The brief heating of liquid or pasty food to 75 to 100 ° C is called pasteurization if it is intended to preserve milk, fruit and vegetable juices, liquid egg and other foods.
Pasteurization is the brief heating of liquid or pasty foods. (Photo by: crewcut / Depositphotos.com)
The process was named after its inventor, the French biologist and chemist Louis Pasteur (1822 - 1895), who developed the method to make milk or fruit juices germ-free and therefore more durable.
Bacteria and fermentation-promoting mold and yeast are known as pathogenic microorganisms. These pathogenic microbes in a liquid food such as milk are destroyed by heating between 75 and 100 ° C, while at the same time vitamins, nutrients and flavors are largely retained.
In contrast to sterilization, the spores contained remain germinable. Therefore pasteurized foods have a limited shelf life.
Fish, crabs and crayfish tails pretreated with salt or roast are also pasteurized. These fish products can then be kept for at least 6 months.
Various pasteurization processes are permitted for milk products:
- Short-term heating 15-40 seconds to 71-74 ° C
- High temperature 10-15 seconds at 85 ° C
- Continuous heating for 30 minutes to 62-65 ° C
UHT milk is heated to an extremely high temperature of 135-150 ° C for at least 1 second. In the process, germs capable of reproduction are killed, but also valuable milk components are destroyed.