Gelling and emulsifying properties of soy protein hydrolysates in the presence of a neutral polysaccharide.

Soy protein hydrolysates (SPH) with different degrees of hydrolysis (DH 0-16%) were obtained by varying the time of hydrolysis with bromelain. The objective of this study was to evaluate how selected techno-functional properties (gelation, emulsification) of SPH were affected by the presence of a non-gelling polysaccharide. A slight hydrolysis was beneficial to increase gel strength. Also, the emulsifying activity was improved for low DHs, whereas hydrolysis was detrimental for emulsion stability. Under certain conditions the presence of the non-gelling polysaccharide was beneficial to improve SPHs' functional properties, but the effect was in general complex and strongly dependent on both biopolymers' concentration and molecular weight. Nevertheless, it was demonstrated that by using SPH and galactomannan mixtures and controlling the biopolymers' concentration and molecular weight, improved functionalities can be obtained with useful applications in food formulation.