Phytochemical profiles and antioxidant activities of wine grapes

Grapes are rich in phenolics, flavonoids and resveratrol, which have been suggested to be responsible for their health benefits. The concentrations of phenolic, flavonoid, anthocyanins and resveratrol of 14 grape varieties grown in the Finger Lakes area of New York State were examined. Among the varieties tested, Cabernet Franc and Pinot Noir contained the highest total phenolic content with 424.6 ± 3.8 and 396.8 ± 12.4 mg/100 g, respectively. The total flavonoid content of Pinot Noir (301.8 ± 6.2 mg/100 g) was around 3.1-fold higher than that of Baco Noir. Baco Noir had the highest resveratrol content (571 ± 30 μg/100 g) of the varieties tested. Cabernet Franc possessed the highest antioxidant activity. Total antioxidant activities of grape extracts are well correlated with total phenolic content. The proliferation of Caco-2, HepG2 and MCF-7 human cancer cells was significantly inhibited in a dose-dependent manner after exposure to Pinot Noir, Cabernet Franc, Chardonnay, Catawba, Concord, Sheridan, Niagara and Riesling. The results suggest that phytochemicals in the selected wine grapes have potent antioxidant and antiproliferative activities.