by-nc-sa-3.0}}

<quiz display=simple>
{1. Which is the following is the most accurate description of milk?
|type="()"}
- Milk is a liquid.
- Milk is aqueous.
- Milk is an emulsion.
+ Milk is an oil-in-water emulsion.
- Milk in a water-in-oil emulsion.
</quiz>

<quiz display=simple>
{2. In addition to acting as a sweetening agent, what is the primary role of sugar in jam?
|type="()"}
- Browning agent.
- Fermentation.
+ Preservative.
- Produce hot supersaturated liquid.
</quiz>

<quiz display=simple>
{3. French fries are quickly prepared in deep fat frying due to oil's ability to:
|type="()"}
- aerate
- carry aroma
- lubricate
+ withstand high temperature
</quiz>

<quiz display=simple>
{4. Type to match functional properties to the appropriate major food component.
|type="{}"}
Traps air to form foams and water to form gels. { Proteins }
Carries food aromas, therefore, contributes to food flavour. { Fats }
Often used as a thickening agent or stabilizer. { Carbohydrates }
</quiz>

<quiz display=simple>
{5. Which of the following statements is the correct statement about starch?
|type="()"}
- Granules are insoluble in hot water.
- Is indigestible and forms part of dietary fibre.
+ Does not interact with taste receptors.
- Starch undergoes gelatinization which results in a loss of water.
</quiz>

Course:FNH200/Lessons/Lesson 01

2020-06-24T00:13:16Z

YihangChen:

<big><big><big>'''Food Science and the Canadian Food System'''</big></big></big>

== 01.0 Overview ==
In this lesson, we will define the field of food science, and discuss the size and scope of the food industry in Canada. We will take a look at food production, importation, and distribution within Canada. Apple production and processing will be discussed as an example of the conversion of an agricultural product into a variety of food products. Finally, we will monitor some food consumption patterns and trends which have occurred over the past 40 years.

'''Objectives'''

After completing this lesson, you should be able to:
*describe the field of Food Science;
*describe the breadth and relative magnitude of various sectors of the Canadian food industry;
*identify the trends in food consumption in Canada;
*illustrate the ways that foods are distributed to consumers in Canada; and
*discuss how apples are converted into a variety of food products and how they are store
'''Optional Reading'''

Top 10 Food Trends for 2019: http://www.ift.org/food-technology/past-issues/2019/april/features/2019-top-10-food-trends.aspx

== 01.01 What is the Definition of Food Science? ==
Foods, as such, are complex systems subject to many forms of changes, including biochemical, nutritional, physical and/or sensory changes. The multidisciplinary science known as food science is used to pull together the wide range of knowledge that deals with food.

'''''Food Science''''' can be defined as the application of the principles of science, engineering, and mathematics in order to study and acquire new knowledge on the physical, chemical and biochemical nature of foods. Food science is a broad field that is composed of specializations in food microbiology, food chemistry, and food engineering. Food science also involves the study of sensory properties of food, and therefore, the psychology of food choice. From the information gathered by food science, the corresponding technologies can be applied to the utilization, processing, preservation and storage of food. This is known as '''''food technology'''''.

Here is a brief explanation of the main components (sub-fields) of Food Science''(adapted from Potter and Hotchkiss, 1995):''
* ''Food Chemistry'': deals with the composition, structure and properties of food, as well as the chemistry of changes that occur during processing.
* ''Food Analysis'': covers the principles and methods for quantitative physical and chemical analyses of food products and ingredients. These analyses are related to the standards and regulations for food processing.
* ''Food Microbiology'': relates to the study of microbial ecology in relation to food, the effect of environment on food spoilage and food manufacture, the physical, chemical, and biological destruction of microorganisms in food, the microbiological examination of food stuffs, and public health and sanitation microbiology.
* ''Food Processing'': covers the principles of food preservation and the general characteristics of raw food materials, processing factors that influence quality, packaging, waste management, good manufacturing practices, and sanitation procedures.
* ''Food Engineering:'' relates to the study and application of engineering concepts and unit operations used in food processing. Engineering principles include material and energy balances, thermodynamics, fluid flow, and heat and mass transfer.

