Effects of high pressure treatment on the yield of cheese curd from bovine milk

Cheesemaking properties of milk are affected by high pressure (HP) treatment; this study focussed on HP-induced changes in curd yield. Yield was not influenced by treatment at pressures ≤250 MPa, but at higher pressures, curd yield was increased, by up to 25% after treatment at 600-800 MPa. In parallel with increased curd yield, increased curd moisture content and reduced protein content in the whey were observed after treatment at such pressures. Denaturation of α-lactalbumin or β-lactoglobulin occurred at >400 or >100 MPa, respectively. Curd yield and curd moisture content increased and protein content in the whey decreased with increasing treatment time (0-30 min of treatment at 400 or 600 MPa). Increased curd yield is probably a result of both the incorporation of denatured whey proteins and enhanced moisture retention in the curd. HP-induced increases in curd yield may indicate possible applications of HP treatment of milk for cheese manufacture.