Usually, the milk in bags sold in the market is produced by pasteurization. Fresh milk is collected at the factory, processed at low temperature, and then pasteurized. Bags of milk produced in this way can usually be stored for longer periods of time.
A milk pasteurizer is a pasteurization method that uses heat below 100 degrees Celsius to kill microorganisms. The bioactive substances in fresh raw milk are very heat-resistant. If the pasteurization method at 100 degrees Celsius is used, the biologically active substances in the raw milk will be destroyed, and the vitamins and proteins in the raw milk will also be lost.
There are two main types of pasteurization methods commonly used in the world:
One is to heat the milk to 62~65°C and keep it for 30 minutes. By using the method, various growth-type pathogenic bacteria in milk can be killed, and the pasteurization efficiency can reach 97.3% to 99.9%. After disinfection, only some thermophilic bacteria, heat-resistant bacteria and spores are left, but most of these bacteria are lactic acid bacteria, which are not only harmless to the human body, but also beneficial to health.
The second method heats the milk to 75~90°C and holds it for 15~16 seconds. The pasteurization time is shorter and the work efficiency is higher. But the basic principle of pasteurization is that it kills pathogenic bacteria. If the temperature is too high, there will be more nutrient losses.