Today, there are many kinds of procedures for the use of the PAP. "Low temperature long time" (LTLT) treatment is a batch process, and now only a small dairy plant used to produce some cheese products. "High temperature and short time" (HTST) treatment is a "flow" process, usually in the plate heat exchanger, is now widely used in the production of drinking milk. Products obtained by this way are not sterile, that is, there are still micro-organisms, and in the process of storage and processing need to be refrigerated. "Fast sterilization" is mainly used in the production of yogurt dairy products. At present, there are two kinds of international common high temperature sterilization method:
One is to heat the milk to 62~65 degrees Celsius, to maintain 30 minutes. Using this method, can kill milk in a variety of pattern of growth of pathogenic bacteria, sterilization efficiency can reach 97.3%~99.9%, after disinfection residual is only part of the thermophilic bacteria and heat-resistant bacteria and Bacillus etc., but these bacteria most is lactic acid bacteria, lactic acid bacteria not only harmless to people but is good for your health.
Second ways to heat the milk to 75~90 degrees, heat preservation 15~16 seconds, the sterilization time is shorter, the work efficiency is higher. But the basic principle of sterilization is that the pathogen can be killed, the temperature is too high, but there will be more nutritional losses
