关键词: 鱼明胶；果胶；氢键；疏水相互作用；静电排斥作用；凝胶特性

Abstract: This study aimed to explore the effects of changing the non-covalent interactions hydrogen bonds, hydrophobic interactions and electrostatic repulsion by adjusting pH (4, 5, 6, 7, 8, and 9) on the characteristics of fish gelatin-pectin composite gel systems. At pH 5, the composite gel system formed a supermolecular complex with the strongest hydrophobic interaction and there was a strong electrostatic attraction among the complexes. The composite gel system exhibited the strongest hydrogen bond at pH 7, and the strongest electrostatic repulsion at pH 9. The stability of the composite gel system dominated by hydrophobic interaction was poorer, but the melting and gelling temperature were relatively higher, while the composite gel system driven by electrostatic repulsion had higher gel strength and stability. The composite gel system dominated by hydrogen bonds formed a stronger and more stable gel network structure. Therefore, the different non-covalent interactions had different effects on the properties of fish gelatin-pectin complex systems, which would provide a foundation for developing protein-polysaccharide complex gel systems with desired properties.

Key words: fish gelatin; pectin; hydrogen bond; hydrophobic interaction; electrostatic repulsion; gel properties