Water content threshold switches the direction and mechanism of mixing temperature effect on dough sheets stickiness

Dough sheet stickiness is synergistically regulated by water content and mixing temperature, yet the underlying interaction mechanisms remain unclear. Using water contents of 34%, 37%, and 40% and mixing temperatures from 4 to 45 °C, this study investigated dough sheet stickiness in relation to water state and distribution, gluten network structure, and gliadin behavior. A threshold-like transition was observed between 34% and 37% water content, where the effect of increasing mixing temperature on dough sheet stickiness shifted from inhibitory to promotive. At 34% water content, stickiness first increased and then decreased with temperature, peaking at 25 °C and declining by 69.96% at 45 °C compared with the peak value at 25 °C. In contrast, at 40% water content, stickiness increased monotonically with temperature, rising by 48.24% at 45 °C relative to that at 4 °C. Mechanistically, under low water content (34%), elevated temperature relative to 25 °C induced heterogeneous hydration, reduced weakly bound water, enhanced gluten network strength, and restricted gliadin migration, resulting in reduced stickiness. By contrast, under high water content (≥ 37%), elevated temperature markedly disrupted hydrogen bonding and promoted gluten network depolymerization. These changes were accompanied by a pronounced increase in free water and enhanced exudation of ω-subunits, which collectively intensified dough sheet stickiness. These findings provide mechanistic insight into water-temperature-dependent stickiness regulation and practical guidance for dough processing control.