Jump to content

Course:FNH200/Projects/2025/Olive Oil

From UBC Wiki

Introduction

Olive oil

Olive oil is a cooking oil that is made by pressing fresh olives. The three countries that produce the majority of the world’s olive oil supply are Italy, Greece, and Spain.[1] Olive oil is commonly used in foods and contains monounsaturated fatty acids.[2] It is used in a variety of cooking methods such as grilling, sautéing, roasting, frying, and baking. Olive oil's subtle flavour enhances food without overpowering dishes and can provide a base for spice-infused dressings and sauces. It can also be used as an alternative to other vegetable oils or substituted for margarine or butter.[3]

History

Ancient Olive Oil Mill

The edible olive has coexisted with humans for around 5000-6000 years, going back to the early Bronze Age (3150 to 1200 BCE). In countries such as Greece, Egypt, and western Turkey, there are many archaeological sites with olive oil related findings such as clay tables, clay vessels called amphora to transport olive oil, milling stones, decantation basins, and ancient writings.[4] The history of olive oil begins in the classical era when Phoenicians, Greeks, and Romans, began to grow olive trees and extract juice from the olives.[5] It is believed that olives were taken to Spain and North Africa around 1000 BCE by the Phoenicians and the Greeks had imported the trees into Italy. In these times, olive oil had many uses including lamp fuel, rituals for royalty or religious practices, and pharmaceutical ointments.[4] Olive branches and olive oil were also used during the Olympic Games. The branches as crowns and the oil was used for massages before competitions.[5] It was during the middle ages that olive oil increased in production in Spain, Italy, and Greece. Specifically, during the 1700s, olives were largely planted to supply the growing populations of cities. In the late 19th and 20th centuries, the development of low-cost solvent extraction methods for seed oils and use of other sources of light resulted in a drop in demand for olive oil. The development of the International Olive Oil Council was part of a response to widely spreading fraud in the olive oil trade.[4]

Nutrition and Health

Oils and fats play a crucial role in our daily lives, not only in cooking and food preparation but also in providing energy for our bodies and aiding in the absorption of fat-soluble vitamins such as A, D, E, and K.[6] However, not all fats and oils confer the same health benefits, with certain fats and oils high in saturated and trans fats, decreasing healthy HDL cholesterol and increasing unhealthy LDL cholesterol.[6] Research has indicated that among the different types of fats, monounsaturated fats have been shown to improve blood cholesterol levels.[6] One of the most common monounsaturated fats is olive oil.

In a study conducted by García-González et al., virgin olive oil was ranked the highest in nutritional quality scoring with common olive oil and pomace olive oil following close behind.[7] Olive oil is composed of 13.8% saturated fat, 10.5% polyunsaturated fat, and 71% oleic acid.[8] Oleic acid is linked to reduced inflammation, oxidative stress, and could have positive effects on cancer prevention, making olive oil a better choice compared to other fats and oils.[8] In addition, olive oil contains many powerful antioxidants, helping to reduce risk of cardiovascular and central nervous system diseases.[8] Antioxidants fight inflammation, protecting blood cholesterol from oxidation which also may lower risks of heart disease. [8]

Excessive caloric consumption leading to weight gain and obesity is a growing issue in the North American contexts, with fats contributing a significant amount. However, studies have shown that diets higher in olive oil helped to promote weight loss more than diets lower in olive oil. [8]

The complex aroma and flavour of olive oil comes from many different components. In a high quality olive oil, compounds such as aldehydes, alcohols, esters, hydrocarbons, ketones, and furans have been found to be high contributors to olive oil’s unique flavour profile.[9] In addition, volatile compounds formed in the olive fruit through enzymatic processing such as Hexanal, trans-2-hexenal, 1-hexanol, and 3-methylbutan-1-ol play a significant role in flavour of the oil.[9] Different types of olives, levels of maturity, storage conditions, and methods of processing all influence the aroma and taste profile of olive oil. [9]

Production

The production of olive oil starts with cleaning the olives of any branches and debris, and then pressing the oil out through milling followed by malaxation. Then, the oil is extracted using a centrifuge. It is then processed to reduce the chance of fermentation and to remove impurities. The exact process depends on whether the final product is extra virgin olive oil or non-virgin olive oil.

