Physicochemical and Digestive Properties of Yam Starch/Oat β-Glucan Blends

In order to study the effect of oat β-glucan on yam starch, the yam starch/oat β-glucan blends were prepared by rapid visco analyzer. The gelatinizing properties, thermal properties, rheological properties and digestive properties of the blends were investigated. The gelatinization analysis showed that oat β-glucan could reduce the viscosity and regeneration value of yam starch, and inhibit the short-term regeneration of yam starch. The results of thermal properties showed that the gelatinization enthalpy ΔH of blends was significantly decreased with the addition of oat β-glucan (P<0.05), and the lowest value was 7.34 J/g. Infrared spectrum analysis showed that yam starch and oat β-glucan had no covalent binding and mainly through hydrogen bond. The texture analysis showed that the addition of oat β-glucan weakened the gel structure of the blends. Static rheological properties analysis showed that the apparent viscosity of oat β-glucan decreased with the addition of oat β-glucan. Dynamic rheological analysis showed that oat β-glucan could significantly reduce the viscoelasticity of yam starch. X-ray diffraction results showed that the gelation changes the crystal type, and the relative crystallinity decreased from 38.40% to 16.30%. In addition, the addition of oat β-glucan decreased the digestibility of the blends and increased the content of resistant starch. The highest resistant starch content of samples was 49.24%. This study could provide theoretical basis for developing oat β-glucan/starch based food.