Multiple spectra analysis and calculation of the interaction between Anthocyanins and whey protein isolate

The objective of this work was to investigate the interaction between whey protein isolate (WPI) and anthocyanins (AN) by various spectral techniques (Fluorescence, ultraviolet (UV) and Fourier transform infrared spectra). The results indicated that the apparent binding constants of the interaction between AN and WPI at different temperatures were 0.49 × 10 4 (298 K), 1.13 × 10 4 (306 K) and 1.88 × 10 4 (314 K) L/mol, respectively. The corresponding binding sites were 0.91, 0.99 and 1.05 respectively; The reaction between AN and WPI was a spontaneous endothermic process according to the thermodynamic data results, and the main acting force was hydrophobic interaction. The results of ultraviolet (UV) spectra and Fourier transform infrared spectra showed that the addition of AN changed the conformation of WPI. At the same time, the emulsifying properties of the WPI-AN composite solution were significantly improved. • Explore how WPI interacts with AN. • The different mass ratio of WPI and AN has a great influence on the structure and properties of WPI-AN. • The combination of WPI and AN significantly improved the emulsification and emulsion stability of the complex.