Effect of somatic cell count on milk composition and mozzarella cheese quality

Abstract

The aim of this study was to investigate the effect of somatic cell count (SCC) on mozzarella cheese quality. Three categories of raw milk were selected: low (SCC <115 000 cells/ml), medium (SCC=422 000 cells/ml), and high (SCC>987 000 cells/ml). Cheeses were produced on the same day of milk collection and were vacuum packed in plastic bags and analysed weekly for 60 days at cold storage (4 °C). As somatic cell count increases, casein content, casein as a percentage of true protein, lactose content, and titratable acidity decrease signifi cantly in raw milk. No signifi cant differences were observed in moisture, fat, and total protein contents among mozzarella cheese samples from the different SCC categories. However, cheese samples produced from high SCC milk had signifi cantly higher pH (6.83) compared to samples produced with low and medium SCC milk, 5.58 and 5.46, respectively. The extension of proteolysis was not signifi cant for cheese samples made from raw milk with low SCC during the fi rst 30 days of cold storage. Proteolysis levels increased signifi cantly on the 15th storage day for cheeses made with medium and high SCC, whereas signifi cant increases were only observed on the 45th storage day for cheeses made with low SCC.