Effect of wheat bran arabinoxylan on the gelatinization and long-term retrogradation behavior of wheat starch

The effect of wheat bran arabinoxylan (WBAX) with different molecular characteristics on the gelatinization and long-term retrogradation behavior of wheat starch (WS) have been evaluated. WBAXs with M w of 280–754 kDa and Ara/Xyl of 0.45–0.62 were obtained through alkaline extraction with graded ethanol precipitation . WBAXs with larger M w and branching degree could impede gelatinization process of wheat starch by effectively decreasing the water availability for starch gelatinization. The hydrogen-bonding interactions between WS and WBAX could enhance the gel strength of WS-WBAX mixed pastes. WBAXs with lower branching degree could inhibit the long-term retrogradation of starch through hindering the rearrangement of amylopectin and double-helical associations of amylose during long-term storage, due to hydrogen-bonding interaction between WBAX and starch. Low-field nuclear magnetic resonance (LF-NMR) relaxometry analysis confirmed that the addition of WBAXs could improve the water holding properties of retrograded starch gels.