Aroma Components of Vitis vinifera L. cv. Chenin blanc Grapes and Their Changes During Maturation

Abstract

Samples of Chenin blanc grapes from 3 localities and at various stages of maturity were harvested over a period of 11 weeks. The freon extracted aroma components were subjected to gas chromatographic and coupled gas chromatographic-mass spectrometric analyses. No measureable amounts of terpenoid components were detected in any of the samples. Two isomers of 2,4-decadienal, a novel component in Vitis vinifera L. cultivars, occurred in relatively large concentrations in all samples. Origin of sample and degree of maturity have an insignificant effect on the concentration of selected aroma components. Vitis vinifera L. cv. Chenin blanc is economically the most important wine grape cultivar grown in the Republic of South Africa and comprises approximately 26% of all vines. Chenin blanc grapes have a neutral taste and this neutrality extends to the wine as far as cultivar character is concerned. Most young Chenin blanc wines exhibit a fruity-estery aroma caused by volatiles formed during fermentation. Occasionally some wines of this cultivar exhibit a highly desireable guava-like aroma. This aroma is, however, also found in other cultivars eg. V. vinifera L. cv. Colombar (Du Plessis & Augustyn, 1981) and dis-appears with ageing of the wine. To date no information relating to the volatile aroma components of Chenin blanc grapes has been published. This study was initiated to determine the volatile aroma components of Chenin blanc grapes and to monitor con-centration changes in selected components during berry maturation.