Hydrophobic bonds-dominated key off-odors/silver carp myofibrillar protein interactions, and their binding characteristics at cold storage and oral temperatures

This study revealed the interaction mechanism between silver carp myofibrillar protein (MP) and key off-odors by combining fluorescence spectroscopy with molecular dynamics (MD) simulation. Spectroscopic results exhibited a dynamic quenching mechanism between MP and off-odors. Thermodynamic analysis indicated that the MP/off-odors interaction was spontaneous (Delta G degrees < 0) and dominated by hydrophobic interactions (Delta H degrees > 0, Delta S degrees > 0). Meanwhile, the binding affinity was in the order of nonanal (n = 1.38) > hexanal (n = 0.89) > 1-octen-3-ol (n = 0.65), which was further verified by the MD results. Among off-odors, nonanal had the highest binding energy with myosin (8105.66 kJ/mol) and formed more hydrophobic binding sites to Trp residues in myosin head (e.g., Trp820 and Trp822), thereby changing myosin conformations via both physical and chemical interactions. Additionally, higher binding energies of myosin/off-odors were observed at oral temperature (37 degrees C) than at cold storage temperature (4 degrees C), implying that less off-odors were released at 37 degrees C.

Automated summary

This study combines fluorescence spectroscopy with molecular dynamics simulation to reveal the interaction mechanism between silver carp myofibrillar protein and key off-odors. The results show that the interaction is spontaneous and mainly driven by hydrophobic interactions. Nonanal has the highest binding energy with myosin and can change its conformation through physical and chemical interactions. The binding energy between off-odors and myosin is higher at oral temperature.