Evaluation of Headspace Volatiles of Cabernet Sauvignon Wines Sampled by an On-Column Method

An on-column method for direct headspace sampling was used to quantify volatiles of 20 1986 Cabernet Sauvignon wines from six regions in Napa Valley, CA. Most of the compounds were products of yeast fermentation, although 1-(1-methylethoxy)butane and 3-propylcyclopentene have not been reported in wine previously. The wines were classified correctly into region by stepwise discriminant analysis using six peaks, while principal component analysis (PCA) of the GC peaks showed some clustering by region. In contrast PCA of sensory ratings of these wines described elsewhere failed to cluster the wines on the basis of origin. Although the headspace method is reproducible and would be useful for analysis of major grape and fermentation volatiles, it cannot detect trace compounds, many of which are significant sensorially.