Effect of water-extractable arabinoxylan with different molecular weight on the heat-induced aggregation behavior of gluten

Water-extractable arabinoxylan (WEAX) can improve the cereal food quality by enhancing gluten characteristics. Although the effect of WEAX on gluten quality at the dough formation stage has been extensively studied, interactions between WEAX and gluten upon the cooking stage remain far more to be revealed. In this work, the effect of WEAX with same branching degree but varied in molecular weight (Mw) on the heat-induced aggregation behavior of gluten was comparatively studied. The results showed that addition of WEAX, especially low Mw WEAX (L-WEAX) could improve the viscoelasticity of gluten during heating. WEAX induced higher enlarged degree of particle size and aggregation trend of gluten upon heating, indicating that WEAX promoted the thermal aggregation of gluten. Moreover, gluten with L-WEAX was more likely to aggregate than that with high Mw WEAX (H-WEAX). The enhanced aggregation ability of HMW-glutenin subunit x-type, LMW glutenin subunits (mainly i- and s-type), gamma-gliadin and CSB_alpha gliadin 9/18 contributed to the promoted heat-induced aggregation behavior of gluten by WEAX. This study can provide a theoretical basis for the exploitation of WEAX as a high-efficiency dough improver.