Cleaning

Olives from an Olive Washing Machine

The purpose of this step is to remove dirt, leaves, twigs, and other debris that could introduce impurities into the olive oil. Traditionally, olives were cleaned by soaking and stirring them manually in water, while modern factories use automated washing machines to improve efficiency and hygiene in large-scale production[10].

One example of modern equipment is the Alfa Laval olive washing machine, which uses pressured water jets to wash off debris from the olives[10], ensuring a more thorough and efficient cleaning process.

Milling

Traditionally, olives are crushed into a course paste using stone mills, often powered by a donkey or mule[11]. In contrast, in modern times, olives are crushed using industrial millstones or steel hammer mills at corporate oil mills to produce a fine paste. This paste is layered onto synthetic fibre discs that are easier to clean than traditional Frails, stacked, and subjected to immense hydraulic pressure[12].

Malaxation of olive paste

Malaxation

Traditionally, the olive paste was kneaded by hand or with wooden paddles, then packed into woven baskets called frails. The frails are then stacked and pressed under heavy stones to extract the oil. In contrast, modern systems mechanically mix the olive paste, then layer it onto synthetic fibre discs[13], which are stacked and pressed under immense hydraulic pressure to separate the oil from the solids. The use of synthetic fibre discs is more hygienic because it is much easier to clean than traditional frails[13].

Extraction

After malaxation, the oil is separated from the oil paste. The traditional method was to use a press to force out the oil, in which the paste was loaded onto mats and compressed to extract the liquid.[14] This method was time-consuming, less hygienic, and not as efficient as methods today. Nowadays, centrifuges are used to perform the same task.[14] These machines spin the paste at high speeds, taking advantage of the difference in density of the oil and impurities to separate everything.[14] Centrifuges are much more hygienic and efficient as opposed to the traditional pressing method. Thus, the resulting oil quality is more reliable and scalable.

Filtration

Once the oil is extracted, there will still be some water and solids inside it. This can cause unwanted microbial activity if not removed. To filter the unwanted impurities out, the oil is stored in tanks for up to 48 hours to allow heavy particles and water to sink to the bottom of the tank.[15] Every few hours, these settlings are drained from the bottom of the tank.[15] This greatly lowers the possibility of unintended fermentation. In some processes, an additional filtration step may occur to further remove impurities.[15]

Non-Virgin Olive Oils

For non-virgin olive oils, they go through an additional refining step before filtration. These processes are used in order to lower the acidity and remove bitterness. [16] Many different processes are combined in various ways to achieve the desired effects: degumming, which involves treating the oil with hot water and spinning it in a centrifuge; neutralization, which uses an inorganic compound is used to remove colour and fatty acids from the oil; bleaching, which eliminates pigments through heat and acid; winterization, where the oil is chilled to remove waxes; and deodorization, which uses steam under vacuum to strip away odours and flavours.[16]

Regulation and Grading

Food and Agricultural Organization of the United Nations - Responsible for Codex International Standards

There are many different types of grades and regulations relating to Olive Oils, which vary from country to country. This article will focus primarily on the Canadian regulations, but know that these may differ depending on country or region.

In Canada, Olive Oil labelling and regulations are set and enforced by the Canadian Food Inspection Agency (CFIA). The CFIA defines Olive Oil as “Products that are represented or sold as olive oil or pure olive oil are subject to the standard of composition for this product, which states in part, that olive oil shall be obtained from the fruit of the olive tree (Olea europaea L) [8.1.2, CFCS].” The Olive Oil grades “Extra Virgin” and “Virgin” are subject to the standards of the International Olive Council (IOC) and Codex Alimentarius International Food Standards. According to these standards, the term “Extra Virgin” is only applicable to Olive Oil, and any products labelled as such must meet the IOC and Codex standards. However, other vegetable oils aside from Olive Oil can use “Virgin” or “Cold-pressed” on their label if they meet the quality standards.[17]

Codex standards and definitions for Olive Oil:

“Olive oil is the oil obtained solely from the fruit of the olive tree (Olea europaea L.), to the exclusion of oils obtained using solvents or re-esterification processes and of any mixture with oils of other kinds.”

