Acid-generated soy protein hydrolysates and their interfacial behavior on model surfaces.

The present work attempts to provide data to warrant the consideration of soy proteins (SP) as potentially useful biomolecules for practical chemical and surface applications. Despite their sundry properties, SP use has been limited by their high molecular weight. In response to this limitation, we analyze acid hydrolysates of soy proteins (0.1 N HCl, 70 °C) for surface modification. Techniques typical in protein (SDS-PAGE) as well as colloidal (charge demand and electrophoretic mobility) analyses were used to follow the effects of molecular changes that occur upon hydrolysis. Adsorption experiments on hydrophobic (polypropylene) and mineral (aluminum oxide) surfaces were subsequently carried out to further interrogate the surface activity resultant from soy hydrolysis. It was found that during adsorption the hydrolysates tended to form less surface aggregates and adsorbed at faster rates compared with unmodified SP. Overall, the benefits derived from the application of SP hydrolysates are highlighted.