Cold storage: A cold storage is a commercial facility for storing perishable products such as fruits, vegetables, meat, fish etc. under controlled conditions for longer periods. Based on the storage conditions, cold storages may be classified into three categories:


i)                    Short-term or temporary storage

ii)                   Long-term storage, and

iii)                 Frozen storage


For short and long term storage, the product is cooled and stored at a temperature that is slightly above the freezing point. Depending upon the product, the storage temperature varies and in general it may lie anywhere between - 2oC to 16oC. Short-term or temporary storage is usually associated with retail establishments such as supermarkets, where rapid turnover of the product is normally expected. Depending upon the product the storage period may vary from 1 to 15 days. Long-term storage is usually associated with large-scale cold storages. The storage period again depends upon the type of product and also the condition of the product at which it is brought in to the cold storage. This period may be as short as 7 to 10 days for sensitive products such as ripe tomatoes and as long as 6 to 8 months for products such as onions and potatoes. Using frozen storage, most of the food products can be stored for considerably longer periods, sometimes as high as a few years. However, certain fresh products such as tomatoes cannot be stored under frozen conditions. The storage temperatures for frozen foods typically lie between 23oC to 12oC, with 18oC being the most frequently employed storage temperature.