THE INFLUENCE OF MILK PASTEURIZATION TEMPERATURE AND PH AT CURD MILLING ON THE COMPOSITION, TEXTURE AND MATURATION OF REDUCED FAT CHEDDAR CHEESE

Reduced fat milks were pasteurized, for 15 s, at temperatures ranging from 72 to 88 degrees C to give levels of whey protein denaturation va rying from similar to 3 to 35%. The milks were converted into reduced fat cheddar cheese (16-18% fat) in 500 litre cheese vats; the resultan t cheese curds were milled at pH values of 5.75 and 5.35. Raising the milk pasteurization temperature resulted in impaired rennet coagulatio n properties, longer set-to-cut times during cheese manufactures, high er cheese moisture and moisture in the non-fat cheese substance, lower levels of protein and calcium and lower cheese firmness. Increasing t he pH at curd milling from 5.35 to 5.75 affected cheese composition an d firmness, during ripening, in a manner similar to that of increasing milk pasteurization temperature. Despite their effects on cheese comp osition and rheology, pasteurization temperature and pH at curd millin g had little influence on proteolysis or on the grading scores awarded by commercial graders during ripening over 303 days.