Protective effects of α-casein or β-casein on the stability and antioxidant capacity of blueberry anthocyanins and their interaction mechanism

Abstract

The impacts of α-casein or β-casein on the stability and antioxidant ability of blueberry anthocyanins were investigated and they exhibited remarkable outcomes. β-casein is a little more effective than α-casein. To detect the protective mechanism, the binding of α-casein or β-casein with malvidin -3-o-galactoside (M3G), the major monomer in blueberry anthocyanins, was examined by fluorescence and ultraviolet–visible absorption spectroscopy. Results showed that the binding of α-casein or β-casein with M3G would lead to static quenching and their binding forces were Van der Waals forces and hydrogen bonding. CD spectroscopy presented structure alterations in α-casein and β-casein after interacting with M3G. Moreover, molecular modeling displayed the conformation of casein-M3G complexes. The findings outlined in the current study showed that α-casein or β-casein could encapsulate M3G through binding with it, which formed the basis for the promoting effects of α-casein or β-casein on the stability and antioxidant ability of blueberry anthocyanins.