Influence of high-molecular-weight glutenin subunits and salt types on dough rheology and gluten aggregation: A combined experimental and computational approach

This study investigates the impact of various salts (NaCl, KCl, CaCl₂, MgCl₂) on gluten aggregation, with an emphasis on the role of high-molecular-weight glutenin subunits (HMW-GS) in modulating these impacts. The results demonstrated that NaCl significantly improved dough springiness and adhesiveness, while divalent salts like CaCl₂ and MgCl₂ had a greater effect on increasing dough hardness, with KCl showing the least impact among all salts. Differential responses were observed in HMW-GS deletion lines, where Bx7 was more responsive to NaCl and CaCl₂, whereas By8 showed stronger interactions with KCl and CaCl₂. The observed reductions in zeta potential and decrements in ionic bond content during salt-induced gluten aggregation supported the ‘electrostatic shielding’ mechanism, with hydrophobic interactions and hydrogen bonding emerging as key contributors to aggregate stability. Molecular dynamics simulations further corroborated these findings, revealing stronger Coulomb-SR interactions and enhanced binding affinities for divalent ions, in agreement with experimental data. These insights provide a theoretical foundation for optimizing low-sodium formulations in wheat-based products.