Effects of gliadin-to-glutenin ratio on the thermal aggregation behavior of reconstituted wheat gluten.

Gluten proteins are important in determining the processing properties and textural characteristics of wheat-based products. Their thermal responsiveness directly influences the quality and stability of the final product. This study investigates the mechanism underlying changes in the rheological behavior of reconstituted gluten proteins during heat treatment. Various gliadin-to-glutenin (Gli:Glu) ratios were examined. Results demonstrated that the 2:8 ratio sample exhibited the highest storage modulus (G') and loss modulus (G″), together with relatively low loss tangent (tan δ) values, indicating superior overall viscoelastic performance. Power-law model fitting of dynamic rheology and creep-recovery tests further corroborated this finding. These results indicated a more balanced elastic-viscous behavior. Proteins at this ratio showed the highest disulfide bond content. They also exhibited the lowest SDS-soluble protein fraction, indicating greater covalent aggregation. FTIR and Raman analyses revealed reduced α-helix content. Increased β-sheet and aggregate proportions were observed, indicating conformational reorganization. Fluorescence spectroscopy suggested enhanced tryptophan burial and denser protein packing. Among non-covalent interactions, hydrophobic forces and hydrogen bonds cooperatively reinforced network formation. Imaging analysis confirmed a more continuous microstructure. These findings collectively demonstrate that the rheological performance of gluten proteins is coordinately regulated by multiple factors, including composition, structure, intermolecular forces, and microstructure. Appropriately reducing gliadin content promoted heat-induced aggregation and network stabilization. The findings should be interpreted in the context of the purity limitations of the extracted protein fractions, and further studies are required to determine whether the structural and rheological characteristics observed in the reconstituted protein system can be translated into practical wheat-based products.