Influence of heat treatment of milk on cheesemaking properties

Abstract

High heat treatment of milk causes denaturation of whey proteins and complex interactions among denatured whey proteins, casein micelles, minerals and fat globules. It is well established that interactions of whey proteins have both positive and negative implications in cheese manufacture. On the one hand, denatured whey proteins could be incorporated into cheese curd, resulting in a higher yield from a given quantity of milk while, on the other, the interactions of whey protein with casein micelles interfere with the rennet coagulation process, resulting in long coagulation times and weak curd structures. The cheeses made from heated milk differ from traditional cheese in body, texture and flavour profiles. This paper reviews current information on the relationships between whey protein interactions in heated milk and rennet coagulation properties, and discusses possible mechanisms involved. Methods that may be used to improve renneting properties of heated milk are described. In addition some recent results on the interactive effects of heat treatment, ultrafiltration concentration and pH on properties of interest to cheesemaking, in particular rennet-induced gel formation, are presented.