There are various techniques for preserving foods so that they do not spoil, lose their nutritional value, or undergo any kind of alteration.
The main ones are: boil, cooling / freeze and dehydration.
Cooked foods last longer than raw foods, because boiling kills the microorganisms contained in the food. High heat conservation is widely used by industries, eg pasteurization.
Cooling and freezing
To cool the food normally the refrigerator Or the fridge, where foods are subjected to low temperatures, but above 0 ° C. This process saves them for a few days, varying the timeframe from one food to another.
Freezing occurs at temperatures below 0 ° C. In the freezer or freezer, foods are commonly subjected to between -10 ° C and -30 ° C. Frozen foods, because of the difference in temperature, are stored longer than just chilled foods.
Low temperatures present unfavorable environmental conditions. That hinders the development of the microorganisms responsible for decomposition, ie by rotting food.
Traditional processes of dehydration
Although there are currently advanced technologies employed for food preservation, we will cite some traditional processes that can be carried out on a large industrial scale as well as in small artisanal productions. They are: smoking, salting and isolation.
THE smoking It is commonly used for the conservation of fish, meat and sausages. In this process the food is dried using smoke.
O salting It is the simplest way to preserve beef, pork and fish. An alternative is to salt it and dry it in the sun. Cod and jerky or beef jerky, well known in our cuisine, are preserved in this way.
O isolation It is another way of preserving food. This technique consists of keeping the food in the vacuum package from which the air is removed. This contributes to the preservation of food for a long time, since microorganisms do not survive the lack of oxygen, which is necessary for the life of many of them.
Hermetically sealed jars also help in food preservation.
Additives and other preservation techniques
In the food industry, it is still very common to use additives, which are substances added to foods to conserve, sweeten, enhance flavor, color and aroma.
The dyesFor example, they are widely used in candy and soft drinks.