Effects of Time and Temperature of Holding Milk Heat-Treated at Various Temperatures upon Its Subsequent Coagulation by Rennet

The author (1) has shown that artificial "milks" composed of a calcium caseinate-colloidal calcium phosphate sol exhibit a hysteresis-like effect when heat-treated and coagulated with rennet at various intervals after heating. This effect which results in a progressive loss of coagulability as the interval between heating and addition of rennet increases, has been shown by Mattick and Hallett (2) and Moir (3) to occur in natural milk. In order to obtain further data on this phenomenon in natural milk observations were made on the effects of the time and temperature of holding on the rennet coagulability of heat-treated skimmilks.