71. The Heat Denaturation of Albumin and Globulin in Milk

Abstract

The heating of milk causes denaturation of the lactalbumin and lactoglobulin to an extent depending on both the temperature and the time of heating.A series of data has been given for the amounts of albumin and globulin denatured on heating samples of milk at various temperatures from 63 to 80° C, for periods of from 2½ to 60 min.An average of 10·4 per cent, of the total soluble protein was denatured after 30 min. heating at as low a temperature as 63° C.Smooth curves were obtained for the progress of denaturation with time at each temperature, and, over the range of 63–75° C, the relative increase in velocity of denaturation for each rise in temperature of 1° C. was found to be constant, the temperature coefficient of the reaction being 1·5.