==== Are Food Science and Nutrition the same? ====
''"the difference between food science and nutrition is that nutrition deals with the effects of foods in the person who consumes them, while food science is concerned with the study of the chemical, microbiological, physical, and sensory properties of foods and their ingredients during processing, manufacture, and storage."'' Murano (2003)

== 01.02 How Old is the Discipline of Food Science? ==
[[File:FNH200_Lesson01_AncientWine.jpg|thumb|left|200px|Fig 1.1 Ancient Egyptian Wine Making Scene]]
[[File:FNH200_Lesson01_CanningJar.jpg|thumb|right|100px|Fig 1.2 Nicolas Appert's Canning Jar]]Food science as a distinct discipline is quite new. However, many aspects of "food science" have existed for many centuries. Products derived from food fermentation (''biotechnology'') have existed for thousands of years.For example, there is evidence that people were fermenting beverages in (A) Babylon circa 5000 BC, (B) ancient Egypt circa 3000 BC, and (C) pre-Hispanic Mexico circa 2000 BC. Today we know that fermentation not only contributes to a wide variety of food products, but it also involves food processing and preservation.
{| class="wikitable"
|}
Another example dates back to 1795, when Emperor Napoleon offered 12,000 francs for a new way of preserving food for its army. It was the French confectioner François Nicolas Appert who won the prize by placing food in wide-mouthed bottles, then corking and heating them in a water bath. The existence of bacteria was not known at the time, and Appert did not know the principle upon which his process depended; however, he was correct in the thought that heat could preserve food. Appert is therefore known as the discoverer of the process later known as canning.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Make a list of questions you have about the science of foods. For example; why tomatoes are red, why gravy thickens, what is used to make "sugar-free" candy? Save your questions and search for answers as you complete this course.
|}

== 01.03 Extent of Canada's Food System==
[[File:FNH200_Lesson01_CdnFoodSystem.gif|thumb|right|500px|Fig 1.3 Canadian Food System]]
In Canada, we have a diverse food system with thousands of food products available for purchase. Those products include foods produced in Canada as well as food products imported from many countries around the world.

The Canadian food system is depicted in Figure 1.1. Foodstuffs (fruit, vegetables, cereal grains, oilseeds, animals, fowl) are produced by farmers involved in primary agricultural production. Fin fish, molluscs and crustaceans are harvested from the wild or raised on fish farms. Unprocessed foodstuffs and fish are also imported for sale or processing in Canada. These products are shipped directly to farmers' markets, processors or distributors. Many agricultural and fishery products undergo some form of processing/preservation prior to distribution to the consumer market. Many foods are fabricated from the foodstuffs produced by primary agricultural and fishery harvesting. Examples of fabricated foods are bread, smoked and cured luncheon meats, soft drinks, yogurt and chewing gum, to name a few.

Food products from processors or primary producers often pass through various distributors before they reach retail stores or food service outlets. Foods are retailed through chain stores and smaller independent stores, as well as numerous convenience stores which may be part of a chain or may be owned by an independent operator, as well as food co-operatives.

* Vegetables are sold in the fresh market as well as being processed (canned, frozen, dehydrted, fermented) to increase storage life.
* Greenhouse production of vegetables is an increasingly important component of the fresh market supply (cucumbers, peppers, lettuce, tomatoes) particularly in the fall and winter seasons.
* Seafood products are harvested and processed primarily in Atlantic Canada and in British Columbia. Seafood production includes the harvesting of wild stocks as well as production of salmon, oysters, clams and lobsters, under intensive production systems ('farmed' seafood). Cultivation of fish (trout) in fresh water occurs in a number of regions of Canada.
* Some products are transferred to the consumer market with a minimum of processing (e.g., fresh fruits, fresh vegetables) while others (e.g., beef, pork, poultry, milk, wheat) go through more extensive processing before being transported to the retail market. Many agricultural products (e.g., wheat flour, corn flour, corn starch, corn syrup, fruits, vegetables, milk, and milk components) become sources of ingredients for the production of other food products.
Below are the major Provinces in Canada involved in the production of different agricultural food commodities:
{| class="wikitable"
!Food commodity production
!Province
|-
|Animal (beef, pork, poultry)
|Widespread around Canada
|-
|Dairy milk production
|Across Canada, Ontario, Quebec
|-
|Cereal grains
|Alberta, Saskatchewan, Manitoba
|-
|Tree fruit; small fruits; cranberries, blueberries, raspberries
|British Columbia; Ontario, Nova Scotia; Almost every province; British Columbia
|-
|Vegetables
|All across Canada
|-
|Seafood
|Atlantic Canada and British Columbia
|}
Many ''agricultural commodities'', ''finished food products'' and ''ingredients'' are imported into Canada as well. These imported products must meet the same standards and regulatory requirements as foods produced in Canada. This aspect is discussed in more detail in the section of the course dealing with regulatory issues and standards (Lesson 4).
{| class="wikitable"
|'''Want to learn more?'''
|-
|How does this image from a trading store (''ca. 1910'') compare to the typical grocery store (supermarket) of today?

