Changes in the rheology and aggregation behavior of wheat glutenin and gliadin mediated by low-sodium salt

Reducing sodium in cereal-based foods without reducing quality is still a major challenge, largely because the mechanistic role of salt substitutes in modulating key gluten components is unclear. This study aimed to decipher the distinct responses of glutenin (Glu) and gliadin (Gli) to low-sodium salt (LSS). By analysis, we demonstrated that LSS improved elasticity, tensile resistance and strain-hardening ability of Glu. Size-exclusion chromatography and fluorescence spectroscopy revealed that aggregation and hydrophobic exposure were promoted in Glu. Atomic force microscopy visualized the formation of larger Glu aggregates, while LF-¹H NMR indicated a more tightly hydrated protein network. In contrast, Gli exhibited weaker structural and functional changes. In short, the efficacy of LSS was not uniform but structurally selective: it primarily targeted and reinforced Glu network due to Glu's unique polymeric structure, which was highly sensitive to ionic environment. This work provided mechanistic foundation for the rational design of sodium-reduced cereal products.