There are various types of pasteurization procedures used today. “ Low temperature for a long time; LTLT processing is an intermittent process that is now only used by small dairy factories to produce some cheese products. “ High temperature for a short period of time; (HTST) processing is a“ Flow” The process, usually carried out in plate heat exchangers, is now widely used in the production of drinking milk. The products obtained through this method are not sterile, meaning they still contain microorganisms and require refrigeration during storage and processing. “ Rapid Pasteurization; Mainly used in the production of yogurt and dairy products. There are currently two commonly used pasteurization methods internationally:
One method is to heat the milk to 62-65 ℃ and maintain it for 30 minutes. By using this method, various growth pathogenic bacteria in milk can be killed, and the sterilization efficiency can reach 97.3%~99.9%. After disinfection, only some thermophilic bacteria, heat-resistant bacteria, and spores remain, but most of these bacteria are lactic acid bacteria. Lactic acid bacteria are not only harmless to humans but also beneficial to health.
The second method is to heat milk to 75-90 ℃ and keep it warm for 15-16 seconds, which results in shorter sterilization time and higher work efficiency. But the basic principle of sterilization is to kill the pathogenic bacteria, as high temperatures can actually result in significant nutrient loss