Evolution of Catechins and Oligomeric Procyanidins during Grape Maturation of Castelão Francês and Touriga Francesa

Abstract

Quantitative changes in oligomeric procyanidins [dimeric procyanidins (B1, B2, B3, B4), galloylated dimeric (B1-3-0-gallate, B2-3-0-gallate, and B2-3’-0-gallate), trimeric procyanidins (C1, T2)] and monomers [(+)-catechin and (-)-epicatechin] in seeds, stems, and skins of maturing Castelão Francês and Touriga Francesa (Vitis vinifera L.) grapes were measured using reversed-phase high-perfomance liquid chromatography (HPLC). For skins, only dimeric procyanidins (B1, B3, and B4) were detected during maturation. The level of oligomeric procyanidins from seeds, stems, and skins in both grape cultivars studied decreased during ripening, mainly in the first stages of maturation. (+)-Catechin and (-)-epicatechin from seeds in both grape varieties increased during the first stages of ripening, followed by a strong decrease and stabilization. Procyanidins B4 and B2 were the most abundant individual oligomeric procyanidins from seeds in Castelão Francês and Touriga Francesa, respectively, during maturation, while in the case of stems and skins, B1 was the principal oligomeric procyanidin in both grapes cultivars studied.