Regulatory mechanism and flavor perception of heat induced conformational changes in chicken myofibrillar proteins on the binding affinity with sanshool and capsaicin.

The interaction mechanisms between sanshool and capsaicin with chicken myofibrillar proteins (MPs) under thermal-induced conditions (25-100 °C) have been systematically investigated. By analyzing the characteristics of MPs- sanshool/capsaicin -complex, heating process significantly altered MPs conformation, exposing internal hydrophobic groups and disulfide bonds, affecting binding properties. Flavor adsorption experiments demonstrated enhanced release of linalool and progressively strengthened adsorption of trans-2-decenal and trans-2,4-decadienal with rising temperatures. Molecular docking simulations indicated that sanshool and capsaicin spontaneously bind to TRPV1/TRPA1 sensory receptors through hydrogen bonds, hydrophobic forces, and van der Waals interactions. Sanshool binds to TRPV1 with energies of -6.42 and -6.06 kcal/mol, lower than capsaicin's -4.96 and -4.52 kcal/mol. This enhanced energy release potentiates neuronal tingling perception. Fluorescence analysis showed that the formation of the MPs-capsaicin complex is dominated by hydrogen bonds and van der Waals forces, while the formation of the MPs-sanshool complex primarily relies on hydrophobic interactions and electrostatic forces.