Structure-dependent interactive modulation of polyphenols: enhancing gelation and oxidative stability in...

This study elucidated the structure-function relationships of polyphenols (gallic acid [GA], taxifolin [TF], epigallocatechin gallate [EGCG]) in modulating Fenton-oxidized myofibrillar protein (MP) and soybean protein isolate (SPI) composite systems. Results indicated that polyphenols induced conformational changes in proteins, with TF and EGCG demonstrating significantly greater efficacy than GA in inhibiting protein oxidation. Specifically, TF and EGCG achieved reductions of 3.4-fold and 3.0-fold in carbonyl content, respectively, while enhancing gel properties. Notably, TF, characterized by its dihydroflavone skeleton, was particularly effective in maintaining color stability of the oxidized gel. Molecular dynamics identified hydrogen bonding stabilizes the MP-SPI-TF complex, with TF anchoring key residues of MP and SPI via non-covalent interactions, forming a stable interfacial bridge that avoids single-protein gel deterioration under high phenolic doses. This study insightfully elucidated the molecular mechanisms by which polyphenols regulate oxidation-driven protein aggregation and gel function, highlighting their dual roles in competitive binding and interfacial bridging.