A Global Survey of Trans-Resveratrol Concentrations in Commercial Wines

Abstract

Using a solid-phase extraction followed by direct-injection gas chromatography-mass spectrometry, the concentration of trans-resveratrol was measured in a representative selection of wines from most of the prominent wine-producing countries and regions of the world. With the exception of Swiss and German wines, virtually all of the white wines tested had trans-resveratrol concentrations <0.1 mg/L. Consistently high concentrations were measured in wines from Pinot noir, irrespective of origin. On the other hand, Cabernet Sauvignon wines covered a wide range of concentrations, with relatively high values in those from cool-climate countries such as Ontario and the Bordeaux region of France, whereas such wines from warmer climates such as California, South America, and Australia tended to have much lower concentrations. Differences between the communes of Bordeaux and Burgundy were noted, with Cotes de Nuits wines having higher concentrations than those of Cotes de Beaune, and in Bordeaux, wines of the Medoc, St. Emilion, and Pomerol had lower concentrations than those found in wines from other communes. Among the other prominent wine-producing regions, wines from Italy, Spain and Portugal tended to have low concentrations in line with their relatively warm and dry climatic conditions, but those of the Rhone Valley where the climate is similar had relatively high trans-resveratrol concentrations. The higher concentrations reported in this study compared with three earlier reports could be due to the quantitative recovery inherent in the solid-phase extraction used in the present assay, and/ or losses occurring during organic phase extraction in the latter.