Food Preservation


Food preservation is a set of procedures and resources to prepare and package food products in order to store them and consume them long after.

The substances that constitute food are altered with certain rapidity. Said alteration is caused by the microbes that use their nutritional elements for their development, which causes their decomposition. The alteration of food is also due to the action of enzymes, chemical compounds that speed up the speed of reactions.

The main objective of food preservation is to prevent or delay the damage caused by microbes, and therefore their harmful effect on the food. For this, it is necessary to apply an adequate treatment; Foods subjected to this treatment are called food preserves.

The following are the conservation techniques most used today:

• Freezing: it consists of subjecting the food to temperatures between 0ºC and -4ºC, in order to eliminate the heat; This method makes it possible to temporarily stop the development of microorganisms and decreases the speed at which the enzymes act.
• Refrigeration: it is characterized by storing food at a temperature of 5 ºC or less; It is used to keep food fresh and preserve it for some time.
• Drying or dehydration: it can be natural or artificial. With this method, microorganisms do not develop and enzymes do not exert their action in dry foods. In the natural drying the Sun intervenes, it can be used in fruits (raisins), grains, legumes. Today they can be dried using ovens, tunnels or drying drums.

• Salting and smoking: by adding salt to food, it releases its water, and bacterial and enzymatic activity is slowed down. When food is subjected to wood smoke (beech, cradle, birch), a series of chemical substances with great sterilizing power are originated and that, in addition, give a typical aroma and flavor to food.
• Canning: consists of sterilizing the food and the container. The containers can be made of glass, tin, aluminum and cardboard. Before being packaged, the food is cooked and cleaned. Different temperatures and times are used in cooking depending on whether it is meat, fish or fruit.
• Pickled: used on cabbage, cucumber, cauliflower, grains, olives, etc. The foodstuffs are salted and then preserved in vinegar, with or without spices. This technique includes curing, includes smoking, salting and marinating in brine or vinegar, the first two are used in red meat.
• Sugar concentrate: it consists of adding sugar to fruit and/or plant preparations. High concentrations prevent the proliferation of microorganisms, except for some fungi. To stop their growth, oxygen is removed from the containers by covering the surface with paraffin or paraffin. vacuum sealed containers.
• Chemical additives: are non-nutritive substances intentionally added to food in small amounts to improve appearance, flavor, consistency or preservation properties. The most used for food preservation are sodium benzoate, acetic acid, sodium citrate, sulfur and sodium nitrite.
• Other modern methods: some radiation, such as X-rays, ultraviolet light, etc., are forms of energy that affect living matter, and seriously affect it, leaving food free of microorganisms, and preserving it for long periods.