Impact of different level of α-s1 casein on curd stretchability in the production of mozzarella cheese from goat milk

The extensive casein polymorphism in dairy goats can influence the chemical-physical and sensory properties of milk and derivatives. The present study investigated the aptitude of goat milks with different levels of α-S1 casein (α-S1-CN) at producing mozzarella cheese. Two goat farms producing milk with high and low level of α-S1-CN (HI and LO, respectively) were selected to perform cheesemaking trials. The outcomes highlighted a strong relationship between curd stretchability and presence/absence of α-S1-CN. A pH value of 5.0 was suitable for stretching both types of curd, but the presence of this casein fraction determined better elasticity and a wider pH range for stretchability. The profiles of the volatile organic compounds of the mozzarella samples showed significant differences under both the qualitative and quantitative point of view, while the results of the sensory analysis indicated the presence of differences in odour/aroma of the samples, with LO cheese having higher “goaty” flavour.