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

Abstract The effects of concentration and molecular weight of oat β-glucans on properties of soya bean protein isolate (SPI) thermal gels prepared by heating at 90℃for 30 min were investigated. Compared with control (free of β-glucan) formulations, the presence of β-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 β-glucan concentration and molecular weight. It is possible that β-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 β-glucan into SPI reduced water-holding capacity of mixed gels, high molecular weight of β-glucan improved their water-holding capacity compared to control formulations attributed to the improvement of the structural integrity of the mixed gel network.