Sterilization and Ultra High Temperature Processing

We know milk is a highly perishable commodity. Its myriad nutrients makes it extremely favourable medium for the growth of microorganisms. It is, therefore,essential that milk is subjected to certain processing treatments for enhancing its keeping quality and ensuring safety to consumers.

Thermal processing is the most prevalent preservation process employed in the dairy and food industry. Starting from pasteurization, which is a mild heat processing technology, in-bottle/in-package sterilization emerged as a means of extending shelf life of milk for several weeks at room temperature. Considerable changes in nutritional and sensory quality due to severity of heat treatment in this process, restrict its application to only special milks. Ultra-high-temperature processing, a relatively new processing know-how, became popular as it uses very high temperature (140OC) for short time (2 s) to sterilize milk. Such a time-temperature combination ensures minimal change in the product quality. Sterilized milk is then packaged in sterile container under aseptic conditions to prevent post-processing contamination. The product thus obtained has very long storage life.