## 3 Results and Discussion
### Phenolic Compounds  
A total of 72 phenolic compounds were identified and quantified in Cabernet Sauvi-gnon and Marselan dry red wine. These phenolic compounds were classified into 10 categories, including monomeric anthocyanins, anthocyanin derivatives (vitisins, pinotins, acetaldehyde-bridged anthocyanin-flavan-3-ol condensation products (A-e-F), flavanyl-pyranoanthocyanins (A-v-F), and direct anthocyanin-flavan-3-ol condensation products (F-A/A-F)), flavan-3-ols, hydroxybenzoic acids, hydroxycinnamates, and flavonoids (Table 3). A paired \(t\)-test was carried out to identify the differences in phenolic compounds between Cabernet Sauvignon and Marselan wines (Table 3). A total of 13 compounds showed significant differences, mainly including 9 anthocyanin derivatives and 3 phenolic acids. Figure 1: Partial least squares–discriminant analysis of Cabernet Sauvignon (CS) and Marselan (MA) dry red wines from five regions in China based on aroma compounds. Trigles represent the explanatory variables (X, aroma compounds). Circles represent the two studied categories (Cabernet Sauvignon and Marselan). Squares represent wine samples and sample names are in accordance with Table 1.  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**No. ** & **Compounds** & **Abbreviation** & \multicolumn{4}{c}{**Abbreviation**} & \multicolumn{4}{c}{**AbceneSawignon**} & \multicolumn{4}{c}{**Marsella**} \\ \cline{2-10}
**1** & **Cyanidine-shooxide** & **Cr3** & **0.19** & **1.7** & **1.5** & **0.15** & **2.45** & **0.95** & **0.792** \\
2** & **Cyanidine-shooxide** & **Cr4** & 0.17 & 1.87 & 0.94 & 0.12 & 2.41 & 0.9 & 0.791** \\
3** & **Cyanidine-O-superhydrophobic** (_cis_ \(\sim\)_trans_) & **Cr4** & 0.12 & 1.85 & 0.65 & 0.11 & 1.56 & 0.67 & 0.653 \\
4** & **De  
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline \multicolumn{1}{c}{**No. **} & \multicolumn{2}{c}{**Compounds**} & \multicolumn{2}{c}{**Abbreviation**} & \multicolumn{2}{c}{**Calement Sauvignon**} & \multicolumn{2}{c}{**Marselian**} & \multicolumn{2}{c}{**\(p\)-Values**} \\ \hline
41 & Multi-3-O-acetyl  
Among the nine anthocyaninin derivatives and three phenolic acids, the mean concentrations of the malvidin-3-O-glucose-4-vinylsyringol (mv-vsol), malvidin-3-O-glucose-4-vinylsquaicol (mv-vgol), malvidin-3-O-glucose-4-vinylcatech (mv-vcol), malvidin-3-O-coumaroylglucose-4-vinylbaiacol (mvC-vgol), malvidin-3-O-glucose-4-vinyl(epi)catechin (mv-v(e)cat), malvidin-3-O-coumaroylglucose-4-vinyl(epi)catechin (mv-d(e)cat), malvidin-3-O-glucose-di(epi)catechin (mv-di(e)cat), and caffe acid (cafA) were higher in Marselan wines than Cabernet Sauvignon wines (Table 3). The higher concentrations of these compounds may be the reason for the deeper color and red hue of Marselan. A relevant study observed more orange hue in anthocyanin with more methoxy substitution (malvidin, petunidin, and peonidin) than hydroxyl substitution (delphinidin and cyanidin) [22]. Moreover, the previous study also showed that aglycones (delphinidin, cyanidin, petunidin, peonidin, malvidin, and pelargonidin) differ from each other in the number of hydroxyl and methoxyl groups on the B-ring, such as the increasing hydroxylation conferring an increase in the blue tint and increasing methylation conferring an increase in the red tint [23; 24]. In our study, the myricetin-3-O-galactoside (myr-3-gal) and quercetin-3-O-galactoside (que-3-gal) concentrations were relatively higher in Cabernet Sauvignon wines. PCA exploratory data analysis was also carried out on the phenolic compounds and found that the phenolic compounds were less influenced by the variety. Then, an overview of the differences in phenolic compounds between Cabernet Sauvignon and Marselan was obtained by PLS-DA (Figure S2). However, the model was not reliable after parameter verification (Q\({}^{2}\) = \(-\)0.291, R\({}^{2}\)X = 0.499, R\({}^{2}\)Y = 0.553).