Free Fatty Acid, Tyrosine, and pH Changes during Ripening of Blue Cheese Made from Variously Treated Milks

Open Access
Publisher Website
Google Scholar
Abstract
Blue cheeses made from untreated milk, raw homogenized milk, heat-treated homogenized milk and pasteurized homogenized milk were analyzed for changes in amounts of free fatty-acids, tyrosine and pH values during curing. Cheeses made from raw and heat-treated (145 F for 20 sec.) homogenized milk contained about 40 [mu] eq/g of caproic and higher molecular weight acids per g of cheese at one week of age. These acids were detected at about 18 wk.of age in untreated milk cheese and at 4 to 8 wk.of age in pasteurized homogenized milk cheese. These values generally increased during ripening. Butyric acid was detected in significant amounts in untreated milk cheese at about 27 to 29 wk. of age, in raw homogenized milk cheese and in heat-treated homogenized milk cheese at about 23 wk. and in pasteurized homogenized milk cheese at 17 wk. Blue cheese flavor also became evident then. There were no real differences in tyrosine values among the various types of cheese during ripening. The pH changes in the cheeses during ripening were influenced by treatment given the milk.