What is pasteurization and sterilization

Pasteurization, pasteurization

English: Pasteurization
French: Pasteurization
Italian: Pastorizzazione
Spanish: Pasteurizaci n

Table of Contents

The term Pasteurization is after the French chemist Louis Pasteur (1822-1895) named. Pasteurization is a process used to preserve mostly liquid foods. During pasteurization, food is briefly heated to a core temperature of below 100 ° C. The core temperature varies depending on the process and food, but never above 100 ° C. This process is used for foods where long heating (such as during sterilization) affects proteins, vitamins, minerals or the color.

Pasteurization kills most heat-sensitive microorganisms such as yeast or mold. However, a few germinable bacterial spores are still preserved. Pasteurized foods are therefore not aseptic, but only low in germs. They therefore only have a limited shelf life.

Pasteurization is used, for example, for milk, liquid eggs, pickled vegetables, fruit or fruit juices. Pasteurization is used for products that only have a short shelf life but are still more or less fresh should be or, in the case of acidic products, below a pH value of 4.5. Products with a pH value of 4.5 and lower also have a long shelf life, since they are then usually pickled. Incidentally, sterilization does not take longer than pasteurization, only the temperature is higher! The time-determining factor is the heat transfer in the product (convection - conduction). Beer is also pasteurized to kill the yeast.

Solid food pasteurization

There are only prescribed temperature specifications for pasteurizing milk. There are no fixed temperature specifications for the production of pickled preserves, for example. The food is mostly heated in open systems in which, for physical reasons, it cannot get hotter than 100 ° C.

Pasteurization of milk

When milk is pasteurized, not only undesirable microorganisms are killed, but also lactic acid bacteria, which help fresh milk to turn sour quickly. In addition, pasteurization makes milk easier to digest.

There are three types of milk pasteurization:

  • Continuous heating to 62 - 65 ° C for 30 minutes
  • Brief heating to 72 - 75 ° C for 15 to 30 seconds
  • High heating at 85 ° C for 4 to 10 seconds.

Summary and brief information

  • Fruit juice is produced through pasteurization