Knowledge Summary of Pasteurization Machine (Part 1)

Within a certain temperature range, the lower the temperature, the slower the bacterial reproduction; the higher the temperature, the faster the reproduction. But if the temperature is too high, the bacteria will die. Different bacteria have different optimal growth temperatures and heat and cold resistance. Pasteurization sterilize machine is to use the characteristics of pathogens are not very heat-resistant, with appropriate temperature and holding time treatment to kill them all. However, after the sterilization machine, a small part of harmless or beneficial, heat-resistant bacteria or bacterial spores are still retained.

The pasteurization method originated from Pasteur's efforts to resolve the acidity of beer after brewing. At that time, the French brewing industry was faced with a headache, that is, beer will become sour after brewing, and it is impossible to drink. Moreover, this acidification phenomenon often occurs. Pasteur was invited to study this issue. After a long period of observation, he discovered that the culprit that made the beer sour was Lactobacillus. Nutritious beer is simply a paradise for the growth of Lactobacillus. A simple method of boiling can kill Lactobacillus, but then the beer will be boiled. Pasteur tried to use different temperatures to kill Lactobacillus without destroying the beer itself. Finally, Pasteur ’s research results are: heating beer at a temperature of 50 to 60 degrees Celsius for half an hour can kill the Lactobacillus and spores in the beer without boiling. This method saved the French wine industry. This sterilization method is also called the "pasteurization method".

Pasteurization Sterilize Machine

Principle of sterilization:

Pasteurized milk should be stored at a temperature of about 4 ° C, and can only be stored for 3 to 10 days, up to 16 days.

Sterilization method:

There are many types of pasteurization procedures in use today. The "low-temperature long time" (LTLT) process is a batch process that is now only used by small dairy plants to produce some cheese products. The "High-Temperature Short Time" (HTST) process is a "flow" process, usually performed in a plate heat exchanger, and is now widely used in the production of drinking milk. The product obtained in this way is not sterile, ie it still contains microorganisms, and needs to be refrigerated during storage and handling. "Quick pasteurization" is mainly used in the production of yogurt and dairy products. There are two main types of pasteurization in the world:

One is to heat the milk to 62 ~ 65 ℃ for 30 minutes. Using this method, it can kill all kinds of growth pathogenic bacteria in milk. The sterilization efficiency can reach 97.3% ~ 99.9%. After disinfection, only some thermophilic bacteria, heat-resistant bacteria, and spores remain, but most of the bacteria are lactic acid bacteria, which are not only harmless to humans but also beneficial to health.

The second method heats the milk to 75 ~ 90 ℃ and keeps it warm for 15 ~ 16 seconds. The sterilization time is shorter and the working efficiency is higher. But the basic principle of sterilization is that it can kill the pathogenic bacteria. If the temperature is too high, there will be more nutrient loss.