Canning : the impact on the shelf life of foods

Abstract

Since ancient times, food preservation has always been felt as a need. The purpose of preserving food has evolved throughout the years with the discovery of different methods and their improvement. Why is food preservation so important? Famines and shortages of food were a common picture before mankind mastered the science of preserving food. People needed to have food 'stored' when abundant to have it available when in shortage. Thus reducing the waste in favorable seasons and, if the food was correctly treated, minimizing food poisoning. But food spoilage occurred before the food was consumed. Therefore they needed to prolong the time period in which food could be consumed before spoiling; in simple words the priority became the extension of the shelf life. Canned foods have changed the lifestyle of different populations: from those of 18th century France to England later that century right up to modem times. The reason which led to the breakthrough of the canning process, was a need for nutritive food to be preserved for a long period of time and transported by the French armies to the front. Although different methods have been used since 2000 BC, canning is still the mostly used means of preserving food. Anyone who enters a modem supermarket cannot but notice that the majority of the foodstuffs are found on shelves as canned foods. Why? The needs of people have also changed. Does this show that canned food is the answer to the consumer's needs regarding food? How has canning influenced the preservation of food? Is it the most popular method among consumers? What advantages does this process offer? This dissertation will try to identify the answers to these questions giving evidence of the effect canning has produced on the preservation of food, that is, the extension of the shelf life of foods.