Analysis of the interaction mechanism of Anthocyanins (Aronia melanocarpa Elliot) with β-casein

Abstract The interaction between anthocyanins and β-casein was investigated by fluorescence quenching technique and circular dichroism spectroscopy. The results of the fluorescence titration revealed that Anthocyanins in Aornia mealnocarpa (AMA) could strongly quench the intrinsic fluorescence of β-casein by static quenching. The apparent binding constants KSV and number of binding sites n of AMA with β-casein were obtained by fluorescence quenching method. The thermodynamic parameters, enthalpy change (△H) and entropy change (△S), were calculated to be 20.47 kJ mol−1 >0 and 92.47353 J mol−1 K−1 >0, respectively, which indicated that the interaction of AMA with β-casein was driven mainly by hydrophobic forces. The binding process was a spontaneous process of Gibbs free energy change. Based on Forster's nonradiative energy transfer theory. The conformations between the two were analyzed using infrared spectroscopy and circular dichroism (CD). The results of synchronous fluorescence spectroscopy showed that the binding of AMA to β-casein induced the conformational change of β-casein. The purpose of this paper was to investigate the effect of the interaction between AMA and β-casein on the stability, and lay the foundation for the application of AMA as a dairy additive with high protein content in the food industry.