Eating expired food: Can cooking make it safe? Doctor explains what happens to meat, fish and paneer

What does an expiry or use-by date mean?

An expiry or use-by date indicates the period during which a food product is expected to remain safe and suitable for consumption when it is stored as recommended. In some packaged foods, preservatives help slow the growth of bacteria, yeast and mould and extend shelf life. However, their effectiveness is not indefinite. Over time, changes in the food, packaging or storage conditions can increase the possibility of microbial growth or deterioration, even when the product appears properly packaged.

The date, therefore, provides an important safety window rather than suggesting that food suddenly becomes unsafe the day after it expires.

What can happen after consuming expired food?

The risk depends on the type of food, how it has been stored and how far beyond its recommended date it has been consumed. Highly perishable foods such as meat, fish and paneer can support the growth of harmful microorganisms if they are stored for too long or at unsuitable temperatures.

The risk and severity of illness can vary from person to person and depend on the nature and amount of contamination.

Does cooking expired food make it safe?

Cooking can destroy many bacteria and other microorganisms when the food is heated adequately. However, it cannot always make spoiled or contaminated food safe. Certain microorganisms can produce toxins that may remain in the food even after heating. Some bacteria can form spores that are much more resistant to heat than ordinary bacterial cells. Besides, even properly cooked food can become contaminated again if it comes into contact with raw meat, contaminated utensils, surfaces or hands. Cooking does not reverse deterioration that has already occurred or make food safe indefinitely.

This is why cooking should not be considered a way of extending the safe life of food beyond its recommended date.

What about meat, fish and paneer?

These foods are particularly sensitive because they contain nutrients and moisture that can support microbial growth. Fish and meat may deteriorate quickly when refrigeration is inadequate, while paneer can also develop bacterial contamination when kept beyond its recommended storage period.

Changes in smell, colour, texture or appearance can indicate deterioration, although unsafe food does not always show obvious signs of spoilage.

What about canned and preserved foods?

Canning and preservation significantly extend the shelf life of food by controlling microbial growth and protecting the product from contamination. However, the process does not make food permanently safe. Damaged, leaking, swollen or severely dented cans should not be consumed, particularly when their integrity has been compromised.

Under certain conditions, harmful bacteria can grow in improperly preserved foods and produce toxins that may cause serious foodborne illness.

Food should ideally be consumed within the recommended period and stored according to the instructions on the package.