Course:FNH200/Projects/2026/Nescafe Coffee Pods/Capsules - What is inside?

Title: Single-Serve Coffee Capsules: Packaging Engineering, Extraction Chemistry, and Shelf-Life Dynamics

Product: Nescafe coffee pods (Single serve capsules)

Related Past FNH 200 projects: FNH200/Projects/2021/Instant Coffee (https://wiki.ubc.ca/Course:FNH200/Projects/2021/Instant_Coffee)

Coffee is one of the world’s most popular beverages and instant coffee is an essential item for many individuals in their daily life. The single pod coffee capsule has been on the market for a while and we are going to take a closer look at its properties. Previous FNH 200 projects have focused on instant coffee before but we are going to focus on single serve technology of the capsules and the packaging of capsule coffee pods in this manner. Our focus is to understand the core properties of capsule coffee pods and examine how advanced packaging and processing techniques alter its physical chemistry and shelf life relative to traditional instant coffee.

Processing and extraction chemistry

Compare the extraction method and preparation:

Coffee pod vs Instant coffee (pressure vs solid dissolution). Investigate the reconstitution process when the consumer inserts the coffee pod into the machine:

Coffee pods can make coffee within a minute, but manufacturing takes 30 to 60 days to prepare for consumers fully. Firstly, all of the pods or capsules need to be sterilized. They use high-pressure air to remove contaminants inside, then pass it through a UV sterilizer to kill any microorganisms. Before the coffee is filled, they need to grind the coffee first. They need to grind the coffee beans to a fine grind, which is finer than for espresso. To grind the coffee beans, they use roller mills to break the beans, then break them into smaller pieces, and then to grind the coffee to the desired size. Once the coffee beans are ground, manufacturers use nitrogen flushing. Coffee aroma is very important to produce different flavours and to enjoy the drink. This nitrogen flushing can help the coffee capsules to stay fresh and maintain taste and aroma for a longer period by lowering the amount of oxygen level in the pod through adding nitrogen. For food-grade applications, manufacturers achieve a 99.9% nitrogen level and less than 1% oxygen level. If coffee capsules are prepared without nitrogen flushing, the ground coffee will oxidize, leading to a decline in flavour quality as well as freshness. In other words, the nitrogen flushing method prevents the coffee beans from oxidation and preserves volatile compounds for many months.

Figure 1: Coffee Pod Machine

For extraction, the coffee pod’s aluminum foil lid is punctured by the machine as it is placed into the machine. The water nozzle is then pierced to form a machine-coffee pod complex (4). The machine heats up and injects hot water through a piston pump. Then the hot water enters the pod to start the brewing process. Once the coffee grinds are fully saturated with hot water, it generates flow resistance, which builds pressure. This pressurized system also aids in the extraction of coffee pods. Then, water injection stops and the air pump activates to finish the final extraction. This final process ensures that the residual liquid is removed.

Previously, manufacturers used the spray drying method to quickly evaporate the brewed coffee, leaving coffee powder that is ready to be mixed with hot water again. However, the drying process has transitioned from spray drying to freeze drying to allow the coffee powder to retain more flavour and aroma. Similarly, the manufacturer would roast, grind, and brew the coffee, then obtain an extract that contains about 40% solids through evaporation. Then, it goes through the freeze-drying process at -40C. Although freeze-drying is a better process, it does not fully preserve the flavour and aroma. Therefore, manufacturers spray caffeol, which is a volatile compound that gives coffee flavour, to give the final instant coffee product very similar to freshly brewed coffee. Then, it goes through the final step, which is agglomeration. This step fuses small coffee particles into a more dense size so that they sink in water and dissolve instantly when making instant coffee, enhancing the solubility of the particles.

Figure 2: Flowchart of Instant Coffee

Investigate the factors that affect the coffee extraction process when the consumer inserts the coffee pod into the machine.

Particle size of the coffee grounds: The smaller the size of the coffee grounds, the easier it is for the soluble compounds to diffuse out during the process of brewing.

The amount of water used during brewing plays an important role in extraction and final concentration of coffee. Using an optimal, suggested amount is vital for a balanced flavor as using too much water can dilute the beverage and produce a more bitter and astringent compound. Therefore, water volume used to brew coffee affects both concentration and flavour profile of the final beverage.

