Fat Degradation in Cheddar Cheese Made from Pasteurized Milk, Without and With Added Lipase1,2

Abstract

Summary The fat acidities of cheddar cheese made from pasteurized milk without added lipase were very similar when the cheese were 3 days old. Increases occurred throughout the ripening period. The increases were not uniform with the different lots of cheese and could not be correlated with the pH of the cheese, the acidity of the whey at milling, or the moisture or fat content of the cheese. The fat acidities of cheese made with rennet extract and with rennet powder increased at approximately the same rate. Purified butterfat, obtained from pasteurized sweet cream and held at the cheese ripening temperature (50° F.), did not increase significantly in acidity. Addition of a small amount of rennet paste (13 to 40 grams per 1,000 pounds milk) resulted in an increase in fat acidity of the cheese. Some of the cheese showed varying degrees of rancidity early in the ripening, but this rancidity disappeared or nearly disappeared before the cheese were 6 months old. The cheese (made with rennet paste) that were not rancid were superior in flavor to the control cheese. The use of a small amount of rennet paste tended to mask the sour, acid flavor frequently encountered in the control cheese. Addition of a larger amount of rennet paste (50 to 225 grams per 1,000 pounds of milk) resulted in a significant increase in fat acidity of the cheese. All of the cheese showed rancidity at some time during the ripening and certain lots were rancid when the cheese were 6 months old. The addition of mulberry juice to pasteurized milk did not improve the flavor of the resulting cheese. Small amounts had little effect on the flavor while larger amounts resulted in rancid and unclean flavors. The use of a certain amount of aged cheese showing definite fat hydrolysis was beneficial from the standpoint of flavor of process cheese. Process cheese containing some aged cheese made with addition of rennet paste had more flavor than process cheese made with an equivalent amount of aged control cheese.