“Virgin olive oil is the oil obtained from the fruit of the olive tree solely by mechanical or other physical means under conditions, particularly thermal conditions, that does not lead to alterations in the oil, and which has not undergone any treatment other than washing, decanting, centrifuging and filtration”

“Olive-pomace oil is the oil obtained by treating olive pomace with solvents other than halogenated solvents or by other physical treatments, to the exclusion of oils obtained by re-esterification processes and of any mixture with oils of other kinds.”[18]

Oleic Acid content

Oleic Acid is the main fatty acid of Olive Oil, and is a monounsaturated fatty acid generally in the form of triglycerides. A “free” fatty acid is when glycerol is detached from the chain of fatty acids. Free fatty acid content is one of the major determinants of the quality of Olive Oil and is denoted as Oleic Acid content. The lower the oleic acid content, the higher the quality of the olive oil is considered. Higher free fatty acid content can be a consequence of many factors, including poor handling, poor storage, bugs or pests, etc. Oleic Acid content affects the stability and smoke point of the olive oil, but more importantly, can shorten the shelf life of the olive oil. However, free fatty acids do not affect the taste of the olive oil and can only be determined by a laboratory test. [19]

Food-grade Olive Oil is separated into three main grades or categories, which are Virgin Olive Oil, Olive Oil, and Olive Pomace Oil. Virgin Olive Oil is considered the highest quality Olive Oil, followed by Olive oil then Olive Pomace Oil.

Extra Virgin Olive Oil

Virgin Olive Oil is designated by the IOC as “[Virgin Olive Oils] are oils which are obtained from the fruit of the olive tree (Olea europaea L.)” which must only be processed mechanically or physically by other means that have not altered the oil in any way. The oil must not have undergone any other treatment other than washing, decantation, centrifugation, and filtration. Under this, “Extra Virgin” Olive Oil is defined as Virgin Olive Oil with a free acidity (oleic acid) content of no more than 0.80 grams per 100 grams, which must also pass both chemical properties and sensory aroma tests to be labelled Extra Virgin Olive Oil. “Regular” Virgin Olive Oil is subject to similar tests at a lower standard, usually at a higher oleic acid level of 3.3 grams per 100 grams. Lampante Virgin Olive Oils have a higher oleic acid level of 3.3g per 100g and are meant to be further refined and processed into regular Olive Oil. [20] Extra Virgin Olive Oils are considered the highest quality of olive oil, and they generally have the a deep yellow-green hue with the strongest flavour. Extra Virgin Olive Oils are sometimes marketed as "Cold-Pressed" which means that the olives were not heat treated in anyway, complying with regulations. [21]

“Regular” Olive Oils are split into two categories, which are Refined Olive Oil or Olive Oil. Refined Olive Oil have been refined from Virgin Olive Oils but still maintains its original glyceride structure and must have an oleic acid content of under 0.3 grams per 100 grams. Olive Oil is comprised of refined olive oil and Virgin Olive Oil, and must have an oleic acid content of 1.0 grams per 100 grams. [19] Regular Olive Oils are between Virgin and Pomace Olive Oils in terms of quality. The specific colour and hue can greatly vary depending on quality and percent of Virgin Olive Oil in the mixture, and its taste is usually inferior to Virgin Olive Oil. [21]

Olive Pomace Oils can be considered the “lowest” quality olive oil that is extracted from the “pomace,” which is the leftover olive paste after the initial extraction of oil. The pomace is generally treated with solvents and other physical treatments for the extraction of the leftover oil. Crude olive pomace oil is the product extracted from the olive pomace and must be refined to be fit for consumption. Refined olive pomace oil is the product of refining, and like regular Olive Oil, must maintain its original glyceride structure with an oleic acid content of no more than 0.3 grams per 100 grams. This oil can be combined with other virgin olive oils or regular olive oils to create an oil blend, but cannot be called “Olive Oil”. [22]

Packaging

Consumer Olive Oil comes in a few common types of packaging meant to protect the olive oil from light and air to prevent the loss of volatile flavour compounds, antioxidants, fatty acids, and preserve overall quality. Any Olive Oil will degrade or go rancid eventually with exposure to heat and light. [23]

A variety of Olive Oil packaging, including glass, ceramic and metal containers.

