Flavonoid and aromatic profiles of two Vitis vinifera L. teinturier grape cultivars

Background and Aims Yan73 and Kolor are Vitis vinifera grape cultivars with both red skin and red pulp. The aim of the present work was to determine the distribution of flavonoid compounds in the skin, pulp and seed, as well as the aromatic composition of the whole berry. Methods and Results Anthocyanin and flavonol were extracted from grape skin and pulp, while proanthocyanidin was isolated from skin, pulp and seeds; individual anthocyanins, flavonols and proanthocyanidins were then separated and determined by LC/MS. Anthocyanin was dominated by malvidin derivatives in the skin and by peonidin derivatives in the pulp. The distribution of flavonols in the skin and pulp of the two cultivars showed no consistent trend. Proanthocyanidins were unequally distributed in the skin, pulp and seeds. Proanthocyanidin content, composition and mean degree of polymerisation varied distinctly in the three tissues, especially the profile of the proanthocyanidin terminal and extension subunits. Yan73 and Kolor contained similar aroma compounds, both in free form and as glycosidically bound precursors, as determined by GC/MS, but their content varied significantly. Conclusions Flavonoid compounds were asymmetrically distributed in the skin, pulp and seeds. Epicatechin was the common predominant extension subunit in the three tissues, while epigallocatechin, catechin and epicatechin‐3‐O‐gallate were the characteristic extension subunits of the skin, pulp and seeds, respectively. Kolor accumulated more C6 aldehydes in the free fraction and more alcohols in bound fraction, while Yan73 was characterised by a higher content of terpenes. Significance of the Study The results define the distribution of flavonoid compounds in two teinturier cultivars.