Influence of Somatic Cell Count on Ewe’s Milk Composition, Cheese Yield and Cheese Quality

Milk samples with low (<500,000/ml), medium (500,000-1,000,000/ml) and high (1,000,000-2,000,000/ml) Somatic Cell Counts (SCC) were obtained from a flock of 120 Sarda breed ewes. Milk was analysed for chemical composition and rheological properties (Formagraph), and used for a laboratory scale cheesemaking. The milk of the three groups showed differences (P<0.01) in pH, lactose, whey protein and total Na content. Soluble casein, casein to protein ratio, soluble Ca and total K content were significantly different at P<0.05. Rennet clotting time (R), rate of curd firming (K 20 ) and curd firmness (A 2R ), in milk with nonstandardised pH value, were significantly different (P<0.01). Protein recovery rate was higher in cheese from low SCC milk (P<0.01), while adjusted cheese yield did not show significant differences. Protein losses in whey were greater (P<0.05) when medium or high SCC milk was processed. Neither 1 d-old nor fully ripened cheeses showed significant differences in chemical composition or rheological characteristics.