Effects of Different Polyphenols on the Co-pigmentation of Blueberry Anthocyanin Monomers

In order to explore the influence of different polyphenols on the co-pigmentation effects of blueberry anthocyanins, this study analyzed the effects of different polyphenols on color, absorption peak and anthocyanin content of four blueberry anthocyanin solutions, and identified the suitable polyphenol copigment for four anthocyanin monomers. The results showed that chlorogenic acid and epicatechin significantly increased the absorption peaks of malvidin-3-O-galactoside (Mal-3-O-gal), malvidin-3-O-arabinoside (Mal-3-O-ara), delphinidin-3-O-galactoside (Del-3-O-gal) and delphinidin-3-O-arabinoside (Del-3-O-ara) by 21%~37% (P<0.05). The a^* values of the four anthocyanin monomers were significantly enhanced (P<0.05), while L^* values were significantly decreased by chlorogenic acid and epicatechin, resulting in a significant reddening of color. Gallic acid and vanillin had no significant effect on the maximum absorption wavelengths, color, and anthocyanin content of Mal-3-O-gal, Mal-3-O-ara, and Del-3-O-gal (P>0.05), but they significantly increased the absorption peak of Del-3-O-ara by 23.33% (P<0.05). Ferulic acid and caffeic acid had an adverse effect on the anthocyanin solution, causing a color shift from red to purplish and significant fading. Therefore, chlorogenic acid, epicatechin, gallic acid and vanillin can be used as effective co-colorants for blueberry anthocyanins, which could be used in the blueberry processing industry to improve the color stability of blueberry juice.