# Free Monoterpene Isomer Profiles of _Vitis Vinifera_ L. cv. White Wines
## 2 Materials and Methods
### Enantiomer Fraction (EF) in Varietal Wines
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\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline  & **S(\(\rightarrow\)–)** & **(ER,4S)(\(\rightarrow\))-(\(\rightarrow\))cis** & **(ER,4R)-(\(\rightarrow\))** & **(ER,5R)(\(\rightarrow\))** & **(ER,5S)(\(\rightarrow\)–)** & **(ER,5S)(\(\rightarrow\))** & **(\(\rightarrow\))-** \\  & **limonenter/total** & **rose** & **trans-rose** & **trans-linal** & **cis-linal** & **cis-linal** & **solid/total** & **finalool/total** & **-terpine/total** \\ \hline \hline \multicolumn{1}{c}{Chardenay} & 0.39 \(\pm\) 0.00 \({}^{\rm a}\) & 0.23 \(\pm\) 0.00 \({}^{\rm a}\) & 1,00 \(\pm\) 0.00 \({}^{\rm c}\) & 0.78 \(\pm\) 0.02 \({}^{\rm b}\) & 0.77 \(\pm\) 0.01 \({}^{\rm d}\) & 0.59 \(\pm\) 0.02 \({}^{\rm d}\) & 0.79 \(\pm\) 0.03 \({}^{\rm b}\) & 0.86 \(\pm\) 0.05 \({}^{\rm b}\) \\ \multicolumn{1}{c}{[PERSON]} & 0.66 \(\pm\) 0.02 \({}^{\rm b}\) & 0.25 \(\pm\) 0.02 \({}^{\rm b}\) & 0.86 \(\pm\) 0.03 \({}^{\rm b}\) & 0.49 \(\pm\) 0.03 \({}^{\rm c}\) & 0.49 \(\pm\) 0.03 \({}^{\rm d}\) & 0.42 \(\pm\) 0.00 \({}^{\rm b}\) & 0.52 \(\pm\) 0.01 \({}^{\rm a}\) & 0.49 \(\pm\) 0.00 \({}^{\rm a}\) \\ \multicolumn{1}{c}{Muscat} & 0.63 \(\pm\) 0.01 \({}^{\rm b}\) & 0.41 \(\pm\) 0.05 \({}^{\rm d}\) & 0.76 \(\pm\) 0.05 \({}^{\rm b}\) & 0.70 \(\pm\) 0.02 \({}^{\rm b}\) & 0.67 \(\pm\) 0.01 \({}^{\rm b}\) & 0.43 \(\pm\) 0.00 \({}^{\rm b}\) & 0.54 \(\pm\As can be seen in Table 3, _S_-(\(-\))-limonene EF was 0.39 in Chardonnay and Pinot gris, and 0.50 in Sauvignon blanc wines, which were significantly different from other varietal wines (\(p<0.05\)). (\(2R\),\(4S\))-(+)-_cis_-Rose oxide EF was lower than 0.50 for all of the wines, which indicates that (\(2S\),\(4R\))-(\(-\))-_cis_-rose oxide was the main _cis_-rose oxide enantiomer in all varietal wines. (\(2R\),\(4S\))-(\(-\))_-trans_-Rose oxide EF was greater than 0.50 in all varietal wines and implies that (\(2R\),\(4R\))-(\(-\))_-trans_-Rose oxide was the main _trans_-rose oxide enantiomer. (\(2R\),\(5R\))-(\(+\))_-trans_-Linalool oxide and (\(2R\),\(5S\))-(\(-\))_-cis_-linalool oxide had EFs greater than 0.50 in all varietal wines, except Viognier wines (0.37). _S_-(\(-\))-nerol oxide and \(R\)-(\(+\))-nerol oxide had very similar EF in all of the varietal wines. \(R\)-(\(-\))-linalool and _S_-(\(-\))-\(\alpha\)-terpineol were both more than or equal to the corresponding enantiomer pair in all of the wines. The enantiomeric differences in the wines from different varieties can be seen vividly in Figure 4 and Figure S3. Varieties were separated into two scatterplots (Figure 4 and Figure S6) for the same enantiomer pair. The fitted lines were plotted for all wines from a single variety with some exceptions (Table 4), for example, Chardonnay, Pinot gris, and Sauvignon blanc wines in _S_-(\(-\))-limonene vs. \(R\)-(\(+\))-limonene scatterplot did not have fitted lines since there were only one or two data points in the scatterplot for these varieties. The coefficient of determination \(R^{2}\) is the square of correlation between the actual value and the predicted value in a linear model, and can be interpreted as a measure of the variability in the response variable of enantiomeric ratios in each variety (higher \(R^{2}\) values indicating less variability of the response with respect to the fitted line). Most of the varieties showed high \(R^{2}\) values in enantiomer  
Figure 4: X-Y scatterplots of enantiomer pair concentrations (\(\mu\)g/L) in all varietal wines with fitted lines and adjusted \(R^{2}\). pairs, with \(R^{2}\) values greater than 0.8 (Table 4). Only one enantiomer pair had low \(R^{2}\) values (lower than 0.8) in Chardonnay, Pinot gris, and Viognier wines. The low \(R^{2}\) values in \(S\)-(\(-\))-limonene pair of Riesling and Torrontes wines were all from medium sweet and sweet styles.