Cross-linked corn bran arabinoxylan improves the pasting, rheological, gelling properties of corn starch and reduces its in vitro digestibility

Due to the unsatisfying property of native corn starch (CS) during processing, cross-linked corn bran arabinoxylan (CLAX), which is a dietary fiber with good gelling and prebiotic activities, was used to modify CS to improve its physicochemical property. In the present study, the effects of CLAX on the pasting, rheological, and gelling property of CS as well as its in vitro digestibility were evaluated. The peak, trough, and final viscosity of CS were increased 74.3%, 85.6% and 90.4% with 0.4% CLAX addition during gelatinization compared with CS without CLAX, respectively. Moreover, the increase of the viscosity of CS was in a CLAX concentration-dependent manner. It may be due to that CLAX could promote the swelling power of CS as the enlarged granule size of CS with CLAX addition observed in the confocal laser scanning microscopy. The gel strength, hardness, and thermal stability of CS-CLAX composite gels were also increased with the addition of CLAX. In addition, both the digestion amount and digestion rate of CS were decreased with the addition of CLAX. The results from this study could provide new insights into the interaction between CS and CLAX, and may be useful for the rational design of healthier functional foods with a reduced digestibility.