## 2 Results
### Evolution of Aroma Compounds during Cold Maceration Stage
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Aroma Components**} & \multirow{2}{*}{**Retention**} & \multirow{2}{*}{**Standards**} & \multirow{2}{*}{**Quantitative**} & \multicolumn{2}{c}{**Concentrations (\(\mu\)g/kg)**} \\ \cline{5-5}  & & & & **Methods** & **Marselan** & **Merlot** \\ \hline C6/C9 compounds & & & & & \\
1-Hexanol & 1349.2 & 1-Hexanol & A.Q. & 63.7 \(\pm\) 6.01 ** & 40.07 \(\pm\) 5.15 \\ (_Z_)-3-Hexen-1-ol & 1381.7 & (_Z_)-3-Hexenol & A.Q. & 38.76 \(\pm\) 4.49 ** & 11.08 \(\pm\) 0.88 \\ (_E_)-2-Hexen-1-ol & 1402.4 & (_E_)-2-Hexenol & A.Q. & 44.27 \(\pm\) 6.54 & 92.76 \(\pm\) 3.52 ** \\ 2-Nonanol & 1084.2 & 2-Nonanol & A.Q. & 0.27 \(\pm\) 0.02 & 0.28 \(\pm\) 0.03 \\ 1-Nonanol & 1659.3 & 2-Nonanol & R.Q. & 0.32 \(\pm\) 0.07 & 0.32 \(\pm\) 0.13 \\ (_Z_)-3-Nonen-1-ol & 1685.6 & 2-Nonanol & R.Q. & 0.17 \(\pm\) 0.03 & 0.20 \(\pm\) 0.01 \\ Straight-chain aliphatics & & & & & \\
2-Heptanol & 1315 & 2-Heptanol & A.Q. & 0.66 \(\pm\) 0.09 ** & 0.24 \(\pm\) 0.02 \\
2-Octanol & 1550.6 & 1-Octanol & R.Q. & 0.26 \(\pm\) 0.02 & 0.28 \(\pm\) 0.03 \\
1-Octen-3-ol & 1446.8 & 1-Octen-3-ol & A.Q. & 0.57 \(\pm\) 0.09 & 1.24 \(\pm\) 0.41 \\
1-Heptanol & 1451.5 & 1-Heptanol & A.Q. & 0.68 \(\pm\) 0.07 & 0.64 \(\pm\) 0.2 \\
1-Decanol & 1970.2 & 1-Decanol & A.Q. & 0.18 \(\pm\) 0.05 & 0.19 \(\pm\) 0.06 \\
1-Octanol & 1555.4 & 1-Octanol & A.Q. & 0.58 \(\pm\) 0.06 & 0.62 \(\pm\) 0.22 \\ Branched-chain & & & & & \\ aliphatics & & & & \\ Isoamyl alcohol & 1199.8 & 3-Methylpentanol & R.Q. & 7.91 \(\pm\) 1.42 & 12.71 \(\pm\) 5.75 \\
2-Ethylhexanol & 1486.6 & 2-Ethylhexanol & A.Q. & 0.52 \(\pm\) 0.19 & 0.57 \(\pm\) 0.11 \\ Aromatic compounds & & & & & \\ Methyl salicate & 1793.3 & Methyl salicate & A.Q. & 1.85 \(\pm\) 0.29 & 2.92 \(\pm\) 1.43 \\ Benzyl alcohol & 1885.7 & Benzyl alcohol & A.Q. & 235.87 \(\pm\) 28.17 & 512.25 \(\pm\) 10.05 ** \\ Phenethyl alcohol & 1921.3 & Phenethyl alcohol & A.Q. & 181.72 \(\pm\) 25.1 * & 106.52 \(\pm\) 21.13 \\ Phenol & 2015.8 & Phenol & A.Q. & 4.50 \(\pm\) 0.3 & 4.99 \(\pm\) 0.37 \\ Tepenes & & & & & \\ Linalool & 1546.1 & Linalool & A.Q. & 1.59 \(\pm\) 0.19 * & 0.76 \(\pm\) 0.35 \\ \(\alpha\)-Terpineol & 1702.3 & \(\alpha\)-Terpineol & A.Q. & 1.42 \(\pm\) 0.16 ** & 0.60 \(\pm\) 0.11 \\ Norisoprenoids & & & & & \\ Vitispirane A & 1539.3 & \(\beta\)-Damascenone & R.Q. & 14.93 \(\pm\) 1.58 ** & 8.15 \(\pm\) 0.09 \\ Vitispirane B & 1542 & \(\beta\)-Damascenone & R.Q. & 13.82 \(\pm\) 1.37 ** & 7.93 \(\pm\) 0.39 \\ (_E_)-\(\beta\)-Damascenone & 1835.3 & \(\beta\)-Damascenone & A.Q. & 20.98 \(\pm\) 1.6 & 19.11 \(\pm\) 0.53 \\ \hline \hline \end{tabular} Note: * \(p\) \(<\) 0.05; **_p_ \(<\) 0.01. A.Q.: absolute quantification; R.Q.: relative quantification.  
\end{table} 
Table 2: Comparison of glycosidically bound aroma compounds between ‘Marselan’ and ‘Merlot’ grapes. (_E_)-\(\beta\)-damascenone in 'Marselan' showed a clear upward trend, while they remained at a low level in 'Merlot' (Figure 1C). However, the levels of glycosidically bound alcohols, isoamyl alcohol, (_E_)-2-hexen-1-ol, and 1-hexanol showed a continuous increase in both 'Marselan' and 'Merlot'. 'Marselan' had a higher overall increasing rate compared to 'Merlot' (Figure 1C). Cluster 3 contained 11 aroma compounds, most of which were in free form, with the exception of ethyl acetate and 1-nonanol in the bound form. Additionally, these compounds in Cluster 3 did not show significant difference between two varieties, with similar leaching rates (Figure 1D). The compounds in cluster 4 and cluster 5 exhibited minimal fluctuations during the soaking process. Cluster 4 primarily comprised of bound-form phenethyl alcohol and free-form (_E_)-2-hexenal, while cluster 5 mainly consisted of aromatic alcohols and ketones. It is worth noting that most aroma compounds were only detected in 'Merlot'.