Comprehensive Multi-Spectroscopy and Molecular Docking Understanding of Interactions between Fermentation-Stinky Compounds and Mandarin Fish Myofibrillar Proteins

The release of flavor compounds is a critical factor that influences the quality of fermented foods. A recent study investigated the interactions between four fermentation-stinky compounds (indole, isovaleric acid, dimethyl disulfide, and dibutyl phthalate) and myofibrillar proteins (MPs). The results indicated that all four fermentation-stinky compounds had different degrees of binding to MPs, with dibutyl phthalate and dimethyl disulfide exhibiting stronger interactions. Reduced hydrophobicity enhanced these interactions. Multi-spectroscopy showed that static fluorescence quenching was dominant in the MPs-fermentation-stinky compound complexes. The interaction altered the secondary structure of MPs, predominantly transitioning from β-sheets to α-helix or random coil structures via hydrogen bond interactions. Molecular docking confirmed that these complexes maintained steady states due to stronger hydrogen bonds, van der Waals forces, ionic bonds, conjugate systems, and lower hydrophobicity interactions. Hence, it is a novel sight that the addition of hydrophobic bond-disrupting agents could improve the flavor of fermented foods.