Glass bottles are the most common type of packaging for consumer olive oils, as glass is very non-reactive, impermeable to air, and strong against punctures or slashes. Most bottles are a darker colour like dark green, which helps to protect the oil from light and can look appealing to consumers. [24]

Large metal cans made of tin, aluminum or some other metal are another type of container for olive oil and are generally sold in larger volumes of oil. They are preferred over glass for larger quantities due to being lightweight and cheaper to produce. Metal tins are very durable and completely block both light and air from interacting with their contents.

Plastic Bottles are another common type of packaging, and are generally reserved for more refined types of olive oil, like Olive Pomace Oil, due to the oils being more stable and resistant to light and heat. They are cheap to produce, durable, and lightweight, but can chemically react with olive oils depending on the plastic formula.

Other packaging and containers include “bag-in-box” systems, usually for commercial sales or larger volumes, where a bag is placed inside a cardboard box and filled with oil with a spigot installed. The bag and box combo is cost-efficient and good at protecting the oil from light and air. Ceramic bottles are also used for Olive Oil, though much rarer and reserved for higher-end consumer products due to their higher costs for production. Ceramic has similar properties to glass in terms of protecting the oil from air and heat, but is opaque, making it superior in blocking light. [25]

Fake Olive Oils

With the rise in popularity and availability of Olive Oil around the world, there has also been a rise in ‘fake’ Olive Oils appearing on supermarket shelves. Extra Virgin Olive Oil is the highest quality of Olive Oil, which is held to very strict standards and regulations mentioned previously. Due to these standards and grading, many Olive Oils do not qualify as Extra Virgin, and must either be sold as Virgin Olive Oil or further refined and sold after. However, multiple studies have found that many bottles sold in stores labelled as “Extra Virgin” olive oil are not “Extra Virgin” at all, failing the proper requirements for their labels. [26]

A 2015 test by the National Consumer League (NCL) of more than ten bottles of Olive Oil labelled “Extra Virgin” from large grocery chains in the US, more than half failed to meet proper standards. Some oils failed simply due to not being “Extra Virgin” olive oils in the first place, with brands just using refined “regular” Olive Oil or oil from old/rotten olives. A common tactic is to mix Olive Oil with cheaper seed oils and add colour to mimic the look of Extra Virgin Olive OIl, reducing the price to produce per bottle. Another explanation was that brands were not properly packaging the oils or labelling with an improper best-before date, leading to degraded, lower-quality Olive Oil by the time the product was on shelves.[23] In Canada, the CFIA designates Olive Oil to be under higher surveillance for “Food Fraud” with it “[Olive oil is] at risk of being adulterated with cheaper oils, both in Canada and abroad.” Their study in 2020/2021 found that approximately 12% of the Olive Oils tested failed to meet standards, with products being seized and sent back to their origin country. [27]

Exam Question

Question:

Why is Olive Oil often stored and sold in dark glass bottles?

A: The packaging and colour appeal to consumers and give the impression of quality

B: Glass bottles are the most cost-efficient way of packaging; the packaging provides physical protection for shipping/handling

C: Glass is non-reactive while being impermeable to air, and the dark colour minimizes light penetration, keeping the oil from degrading too quickly

D: As per the regulation established by CFIA in the year 2011, mandating the use of glass bottles for all extra virgin olive oils

Answer: C

Explanation:

We believe that our question should be included in the final exam because we learned extensively on different packaging techniques and its effects on food quality and preservation.

