In 2000, Spanish scientists used low-level UV light to triple resveratrol content in wine grapes. 2 years later, that same research team found one grape variety's antioxidant levels had jumped an unbelievable threefold

Low-level ultraviolet irradiation and refrigeration can significantly boost resveratrol levels in grapes. This treatment can make wine a more potent source of beneficial antioxidants. Resveratrol is a compound found in grape skins with antioxidant and anticancer properties. Refrigerating grapes after picking further stimulates enzymes that produce these healthful effects. These findings suggest a way to increase potentially health-promoting compounds in grapes.