A PHYSICOCHEMICAL APPROACH TO THE STRUCTURE AND FUNCTION OF MOZZARELLA CHEESE

There is mounting evidence that the structure and function of mozzarel la cheese are influenced by physico-chemical changes that occur during the first weeks after manufacture. Analyses of the expressible serum obtained from mozzarella cheese by high-speed centrifugation show that intact caseins [alpha(s1)-, alpha(s2)-, beta-, para-kappa-) and casei n-associated minerals (Ca, Mg, Zn) become more soluble during ageing, with an accompanying increase in the water-holding capacity of the che ese. This behaviour is salt-dependent and may be indicative of salt-in duced solvation and swelling of the casein fibres that form the struct ural matrix of the cheese. The distribution of casein-associated miner als between the protein matrix and the serum phase is influenced by ch eese pH, with lower pH favouring greater solubility. Soluble calcium i s of particular interest, because it strongly inhibits salt-induced so lvation of casein and does not contribute to cheese structure.