Resumen de Methoxypyrazines in Sauvignon blanc Grapes and Wines
M. J. Lacey, M. S. Allen, R. L. N. Harris, W. Vance Brown
Three methoxypyrazines were identified and quantified by gas chromatography/mass spectrometry in wine and juice samples of Vitis vinifera L. cv. Sauvignon blanc. Twenty-two wines of Australian, New Zealand, and French origin were analyzed together with 16 juice samples from four Australian regions. 2-Methoxy-3-(2-methylpropyl)pyrazine was present in all wines (0.6 - 38.1 ng/L) and all juice samples (0.6 - 78.5 ng/L); it was invariably the major methoxypyrazine. 2-Methoxy-3-(1-methylethyl)pyrazine was found in 11 wines (0.9 - 5.6 ng/L) and almost all juice samples (0.2 - 6.8 ng/L). In three wines and some juice samples, small quantities of 2-methoxy-3-(1-methylpropyl)pyrazine were found (typically 0.1 - 1.0 ng/L). Methoxypyrazine levels in the New Zealand wines were significantly higher than in the Australian wines (p < 0.001). Fruit grown under cool conditions gave higher grape methoxypyrazine levels than fruit grown under hot conditions. Grape methoxypyrazine levels were relatively high at veraison but decreased markedly with ripening.
