Factors which damage the food materials during storage:
(a) Abiotic factors :
1. Temperature. If food is stored at lower temperature, then enzymes, insects and the other micro-organisms, which spoil the food, become less active. The damage to the stored food is decreased.
2. Moisture. For safe storage of food grains, it is essential that the moisture in the food grains should not be more than 14% by weight.
3. Humidity. Growth of moulds and fungi in food grains takes place due to humidity of air.
4. Material of the container. Food grains should not be stored in lead container, because lead is a toxic metal.
(b) Biotic factors :
1. Rodents, birds and animals.
2. Insects and micro-organisms. Micro organisms like fungi, bacteria, yeast, moulds etc. greatly damage the stored food.
3. Enzymes. Enzymes are biocatalysts. They are found in living cells. They spoil vegetable, fruits, meat, fish etc. When stored for an appreciable period. Moreover enzymes over-ripen the food which results in their spoilage.