Covalent modification using hemp seed polyphenols improves the structural and functional properties of the hemp seed globulin

This study investigated the impact of covalent modification of hemp seed globulin (GLB) with hemp seed polyphenols (HSP) at different concentrations (1-5% w/w) on the structure and function of the protein. Increasing the concentration of HSP resulted in higher polyphenol grafting equivalent, indicating increased attachment of polyphenols to GLB. Concurrently, there was a decrease in free sulfhydryl groups and free amino acids content, indicating successful covalent bonding between GLB and HSP. Spectroscopic analysis revealed noticeable changes in the secondary and tertiary structures of the GLB-HSP conjugates following modification. The GLB-5%HSP conjugate exhibited improved solubility and emulsifying properties across tested pH levels and demonstrated enhanced antioxidant activity and digestibility compared to GLB alone, showcasing the potential synergy between protein function and polyphenol biological activity. These findings underscore the promise of covalent conjugation in combining protein function and polyphenol activity, offering a pathway for the development of innovative and functional protein-based ingredients.