As we all know, there are currently two main liquid milk processing technologies: pasteurization and UHT flash sterilization. The corresponding dairy products are pasteurized milk and UHT milk (often called room temperature milk).
Pasteurization was the first method born, usually a heat treatment at 63-66°C for 30 minutes or at 72-75°C for 15-20 seconds. However, due to the low sterilization temperature and relatively comprehensive nutrition, pasteurization cannot completely kill microorganisms in raw milk. These microorganisms will multiply as the temperature rises. Therefore, the pasteurized milk in the pasteurized milk production line needs to be transported from the production line to sales, sales and storage, refrigerated in a low temperature environment of about 2-4 ° C, and the shelf life is relatively short, only 3-7 days, so the milk source It is far away from the market, and there are certain requirements in the end, so it is difficult to expand the scope of sales.
It's worth noting that ultra-pasteurized milk is not canned aseptically, nor does it meet commercial sterility standards. Therefore, it must be kept at low temperatures during storage and distribution to maintain a similar taste to pasteurized milk.5.