Influence of Pasteurization on Fat and Nitrogen Recoveries and Cheddar Cheese Yield

Cheddar cheese was made from pasteurized (63°C for 30 min) and raw milk to determine the influence of pasteurization on cheese yield and on fat and nitrogen (i.e., protein) recovery in cheese. Pasteurization had no effect on fat recovery in cheese, but nitrogen recovery was higher for cheese made from pasteurized milk. Composition-adjusted cheese yield was higher in cheese made from pasteurized milk. Based on casein measurement by the International Dairy Federation method, it appeared that approximately 5% of the whey protein originally present in the milk, presumably β-lactoglobulin, was associated with casein micelles after milk pasteurization. It was concluded that heat denaturation of whey protein caused by HTST pasteurization of milk prior to cheese making results in a theoretical cheese yield increase of about .01 to .04 kg for a milk with a theoretical Cheddar cheese yield of 10 kg/100 kg of milk. Higher pasteurization temperatures or longer holding times would cause more heat-induced interactions of casein and whey proteins.