- Food production and marketing have come a long way since the 1900s
|}

== 01.04 The Canadian Food Industry ==
The Canadian food industry is a multi-billion dollar a year industry. Foods available to us on the grocery store shelves include both domestically produced products and imported foods.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* The next time you are in a large grocery store, take some time to survey the proportion of shelf space devoted to various food commodity groups and note the vast array and variety of products that are in the grocery store.
|}
Although Canada produces large amounts of fruits and vegetables, vast quantities of fruits and vegetables are imported as fresh product and in lesser amounts as frozen, canned and dehydrated products. This is due to the seasonal nature of fruit and vegetable production in Canada, as well as the need for climates warmer than Canada to grow fruits such as oranges, grapefruit and bananas.

Canada exports meat products (raw meat and processed meat products) to other countries but also imports meat products (raw meats of specific cuts that may be in short supply in Canada, as well as processed meat products). Likewise Canada exports raw fish (fresh and frozen salmon, cod, etc.) and processed fish (canned fish, smoked fish, salmon and herring roe) to other countries, while other types of fish (such as prawns, oysters, processed fish products) are imported into Canada.

== 01.05 Apples and Apple Products ==
[[File:FNH200_Lesson01_AppleProcessing.gif|thumb|right|500px|Figure 1.4 Apple production and processing.]]
The processing of apples will be used as an example of the utilization and conversion of an agricultural commodity to various food products and ingredients (Fig. 1.2). After harvesting, apples can be routed several directions: they can be shipped directly to the fresh market; they can be processed; or they can be put into controlled atmosphere storage facilities where the atmosphere, temperature and humidity are carefully controlled to retard the rate of respiration and ripening of the apples, thus extending the storage life of the fresh fruit. Controlled atmosphere storage of apples is described at:
* <nowiki>http://www.omafra.gov.on.ca/english/crops/facts/12-045.htm</nowiki>
Apples can be processed in various ways. A large proportion of processing apples is converted to '''apple juice'''. The type of apple juice preferred by consumers in Western Canada is the clear apple juice. Apple juice can be used as the starting material for the production of '''apple cider'''. In making cider, apple juice is inoculated with specific ''yeast'' strains which ferment sugar in the juice into ethanol and produce flavours characteristic of apple cider. Apple cider can be further processed by inoculating it with a ''bacterial'' culture that will oxidize the ethanol to acetic acid to produce '''apple vinegar'''.

The apple solids remaining after juice extraction can be used as a feed material for the production of '''pectin''' (a carbohydrate used as gelling agent in the production of jams and jellies), animal feed, or as organic matter that can be returned to agricultural lands. In some cases, the residue may also be trucked to landfill sites which adds to the waste burden entering those sites.

Apples are also processed into '''apple sauce''' and pie fillings. A greater proportion of these products are used as ingredients in the bakery and food service industries than as items in retail stores.

To a lesser extent, apples are used to produce '''dehydrated apple slices, fruit leather, apple-filled snack bars''' and as '''ingredients''' for some confectionary products and breakfast cereals.
{| class="wikitable"
|
|-
|'''Figure 1.2''' Apple production and processing
|}
{| class="wikitable"
| '''Want to learn more?'''
|-
|
* Identify a food that you enjoy. How do you think a food scientist/technologist would be involved in the production, processing and marketing of that food product?
|}

