We often store food so that we can eat it later. However if food is kept for a long time before it is eaten, it may start to "go off". This may be because it is attacked by its own enzymes, oxidized by the air or decomposed by bacteria and fungi. Therefore food preservation is very important.
There are three main methods of preserving food. These are pasteurization and sterilization, refrigeration and freezing and drying. Heating foods and drinks that are sealed in tins or cartons, kills off organisms like bacteria. This process is called sterilization or pasteurization.…
