# Effects of Long-Term Bottle Storage on Red and Rose Wines Sealed with Different Types of Closures
## 3 Results
### Correlations between Sulfur Dioxide, Dissolved Oxygen and Volatile and Phenolic Profiles  
A PCA was applied to understand the influence of SO\({}_{2}\) and dissolved O\({}_{2}\) content on the wine quality. Figure 1A shows that total SO\({}_{2}\) and O\({}_{2}\) contributed together, along with some identified volatile compounds such as butanediol (3), 1-hexanol (8), ethyl hexanoate (13), ethyl octanoate (25), and ethyl decanoate (28), to characterize the Lagrein rose wines closed with both closures.  
Another PCA plot (Figure 1B) was obtained by excluding the rose Lagrein wines, as they had a lower phenolic content than the other three wines, with the aim of better observing the relationship of SO\({}_{2}\) and O\({}_{2}\) with the volatile and phenolic profiles of the red wines. The PCA graph showed that octanoic acid (22) and diethyl succinate (23) showed a stronger relationship with the O\({}_{2}\) content and mainly characterized the Merlot samples. On the other hand, the content of free and total SO\({}_{2}\) were directly correlated with (\(-\))-epicatechin.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Closures**} & **Total Sulfur Dioxide** & **Free Sulfur Dioxide** & **Oxygen Content** \\  & **(mg/L)** & **(mg/L)** & **(mg/L)** \\ \hline \multicolumn{4}{c}{Merlot} \\ \hline C & 38.50 & 26.00 & 1.85 \\ B & 26.50 & 20.00 & 1.05 \\ Pr \textgreater{} F & 0.077 & 0.238 & 0.064 \\ \hline \multicolumn{4}{c}{Lagrein red} \\ \hline C & 37.00 & 22.50 & 0.15 \\ B & 28.50 & 25.00 & 0.10 \\ Pr \textgreater{} F & 0.054 & 0.649 & 0.423 \\ \hline \multicolumn{4}{c}{Lagrein rose} \\ \hline C & 96.00 & 21.00 & 2.00 \\ \hline B & 83.00 & 12.50 & 2.00 \\ \hline Pr \textgreater{} F & 0.049 & 0.003 * & 1.000 \\ \hline \multicolumn{4}{c}{St. Magdalener} \\ \hline C & 36.00 & 16.00 & 0.25 \\ B & 19.00 & 11.50 & 0.05 \\ Pr \textgreater{} F & 0.033 & 0.057 & 0.106 \\ \hline \hline \end{tabular}
\end{table}
Table 5: One-way ANOVA for dissolved oxygen, free and total sulfur dioxide content of wines stored for 30 months and closed with blend closures. Pr > F indicates the \(p\)-value associated with the F statistic. The asterisk (*) means significantly different groups as determined by [PERSON]’s test (\(\alpha\) < 0.01). B and C: blend and conventional closure, respectively.  
Two aspects concerning both PCA plots are noteworthy: in both models, (i) glutathionyl caftaric acid was inversely correlated with total SO2 content and (ii) three fermen  
Figure 1: PCA bi-plot of volatile and non-volatile compounds, SO2 and dissolved O2 contents determined in the wines after 30 months of storage. (**A**) F1 vs F2, Principal Components of three red and one rose wine; (**B**): F1 vs F2; Principal Components of three red wines excluding the rose wine. LRB, LRC: Lagrein rose closed with ’blend’ or ’conventional’ closure, respectively; SB, SC: same for St. Magdalener; LB, LC: same for Lagrein red; MB, MC: same for Merlot. Volatile compounds are represented by numbers, as listed in Table 2. Values were not averaged for experimental replicates (-1: bottle 1, -2: bottle 2).  
tation volatile compounds, including ethyl butanoate (4), isoamyl lactate (17), and octanol (19), were inversely correlated with both free and total SO\({}_{2}\).