Water temperature is known to affect the rate of extraction of chemical compounds from coffee grounds. When coffee is brewed, hot water extracts water soluble compounds to be transferred to the beverage. Generally, one would assume that increasing the temperature of water used for extraction would increase the transfer of compounds to beverage, however, different compounds found in coffee (caffeine, trigonelline etc) have varying rates of transfer at same temperature. Therefore, temperature of water used dictates not only the amount extracted but also chemical composition and final flavour profile of coffee.

References for this section:

1. https://perfectdailygrind.com/2022/09/how-are-coffee-capsules-manufactured-and-filled/#:~:text=This%20is%20mainly%20because%20of%20the%20smaller,second%20set%20breaks%20them%20into%20smaller%20pieces.
2. https://www.saneu.com/why-package-coffee-capsules-flushed-with-nitrogen/
3. https://www.foodunfolded.com/article/how-is-instant-coffee-powder-made#:~:text=How%20Instant%20Coffee%20Powder%20Is%20Made%20Today.,until%20it%20is%20condensed%20into%20an%20extract.
4. https://www.sciencedirect.com/science/article/pii/S0963996916304227
5. https://foodtechnotes.com/2020/08/30/instant-coffee-manufacturing-process/
6. https://www.nespresso.com/au/en/news/coffee-pods-vs-ground-coffee-vs-instant-coffee-whats-your-cup
7. https://pmc.ncbi.nlm.nih.gov/articles/PMC10418593/
8. https://pmc.ncbi.nlm.nih.gov/articles/PMC7553981/

Processing, & Shelf-Life Dynamics in Capsule Systems

Physical chemistry: In capsule coffee pods physical chemistry utilizes the gas exchange, moisture control, and lipid oxidation to make the coffee retain all its flavour. The ground coffee that is used in the pods usually has high unsaturated fats and aromatic volatile organic compounds that give coffee its rich flavor and smell. The volatile organic compounds are usually furans and pyrazines. Due to the nature of the coffee pods one big issue is coffee has a large surface area inside the pods. Due to this it causes exposure to oxygen and often triggers lipid oxidation and leads to the loss of degradation of volatile aroma compounds. The coffee pods utilizes modified atmosphere packaging (MAP). During manufacturing the container is filled with inert gas like nitrogen to remove the oxygen and multilayer materials like aluminium, PET are used. These barrier layers block oxygen, light and moisture from penetrating the capsule. Traditional instant coffee primarily relies on low moisture content and simple airtight jars) but the capsule pod technology creates a controlled environment around the ground coffee which preserves the fresh roast aromatics and prevents any chemical quality decay and also allows extended storage periods. (https://pmc.ncbi.nlm.nih.gov/articles/PMC10931445/)

Shelf life stability: Nescafe coffee pods have a consumption period of up to 15 months. Due to the design of the pods it allows the pods to preserve quality, freshly roasted and accurately measured coffee grounds are sealed directly inside aluminium capsules. The usage of aluminium allows airtight packaging which protects the coffee from light, oxygen, and moisture, preserving its unique aroma and profile. The pods have aluminum or high-barrier polymer properties that block oxygen, light, and moisture, preventing staling and lipid degradation. (https://www.nespresso.com/pro/kr/en/story/capsule-coffee-expiration-date)

Flavouring profile for each coffee pod: Inside the Nescafe coffee pods there is 100% fine roast and ground coffee and while there is a variety of flavours it typically contains Arabica, Robusta, or calibrated multi origin blends. Usually it is sealed without added preservatives to prevent the volatile organic compound loss and loss of any flavor and aroma.

Figure 3: Design of the Coffee Pod

Furthermore, the flavor profile is dictated by the specific bean origin, roast profile kinetics and high pressure extraction within the capsule chamber. If it's a lower intensity roast then it highlights the top notes of the coffee, presenting bright citrus acidity, floral aromas and delicate toasted cereal characteristics finished with a light creme. Conversely, the dark roasted ones undergo further Maillard reactions creating a bitter sweet cocoa, warm spices and caramel flavours. Also, this varies between pods tremendously on the flavor, origin and official specifications of the bean sourcing, extraction dynamics of where the coffee pods were manufactured.

