Anthocyanin composition and extractability in berry skin and wine of Vitis vinifera L. cv. Aglianico

BACKGROUND: The present article reports the anthocyanin content in the berry skin and wine of the Italian red grape cultivar Aglianico (clone VCR11 grafted onto 1103 Paulsen), one of the most ancient vines and famous for its deep-red colour. Anthocyanins were extracted from frozen berry skin in an acidified methanol solution. The extraction mixtures, monitored for 120 h, were analysed by high-performance liquid chromatography. RESULTS: The extraction from berry skin of delphinidin, petunidin and malvidin appeared to be a time-independent process, whereas the concentration of peonidin increased linearly with time. Peonidin-O-acetyl-glucoside was transferred from skin more slowly than petunidin-O-acetyl-glucoside and malvidin-O-acetyl-glucoside. The anthocyanin composition of the resulting wine showed that the total anthocyanin content was about one-tenth of the corresponding berry skin content. The ratio acetyl/coumaroyl anthocyanins in the wine was sharply higher than the value in berry skin (0.85 and 0.10, respectively), indicating an enrichment of acetyl derivatives in the wine. CONCLUSION: Levels of single anthocyanins in wine were not always correlated with those detected in grapes, as they were affected by winemaking. The high values of some anthocyanins in Aglianico wine could ameliorate its quality, increasing the chromatic properties, aging stability and product acceptance.