  1. ↑ "Complete Olive Oil Guide: Regular Olive Oil Vs. Extra Virgin, Different Types of Olive Oil, and How to Pick the Best Olive Oil". MasterClass. August 4, 2021. Retrieved August 2, 2025.
  2. ↑ "Olive Oil - Uses, Side Effects, and More". WebMD. Retrieved August 2, 2025.
  3. ↑ "Cooking Uses by Type". North American Olive Oil Association. Retrieved August 2, 2025.
  4. ↑ 4.0 4.1 4.2 Vossen, Paul (August 1, 2007). "Olive Oil: History, Production, and Characteristics of the World's Classic Oils". ASHS Publications. 42.
  5. ↑ 5.0 5.1 "The history of Olive Oil (I)". Olive Oils From Spain. February 24, 2016. Retrieved August 3, 2025.
  6. ↑ 6.0 6.1 6.2 "Dietary Fats, Oils, and Cholesterol". Heart and Stroke Foundation of Canada. Retrieved August 7, 2025. |first= missing |last= (help)
  7. ↑ García-González, Aida; Quintero-Flórez, Angelica; Ruiz-Méndez, María-Victoria; Perona, Javier (April 2023). "Virgin Olive Oil Ranks First in a New Nutritional Quality Score Due to Its Compositional Profile". Nutrients. 15 (9). doi:https://doi.org/10.3390/nu15092127 Check |doi= value (help).
  8. ↑ 8.0 8.1 8.2 8.3 8.4 Leech, Joe (June 3, 2024). "11 Proven Benefits of Olive Oil". Healthline. Retrieved August 7, 2025.
  9. ↑ 9.0 9.1 9.2 Kiritsakis, A.K. (June 1998). "Flavor components of olive oil—A review". Journal of the American Oil Chemists' Society. 75: 673–681. Invalid |doi-access=https://doi.org/10.1007/s11746-998-0205-6 (help); |doi-access= requires |doi= (help)
  10. ↑ 10.0 10.1 "Olive Washing Machines: How It Works". Alfa Laval. Retrieved August 8th, 2025. Check date values in: |access-date= (help)
  11. ↑ "Gordon Ramsay Learns The Medieval Way Of Making Olive Oil". The National Geography Cooking: Gordon Ramsey. Retrieved August 8th, 2025. Check date values in: |access-date= (help)
  12. ↑ "The Seven Phases of Olive Oil Production". The Lazy Italian Culinary Adventures. Retrieved August 8th, 2025. Check date values in: |access-date= (help)
  13. ↑ 13.0 13.1 "A Comprehensive Guide: How Olive Oil Is Made". Brightland. Retrieved August 8th, 2025. Check date values in: |access-date= (help)
  14. ↑ 14.0 14.1 14.2 "Olive Oil | How it's made". Food Unfolded. September 1, 2025. Retrieved August 6, 2025.
  15. ↑ 15.0 15.1 15.2 "Olive Oil Processing". UC Food Quality. Retrieved August 6, 2025.
  16. ↑ 16.0 16.1 "A Comprehensive Guide: How Olive Oil Is Made". Brightland. Retrieved August 10, 2025.
  17. ↑ "Labelling requirements for fats and oils". Retrieved August 4, 2025. Check date values in: |date= (help)
  18. ↑ "Standard for Olive Oils and Olive-Pomace Oils" (PDF). Codex Alimentarius. 2024. Retrieved August 5, 2025. Check date values in: |date= (help)
  19. ↑ 19.0 19.1 "Olive Oil Acidity Explained". Retrieved August 5, 2025. Check date values in: |date= (help)
  20. ↑ "Standards, Methods, and Guides". Retrieved August 4, 2025. Check date values in: |date= (help)
  21. ↑ 21.0 21.1 "The Ultimate Guide to Different Types of Olive Oil". Retrieved August 6, 2025. Check date values in: |date= (help)
  22. ↑ "TRADE STANDARD APPLYING TO OLIVE OILS AND OLIVE POMACE OILS" (PDF). International Olive Council. November 2024. Retrieved August 2, 2025. line feed character in |title= at position 38 (help)
  23. ↑ 23.0 23.1 "Olive Oil Mislabelling". May 19, 2015, Retrieved August 7, 2025. Check date values in: |date= (help)
  24. ↑ "Olive oil packaging: why buy products in dark packaging?". Retrieved August 7, 2025. Check date values in: |date= (help)
  25. ↑ "Olive Oil's Packaging Puzzle: Glass or Plastic?". 2024, Retrieved August 7, 2025. Check date values in: |date= (help)
  26. ↑ Olmsted, Larry (September 30. 2016. Retrieved August 7, 2025). "It's Extra Virgin Olive Oil Day - Is Your EVOO Real Or Fake?". Check date values in: |date= (help)
  27. ↑ "Food Fraud Annual Report 2020 to 2021". 2024. Retrieved August 7, 2025. Check date values in: |date= (help)
Retrieved from "https://wiki.ubc.ca/index.php?title=Course:FNH200/Projects/2025/Olive_Oil&oldid=869889"