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

The influence of different polyphenols on the co-pigmentation effects of blueberry anthocyanins was investigated to figure out the proper co-pigments for the anthocyanins. The color change, absorption spectra, and anthocyanin content changes was carried out for four anthocyanin monomers co-pigmented by six polyphenols. 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, 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.