Pasteurization is a low-temperature disinfection method, which is generally carried out between 60- 100℃, and has a good disinfection effect on beverages such as milk and juice. The advantage of this disinfection method is that it can kill most bacteria and prolong the shelf life of food without destroying the original flavor and nutritional value of food. However, due to the low temperature of pasteurization, some bacteria with strong resistance may not be completely killed, so the shelf life is relatively short, generally not more than 7 days.
High-temperature sterilization is a kind of high-temperature short-time disinfection method, which is generally carried out above 120℃ and has good disinfection effect on various foods. Because of the high sterilization temperature, it can kill most bacteria and viruses in a short time, including some bacteria with strong resistance, so it has a stronger sterilization effect. In addition, high-temperature sterilization can also be carried out at room temperature, so that the original flavor and nutritional value of food can be maintained for a longer time. However, some harmful substances, such as protein denaturation, may be produced in the process of high-temperature sterilization.
When choosing pasteurization and high-temperature sterilization, it is necessary to comprehensively consider factors such as food types, storage time and use requirements. For some foods that need to retain their original flavor and nutritional value, such as milk and juice, pasteurization has more advantages; For some foods that need to be preserved at room temperature for a long time, such as canned food and meat, high temperature sterilization is more suitable. The specific choice of disinfection method needs to be decided according to the actual situation.
Difference between pasteurization and high temperature sterilization
1, the working principle is different: pasteurization is to heat the mixed raw materials to 68 ~ 70℃, and keep this temperature for 30min before rapidly cooling to 4 ~ 5℃. Ultra-high temperature sterilization is a sterilization process in which the heating temperature is set to 135- 150℃ and the heating time is 2-8s, and the heated product meets the commercial aseptic requirements.
2. Different storage time: after pasteurization, a small number of harmless or beneficial bacteria or bacterial spores with heat resistance are still retained, so pasteurized milk should be stored at about 4℃, and it can only be stored for 3~ 10 days, at most 16 days. After ultra-high temperature instantaneous sterilization, the product can be packaged in a sterile environment, which can effectively control the total amount of microorganisms in the product, greatly extend the shelf life of food, and preserve the nutrition and flavor of the product to the maximum extent because of the short sterilization duration.
3. Different equipment: the equipment used for pasteurization is a pasteurizer. The equipment used for high temperature sterilization is steam or heat exchanger.