Catechin and Procyanidin Composition of Seeds from Grape Cultivars Grown in Ontario

The quantities of 11 flavan-3-ols were determined using HPLC in the seeds of 17 vinifera, hybrid, and labrusca type red and white grape cultivars grown in the Niagara region of Ontario, Canada. The ranges of concentrations (mg/100 g of seeds) were as follows: (+)-catechin, 21−244; (−)-epicatechin, 23−284; B1, 3−62; B2, 9−106; B3, trace−71; B4, 2−149; B1-3-O-gallate, trace−74; B2-3-O-gallate, trace−26; B2-3‘-O-gallate, trace−11; C1, 0−10; T2, trace−76. The monomers (+)-catechin and (−)-epicatechin were present in most cultivars in greater quantities than any one of the procyanidins. In all but three cultivars, B2 was the most abundant procyanidin and the galloylated procyanidins were present in considerably lower concentrations than the nongalloylated ones. Cultivar influenced the flavan-3-ol composition of the seeds. Gamay, Pinot noir, Baco noir, and Vincent seed were the best sources for these compounds among the cultivars examined.