Abstract:
This study investigated the efficacy of a novel magnetic field-assisted dough resting (MFADR) technique in modifying the quality attributes of non-fermented wheat dough. The primary objective was to evaluate the impact of varying static magnetic field intensities during the resting period on the dough's physicochemical, structural, and rheological properties. The findings aim to provide a theoretical foundation for optimizing dough processing in the continuous industrial production of non-fermented flour-based products. The experimental methodology involved preparing a standardized dough by mixing 300 g of wheat flour with 150 g of water for 15 minutes. The dough was then sheeted by passing it through a rolling machine ten times and subsequently divided into uniform pieces. For the resting process, samples were sealed in plastic bags and subjected to static magnetic fields of different intensities (0, 1, 2, 3, 4, and 5 mT) for 30 minutes at a controlled temperature of 25 ℃ and relative humidity of 45%. A control sample (CK) with no resting period was also included. The treated samples were designated as MF-0 to MF-5, corresponding to the applied magnetic field strength. A comprehensive suite of analytical techniques was employed to characterize the dough. A texture analyzer was used to assess stress relaxation and textural properties, while a dynamic rheometer evaluated viscoelastic behavior. Low-field nuclear magnetic resonance (LF-NMR) measured water distribution and migration. The balance between free sulfhydryl and disulfide bonds was quantified using an ultraviolet-visible spectrophotometer. Protein secondary structure was analyzed via Fourier transform infrared spectroscopy (FTIR), and the dough's microstructure was visualized using scanning electron microscopy (SEM).The results demonstrated that MFADR significantly influenced dough quality, with the most pronounced effects observed at 4 mT. Compared to the non-magnetic field-rested sample (MF-0), the MF-4 sample exhibited a more desirable textural profile, characterized by an 8.59% decrease in maximum stress and an 8.71% decrease in equilibrium stress during relaxation tests, alongside a 23.06% reduction in hardness and a 13.33% increase in springiness. Rheological measurements indicated that the MF-4 dough possessed a more stable structure with a tendency towards solid-like, plastic behavior. LF-NMR analysis revealed a significant (
P < 0.05) transformation in water status, with an increase in strongly bound water content and a corresponding decrease in weakly bound water. This suggests that the magnetic field promoted tighter binding between gluten proteins and water molecules. Biochemical assays showed a 27.47% increase in disulfide bond content and a 29.16% decrease in free sulfhydryl groups in the MF-4 sample, indicating enhanced protein polymerization and network cross-linking. FTIR analysis corroborated this by showing a 6-percentage-point increase in the stable
β-sheet structures and a 9-percentage-point decrease in the less-ordered
β-turns within the protein secondary structure. This shift implies a more extended and stable protein peptide chain conformation. Finally, SEM micrographs of the MF-4 dough revealed a well-developed and continuous gluten network with reduced structural fragmentation, more uniform pore distribution, and smaller pore sizes compared to other samples. In conclusion, the application of a 4 mT static magnetic field during a 30-minute dough resting period (MFADR) proved to be the optimal condition among those tested. This treatment effectively enhanced the processing characteristics of non-fermented wheat dough by improving water distribution, promoting disulfide bond formation, stabilizing protein secondary structures, and refining the gluten network microstructure. This research offers valuable insights for improving the quality and consistency of non-fermented dough products in industrial settings.