Nowadays, the use of pasteurization machines is becoming increasingly widespread. Pasteurization machines are a sterilization method for milk, which can kill harmful pathogens to health and minimize changes in milk quality. That is to say, based on the principle of the difference between the heat death curve of tuberculosis bacteria with strong heat resistance and the heat damage curve of cream separation that is easily affected by heat in milk, a method of heating treatment is carried out for a long time at low temperature or a short time at high temperature. Among them, heating below 60 ℃ for 30 minutes has long been widely adopted as the standard for low-temperature sterilization worldwide. By using high-temperature treatment, although it may have some impact on the quality of the milk, it can enhance the sterilization effect. This method is called high-temperature sterilization, which means heating at 95 ℃ or above for 20 minutes. The pasteurization method can also be applied to fermented products in addition to milk.
        Usually, bagged milk sold in the market is produced using the pasteurization method. The factory collects fresh milk, which is first subjected to low-temperature treatment and then sterilized using pasteurization. Bagged milk produced using this method can usually be stored for a longer period of time. Of course, the specific processing and techniques are much more complex, but that's the overall principle.
        It should be pointed out that drinking fresh milk (referring to freshly squeezed milk) is actually unsafe because it may contain harmful bacteria to our body. Another point is that pasteurization is not omnipotent, and milk treated with pasteurization still needs to be stored at a lower temperature (generally<4 ℃), otherwise there is still a possibility of spoilage. Therefore, many methods of selling bagged milk in the market are very non-standard.
Pasteurized milk is the most commonly consumed milk variety in the world. In countries such as the UK, Australia, the US, and Canada, the consumption of pasteurized milk accounts for over 80% of liquid milk. The varieties include fully skimmed, semi skimmed, or full fat. In the US market, almost all of it is actually pasteurized milk, and it comes in large packages (1 liter, 2 liters, 1 gallon). Citizens can buy enough fresh milk to drink for a week at supermarkets once. There are few sterilized pure milk products sold in the market, and some small towns simply cannot buy them.
          Pasteurized pure fresh milk preserves the nutrition and natural flavor of milk well, making it a good choice among all milk varieties. In fact, as long as pasteurized milk is stored at a temperature of around 4 ℃, the reproduction of bacteria is very slow, and the nutrition and flavor of milk can remain unchanged for a few days.
        At present, pasteurization machines are mainly used for commercial purposes in the market, and pasteurization is also an internationally recognized sterilization standard used by many large enterprises. Pure milk and other flavors of yogurt on the market are now pasteurized. With the development of green and healthy food, pasteurization machines are now used in many small dairy farms. Small dairy farms use 100 or 200 liters, mainly to produce fresh pure milk and distribute it to the market.
          The current pasteurizer is equipped with a cold water circulation system, and there are usually two types of refrigeration methods. One is compressor refrigeration, which is fast and effective. The other is cold water circulation refrigeration, which mainly uses logistics cooling to reduce costs.