Varietal wines

Certain aroma components from fruits are responsible for the characteristic odor of many wines. An example is the typical aroma of many V. labrusca grapes which often gives their wines a distinctive aroma and flavor. Furthermore, some volatile constituents are characteristic of certain varieties and their wines are recognized by these distinctive aromas. This is significantly important for varietal wines (grape) where their distinct aromas are a prerequisite in rating the quality at the highest level. In addition to the importance of variety in the aroma and flavor of wines, other variables known to influence the volatile components within the fruit variety are maturity, location, climatic conditions, and cultural practices. 

Even when no additive is used in winemaking, the necessity for small-lot trial before production scale operation is apparent. Because a high percentage of wine is consumed only after chilling, and because chilling may accelerate the precipitation of potassium acid tartrate, ill-defined colloids, anthocyanin-tannin polymers, proteins, etc., simple cold stabilization by refrigeration in the winery may irreversibly alter the product and its eventually-perceived quality level. It often happens, especially in heavy-bodied red varietal wines, that a dark, amorphous precipitate may form in the bottle over several years. Usually tannoid,... 

Wines without a designation of origin current wines (table wines), and wines with an indication of the grape variety and the vintage (varietal wines). 

French varietal wines and in grapes during noble rot development. ]. Agric. Food Chem. 50, 2046-2052. 

Pozo-Bayon, M. A., Pueyo, E., Martfn-Alvarez, P. J., and Polo, M. C. (2001). Polydimethylsi-loxane solid-phase microextraction-gas chromatography method for the analysis of volatile compounds in wines Its application to the characterization of varietal wines.. Chromatogr. A 922,267-275. 

Although current regulations require only 51 percent of a varietal wine be produced from the stated variety, most premium varietals already have a considerably higher percentage of the stated variety. The new requirements probably will have little effect on either the quality of the wine or the availability of grapes. 

Landrault, N., Larronde, R, Delaunay, J.-C., Castagnino, C., Vercauteren, J., Merillon, J.-M., Gasc, R, Cros, G., Teissedre, P.-L. (2002). Levels of stilbene oligomers and astilbin in French varietal wines and in grapes during Noble Rot development. J. Agric. Food Chem., 50, 2046-2052. 

Table 13.4 Results of the application of one-way ANOVA for octanoic acid content in four varietal wines. ANOVA table ...

Table 13.14 Results of applying principal components analysis to the 10 volatile compounds analyzed in 16 varietal wines. Factor loadings matrix ...

As an example, Tables 13.14 and 13.15 show the results of applying principal components analysis to the 10 volatile compounds (methanol, 1-propanol, isobutanol, 2-and 3-methyl-1-butanol, 1-hexanol, cw-3-hexen-l-ol, hexanoic acid, octanoic acid, decanoic acid and ethyl octanoate) analyzed in 16 varietal wines (Pozo-Bay6n et al. 2001), obtained with the STATISTICA program Factor Analysis procedure in Multivariate Exploratory Techniques module, and using Principal Components as Extraction method). The results include the factor loadings matrix for the two first principal components selected q = 2), which explains 70.1% of the total variance (Table 13.14). The first principal component is strongly correlated with d.y-3-hexen-l-ol (-0.888), 1-hexanol (-0.885), 1-propanol (0.870), and... 

Fig. 13.4 Plot of the 16 varietal wines in the plane defined by the first two principal components...

Table 13.16 Results of applying the four groups of varietal wines...

Table 13.17 Results of applying LDA to the data of 10 volatile compounds in order to discriminate the four groups of varietal wines. Posterior probabilities ...

Applications of the Kaltron method and GC-MS in wine aroma analysis were reported by Rapp et al. (1996). The study of the data repeatability in the analysis performed using both Kaltron (Rapp et al., 1994) and polystyrene XAD-2 resin (Gunata et al., 1985 Versini et al., 1988 Voirin et al., 1992) extraction, has already been performed in the cited papers. Besides this, a test with eight repetitions of the whole analytical process using XAD-2 resin has been performed both on a non-floral (Pinot blanc) and a floral (Morio-Muskat) varietal wine for the quantification of 25 varietal and fermentation compounds (Carlin, 1998) for each wine sample the mean CV % values ranged from about 7.0 to 7.5 with a standard deviation from about 3 to 4.7 %, respectively, depending on the different level of some compounds, mostly monoter-penes, in each wine type. 

Common Fermentative Sulphur Volatiles (CFSV) in wine recent results in qualification and discrimination of different varietal wines at different storage time... 

Figure 5.7 Evolution of DMS (a) and ME (b) during the period 1998-2005 in a straight line model for varietal wines from grape Chardonnay (C), Merlot (M), Marzemino (Ma) and Teroldego (T) four wines per vintage were considered...

Figure 5.8b Principal Component Analysis on the four varietal wines. Representation of the loadings of the variables in PCI and PC2 in the by-plot schema of Figure 5.8a...

Tropical Fruit Scenting Sulphur Volatiles (TFSV) in wine recent additional results in quantification and ranging in different varietal wines of Italy... 

Versini, G., Moser, S. and Carlin, S. (2005) Methyl salicylate as a remarkable almost bound compound in some renowned Italian varietal wines, Abstract Proceed. In Vino Analytica Scientia , Montpellier. 

Formation and metabolism of monoterpenes by yeasts. Although certain species of yeasts are capable of producing monoterpenes (80,81), the wine yeast species Saccharomyces cerevlslae appears not to share this capacity (82). Accordingly, it has been concluded that terpene composition in various grape cultivars and varietal wines is not Influenced by fermentation (6,82). Although apparently unable to biosynthesize monoterpenes, wine yeasts may carry out certain transformations of these compounds (e.g. double bond reduction) (83). 

Enhancing varietal wine flavour during fermentation... 

Pineda, A., Carrasco, J., Pena-Farfal, C., Henrfquez-Aedo, K., Aranda, M. (2012). Preliminary evaluation of biogenic amines content in Chilean young varietal wines by HPLC. Food Control, 23, 251-257. http //dx.doi.Org/10.1016/j.foodcont.2011.07.025. 

The presence of and relationship between trans- and cis-resveratrol monomers in the varietal wines from Dalmatia (Croatia), produced according to the Croatian appellation of origin system, were reported [19]. Standard methods of analysis for general wine components were used for a preliminary control of the selected wines. Resveratrol monomers in wine were measured by HPLC. Significant differences... 

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