红葡萄酒
Red wine contains between 0.2 and 5.8 mg/l, depending on the grape variety. White wine has much less because red wine is fermented with the skins, allowing the wine to extract the resveratrol, whereas white wine is fermented after the skin has been removed. The composition of wine is different from that of grapes since the extraction of resveratrol from grapes depends on the duration of the skin contact, and the resveratrol 3-glucosides are in part hydrolysed, yielding both "trans"- and "cis"-resveratrol.