Cereal Chem 57:376 - 379.  |  VIEW ARTICLE
Inactivation of Trypsin Inhibitors in Aqueous Soybean Extracts by Direct Steam Infusion.

L. A. Johnson, C. W. Deyoe, W. J. Hoover, and J. R. Schwenke. Copyright 1980 by the American Association of Cereal Chemists, Inc. 

A means of direct steam-infusion cooking of aqueous soybean extracts for milk analogs was developed. The effect on trypsin inhibitor (TI) activity of heat in continuous processing was quantified over the temperature range 99-154 C. As process temperature increased each 11 C at pH 6.7, the rate of TI inactivation doubled. At 154 C, pH 6.7, 40 sec of heat treatment produced TI inactivation equivalent to that in 60 min at 99 C (7.6% residual TI activity). Increasing the pH of the slurry to 9.5 substantially increased the rate of TI inactivation. Inactivation of TI activity by high-temperature, short-time processing exhibited reaction kinetics similar to the summation of two first-order reactions with different heat stabilities. We speculate that the heat-labile inhibition stemmed from the Kunitz inhibitor and the more heat-stable inhibition, from the Bowman-Birk inhibitor.