Do Coffee Pods Have an Expiration Date?

Very often, people ask “do coffee pods have an expiration date?” This is a more than legitimate question when deciding what to do when the pods exceed the date indicated on the package. Before answering, it is important to remember the difference between the expiration date and the minimum shelf life (MSL).

Do coffee pods have an expiration date? Difference between expiration date and minimum shelf life

According to Legislative Decree 27 January 1992, no. 109 and subsequent amendments, the minimum shelf life (MSL) is the date until which the food product retains its specific properties under appropriate storage conditions. It is determined by the producer or packager or, in the case of imported products, by the first seller established in the European Union, and it is affixed under their direct responsibility.(1)(2)

That is, the MSL only indicates until when the organoleptic, taste, or nutritional characteristics of the food are preserved. After this period, the food is still consumable, but the aforementioned characteristics are not guaranteed. In short, it refers solely to the organoleptic and taste characteristics of the product and not to safety.

Conversely, for pre-packaged products that are rapidly perishable from a microbiological point of view and can pose a health hazard after a short time, the minimum shelf life is replaced by the expiration date; it must be preceded by the phrase “to be consumed by” followed by the date itself or the mention of the point on the package where it appears. (1)(2)

Which of the Two Indications on Coffee Pods?

So, do coffee pods have an expiration date? Coffee pods usually have the minimum shelf life (MSL) indicated unless otherwise specified.

While the company has the freedom to choose the date of the minimum shelf life to be affixed, it is easy to find MSLs of 12-24 months from the production date within which the organoleptic and nutritional characteristics should be preserved.

But is it always like this? Scientific research comes to the rescue…

Do Coffee Pods Have an Expiration Date? The Tests

Despite the global importance of coffee products, unfortunately, there is still little data available on their shelf life and the evaluation methodologies used to determine it. (3)

To determine the shelf life of a product, one can identify the most critical chemical, physical, or biological event that leads to the depletion of the product’s quality and then find indicators that can identify the event.

The second step is to evaluate the changes in the selected quality indicators over time and under actual storage conditions to determine the reaction rate by applying a kinetic approach.

Numerous articles regarding this now recognized procedure have produced vast amounts of data on the rate of quality deterioration of various foods under different environmental conditions.

Although these studies have provided in-depth knowledge of the kinetics of food deterioration, these kinetics are not enough to determine shelf life. To convert kinetic data into shelf-life data, it is absolutely necessary to know the acceptability limit. (3)

At present, much of the composition of the substances present in coffee is still unknown. This is the main reason for the inadequate scientific knowledge about the causes and variables that affect the loss of product quality during storage.

Although coffee is believed to be a stable product, roasted coffee undergoes significant chemical and physical changes that greatly affect its quality and consumer acceptability. (3)

The main physical and chemical events involved in the formation of the stale (negative) flavor of roasted coffee during storage are the release of volatile compounds and carbon dioxide, the migration of oils to the surface, and oxidation reactions. (3)

A lower amount of carbon dioxide also results in less crema in the espresso created from coffee pods, and the lipids exposed to air become more prone to oxidation. The development of the typical stale flavor of aged coffee is the result of two different phenomena: the release of volatile substances and the development of aromas resulting from the oxidation of some of them.

No scientific research has been found regarding the shelf-life of coffee pods; however, experiments have shown that ground coffee contained in cans with inert gas and a residual oxygen percentage of 1-2% has a preservation period indicated before product alteration of 6-8 months. (3)

As previously written, the first important step in coffee shelf life tests is the identification of the chemical, physical, or biological event that most critically influences the product’s quality and the identification of the resulting indicators.

Scientific literature has often evaluated as indicators of oxidative reactions that lead to a change in the aromatic profile the concentration and quality of volatile compounds. Other indicators can be evaluated using a tasting panel.

Once the indicators are found, it is necessary to indicate the acceptability limit, that is, the limit beyond which a certain percentage of consumers reject the food. Since coffee-based products generally do not present safety risks, sensory evaluation is the key factor in determining the acceptance limit. However, the choice of scientists and companies for coffee acceptance limits is still independent of the actual consumer attitude to drink it or not. (3)

Shelf life evaluation, to be objective and real, must be based on sensory studies involving consumers.

According to industrial policy, the food company can choose more or less risk by selecting, as the acceptance limit, the appropriate percentage of consumers who reject the product. This powerful methodology has been applied only rarely to the evaluation of the shelf life of coffee-based products. (3)

Risk levels can be very low (10% rejection), low (25% rejection), medium (50% rejection), and high (75% rejection).

It might finally be useful, as has sometimes been done, to build mathematical models that can correlate the increase (or decrease) in the concentration of certain substances with the acceptability level of the product outlined by the tasting panel. In this way, it would be possible to obtain a better and more precise indication of the limit values of the substances and the consequent shelf life. However, laboratory conditions rarely manage to simulate real storage conditions (e.g., at home, at various seasonal temperatures) (3), so it would be desirable to also take into account the different factors that lead to a more rapid deterioration of the coffee material.

Conclusions

The law requires that the company set, at its own responsibility, the minimum shelf life date. It would be desirable for the protection of the company and the customer that this term be supported by tests properly conducted on the food, in order to always offer the highest quality.

Bibliography:

1- Legislative Decree 23 June 2003, no. 181
2- Legislative Decree 27 January 1992, no. 109
3- Nicoli M., Calligaris, S., Manzocco, L. (2009). ShelfLife Testing of Coffee and Related Products: Uncertainties, Pitfalls, and Perspectives. Food Engineering Reviews.