Spoilage of foodstuffs is caused by microorganisms which decompose them to produce acid, alcohol, etc. Bacteria are always present in the atmosphere. When freshly prepared food is kept in the open for long periods it gets contaminated. The bacteria then act upon the foodcomponents such as proteins, carbohydrates and fats and break them down to products which due to their off-odours or bad-taste are not suitable for consumption. Factors such as high temperature and humidity help the bacteria to grow.
Spoilage of food can be prevented by treatments like heat sterilization, refrigeration, deep-freezing and desiccation.
