Milk is a highly perishable food that can be stored and distributed without deterioration and does not pose a health hazard due to the growth of pathogenic bacteria. Therefore, the Milk Production Line is heat treated. In many parts of the world, the most common type of heat treatment is pasteurization, which is carried out at a temperature of at least 72 ° C for 15 seconds. This is the minimum heat treatment required to destroy most pathogenic microorganisms and is the minimum heat treatment required to destroy most spoilage organisms. However, after pasteurization and packaging, a small amount of bacteria still exists and grows during storage. This growth is very slow at low temperatures, so pasteurized milk is always refrigerated. Even in cold storage, pasteurized milk can only be stored for about two weeks.
One way to extend the shelf life of milk is to heat the milk to a temperature sufficient to destroy almost all microorganisms and store it in a sealed container without contamination by bacteria. There are two ways to do this: in-container sterilization and ultra-high temperature (UTT) treatment. Both produce a "commercially sterile" product, which means that the milk contains no microorganisms which can be grown under normal storage conditions, in which case the storage conditions are room temperature 2,3.
In-tank sterilization using canned technology is a batch operation involving heating the final milk container at 110 - 120 °C for 10-20 minutes in an autoclave. In contrast, ultra high temperature processing involves heating the milk at a temperature of about 140 ° C for a very short period of time - about 5 seconds in a continuous flow system.
Although the two methods have the same microbial effect, their chemical effects on milk components are quite different. Sterilized milk in containers usually has a noticeable ripeness and a slight brown color. On the other hand, ultra-high temperature milk tastes much worse, and brown discoloration is rare, if any. The difference in the quality of these two sterilized milk products is the main driving force behind the production of shelf-stable products for UHT Milk Machine. However, the main driver of its commercialization and widespread adoption is the development of aseptic packaging, in which sterile milk is packaged as sterile packaging and sealed.
