A comparative study of the effects of three typical phenolic compound on surimi gel and its mechanism

The effects of different phenolic compounds (Epigallocatechin gallate, EGCG; Catechin, CC; Tannic acid, TA) at different phenol hydroxyl concentrations on the gel strength, water holding capacity (WHC), water distribution, and micro-morphology of surimi gels were investigated. Breaking force and deformation of surimi gels treated with EGCG, CC, and TA were increased by 20%, 15%, 12% and 14%, 7%, 4%, compared with untreated surimi gel. Polyphenols increased the WHC of surimi gels and induced the conversion of α-helix to β-sheet in proteins, which was beneficial to the gelation of surimi gel. Surimi gels treated with polyphenols had a complete three-dimensional network structure and relatively uniform and small pores, especially EGCG cross-linked surimi gel. Molecular docking indicated that the interactions between EGCG, CC, TA and myosin heavy chain II A were mainly hydrogen bond and hydrophobic interaction, and their binding energies were −37, −31, and −26 kJ/mol. The binding energy of polyphenols with myosin heavy chain II A correlates with their cross-linking ability with proteins, and the lower the binding energy is, the stronger the cross-linking ability is. This study provides important information to elucidate the mechanism of phenolic compounds regulating the physical properties of surimi gel. • Epigallocatechin gallate, catechin and tannic acid enhanced the texture of surimi gel. • EGCG, catechin, and tannic acid promoted α-helix to β-sheet conversion in proteins. • EGCG, catechin, tannic acid bond to myosin with energies of −37, −31, −26 kJ/mol.