RELATIONSHIPS BETWEEN PHYSICOCHEMICAL CHA RACTERISTICS AND CHEESE-MAKING PROPERTIES OF MILKS

The cheesemaking ability of a milk is partially determined by its phys icochemical characteristics. Predicting formulae for cheese yield show that yield is closely related to milk composition, more especially ca sein and fat contents. But several studies have shown that other param eters are related with cheesemaking properties of milk, by their effec t on behaviour of milk towards coagulation and curd syneresis. Besides the effect of casein content on rennet curd firmness, renneting prope rties of milk are also influenced by individual caseins proportions, m icelles size and mineralization, and salt equilibria. Moreover, the ef fect of protein genetic polymorphism on cheesemaking ability can be ex plained by physicochemical differences between milk of different genot ypes. Changes in physico-chemical properties of milk due to cold stora ge and heat treatments are responsible for an alteration of its techno logical behaviour. Although the cheesemaker disposes of methods to adj ust the technological properties of a deficient milk, it is important in cheesemaking to use a milk which physico-chemical properties will p ermit to ensure a good control of cheesemaking efficiency and product quality.