The power of tempera­ture in shelf life

With summer temperatures increasingly reaching extreme highs, we’re being confronted with a simple truth: temperature is a key factor in the shelf life of food. Even minor temperature fluctuations can have a major impact on both the quality and safety of products. When food spoils, we throw it away. Wasting food harms the environment and our wallets. But constant refrigeration isn’t cheap either…

To determine whether products are still safe to consume, and for how long, shelf life tests are carried out, often in real time. Products are stored under what are considered ‘normal storage conditions’ and periodically checked for spoilage and quality loss. But that raises the question: what exactly counts as ‘normal’ conditions?

After production and in retail, refrigeration typically means cooling to 4°C. That sounds careful enough. But the moment a product leaves the store, that temperature changes. On the way home, the temperature of a steak or salmon fillet can easily rise to 15°C before it’s put back in the fridge. And the average household fridge is rarely set to 4°C. It’s usually closer to 8 or 9°C. So is it even feasible to keep food at 4°C throughout the entire journey from production to consumption? And is that 4°C, used as the standard in most shelf life tests, actually a realistic assumption?

There’s also plenty of confusion about the ‘best before’ and ‘use by’ dates. Most consumers barely know what they mean. Meanwhile, we’re still using terms like ‘TGT’ and ‘THT,’ even though you and I both know those abbreviations are no longer permitted, but that’s another story. The point is, it’s not just the meaning of these dates that’s unclear. The way they’re determined, written, and positioned on packaging adds to the confusion. What doesn’t help either is that the rules for shelf life testing within the EU vary from country to country. In France, for example, a temperature shock test is required, where products are exposed to rapid and extreme changes in temperature. Maybe it’s time for the Netherlands to take a more critical look at this as well?

Karina Marsilje
Commercial Director, Nutrilab