Incorporation of Soy Proteins into Curds of Cow Milk

Abstract

Rennet and various amounts of 7S globulin (7S), 11S globulin (11S) and soy isolate (SI) were added to cow milk fermented by lactic acid bacteria. When left to stand at 30°C for 12 hours after the addition of 7S, 11S or SI, curd was formed in all the samples. The order of the amounts of soy proteins incorporated into the curds was 7S>SI>11S. In the samples to which 7S or SI were added, all the subunits of 7S were very efficiently incorporated into the curd. 11S was more efficiently incorporated into the curd in the case of the addition of SI than in the case of 11S alone, although the efficiency is still lower than that of 7S. The curd formed in the presence of 7S tended to become soft, while other curds did not.