CHEDDAR CHEESE: COMPARISON OF EFFECTS OF RAW AND HEATED MILK ON QUALITY AND RIPENING

Abstract

Abstract2 Portions of identical milk of manufacturing quality were made into cheese: (a) without heating; (b) after pasteurizing by the holder method; (c) after short-time heating at 71 C; (d) over 71 C (74–87); and (e) less than 71 C (50–69). These variations in heating did not require extensive modifications of cheese-making operations. Measurements were made of moisture, pH, and salt. Cheese was cured at 7 C, scored at 1, 3, 6, and 12 months, and analyzed for total nitrogen, water-soluble nitrogen, and amino nitrogen at 3, 6, and 12 months. Milk pasteurized by the holder method or by heating to 71 C produced better cheese than raw milk or milk heated for a short time at less than 71 C. Raw-milk cheese cured most rapidly, had the most intense flavors, and was least stable in storage. Rate of curing and intensity of flavor decreased and storage stability increased with the severity of heat treatments. Changes in protein were less extensive in heated-milk cheese and were more extensive in cheese of lower grades. Although there are risks involved, markets for cheese with pronounced cheese flavor can be met with the products produced from milk heated for short times at less than 71 C.