How the pasteurizer works
There are a wide variety of pasteurization procedures in use today. The Low Temperature Long Time (LTLT) process is a batch process that is now used only by small dairy plants to produce some cheese products. The "High Temperature Short Time" (HTST) process is a "flowing" process, usually carried out in plate heat exchangers, and is now widely used in the production of drinking milk. The product obtained in this way is not sterile, i.e. still contains microorganisms, and requires refrigeration during storage and handling. "Quick pasteurization" is mainly used in the production of yogurt dairy products. At present, there are two main types of pasteurization methods commonly used in the world:
One is to heat the milk to 62~65 °C for 30 minutes. Using this method, it can kill various growth-type pathogenic bacteria in milk, and the sterilization efficiency can reach 97.3%~99.9%. After disinfection, only some thermophilic bacteria and heat-resistant bacteria and spores remain, but these Most of the bacteria are lactic acid bacteria, which are not only harmless to humans but also good for health.
The second method heats the milk to 75~90 °C and keeps it for 15~16 seconds. The sterilization time is shorter and the work efficiency is higher. However, the basic principle of sterilization is that the pathogen can be killed, and the temperature is too high, but there will be more nutrient loss.