Elucidation of interaction mechanisms between myofibrillar proteins and ethyl octanoate by SPME-GC-MS, molecular docking and dynamics simulation

The molecular interactions and mechanisms between four ethyl esters (ethyl acetate, ethyl butyrate, ethyl hexanoate, and ethyl octanoate) and myofibrillar proteins (MPs) were investigated. The gas chromatography and mass spectrometry results showed that binding capability was significantly enhanced as MP concentrations increased (p < 0.05). The four esters bound to MPs (6 mg/mL) with: ethyl octanoate > ethyl hexanoate > ethyl butanoate > ethyl acetate (p < 0.05), according to their binding capabilities. Moreover, hydrogen bonding was the dominant reversible physicochemical force between the MPs and ethyl esters. In addition, ethyl octanoate was the best MP fluorescence quenchera, and the static quenching performed a more predominant role in the fluorescence quenching process. Furthermore, the MPs’ α-helix content gradually decreased as the concentration of ethyl octanoate was increased. Finally, the molecular docking and dynamic simulation verified that hydrogen bonding and van der Waals forces were the primary driving forces in the myosin-ethyl octanoate complex. This study sheds light on the interactions between proteins and ester compounds facilitating flavor regulation in protein-rich foods.