Dietary fibre extracted from different types of whole grains and beans: a comparative study

Dietary fibre (DF) from different whole grains and beans (quinoa, buckwheat, highland barley, pea and mung bean) was extracted by enzymatic action. The components, crystallinity and properties were comparatively studied. Furthermore, we evaluated correlations between DF components and their crystallinity, thermal, physicochemical and functional properties. Results showed quinoa DF had highest polyphenol (25.58 mg GAE per 100 g), pectin (4.68%) and cellulose (52.34%) contents, crystallinity value (CV, 30.24%), ΔH (185.53 J g⁻¹), water-holding capacity (WHC, 5.35 g g⁻¹), α-amylase activity inhibition ratio (α-AAIR, 13.34%) and glucose absorption capacity (GAC), but lowest protein content (9.78%) and T_p (163.05 °C). Mung bean DF had highest lignin content (33.56%), fat adsorption capacity (4.73 g g⁻¹), and T_p (176.25 °C), but lowest CV (15.26%) and ΔH (132.15 J g⁻¹). Correlation analysis showed cellulose content had positive linear correlations with CV, ΔH, WHC, α-AAIR and GAC, but a negative correlation with T_p. The structure and properties of DF are largely attributed to cellulose content.