# Pairing Red Wine and Closure: New Achievements from Short-to-Medium Storage Time Assays
## 3 Results and Discussion
### Phenolic Profile of Wines Sealed with Different Types of Closures
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \(t_{\text{R}}\) **(min)** & **Phenolic Compound** & **[M-H]\({}^{-}\) (m/z)** & **MS\({}^{2}\) product ions** (m/z)** & **Natural Cork 2** & **Micro A** & **Micro E** & **Screw Cap** \\ \hline \multicolumn{5}{c}{_Phenolic acids_} \\
7.03 & Coutaric acid \({}^{\text{a}}\) & 295 & 163 (100) [39] & 17.64 \(\pm\) 2.14 \({}^{\text{a}}\) & 18.35 \(\pm\) 0.32 \({}^{\text{a}}\) & 14.31 \(\pm\) 2.84 \({}^{\text{b}}\) & 17.91 \(\pm\) 0.56 \({}^{\text{a}}\) \\
12.68 & Elagic acid \({}^{\text{b}}\) & 301 & 257 (100), 229 (70) [38] & 8.19 \(\pm\) 2.50 \({}^{\text{a}}\) & 10.19 \(\pm\) 0.62 \({}^{\text{a}}\) & 10.49 \(\pm\) 0.70 \({}^{\text{a}}\) & 9.35 \(\pm\) 0.78 \({}^{\text{b}}\) \\ \multicolumn{5}{c}{_Flavorols_} \\
13.36 & Quercetin-glucuronide \({}^{\text{c}}\) & 477 & 301 (100), & 17.78 \(\pm\) 1.49 \({}^{\text{a}}\) & 19.24 \(\pm\) 0.77 \({}^{\text{b}}\) & 19.07 \(\pm\) 0.62 \({}^{\text{a}}\) & 18.12 \(\pm\) 1.43 \({}^{\text{a}}\) \\
15.39 & Isornhanthen-hexoside \({}^{\text{c}}\) & 477 & 315 (100) [43] & 7.24 \(\pm\) 4.92 \({}^{\text{a}}\) & 10.57 \(\pm\) 0.41 \({}^{\text{a}}\) & 10.31 \(\pm\) 0.43 \({}^{\text{a}}\) & 11.41 \(\pm\) 0.93 \({}^{\text{b}}\) \\ \multicolumn{5}{c}{_Attobeaus_} \\
11.04 & Malvidin-3-O-glucose \({}^{\text{d}}\) & 493 & 331 (100) [42] & 1.84 \(\pm\) 0.18 \({}^{\text{a}}\) & 2.34 \(\pm\) 0.27 \({}^{\text{b}}\) & 2.33 \(\pm\) 0.49 \({}^{\text{a}}\) & 1.82 \(\pm\) 0.11 \({}^{\text{a}}\) \\
17.80 & Peonidin-3-O-glucose \({}^{\text{d}}\) & 625 & 463 (100), 301 (20) [20] & 2.30 \(\pm\) 0.31 \({}^{\text{a}}\) & 2.99 \(\pm\) 0.34 \({}^{\text{a}}\) & 2.26 \(\pm\) 0.17 \({}^{\text{a}}\) & 2.93 \(\pm\) 0.38 \({}^{\text{b}}\) \\
18.44 & Malvidin-3-O-glucoseFrom the 25 compounds identified and quantified in the Douro red wines (Supplementary Material Table S1), only 8 compounds exhibited significant differences among the wines sealed with different stoppers (1 phenolic acid, 4 flavonols, and 3 anthocyanins), which were present in slightly lower amounts in the wines bottled with Natural Cork 1. However, the observed magnitude of variation is subtle, with fold changes < 0.25-fold (Table 6). The slight changes in the phenolic profile of the wines sealed with different closures may be the result of a balance between migrations from cork-related closures and/or chemical modifications that may occur under post-bottling conditions [11; 21]. For instance, an oxidative environment supported by closures may promote oxidative polymerization reactions, which can cause a rapid decrease in free anthocyanins. Flavanols may also be involved in redox reactions [11]. Concerning the polyphenol migration from cork to wine, a previous study showed that natural cork stoppers and agglomerated cork stoppers showed similar behavior, as no significant differences were observed [21]. There is no evidence of significant changes in the total levels of phenolic compounds among wines sealed with different closures. However, considering that Natural Cork 1 tended to exhibit higher OTR compared to Micro A (Figure 1), it may be inferred that OTR may impact the evolution of phenolic compounds in Douro red wine using different types of stoppers. These results can also be correlated with the sensorial analysis, which showed that the wine sealed with Natural Cork 1 exhibited a slightly higher level of oxidation for retronasal perception. However, no obvious association was observed between the evolution of phenolic profiles and the chromatic properties of wines, which seems to make sense, given that the changes are very subtle. For the short storage assay with Burgenland red wines, there are no clear evolution profiles depending on the type of closure; however, in the case of wines sealed with Natural Cork 2, a tendency for decreasing phenolic compounds concentrations was also observed.