Dough surface viscosity during resting process: Effects of water migration and gluten network dynamics

This study determined the relationship between gluten network dynamics, water migration, and surface viscosity during dough resting based on the specific experimental conditions for the five flours examined. LF-NMR relaxation curves and ATR-FTIR hydroxyl stretching vibrational spectroscopy indicated that water migrated from the dough interior to the surface, leading to an increase in dough surface viscosity. Dynamic rheological testing, SEM, and CLSM analyses tracked the evolution of the gluten network structure during the dough resting period. The results showed that the gluten network transformed from an aggregated structure (0–30 min) to a continuous and uniform network (45–60 min), followed by a gradual structural disintegration (90–135 min). Molecular structure analysis shows that non-covalent interactions (hydrogen bonds and hydrophobic interactions) and covalent bonds (disulfide bonds) jointly regulate the polymerization and depolymerization of the gluten network. An appropriate resting time promotes the orderly formation of the gluten structure. Correlation analysis revealed that the gluten index and farinograph quality are key factors in regulating water migration, gluten reorganization, and relaxation. Doughs with poorer gluten quality tend to relax more easily, resulting in faster water release and further accelerated protein chain breakage at the dough surface, this is the fundamental reason for the increased adhesion of the dough surface. Furthermore, the optimal resting time for dough (45–60 min) was consistent throughout this study. Excessive resting times (>90 min) can lead to severe network damage, thereby reducing dough quality. In summary, this study elucidates the mechanisms of water migration and changes in dough surface viscosity during resting, providing a theoretical basis for improving processing techniques and precisely controlling dough quality.