Effect of Curd Firmness on Stirred Curd Cheese Yield

Abstract

Cheese manufactured with different objectively measured curd strengths at cutting were compared to determine the effect of curd firmness on cheese yield. A randomized complete block design with four treatments (curd strengths at cutting of 50, 75, 100, and 125mV) was replicated four times in each of three studies for a total of 48 vats of stirred curd cheese. Calf rennet and Mucor miehei protease were used in Studies 1 and 2, respectively, as coagulants and heal time (cut to cook) varied. Higher dry matter cheese yields and lower fat losses were observed when curd was cut at lowest curd tension. Vats cut at 50mV were healed longer, which allowed coagulum to bind fat globules tighter. In Study 3, calf rennet was used as the coagulating agent and all vats were healed 15min before cooking. Firmest coagulum strength at cut point increased dry matter cheese yield. Protein, fat, and moisture retention in cheese was not affected by treatment in Study 3. Curd healing time influenced cheese yield more than coagulum strength at cut point.