(https://www.nespresso.com/nl/en/koffie-keuze-hulp/overzicht-smaakprofielen#:~:text=Find%20out%20your%20profile.%20Image%20of%20Original,town%20Envivo%20Lungo%20Rood.%20Cape%20Town%20Lungo)

Global food regulations and labelling standards

Mandatory Labelling Elements in Canada:

1. Common Name: All prepackaged coffee capsules must identify by the common name: ground coffee.
2. Net Quantity: The package must declare the qty of coffee in metric units.
3. Ingredients: A plain capsule with only coffee is a single-ingredient food. If there are flavours, milk ingredients, or sweeteners, they must be declared.
4. Allergens: If a capsule contains allergens or sources of gluten, they must be identified in the label under a CONTAINS: statement.
5. Nutrition facts table: Must be calculated under “as consumed” after brewing.
6. Company information: Must identify the name and principal location of business of the company responsible for manufacturing and production.
7. Label must be in English and French
8. Must include a best before date if capsules have a shelf life of 90 days or less.

Sources:

https://laws-lois.justice.gc.ca/eng/regulations/SOR-2018-108/page-14.html

https://inspection.canada.ca/en/food-labels/labelling/industry/requirements-checklist

https://inspection.canada.ca/en/food-labels/labelling/industry/date-markings-and-storage-instructions

Importer Responsibilities:

Coffee capsules that are manufactured outside of Canada must still comply with Canadian food regulations when imported and sold in Canada. Under the Safe Food for Canadians Regulations, importers are responsible for ensuring that imported foods are safe and meet Canadian consumer protections requirements. This includes maintaining preventive controls, verifying that product labels and allergen declarations comply with Canadian standards, and keeping records that can trace products throughout the supply chain and produced upon request. Importers must identify and remove recalled products, and claims made on packaging such as “recyclable” or “compostable” must comply with Canadian rules against greenwashing. A foreign exporter must ensure that their capsule coffee product complies with their own standards, as well as Canada’s.

https://inspection.canada.ca/en/importing-food-plants-animals/food-imports/step-step-guide

https://inspection.canada.ca/en/food-safety-industry/traceability/traceability

https://competition-bureau.canada.ca/en/how-we-foster-competition/education-and-outreach/publications/environmental-claims-and-competition-act

Penalties for Non-Compliance:

In Canada, failure to meet import and food safety requirements can result in product recalls, seizures, suspension of distribution or manufacturing licenses, minor monetary penalties, or prosecution. More serious offenses can result in fines of up to $5 million as well as imprisonment for up to 2-5 years.

Misleading claims on coffee capsule packaging can also result in penalties under the Competition Act. Deceptive marketing practices can result in a $10 million fine for a first violation, and $15 million for subsequent violation. In addition, the CFIA can seize 3% of global revenues for products involved with violation.

https://laws-lois.justice.gc.ca/eng/acts/s-1.1/page-3.html

https://competition-bureau.canada.ca/en/deceptive-marketing-practices/types-deceptive-marketing-practices/false-or-misleading-representations-and-deceptive-marketing-practices

Potential Final exam question

Q. Why are coffee capsules often flushed with nitrogen before they are sealed?

1. To sterilize coffee grounds inside the capsule.
2. To increase the caffeine content.
3. To decrease oxygen inside the capsule to slow down oxidation that affects aroma and flavour.
4. To change the moisture content of the coffee.

Correct answer: C

Why this should be on the exam: Before completing this project, we were unaware that coffee within the capsule is flushed with a gas to maintain its quality. We learned that nitrogen flushing replaces much of oxygen with nitrogen inside the capsule. Nitrogen being a non reactive gas, slows down oxidation responsible for loss of flavor profile, aroma and freshness during storage. This allows coffee to maintain its quality for a longer period before it is opened for consumption within the best before date. We believe this question should be on the exam because coffee capsules are a widely used food product these days and this question connects to important FNH 200 concepts such as oxidation, MAP and shelf life preservation.

Q.  What is the main purpose of using aluminium or high barrier polymer materials in coffee capsule packaging?

1. To increase the coffee content of the coffee.
2. To increase the roasting temperature of the coffee.
3. To make coffee dissolve completely before brewing.
4. To reduce exposure to oxygen, moisture and light to help preserve coffee quality during storage.

Correct Answer: D

Why this should be on the exam: Before our research for the project we mainly thought of coffee capsules as convenient containers to brew a good cup of coffee. Through our research we learned that a particular, good quality packaging material is necessary to preserve coffee against deterioration. Coffee can lose its quality during storage when exposed to oxygen, moisture and light. This eventually leads to oxidation, loss of flavour and aroma. Aluminium and high barrier polymer materials help limit the exposure of coffee to these environmental factors  thus preserving its quality. We think this question should be on the final exam because it connects a commonly consumed food product with important FNH 200 concepts such as food packaging, oxidation and shelf life stability.