Shelf life of food: what it means, how it’s calculated, and how to extend it

Over time, all foods undergo changes, whether in taste, smell, texture, or color—factors that contribute to the consumer's perception of quality. Yet, food quality is not just sensory; it’s also about safety.

To better understand, we can distinguish between two phases of shelf life:

Primary shelf life, the period during which a sealed product retains its sensory and nutritional characteristics, making it acceptable for consumption.

Secondary shelf life, which begins once the package is opened. At this stage, the food is more exposed to environmental factors and must be consumed quickly to avoid risks.

Thus, determining shelf life isn’t just about ensuring the product looks good; it’s also about preserving its hygienic and sanitary safety.

Calculating a food product's shelf life is an essential step for companies producing and packaging food items. It’s a responsibility that requires a thorough understanding of the product’s chemical, physical, and microbiological characteristics.

To begin, the producer gathers key information about the product:

Ingredient composition

Chemical-physical properties, such as pH and water activity (aw)

Thermal treatments or preservation methods applied during production

Packaging type and material

With this information, shelf-life tests are conducted, including microbiological, chemical-physical, and sensory analyses. These tests identify the mechanisms that lead to product deterioration and estimate the time during which the product remains safe and of acceptable quality.

For example:

Microbiological analyses check for pathogenic microorganisms and ensure compliance with European Regulation EC 2073/2005.

Chemical-physical tests measure parameters like pH and free water content, key factors influencing the rate of deterioration.

Organoleptic tests assess taste, smell, color, and texture to understand how the product’s perception changes over time.

In some cases, stress tests are performed, simulating extreme storage or transportation conditions to assess the product and its packaging's resilience.

Extending a product's shelf life is a challenge that requires addressing various aspects of production and storage processes. There’s no one-size-fits-all formula, as each product has unique needs. However, certain techniques are particularly effective:

Physical Treatments

Common methods include freezing, pasteurization, and freeze-drying. Lowering the temperature or removing water slows down microbial spoilage.

Chemical Treatments

The addition of natural preservatives, such as antioxidants, or processes like smoking can inhibit bacterial growth and extend the product's useful life.

Advanced Packaging Technologies

Vacuum packaging or modified atmosphere packaging reduces exposure to oxygen and moisture, factors that accelerate spoilage.

Optimizing production processes is essential: high-quality ingredients, proper manufacturing practices, and effective packaging are the pillars of a long shelf life.

Once shelf life is determined, it must be indicated on the label, as required by EU Regulation 1169/2011. The information can be expressed in two main ways:

• Best Before Date: Used for stable products like pasta, cookies, or preserves. It is indicated with the phrase "best before...". After this date, the product is still safe to consume but may have lost some of its sensory qualities.
• Use By Date: Mandatory for fresh or perishable foods, like dairy or meat. It is marked with "use by...", a strict deadline after which the product may pose health risks.

Clear and precise labeling is not only a regulatory requirement but also an important guarantee for consumers, enabling them to make informed choices.

Shelf life is much more than a number on a label; it’s the result of meticulous research and analysis that combines science and innovation to ensure food is safe and high-quality.

Extending a product’s shelf life requires knowledge, technology, and attention to detail. On our blog, we’ll continue to explore how Tenco solutions can support food companies in this process, offering advanced tools for food packaging and preservation.

If you found this deep dive interesting, stay tuned for more insights on innovative technologies and approaches that can make a difference in your industry!