Liberation of Fatty Acids during Making and Ripening of Cheddar Cheese

Abstract

The content of individual fatty acids of pairs of raw and pasteurized milk Cheddar cheeses was detd. by a chromatographic method. Acetic and butyric acids were formed, apparently from sugar by fermentation, during the making process, but remained almost entirely in the whey. In both raw and pasteurized milk cheese during the first 30 days of ripening, caproic, caprylic, and capric acids were absent, but the butyric acid content was approx. 3 uM per g. cheese for pasteurized milk cheese, and 4 uM for raw milk cheese. Approx. 3 [mu]M acetic acid were present in both types. After 420 days ripening, the following amts. of acids (as [mu]M per g. cheese) were present in raw milk cheese: acetic 5.5, butyric 5, caproic 1.5, caprylic 2.5, and capric 2. Higher acids were not detd. For pasteurized milk cheese, the figures were from 50 to 75% of those for raw milk cheese. No fatty acids having branched chains or an odd number of C atoms were detected. The acids were believed to be liberated from cheese fat by bacterial lipases, probably intracellular lipases liberated by bacterial autolysis.