Abstract: In this study, a ferritin-hesperetin covalent complex was prepared from apoferritin and hesperetin at pH 9. The effect of covalent interaction on the structural and physicochemical properties of ferritin was explored. The results showed that the covalent interaction with hesperetin reduced the fluorescence intensity of ferritin and resulted in a red shift in the fluorescence spectrum, changing ferritin structure. After binding with hesperetin, the solubility of ferritin was changed, and the isoelectric point was decreased. The oxidative deposition of iron was enhanced and the reductive release of iron from ferritin was decreased. Additionally, the thermal stability of the covalent complex was enhanced compared with that of ferritin. In conclusion, covalent modification with hesperetin can endow ferritin with new functional properties, which is of great significance to the development of ferritin-based foods or drugs.

Key words: ferritin; hesperetin; covalent interaction; structure; functional properties