Effect of Transglutaminase on Characteristics of Soybean Protein Gels

In order to explore the effect of transglutaminase(TGase) on the characteristics of soybean protein isolate(SPI),7S and 11S protein gels,the parameters of these TGase-treated protein gels were determined by TA-XT plus SEM(scanning electron microscope) and fluorescence spectrophotometer.Results indicated that gel hardness of TGase-treated SPI gels was significantly increased compared with that of the control.The optimal conditions of TGase treatment for SPI were TGase addition amount of 40 U/g,treatment temperature of 40 ℃,treatment pH of 7.5 and treatment time of 2.5 h.After treatment with TGase,the surface hydrophobicity and water-holding capacity of soy protein isolate gels exhibited a decrease.Meanwhile,heating treatment also resulted in a significant increase in the hardness of TGase-treated protein gels,and TGase-treated SPI gels had the largest gel intensity,followed by 7S and 11S in turn.