Principle of pasteurization device:

The principle of sterilization is that within a certain temperature range, the lower the temperature, the slower the reproduction of bacteria; the higher the temperature, the faster the reproduction. But if the temperature is too high, the bacteria will die. Different bacteria have different suitable growth temperatures and heat and cold resistance. Pasteurization is actually the application of pathogens that are not very heat-resistant, and dispose of them with appropriate temperature and holding time to kill them all. However, after pasteurization, small local harmless or beneficial, heat-resistant bacteria or bacterial spores are still stored.

A wide variety of pasteurization procedures are used today. "LTLT" disposal is an intermittent process and is often used only by small dairy plants to consume some cheese products. "High temperature short time" (HTST) treatment is an "active" process, usually stopped in a plate heat exchanger, and is commonly used for milk consumption. The products obtained through this method are not sterile, that is, they still contain microorganisms, and need to be refrigerated during storage and disposal. "Fast pasteurization" is mainly used in the consumption of yogurt and dairy products.

There are two main types of pasteurization methods used internationally:

One is to heat the milk to 62 ~ 65 ° C and hold it for 30 minutes. This method can kill various growth-type pathogens in milk, and the sterilization efficiency can reach 97.3% ~ 99.9%. After disinfection, only the local thermophilic bacteria and heat-resistant bacteria and spores are left, but these Most of the bacteria are lactic acid bacteria, which are not only harmless to humans, but also beneficial to health.

Another method is to heat the milk to 75 ~ 90 ° C and keep it for 15 ~ 16 seconds. The sterilization time is shorter and the work efficiency is higher. However, the basic criterion for sterilization is that it can kill pathogenic bacteria. If the temperature is too high, there will be more nutrition loss.