The gel properties and microstructure of the mixture of oat β-glucan/soy protein isolates

Oat β-glucan (OG) is a linear non-starch polysacchride which is usually concentrated in the inner aleurone and subaleurone endosperm cell walls, and it exhibits good physiological and functional properties. In this paper soy protein isolate (SPI) which is widely used in the food industry was mixed with OG, then the gel properties and micromechanism of the mixture were studied for a better understanding of the interaction between β-glucan and protein in food. The results showed that, compared with the single OG or SPI, OG/SPI mixture easily formed thermoreversible gels in 4 °C and 25 °C, which reduced the gel forming time; this would be conducive to improve β-glucans application in food production. The glass transition temperature (Tg) and the thermal stability were increased. Scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) were used to analyze the microstructure of the mixture of OG/SPI, and showed that the gathering and interaction of oat β-glucan and soy protein isolate affected the forming of gels. The molecular simulations of the microstructure of OG and OG/SPI mixed system inferred the interaction between OG and SPI were mainly hydrogen bonds.