Unveiling the mechanisms of different alkali-treated wheat glutenins in modulating retrogradation behavior of wheat amylopectin comparative

This study investigated the effects of high- and low-molecular-weight glutenins (HMW and LMW) on the retrogradation behavior of wheat amylopectin (AP) under a range of alkaline conditions (pH 7-11). At pH 10, both AP-HMW10 and AP-LMW10 complexes exhibited the highest disulfide bond content (130.33 and 100.23 μmol/g, respectively) and β-sheet proportion (25.47% and 22.94%, respectively), contributing to a more compact and ordered protein network. Molecular dynamics (MD) simulations further confirmed that both HMW and LMW significantly increased their contact with hydrogen bonds and van der Waals, indicating more compact binding modes with increased molecular interactions. These structural changes effectively restricted the rearrangement of amylopectin chains during storage, as evidenced by the lowest relative crystallinity and retrogradation enthalpy values among all treatments. After 7 days of storage, the retrogradation enthalpy of AP-HMW10 and AP-LMW10 showed the most limited increase which remained at 1.117 J/g and 1.233 J/g, respectively, indicating superior inhibition on amylopectin recrystallization. Moreover, AP-HMW10 and AP-LMW10 groups displayed the lowest in vitro digestibility with the highest resistant starch content (54.71% and 45.27%, respectively). The results demonstrate that certain alkaline treatment (pH 10) can optimize the glutenin network structure, providing an effective strategy for retarding amylopectin retrogradation in starch-based foods. • Glutenin-AP complexes formed a stable binding at pH 10 with a compact network. • Their ordered structure resulted from hydrogen bonds and van der Waals forces • AP-HMW10 is more stable than AP-LMW10 with higher disulfide bond content. • AP-HMW10 has the best inhibitory effect on amylopectin retrogradation.