Cereal Chem 52:655 - 664.  |  VIEW ARTICLE
Modification of Functional Properties of Soy Proteins by Proteolytic Enzyme Treatment.

G. Puski. Copyright 1975 by the American Association of Cereal Chemists, Inc. 

Soy protein isolate was treated with various amounts of neutral protease preparation from Aspergillus oryzae. The extent of enzyme treatment was determined by measuring the increase in free amino agroups. The functional properties of these enzyme-treated soy isolated and untreated controls were examined. As expected, soluble nitrogen was increased, both at neutral pH and at the isoelectric point, and in the presence of 0.03M calcium chloride, with increased enzyme treatment. Even limited enzyme treatment significantly reduced the viscosity of concentrated protein solutions and prevented gel formation. Emulsification capacities, as measured by a modified Swift et al. method, were increased with enzyme treatment, but emulsion stabilities were decreased. The enzyme-treated proteins had slightly increased water absorption and foaming properties, but foam stability was very low.