Submitted to: Food Chemistry
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/21/2007
Publication Date: 7/5/2007
Citation: Lee, J., Rennaker, C.D. 2007. Antioxidant capacity and stilbene contents of wines produced in the Snake River Valley of Idaho. Food Chemistry. 105:195-203. Interpretive Summary: This study examined the current quality of 42 wines produced from grapes cultivated in the Snake River Valley of Idaho. Chemical composition (titratable acidity, pH, specific gravity, color, haze, total anthocyanins, total phenolics, antioxidant activity, and stilbene contents) of these samples were examined. This is the first paper on the chemical quality of Idaho cultivated and produced Cabernet Sauvignon, Chardonnay, Merlot, and Riesling wines.
Technical Abstract: Forty-two Idaho cultivated and produced wines were examined in this study. The samples examined were made up of four monovarietal wines (12 Cabernet Sauvignon, 9 Merlot, 7 Riesling, 14 Chardonnay). Wine samples represented twelve wineries that source their fruit from vineyards located within Idaho's Snake River Valley. Titratable acidity, pH, specific gravity, color measurements (lightness, chroma, and hue), % haze, total anthocyanins, total phenolics, total tannins, antioxidant capacity, and individual stilbene measurements were performed. The antioxidant capacities (ORAC values) of Idaho wines ranged from 3.1 (Merlot wine) to 87.0 (Cabernet Sauvignon wine) micromol of Trolox/ml (mean = 38.5 micromol of Trolox/ml). Mean ORAC values of Merlot wines (mean= 27.6 micromol of Trolox/ml) were lower than the other three styles (mean for Cabernet Sauvignon wines = 41.0 micromol of Trolox/ml, mean for Chardonnay wines = 42.8 micromol of Trolox/ml, and mean for Riesling wines = 39.4 micromol of Trolox/ml). Free stilbene levels (four different stilbenes) were examined by direct-HPLC/DAD/ESI-MS/MS method. Piceid and resveratrol (both trans- and cis-) were found in the samples. Stilbene levels ranged from 0.97 mg (Riesling wine) to 12.88 mg (Cabernet Sauvignon wine) expressed as trans-resveratrol/l. This is the first paper to report the current chemical composition of Idaho wines.