Cross-linking treatment of arabinoxylan improves its antioxidant and hypoglycemic activities after simulated in vitro digestion

The objective of the present study was to evaluate the impact of cross-linking treatment of arabinoxylan (AX) on its structure and physiological functions prior to and after the in vitro gastrointestinal digestion. The AX extracted from triticale bran was cross-linked using laccase. The reaction was monitored spectrophotometrically and verified based on the decrease in the ferulic acid content and an increase in the molecular weight. In comparison to the non-cross-linked AX (A-AX), the cross-linked AX (C-AX) exhibited a higher substitution degree, a more compact microstructure, and higher viscosity in the results of FT-IR, SEM, and rheological tests. The hydroxyl radical scavenging ability and the metal ion chelating ability of C-AX were higher than those of A-AX. After passing through the gastrointestinal tract simulated using an in vitro digestion model, in addition to the retentive larger molecular weight and network structure, the antioxidant activity and the glucosidase inhibition activity of C-AX were higher than those of A-AX. In conclusion, the cross-linking treatment of AX increased its tolerance of the extreme environment during the digestive process by modulating its structural characteristics.