Effects of β-glucans on properties of soya bean protein isolate thermal gels

The effects of concentration and molecular weight of oat -glucans on properties of soya bean protein isolate (SPI) thermal gels prepared by heating at 90?for 30min were investigated. Compared with control (free of -glucan) formulations, the presence of -glucans (0.5-1.5%, w/v) largely enhanced storage modulus (G) and texture properties of SPI (12%, w/v) thermal gels measured by dynamic oscillatory rheometry and texture profile analysis, which were developed as increasing -glucan concentration and molecular weight. It is possible that -glucans could cause the formation of protein aggregates to produce gels through hydrophobic interactions. Mixed gel systems at low ionic strength showed higher G resulting from the lower denaturation temperature of SPI, which was beneficial to the formation of gel structure. In addition, although adding a certain amount of -glucan into SPI reduced water-holding capacity of mixed gels, high molecular weight of -glucan improved their water-holding capacity compared to control formulations attributed to the improvement of the structural integrity of the mixed gel network.