146. The heat denaturation of albumin and globulin in milk. II. Denaturation and degradation of protein at temperatures of 75–120° C

Abstract

1. The denaturation of albumin and globulin took place rapidly in samples of milk heated at temperatures of 75°C. and above, and was complete in approximately 60, 30, 10–15, and 5–10 min. at 80, 90, 95, and 100°C. respectively.2. There was no change in the non-protein nitrogen content of milk on heating at temperatures up to 100°C.; on continued heating at 95 and 100°C. extremely small amounts of proteose were produced by hydrolysis of protein.3. In milk heated at 115 and 120°C. the denaturation of albumin and globulin was followed by appreciable hydrolysis of protein, which resulted in considerable increases in the proteose and in the non-protein nitrogen contents.