Coagulation of Milk for Cheese Making by Ester Hydrolysis

The production of a coagulum in milk with compounds which hydrolyze slowly to produce acids has been investigated. Of the compounds tested (including anhydrides, esters, lactones, and lactides) 1)-glucono-delta-lactone and meso-lactide produced a uniform coagulum suitable for the manufacture of Cottage Cheese. Meso-laetide and D-glucono-delta-lactone at weights equal to 8.8 and 12.3% of the SNF, respectively, gave a pH of about 4.6 after complete hydrolysis. It was necessary to use about 0.02% calcium chloride with the lactide to obtain normal expression of the whey during cooking. The coagulation time varied with the temperature of the milk. Lactide required 2 hr. at 25 C. and 47 min. at 37.5 C. Glucono-lactone required about 15 hr. at 20 C. and 3.5 hr. at 40 C. At higher coagulation temperatures the curd was firm enough to cut at a higher pH than is normally used. The addition of rennet made it possible to cat the curd at pH's higher than normal and thus reduced the setting time. A coagulation temperature above 37 C. caused excessive matting of the curd. The Cottage Cheese produced by this method had a bland flavor and was very similar in appearance to that produced by starter culture.