Vitisin A (pyranoanthocyanin)

Vitisin A is a pyranoanthocyanin, a type of red wine pigment derived from anthocyanins during the aging process. Specifically, it's formed through the reaction of anthocyanins, like malvidin-3-glucoside, with pyruvic acid and a vinylflavanol generated from catechin. This reaction results in a more stable pigment compared to the original anthocyanins, contributing to the color stability of aged red wines. Vitisin A is typically characterized by its ethyl-linked structure. Its presence is considered a marker of wine aging and contributes to the evolution of the wine's color from bright red to a more brick-red or orange hue over time. Beyond color modification, vitisins contribute to the overall sensory properties of wine, although their individual contribution to taste and aroma is still under investigation.