Sterilization, pasteurization and ultra-pasteurization are the processes of thermal processing of products. With their help, they extend the shelf life and destroy pathogens, possibly found in food.
Ultrapaterization, pasteurization and sterilization are technological processes designed to rid food of the presence of pathogens, as well as to extend the shelf life as much as possible. During processing, the products are heated to varying degrees.
What is called "food sterilization"?
Very often dairy products are cooked. In this case, the milk is heated to a temperature of 120-150jC for 30 minutes. Such an effect destroys all microorganisms present in milk.
Unfortunately, along with pathogens, beneficial lactic acid bacteria also die. Therefore, sterilized milk is not suitable for the preparation of sour milk and other lactic acid products. When sterilized milk turns sour, it takes on a pronounced bitter taste. The nutritional value of the product is also quite low. But sterilized milk can be stored for a year.
What is pasteurization?
During pasteurization, a gentle temperature regime is used. The milk is heated to 65jC for 30 minutes or for 15-40 seconds at a temperature of 75jC. If a temperature setting of 85jC is used, the processing time is reduced to 8-10 seconds. Such treatment destroys pathogenic bacteria, but practically does not affect the vital activity of heat-resistant lactic acid bacteria. Modern pasteurization destroys up to 98% of pathogenic microorganisms.
The shelf life of pasteurized milk does not exceed 2 weeks, after which it turns sour. Such a product retains most of the nutrients and can be used to prepare a fermented milk assortment.
Today, ultra-pasteurization is often used for heat treatment, a process during which milk is heated for 3-4 seconds at a temperature of 135oC. Then, the milk is gradually cooled down to 4-5jC and poured into sterilized packaging. The shelf life of milk in this case is 2 months.
Prolonged boiling destroys almost all vitamins, including vitamin C. However, it is advisable not to consume raw milk that has not been pretreated. If milk is not intended for long-term storage, it is better to purchase products that have undergone pasteurization and ultra-pasteurization.
