Targeted metabolomics of anthocyanin derivatives during prolonged wine aging: Evolution, color contribution and aging prediction.

Anthocyanin derivatives and chromatic characteristics of 234 different-vintage red wine were investigated based on a targeted HPLC-MS/MS and CIELAB approach. The K-means cluster analysis showed that the evolution pattern varies amongst anthocyanin derivative classes. Their stabilities are: pinotins > flavanyl-pyranoanthocyanins, vitisin A > monomeric anthocyanin, direct anthocyanin-flavan-3-ols condensation products > vitisin B, anthocyanin ethyl-linked flavan-3-ols products. The proportion of most pyranoanthocyanins becomes more significant among all detected anthocyanin derivatives during wine aging, whereas flavanols-related anthocyanin derivatives (except for flavanyl-pyranoanthocyanins) decreased drastically. PLSR showed that aging tawny characteristics is related to pyranoanthocyanins except for vitisin B, especially pinotins, whereas monomeric anthocyanins and flavanol-related derivates (except for flavanyl-pyranoanthocyanins) contribute to red violet color. But aging color density is more associated with the content of vitisin A and flavanyl-pyranoanthocyanins. Two predictive models based on random forest and support vector machine modeling showed good performance in predicting the extent of wine aging.