Effects of static magnetic field-assisted dough resting on the quality characteristics of non-fermented dough

The magnetic field-assisted dough resting (MFADR) technique can be used to modify the quality attributes of non-fermented wheat dough. This study aims to investigate the effects of varying static magnetic field intensities during resting on the dough's physicochemical, structural, and rheological properties. Dough processing was then optimized in the continuous industrial production of non-fermented flour products. The experimental procedure 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. After that, the samples were sealed in plastic bags and then subjected to static magnetic fields of different intensities (0, 1, 2, 3, 4, and 5 mT) for 30 mins at a controlled temperature of 25 °C and relative humidity of 45% during resting. A control sample (CK) was also included without resting. The samples were designated as MF-0 to MF-5 after treatment, corresponding to the applied magnetic field strength. A series of analytical techniques was also employed to characterize the dough. A texture analyzer was used to assess stress relaxation and textural properties, while a dynamic rheometer was used to evaluate the viscoelastic behavior. Low-field nuclear magnetic resonance (LF-NMR) was used to measure the water distribution and migration. The balance between free sulfhydryl and disulfide bonds was then 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 the best quality of dough was achieved after MFADR treatment at 4 mT. The MF-4 sample also exhibited a better textural profile compared with the non-magnetic field-rested sample (MF-0). The hardness, maximum, and equilibrium stress decreased by 23.06%, 8.59% and 8.71% during relaxation tests, whereas the springiness increased. Rheological measurement indicated that the MF-4 dough possessed a more stable structure with a tendency towards solid-like plastic behavior. LF-NMR analysis revealed that there was a significant (P<0.05) transformation in water status, with an increase in strongly bound water content and a decrease in weakly bound water. The magnetic field also 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 showed that there were a 6-percentage-point increase in the stable β-sheet structure and a 9-percentage-point decrease in the less-ordered β-turns within the protein secondary structure. This shift implied a more extended and stable protein peptide chain conformation. Finally, SEM micrographs revealed that the MF-4 dough shared a well-developed and continuous gluten network with reduced structural fragmentation, more uniform pore distribution, and smaller pore sizes, compared with the rest of the samples. In conclusion, the optimal performance of non-fermented wheat dough was achieved in the 4 mT static magnetic field during a 30-minute MFADR, including the water distribution, disulfide bond formation, protein secondary structures, and the refined microstructure of gluten network. This finding can offer valuable insights to improve the quality and consistency of non-fermented dough products in industrial settings.