The conservation cold is one of the most used in a day-to-day population. Frozen are becoming increasingly frequent in the Brazilian table, and domestic cooling is the main weapon of the population against food spoilage and consequent waste.
While the Heat conservation work with the death of microorganisms and inactivation of enzymes, preservation by a cold factor is that we control microbial proliferation and chemical reactions, such as enzymatic reactions.
We know that there are microorganisms that may be present in food tolerable counts. This means that, depending on the type of food and the type of microorganism, can consume it with certain microbiological load without damage to the quality of the food and, consequently, to our health.
All microorganisms have optimal temperatures for growth and reproduction. Therefore, the basic principle of the cold storage is to keep the temperature below the optimum for microbial growth and proliferation. Similarly, form chemical reactions occur at optimal temperatures, so the principle to minimize them is the same, keeping the temperature below optimum.
There are two types of conservation cold: refrigeration and freezing. Each being adapted to the type of food and the conservation of time they want to reach.
So foods are chilled necessary to keep them at temperatures between 0˚C and 7C. In this case, the impact on the nutritional and sensory properties are milder, with these temperatures, however, able to achieve lower storage times.
For freezing to be efficient, we need to -18C temperatures or lower. There are microorganisms that grow even at temperatures of -10˚C that carries a danger to evil monitored freezing. We know however that under -18C or lower temperature there is total inhibition of microorganisms.