Effects of non-covalent interaction of myofibrillar protein and 6-gingerol on structure and gel properties

The mechanism of non-covalent interaction of 6-gingerol with myofibrillar protein (MP), as well as its effects on the gel properties of the protein was investigated in this study. Fluorescence spectroscopy, Fourier transform infrared spectroscopy, and circular dichroism analysis revealed that 6-gingerol altered the secondary and tertiary structures of MP. Specifically, 50 μmol/g pro 6-gingerol reduced the α-helix content by 9.0 %, while increasing random coil content and β-sheet content by 6.8 % and 4.0 %, respectively. Molecular docking identified the optimal binding conformation with a minimum binding energy of −7.3 kcal/mol. Thermodynamic analysis confirmed that hydrophobic interaction was the main force driving the spontaneous binding of 6-gingerol and MP. Molecular dynamics simulation further demonstrated that hydrophobic interactions and hydrogen bonding stabilized the protein structure. 6-Gingerol significantly improved the gel properties of MP. Compared with natural MP, adding 50 μmol/g pro 6-gingerol increased the gel strength, water-holding capacity (WHC), and immobilized water content of MP gels by 23.3 %, 21.43 %, and 2.31 % respectively, while reducing the free water content by 2.45 %. Rheological properties and scanning electron microscopy results indicated that the MP gel structure became more compact and uniform after polyphenol addition. These results underscore the potential applications of MP–6-gingerol complexes in the food industry. • 6-Gingerol bound with myofibrillar protein to form a stable complex. • Non-covalent binding induced structural changes of protein. • 6-Gingerol bond to myofibrillar protein, leading to static quenching. • Hydrophobic interactions and hydrogen bond stabilized the structure of complexes. • 6-Gingerol significantly improved the gel properties of myofibrillar protein.