Unraveling the Molecular Interactions Between Ferulic Acid and Wheat Glutenin/Gliadin in Different Systems

Ferulic acid (FA) is a phenolic acid mainly present in wheat bran. It has beneficial health effects, but may affect gluten network formation and the processing quality of wheat-based products. This study investigated the interaction mechanisms between FA and glutenin/gliadin in dough and simulated dough systems. The results show that FA's effects on both proteins were dose and system dependent. In dough, low-dose FA (≤0.3 g) promoted structural loosening of glutenin, as suggested by β-sheet conversion to β-turns/random coil structures, increased t-g-t disulfide and free thiols, and reduced particle size, whereas high doses promoted reaggregation via microenvironment reshaping, hydrophobic enhancement, cross-linking, and subunit rearrangement. For gliadin, low-dose FA may have altered local charge and hydrogen-bonding environments, while high-dose FA increased the hydrogen-bonding proportion by 45.71% and g-g-g conformation by 60.85%, suggesting enhanced molecular aggregation. In simulated dough, FA promoted stronger structural loosening of glutenin but favored gliadin aggregation, indicating that starch, lipids, water distribution, and other dough components may redirect FA-protein interactions. Molecular docking, as a complementary approach, predicted the preferential binding of FA to gliadin, LMW-GS and HMW-GS at different sites. These findings provide a theoretical basis for regulating phenolic acid-gluten interactions in whole-wheat and functional wheat-based products.