Flavonoids have been found to be the most abundant phenolic
compounds in grape seeds, mainly the dimeres and trimeres catechin,
epicatechin and epicatechin-3-O-gallate (Naczk et al., 2005).
Thesecompoundsare constituted bymonomeric unit asflavan-3-ols.
In fact, cathechin and epicatechin are easily condensed to oligomeric
procyanidins and polymeric compounds (condensed tannins).