Chemical and Physical Changes in Milk at High Temperatures

Abstract

At the high temperatures that have to be applied to milk to make it commercially sterile, many chemical changes take place. Some of these are important because they change those characteristics of the milk that are easily recognized by a potential buyer, e.g. colour and flavour. Others may change the nutritive value of the milk, or may be of use in assessing the severity of the process given. Most, but not all, of these potential changes are bad for the quality of the finished product. However, the overall quality of the product depends both on the bacterial effectiveness of the heat treatment as discussed in the previous chapter, and the extent of the adverse chemical changes. It is therefore necessary to understand what these changes are, and how they may be influenced by the time-temperature conditions that are applied to make the process bacteriologically effective.