Food in the UK has to have either a best before or a use buy date on it. Use buy dates however determine the date by which a food is safe to eat. They are determined by strict food development techniques and the use by date is influenced by the type of food it is, what is in it and the way it is packaged for sale. How quickly food deteriorates depends on how quickly microbes will grow, the temperature, availability of oxygen and water. Things such as salt, sugar and vinegar all affect a foods shelf life. These are all tested to make sure that a use by dates are accurate and that food is safe for consumers to eat.
Unlike best before dates, a use by date means that after the date on the label food should not be eaten as it would not be considered safe as bacteria such as campylobacter may begin to grow and these foods may constitute an immediate danger to human health. This is very important on fresh foods such as meat, fish and salads. In order for the use by date to be valid all food must be stored in the correct way. Food which is beyond its use by date in accordance with article 14(2) of regulation EC no 178/2002 should not be sold, consumed or further stored in any way, for example by freezing.
It is interesting that there is some debate about if people will eat food after its use by date despite the advice. Most people seem to heed the advice when it concerns fresh meats such as chicken, however foods that contain high sugar levels, vinegar, hard cheese or dried food are much more likely to be eaten after their use by dates as perhaps consumers see less risk of food poisoning.
With food waste an increasing issue, and bearing in mind the advice regarding use by dates, would a clearer system for consumers regarding when we should or should not eat food be better and more understandable. Is having a use by on some foods and a best before on others confusing, and how do consumers actually use this information? What sort of labels would you like to see on foods?