A low-power sono-copigmentation of cyanidin 3-glucoside with geranin type-A: An underlying mechanism study with spectroscopic and Surflex docking insights

Liquid-based stuffs rich in natural pigment, especially anthocyanins, are widely distributed globally. The effect of combining between different concentrations of geranin type-A (G) with different time of low-power sonication (GA-LPS) copigments on the colour intensification of cyanidin 3-glucoside (C3G) was studied using multiple spectroscopic and molecular docking approaches. Furthermore, the hyperchromicity of C3G co-pigmented with GA-LPS was evaluated and their colour stability in the liquid models was tested. Results found that the GA-LPS could enhance the C3G-color, especially the G200-60 based blend, mainly due to their high hyperchromicity, pKH-levels, and heat-constancy. The surflex-docking results highlighted that G could strongly bind with C3G, mostly due to their additional -OH, -COOH groups, and delocalization systems. Sono-pigmentation with G interacted with C3G via H-bonding, van der Waals forces, and & pi;-& pi;-sites, mostly owing to these additional groups. Overall, this is the first study on the sono-pigmentation of geranin type-A-anthocyanins to mimic their natural existence and avoid their antagonistic interactions that might be employed as potential food colorings in liquidbased models. It is recommended to further apply GA-LPS on an industrial-based scale with commercial products and under different conditions.