Storage of food requires as much care as its purchase in the market if the goals of nutrition, maintenance of quality, wholesomeness and economy are to be achieved. If foodstuffs are carelessly stored they will deteriorate and there will be wastage through withering, discoloration, mould and decay. Foods also lose their natural flavor, attractive appearance and vitamin content. Sometimes there can be a complete loss due to poor storage.
Storage at room temperature
Dry foods such as cereals, flours, pulses, non-fat dry milk, sugar, spices have a long life at room temperature. The containers in which they are kept should be tightly closed. Canned foods retain higher levels of Vitamin C and thiamine if they are stored in cool temperature.
Vegetables like potatoes, sweet potatoes, onions, carrots, beetroots, turnips are kept well in the dark, at room temperature; but in houses where room temperature is 21°C or more, only a week’s supply should be purchased at one time.
Bananas and unripe tomatoes should be ripened at room temperature. Citrus fruits can be kept at room temperature for a few days only.
A refrigerator is not intended as a place in which foods can be stored for long periods. Its temperature should be approximately 4-5°C (about 40°F). In the freezer compartment the temperature is around 0°-5° C (about 20°F) and packets of frozen foods will keep for about three days.
Refrigerators should not be over packed; there should be some space for circulating air. Hot foods should not be kept in a refrigerator as they raise the temperature. Covered containers and polythene bags reduce drying of the food. Refrigerators need to be defrosted regularly and cleaned before being started again.
Deep freezing is storage at very low temperatures. In deep freezers the temperature is about -22° to -25° C, far below the freezing point of water. Such cabinets may be used to store perishable foods up to a year, provided the food is frozen quickly and that it is not allowed to thaw and refreeze before its final use.
Deep freezing has been widely used commercially to preserve and sell fruits, vegetables and other processed foods when they are out of season.
Highly perishable protein foods should be stored in the coldest part of the refrigerator. Minced meat, meat of special parts like liver, kidney and fish should be used within 24 hours, while larger pieces of meat will keep for several days.
Milk should be stored in bottles in which it is delivered. Keep the bottles tightly covered. Milk received in vessels should be boiled, cooled, covered and then stored in the refrigerator. It should be used within 1 or 2 days in winter. In summer it does not stay for more than one day: The milk should never be kept near foods with a strong smell such as onions, as it easily absorbs odours. New milk should never be mixed with the old since the bacteria in the old milk will infect the new also.
Eggs can be stored by keeping them chilled. For storing them in a refrigerator they should not be washed as the protective dull coat known as ‘bloom’ is lost by washing and odours and flavors enter the egg through the porous shell. The other method is by keeping the eggs in a mixture of lime and water or in a brine solution. This will prevent the loss of water and the admission of air by stopping up the pores in the shell.
Soft cheese deteriorates rapidly and should be stored for short periods only. It should be used within 1-2 days. Hard cheese should be wrapped in plastics or foil excluding as much air as possible.
Butter, like other milk products also absorbs odours easily. So it should not be kept unwrapped in the refrigerator. It should be stored at the coldest part of it, as otherwise it might melt and also become rancid.
Fruits and Vegetables are best kept by placing them in the hydrator. Berries and plums are especially perishable and should not be washed until just before use.
Frozen foods can be kept for varying periods of time at 0° C, but should be used within a week of storage. Foods are of the best quality if they are used soon after being stored. Maximum storage time for many foods is indicated in the table.
It is always good to mark the date of purchase of food. Keep on checking for spoilage and use it before it becomes unfit for consumption. Always keep the storage place clean and dry.