Contents of Trans-resveratrol in Korean Grape Cultivars, including “Kyoho”

Concentrations of trans-resveratrol were analyzed in 36 Korean-grown grape cultivars, including cv. Kyoho. This cultivar has large irregular berries and a deep-black skin and accounts for >15% of all grapevines grown in Korea. The content of trans-resveratrol is an important quality parameter, and its pattern of variability increased gradually until the time of harvest. Its distribution also fluctuated significantly among leaves, seeds, and exocarps, with the highest amount (1,477 μg g−1 dry weight) occurring in the leaves. Among all cultivars evaluated here, trans-resveratrol contents were significantly higher in “Cheongsoo” and “High Bailey,” their levels being 50% above the overall mean (i.e., 2.0-mg g−1 dry weight), whereas 14 cultivars had contents that were 10% less than that mean value