Heat Inactivation of Trypsin Inhibitors in Soymilk at Ultra‐High Temperatures

Abstract

ABSTRACT Soymilk samples at pH 7.5, 6.5 and 2 were subjected to heat treatment at 93°C and indirect ultra‐high temperature. When heated at 93°C, 121°C and 132°C, trypsin inhibitor activity (TIA) in soymilk was more heat‐labile at high pH than at lower pH. However, the effect of pH on rate of thermal inactivation was less pronounced when the holding temperature was increased to 143°C and 154°C. The point on a curve relating holding temperature and holding time, indicating inactivation of 90% of the TIA in soymilk at pH 6.5 in the range 93–154°C, coincided with the thermal‐death‐time curve of the organism putrefactive anacrobe 3679 at about 125°C.