Nine grape varieties cultivated in organic and conventional systems were compared regarding the
carotenoids, total polyphenols and antioxidant activity. The white grape varieties have a higher carotenoids content
compared with the blue-black cultivars while the blue-black varieties contain higher TPC and exhibit higher
antioxidant activity (except for Muscat Hamburg-ORAC). Vitis vinifera grape skins originating from wine or table
grape varieties can be used as a potential source of natural antioxidants.