Besides this, grape seeds tannins, unlike apple tannins
whose aromatic rings are dihydroxylated, contain galloylated
units with a trihydroxylation pattern. This different hydroxylation
substitution, in addition to their high molecular weight and the
proximity of many aromatic rings and hydroxyl groups, contribute
to increase their antioxidant capacity. The order of antioxidant
activity has been reported as ()-epicatechin < epicatechin-3-Ogallate
< ()-epigallocatechin