Resveratrol content of Palomino fino grapes: influence of vintage and fungal infection.

The objective of this study was to determine the influence of certain factors on the resveratrol content of Palomino fino grapes, cultivated in the Jerez-Xérèz-Sherry area, at the moment of harvest. The results show that the resveratrol content is highly influenced by the climatic conditions prior to the period of maturation of the fruit. On the other hand, the gray mold pressure in the vineyard, a fungal infection caused by Botrytis cinerea, increased the resveratrol contents at the early stages of fungal development. When Botrytis development was extensive, the resveratrol content tended to decrease in the juice but tended to increase in the skin. Physiological stress of the plant leads to increases in the resveratrol content, caused as much by the climatic conditions of the vintage as by biotic factors. In this case resveratrol is present mainly in the glycosylated form.