== 01.06 Trends in Food Consumption in Canada ==

Overall, many changes have occurred in food consumption patterns in Canada in the past few decades, and they continue to change as consumer demands and perceptions change. The advent of new processing technologies have brought new products on the market and this will continue. Consumer perception of those products will determine whether they succeed or fail. Undoubtedly, advertising campaigns for various food products and controversies about the health effects of various food commodities (butter vs margarine; sugar vs non-caloric or low caloric sweeteners; fats vs fat substitutes; trans-fat free products; processed vs unprocessed foods) will continue to influence consumer food buying habits.
{| class="wikitable"
|'''Want to learn more?'''
|-
|
* Read the article in the link below and comment on the following points using your own experience in Canada.
<nowiki>http://www.ift.org/food-technology/past-issues/2019/april/features/2019-top-10-food-trends.aspx</nowiki>
* Insert paragraph
** Cannabis/CBD oil-infused drinks
** Cannabis/CBD oil-infused food
** Zero-waste cooking
** Globally inspired breakfast dishes
** Global flavors in kid’s meals
** Hyper-local
** New cuts of meat
** Veggie-centric/vegetable-forward cuisine
** Chef-driven fast-casual concepts
** Craft/artisan/locally produced spirits
|}
{| class="wikitable"
| '''Critical Thinking'''
|-
|
* Look at the most recent '''food consumption data (2014-2018)''' in the Statistics Canada website: <nowiki>http://www5.statcan.gc.ca/cansim/a26?lang=eng&retrLang=eng&id=0020011&tabMode=dataTable&srchLan=-1&p1=-1&p2=35#customizeTab</nowiki>
* Within each food category, which products have ''increased'' in consumption and which ones have ''decreased''? Can you identify what are the main reasons for these changes in consumption patterns?
** Meat
** Poultry and Eggs
** Fish
** Dairy
** Fruit and Vegetables
** Edible oils
** Beverages
* Review the highlights for 2017 and note any interesting finding: <nowiki>https://www150.statcan.gc.ca/n1/daily-quotidien/180530/dq180530c-eng.htm</nowiki> (Links to an external site.)
|}

== 01.07 Summary of Lesson 1 ==
* Food science studies the production, processing, preparing, evaluating and use of food.
* Technological advancements have led to many "food science discoveries"
* Canada offers a vast and diverse food system
* The Canadian food industry has a strong impact on Canada's economy
* Consumers and consumer demands have a strong influence on the food consumption trends

=== Closing thoughts ===
In conclusion, the food industry in Canada is a large industry that provides employment for a substantial part of the workforce in Canada. The variety of food products available in grocery stores or through food service outlets is immense and is likely to grow in response to consumer demands and changes in demographics, health, animal welfare and environmental concerns.

At this point it is important to recognize that while the amount and variety of foods consumed in Canada are increasing, many people in other parts of our world are unable to even secure enough nutritious food to maintain a healthy lifestyle. It has been estimated that about 3/4 of the world population live in lesser developed countries which are found mainly in Africa, Asia and South and Central America. Most of the inhabitants of these countries cannot get enough nutritious food to eat each day. Nutrients in short supply include fat, protein, vitamins, minerals and clean, safe drinking water. It is important to keep that thought in mind as you proceed through the course.

== References ==
* Murano, P.S. (2003). Introduction to Food Science and Technology. ''Understanding Food Science and Technology'' (Chapter 1). Belmont, California: Thompson Wadsworth.
* Potter, N. N. & Hotchkiss,J. H. (1998). Characteristics of the Food Industry. ''Food Science'' (5th ed.) (Chapter 2). Gaithersburg, Maryland: Aspen Publishers, Inc.
* Potter, N. N. & Hotchkiss,J. H. (1998). Vegetables and Fruits. ''Food Science'' (5th ed.) (Chapter 18 & pp.432-434). Gaithersburg, Maryland: Aspen Publishers, Inc.
* Food Available in Canada. Statistics Canada.<nowiki>https://www150.statcan.gc.ca/t1/tbl1/en/tv.action?pid=3210005401&pickMembers%5B0%5D=1.1&pickMembers%5B1%5D=3.1</nowiki> (Links to an external site.) (Links to an external site.)
* Food Technology Magazine Editors Share Top 10 Food Trend Predictions for 2019. <nowiki>http://www.ift.org/food-technology/past-issues/2019/april/features/2019-top-10-food-trends.aspx</nowiki>

'''Authorship:'''

FNH 200 Course content on this wiki page and associated lesson pages was originally authored by Drs. [http://www.landfood.ubc.ca/person/brent-skura/ Brent Skura], [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], and [http://www.landfood.ubc.ca/person/eunice-li-chan/ Eunice Li-Chan]. Ongoing edits and updates are contributed by past and current instructors including Drs. [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], [http://www.landfood.ubc.ca/person/azita-madadi-noei/ Azita Madadi-Noei], [http://www.landfood.ubc.ca/person/nooshin-alizadeh-pasdar/ Nooshin Alizadeh-Pasdar], and [http://www.landfood.ubc.ca/person/judy-chan/ Judy Chan].

