WHY DOESN'T FROZEN FOOD GET SPOILED?

FROZEN FOOD -

Have you ever wondered why we store perishable foodstuff in the freezer compartment of our fridge? It is because frozen food does not decompose for a long time and can be preserved for many months. There is an interesting fact about the discovery of the method of preserving food through low temperatures. In 1798, some explorers from Norway camped at the mouth of the river Lena in Northern Siberia. All of a sudden their dogs started barking aloud. When the explorers came out, they found the dogs digging in the snow. As they dug deeper they found the huge body of a dead mammoth. The flesh was dry. The explorers then hacked off a piece and cooked it. They found that it tasted like fresh meat. The last mammoths had died out about 30,000 years ago. This was a dramatic discovery. It meant that food could be preserved over such long periods. Since then, the man started preserving food at low temperatures.

What keeps food from getting spoiled at low temperatures? Food materials decompose because of the microscopic organisms called bacteria. At normal temperatures, bacteria flourish and multiply very fast and decompose the food. But at low temperatures, especially when the water present in the food material is frozen, the bacteria become inactive and stop growing. And thus, the frozen food can be preserved for a long time.

Nowadays, several techniques are being employed to preserve food materials. Among the important ones are the cold storage and freezing of foodstuffs. For the cold storage, many factors are to be kept in the mind. The type of food, the storage temperature and the amount of moisture in the storage room have to be taken into consideration. Cold storage temperatures range from 1Deg.C to 10 Deg.C. Freezing, however, is accomplished with dry ice (solid carbon dioxide), liquid air or nitrogen. Although freezing does not destroy the nutritive value of foods, some vitamins may be lost.

Domestic refrigerators are now widely used for food preservation. But, in a refrigerator, we can't preserve food for a long period. By using low-temperature techniques, great quantities of ice cream, frozen meat, fish, fruit, and vegetables are imported and exported throughout the world every year.