Superfine grinding combined with enzymatic modification of pea dietary fibre: Structures, physicochemical properties, hypoglycaemic functional properties, and antioxidant activities

Abstract

N-SDF, S-SDF, E-SDF, and SE-SDF were extracted from natural pea dietary fibre (DF) and modified pea DF by superfine grinding (S), enzymatic modification (E), and superfine grinding combined with enzymatic modification (SE). The structures, physicochemical properties, hypoglycaemic functional properties, and antioxidant activities of the three types of modified SDF were compared with those of natural N-SDF. The results showed that the four SDF types had similar infrared spectra and monosaccharide compositions, whereas their main functional groups, binding degree, and monosaccharide content were different. The molecular weights of S-SDF and SE-SDF decreased compared to that of natural N-SDF, whereas that of E-SDF increased. The microstructure of SE-SDF showed the softest, roughest, and most porous morphology compared with those of the other three SDF types. The hypoglycaemic functional properties (glucose adsorption capacity, glucose dialysis retardation index, and α-amylase inhibition rate) of the three modified SDF types were improved compared with the natural N-SDF. Moreover, SE-SDF had the best effect. In addition, the DPPH· scavenging ability, reducing power, and ·OH scavenging ability of S-SDF and SE-SDF were improved compared with those of natural N-SDF. Remarkably, all four SDF types exhibited excellent ABTS· scavenging ability at a concentration of 0.6 mg/mL. Consequently, SE-SDF holds promise as an outstanding food additive for reducing postprandial blood glucose levels, enhancing antioxidant activities, and mitigating oxidative damage.