Modification of the structure and function of myofibrillar protein by structurally relevant natural phenolic compounds

Protein gelation is an important functional characteristic of shrimp surimi products. The effects of structurally relevant natural phenolic compounds on the structure and functional properties of myofibrillar protein (MP) of the Penaeus vannamei were investigated. In the present study, phenolics improved the oxidative stability of MP, while leading to a decrease in the emulsification properties of MP. The carbonyl and free radical contents and fluorescence quantification of protein oxidation products showed that the addition of phenolic compounds could effectively prevent MP oxidation due to their antioxidant capacity derived from hydroxyl groups. In addition, phenolics could improve the rheological properties and gelling behavior of MP. Finally, the interactions between the substituents of MP and phenolic compounds were explored by molecular docking to elucidate the modification mechanism. Gallic acid (GA), quercetin (QT), and (−)-epigallocatechin-3-gallate (EGCG) interacted with MP mainly through hydrogen bonding to unfold the secondary structure of MP and reduce the surface hydrophobicity. Unlike GA and EGCG, QT interacted electrostatically with MP, maintaining the α-helical structure and leading to a slight increase in surface hydrophobicity. This study demonstrated the great potential of phenolic compounds as natural additives for the functional modification of shrimp surimi products.