Effects of milk somatic cell count on physical and chemical characteristics of mozzarella cheese

The aim of the present study was to investigate the physical and chemical characteristics of mozzarella cheese manufactured from cows milk containing somatic cell counts (SCC) at low ( 800,000 cells/mL) levels. Cheeses were manufactured according to the following sequence: milk pasteurisation (65°C, 30 min), inoculation with starter culture (3%) and calcium chloride, followed by mixing and incubation (34°C, 60 min), addition of rennet, mixing and incubation (34°C, 35 min). The coagulum was cut, drained and stored (4°C, 12-16 h, until pH 5.2). Next, the curd was stretched and kneaded (80-85°C, 5 min), salted in brine (20°B, 20 h) at 10°C and dried (5°C, 48 h). The cheeses were vacuum packed in plastic bags and stored at 4°C for 30 days. Cheese samples were analysed on days 2, 9, 16, 23 and 30 after production. Analyses in cheese included titratable acidity, pH, dry matter, fat dry matter, ash, total protein, casein, extent and depth of proteolysis, lipolysis (expressed as free fatty acids, FFA) and instrumental texture parameters (hardness, springiness an chewiness). SCC in milk did not affect (p>0.05) the yield and the physical parameters of mozzarella cheese over 30 days of storage. However, the total protein and casein decreased, and the FFA content increased in cheese manufactured from high SCC milk (p 800,000 cells/mL) in order to avoid protein losses and a higher lipolysis ratio in the cheese during 30 days of storage.