Phytochemical profiles and antioxidant activities of wine grapes Jun Yang a , Timothy E. Martinson b , Rui Hai Liu a, * a Department of Food Science, Stocking Hall, Cornell University, Ithaca, NY 14853, United States b Department of Horticultural Sciences, New York State Agricultural Experiment Station, 630 West North Street, Geneva, NY 14456, United States article info Article history: Received 25 August 2008 Received in revised form 10 December 2008 Accepted 8 February 2009 Keywords: Wine grapes Phytochemicals Antioxidant activity Antiproliferative activity abstract 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 lg/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 prolif- eration of Caco-2, HepG 2 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. Ó 2009 Elsevier Ltd. All rights reserved. 1. Introduction Grapes, one of the most popular fruits and the most widely cul- tivated throughout the world, contain large amounts of phyto- chemicals including anthocyanins and resveratrol, which offer health benefits (Pezzuto, 2008). There are about 60 species of Vitis, which are mainly found in the temperate zones of the Northern Hemisphere and almost equally distributed between America and Asia (Mullins, Bouquet, & Williams, 1992). Approximately 80% of all grapes are used in winemaking, and 13% are consumed as table grapes. The Vitis vinifera grapes are commonly used for wine pro- duction around the world, principally distributed in Europe. In the United States, species such as Vitis labrusca, Vitis riparia, Vitis aestivalis, Vitis rupestris and Vitis rotundifolia are also used in wine-making. Grape phenolics, especially high in the grape peel (Singleton, 1982), are classified into two groups: the flavonoids and nonflavonoids. The flavonoids include flavan-3-ols (catechin), flavonols (quercetin) and anthocyanins. The nonflavonoids encom- pass hydroxybenzoates (gallic acid), hydroxycinnamates and stilb- enes (resveratrol). The traditional Western diet provides roughly 1 g/day of mixed flavonoids. Besides antioxidant activity, flavo- noids have many biological activities such as the inhibition of plas- ma platelet aggregation and cyclooxygenase activity, the suppression of histamine release and SRS-A biosynthesis in vitro, potent nitric oxide radical scavenging activity and exhibiting anti- bacterial, antiviral, anti-inflammatory and antiallergenic effects (Cook & Samman, 1996). In the grape berry, the flavonoids are mainly localised in the skins, such as the anthocyanins and resve- ratrol, while the flavan-3-ols (catechins and proanthocyanidins) are present both in the skins and in the seeds. However, the com- position and concentration of phenolics in grapes vary with vari- ety, species, season and environmental and management factors such as soil conditions, climate and crop load. Grapes are one of the major dietary sources of anthocyanins, which are responsible for the colouring of black, red and purple grapes; however, they are lacking in white grapes. In particular, anthocyanins mostly accumulate in the skins, whereas procyan- dins are located in the seeds. It was found that the Lomanto and Colobel hybrid grape cultivar had the highest anthocyanin content with 603 mg/100 g; Midsouth cultivar contained the lowest con- tent with 5.5 mg/100 g (Mazza, 1995). The anthocyanins in grape skins are predominately the 3-O-glucosides of malvidin, cyanidin, delphinidin, peonidin and petunidin (Wrolstad, 2000). Malvidin, the reddest of all anthocyanins, is the major one in dark red vinifera grapes, with higher proportions of cyanidin in red grapes. Cyanidin 3-monoglucoside and delphinidin 3-monoglucoside are the major anthocyanins in Concord grapes (Singleton, 1982). Anthocyanins possess antioxidant activity, which is considered to be an impor- tant physiological function. Additively, anthocyanins are reported to have anti-inflammatory activity, anticancer activity, apoptotic induction effect, a-glucosidase inhibition activity, vision benefits and effects on collagen, blood platelet aggregation and capillary 0308-8146/$ - see front matter Ó 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.foodchem.2009.02.021 * Corresponding author. Tel.: +1 607 255 6235; fax: +1 607 254 4868. E-mail addresses: Jun.Yang97@gmail.com (J. Yang), RL23@cornell.edu (R.H. Liu). Food Chemistry 116 (2009) 332–339 Contents lists available at ScienceDirect Food Chemistry journal homepage: www.elsevier.com/locate/foodchem