{{cc-by-nc-sa-3.0}}

<quiz display=simple>
{1. Physical locations where a consumer may purchase and enjoy carrots:
|type="()"}
- Farmer's Market.
- Grocery Stores.
- Food Services Establishments.
+ All of the above.
</quiz>

<quiz display=simple>
{2. When are apples in BC being harvested?:
|type="()"}
- April.
- July.
+ Ocotober.
- December.
</quiz>

<quiz display=simple>
{3. What percentage of the atmosphere is oxygen?:
|type="()"}
- 0.3%
- 3%
+ 21%
- 78%
- 94%
</quiz>

<quiz display=simple>
{4. What changes occurred in the USA due to the publication of a book in 1906 about the meatpacking industry?:
|type="()"}
- The start of the vegetarian movement in the US.
+ Congress passed the meat inspection act and the food and drugs act of 1906.
- Inspectors were fired and taken out of the meatpacking plants.
- Establishment of the US Department of Agriculture.
</quiz>

<quiz display=simple>
{5. A food scientist discovers new information about food through research.
|type="()"}
+ TRUE.
- FALSE.
</quiz>

Course:FNH200/Lessons/Lesson 13/Page 13.4

2020-06-20T16:21:57Z

YihangChen: Created page with "== 13.4 Summary of Lesson 13 == In this lesson you were introduced to the concepts of functional foods, natural health product and probiotics. A few examples of each category..."

== 13.4 Summary of Lesson 13 ==
In this lesson you were introduced to the concepts of functional foods, natural health product and probiotics. A few examples of each category have been provided to solidify the concepts. You have also learned about the regulations pertaining these food products.

 

'''Authorship:'''

FNH 200 Course content on this wiki page and associated lesson pages was originally authored by Drs. [http://www.landfood.ubc.ca/person/brent-skura/ Brent Skura], [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], and [http://www.landfood.ubc.ca/person/eunice-li-chan/ Eunice Li-Chan]. Ongoing edits and updates are contributed by past and current instructors including Drs. [https://ag.purdue.edu/foodsci/Pages/Profile.aspx?strAlias=aliceaga Andrea Liceaga], [http://www.landfood.ubc.ca/person/azita-madadi-noei/ Azita Madadi-Noei], [http://www.landfood.ubc.ca/person/nooshin-alizadeh-pasdar/ Nooshin Alizadeh-Pasdar], and [http://www.landfood.ubc.ca/person/judy-chan/ Judy Chan].
{{cc-by-nc-sa-3.0}}

<quiz display=simple>
{1. Which country led the way in the regulation of functional foods?
|type="()"}
- Canada
- China
+ Japan
- The United States
- Korea
</quiz>

<quiz display=simple>
{2. Which of the following are ways to develop (make/create) functional foods?
|type="[]"}
+ By adding vitamins and/or minerals
+ By adding bioactive ingredients
+ Produce foods with increased levels of bioactive ingredients through breeding and/or genetic modifications
+ Produce food with increased levels of bioactive ingredients through processing and/or livestock feeding
</quiz>

<quiz display=simple>
{3. What type of food is most commonly designed to be a functional food?
|type="()"}
- Snacks
- Desserts
+ Beverages
- Entrees
</quiz>

<quiz display=simple>
{4. How much probiotic bacteria must be in a food for it to have a physiological effect on the consumer? (cells per ml and at least 100 mL consumed twice per week)
|type="()"}
- 10^4
+ 10^6
- 10^8
- 10^10
</quiz>

<quiz display=simple>
{5. Which one is considered a probiotic bacteria?
|type="()"}
- Listeria monocytogenes
+ Lactobacillus acidophilus
- Clostridium botulinum
- Saccharomyces cerevisiae
</quiz>