Influence of phenolic co-pigments on the stability of major anthocyanin in blueberry wine and color changes during storage

Addressing the issue of color loss owing to the degradation of anthocyanins during storage in blueberry wine, we compared the stabilizing effect of phenolics on anthocyanins. Initially, the influences of phenolic co-pigments (catechin, epicatechin, gallic acid, sringic acid, and caffeic acid) on the main monomeric anthocyanin (malvidin-3-O-galactoside) in blueberry wine were evaluated in a model wine solution. Gallic acid showed the highest binding strength (binding constant K  = 24.41 mol/L) and excellent thermal (half-life t 1/2  = 15.20 h) and light stability (half-life t 1/2  = 38.66 h) in the model wine solution, whereas epicatechin distinguished itself in oxidative stability (half-life t 1/2  = 11.37 h). In the subsequent storage, the blueberry wine containing epicatechin or gallic acid as co-pigments displayed markedly improved color stability, evidenced by intensified color enhancement and darker displacement, reduced color change, and maintenance of elevated levels of total phenolics, total flavonoids, and anthocyanins. This work may provide theoretical and practical guidance for stabilizing wine color during the storage of fermented fruit wines such as blueberry wine.