Interaction and, functionality of mixed myofibrillar and enzyme-hydrolyzed soy proteins

Native and briefly heated (85 degreesC for 3 min) soy protein isolates (SPI) were partially hydrolyzed (4% DH) by Alcalase((R)) and Flavourzyme(TM) before incorporation into a pork myofibril isolate (MPI) system. The hydrolysis of soy protein enhanced its interaction with MPI, leading to a decreased thermal stability of both soy and muscle proteins. Alcalase SPI hydrolysates, when compared with nonhydrolyzed SPI, improved viscoelastic properties and hardness of MPI gels, while Flavourzyme SPI hydrolysates had an adverse effect. Hydrolyzed SPI augmented emulsifying properties of MPI; the specific efficacy depended upon the type of enzymes used, the SPI:MPI ratio, and whether SPI was heated before hydrolysis.