Elucidation of the interaction mechanism between sarcoplasmic protein and aldehydes via multi-spectroscopic analysis and molecular docking simulation.

This study systematically elucidated the molecular interaction mechanisms between sarcoplasmic protein (SP) and flavor aldehydes including (E,E)-2,4-decadienal, (E)-2-decenal, (E,E)-2,4-heptadienal, (E)-2-heptenal, (E)-2-octenal, and (E)-2-nonenal. The results indicated that the binding capacity of these aldehydes was positively correlated with protein concentration (P < 0.05). Furthermore, they notably induced SP unfolding, as evidenced by increased surface hydrophobicity and sulfhydryl content, concomitantly with diminished thermal stability. Critically, UV absorption and fluorescence spectroscopy analyses further verified the occurrence of interactions. Molecular docking simulations distinctly revealed that (E,E)-2,4-decadienal exhibited the strongest binding affinity with SP. Furthermore, fluorescence quenching experiments demonstrated that the quenching process by (E,E)-2,4-decadienal entailed both static and dynamic mechanisms. Thermodynamic analysis indicated that the interaction was primarily driven by van der Waals forces and hydrogen bonding. Synchronous fluorescence and infrared spectroscopy indicated that this binding provoked adaptive conformational rearrangements within the local microenvironment and the overall secondary structure of SP. Collectively, this investigation elucidates the interaction mechanism between flavor aldehydes and SP at the molecular level, providing insights for understanding flavor retention and release in food systems.