The molecular weight, solubility and viscosity of oat beta-glucan affect human glycemic response by modifying starch digestibility

► The physicochemical properties of β-glucan influence in vitro starch digestibility. ► As the viscosity of β-glucan increased, the starch digestibility was reduced. ► This effect correlates to β-glucan bioactivity in reducing glycemic responses. ► When the starch digestibility decreased, glucose responses were lowered. ► Higher reduction in glucose responses were found at higher β-glucan/starch ratios.