Effect of Variety, Ultraviolet Light Exposure, and Enological Methods on thetrans-Resveratrol Level of Wine

Abstract

Resveratrol is one of the wine components related to moderate wine consumption and reduction of serum cholesterol levels. The standard addition method was used with a high pressure liquid chromatography procedure to calculate resveratrol levels. Grape variety, UV light exposure, enzyme addition, skin contact time, and the fining agents, carbon and PVPP, affected the resveratrol levels of wines from the white varieties, Chardonnay and Chardonel, and the red varieties, Cabernet Sauvignon, Cynthiana, and Noble. UV light exposure of the grape clusters significantly increased the resveratrol level in Cynthiana and Noble wine produced in 1994, but did not yield a consistent result in the other experiments from the 1995 and 1996 wines. Enzyme addition significantly increased resveratrol levels in Chardonnay wine but not Chardonel wine. Skin contact time influenced the extraction of resveratrol from the skin in the red varieties, but the maximum extraction time was dependent on the variety of the grapes. Carbon addition decreased the resveratrol level in Noble wine but not in Cynthiana in the 1994 wines. The addition of PVPP significantly lowered resveratrol level in Chardonel, Chardonnay, Cabernet Sauvignon, Cynthiana, and Noble wine. However, low levels of added PVPP addition did not cause significant loss of resveratrol.