Effect of temperature on casein micelle composition and gelation of bovine milk

Variation in temperature causes changes in the composition of the casein micelles. Milk samples with 10, 20, 30, 40, and 50% reduction of total β-CN from casein micelles were prepared and analysed. The micelle structure was maintained with minor changes in z-average diameters, zeta potentials, and micellar calcium. During acid gelation decreases in maximum storage modulus, fracture force and firmness were observed with gradual removal of β-CN, but with no significant differences regarding the gelation time among the samples. Decreases in gelation time, maximum G′, fracture force and firmness occurred with gradual removal of β-CN during rennet-induced gelation. Thus, the changes in composition of casein micelle during low temperature treatments had an influence on the gelation properties of bovine milk.