Radiofrequency-induced multiscale deconstruction of black wheat starch and its structural regulation on dough...

This study employed radio frequency (RF) treatment to modify black wheat flour physically, aiming to investigate the impact of RF treatment on the multilevel structure of starch and its correlation with the macroscopic properties of dough. Findings indicate that RF treatment effectively induces the depolymerization of starch molecules. The amylose content significantly increased with treatment duration; molecular weight markedly decreased; and chain length distribution revealed a reduction in long-chain fragments alongside an increase in short-chain fragments, indicating molecular chain breakage. Both the short-range order and relative crystallinity of starch markedly decreased, confirming disruption of its molecular crystalline structure. This structural depolymerization led to reductions in starch gelatinization enthalpy and temperature. Regarding water distribution, low-field nuclear magnetic resonance analysis revealed that while RF treatment did not significantly alter strongly bound water status, it markedly reduced the mobility of weakly bound water. These structural and property transformations profoundly influence the macroscopic dough characteristics, flour water absorption capacity, formation time, and stabilization time shorten, while weakening increases. In summary, RF treatment serves as an effective physical modification method for alteration dough processing properties by triggering the deconstruction of starch structure at the molecular scale.