Water-extractable arabinoxylan improves the properties of gluten during freeze-thaw cycles in steamed bread

Abstract

Water-extractable arabinoxylan (WEAX) significantly maintained the quality and gluten structure of Chinese steamed bread during multiple freeze-thaw cycles. To gain a deeper insight into the potential mechanisms by which WEAX enhances the freeze-thaw resistance of gluten, the effects of WEAX on gluten under freeze-thaw cycles were investigated from the perspective of macroscopic, microscopic and intermolecular force changes. The results suggest that incorporating WEAX led to an increase in disulfide bonds within gluten proteins, enhanced the intermolecular interaction of gluten, lessened the detrimental effects of ice crystals on the gluten network and promoted the water-solid interaction, which effectively protected the structure of gluten protein under freeze-thaw treatment. Meanwhile, low-molecular-weight WEAX was found to protect gluten proteins better than high-molecular-weight WEAX. Following freeze-thaw treatment, the free sulfhydryl (SH) content in the control group increased by 53.68 % and the particle size decreased by 44.93 %, while the free SH content of GLW1 (gluten added 1 % L-WEAX) and GLW1.5 (gluten added 1.5 % L-WEAX) increased by 36.60 % and 47.17 %, and the particle size only decreased by 29.18 % and 35.98 %. These findings indicate that L-WEAX (1 %) effectively stabilizes the gluten structure during freeze-thaw cycles by promoting disulfide bond formation, mitigating ice crystal-induced damage, and optimizing protein aggregation.