Structural characteristics of wheat bran arabinoxylan and its differential effects on the physicochemical properties of A-, B-, and C-type starches.

Abstract

Arabinoxylan was extracted and purified from wheat bran through alkaline extraction, enzymatic removal of starch and protein, and ethanol precipitation. Its interactions with wheat (A-type), potato (B-type), and pea (C-type) starches were systematically investigated and compared. The purified arabinoxylan exhibited a low degree of substitution, with a weight-average molecular weight of 112 kDa and a backbone mainly composed of →4)-d-Xylp-(1→ linkages. Addition of 0.5% arabinoxylan reduced peak viscosity of wheat, potato, and pea starches by 55.3%, 68.8%, and 49.4%, respectively, and significantly decreased setback viscosity (p < 0.05). Rheological analysis revealed reductions in both of the storage and loss moduli, indicating the formation of weakened starch gel networks. Potato starch exhibited the strongest response, suggesting that crystalline type plays an important role in arabinoxylan-starch interactions. These findings highlight the potential of wheat bran arabinoxylan as a functional polysaccharide for modulating the processing and textural properties of starch-based foods.