# Effect of Aging Time on the Composition of the Volatile Components of An-tea
## 3 Results
### Relative Compositions of Volatile Compounds in Differently Aged An-tea Samples
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Type**} & \multirow{2}{*}{**Peak**} & \multirow{2}{*}{**Compound**} & \multirow{2}{*}{**Structure**} & \multirow{2}{*}{**Molecular Formula**} & \multicolumn{4}{c}{**Relative Content \% (Mean \(\pm\) SD)**} \\ \cline{6-9}  & & & & & **HAS** & **MAS** & **LAS** & **CK** \\ \hline  & 5 & Ethylene & & C\({}_{6}\)H\({}_{10}\) & 0.37 \(\pm\) 0.10 & - & - & - \\  & 6 & 6.6-Dimethylfulven & & C\({}_{6}\)H\({}_{10}\) & 0.30 \(\pm\) 0.09 & - & - & - \\  & 7 & Styrene & C\({}_{6}\)H\({}_{8}\) & - & - & 0.28 \(\pm\) 0.07 & - \\  & 11 & \(\beta\)-Pinen & C\({}_{10}\)H\({}_{16}\) & - & - & 1.39 \(\pm\) 0.10 & 0.93 \(\pm\) 0.02 \\  & 14 & \(D\)-Limonene & C\({}_{10}\)H\({}_{16}\) & - & 1.85 \(\pm\) 0.03 & 1.68 \(\pm\) 0.02 & - \\  & 15 & Limonene & C\({}_{10}\)H\({}_{16}\) & 2.55 \(\pm\) 0.37 & - & - & \\ Hydrocarbons & 16 & \(D\)-Limonene & C\({}_{10}\)H\({}_{16}\) & - & - & - & 1.30 \(\pm\) 0.15 \\  & 23 & G-Terpinene & C\({}_{10}\)H\({}_{16}\) & - & - & - & 0.61 \(\pm\) 0.16 \\  & 37 & Naphthalene & C\({}_{10}\)H\({}_{18}\) & 1.35 \(\pm\) 0.03 & 0.51 \(\pm\) 0.02 & 2.03 \(\pm\) 0.14 & 1.58 \(\pm\) 0.15 \\  & 40 & 2-Carene & C\({}_{10}\)H\({}_{16}\) & - & - & 0.51 \(\pm\) 0.05 & - \\  & 41 & \(\alpha\)-Terpinene & C\({}_{10}\)H\({}_{16}\) & 0.78 \(\pm\) 0.04 & - & - & - \\  & 48 & 1-Methylnaphthalene & C\({}_{11}\)H\({}_{10}\) & 0.93 \(\pm\) 0.24 & 0.34 \(\pm\) 0.05 & 0.72 \(\pm\) 0.03 & - \\  & 59 & 4-Isopropyl-1,1-biphenyl & C\({}_{15}\)H\({}_{16}\) & - & 2.59 \(\pm\) 0.52 & - & - \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Cont. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Type**} & \multirow{2}{*}{**Peak**} & \multirow{2}{*}{**Compound**} & \multirow{2}{*}{**Structure**} & \multirow{2}{*}{**Molecular Formula**} & \multicolumn{4}{c}{**Relative Content \% (Mean \(\pm\) SD)**} \\ \cline{5-8}  & & & & & **HAS** & **MAS** & **LAS** & **CK** \\ \hline  & 4 & 1-Ethyl-1H-pyrrole & & C\({}_{\rm H}\)H\({}_{\rm N}\) & 0.34 \(\pm\) 0.10 & - & 0.39 \(\pm\) 0.01 & - \\  & 34 & 1-(1H-pyrrol-2-yl)ethan-1- & & C\({}_{\rm H}\)H\({}_{\rm N}\)O & 0.59 \(\pm\) 0.06 & - & 0.87 \(\pm\) 0.01 & - \\  & 45 & Benzonitrile & & C\({}_{\rm H}\)H\({}_{\rm N}\) & - & - & - & 4.05 \(\pm\) 0.14 \\ Nitrogen-containing compounds & 60 & 1,8-Dimethyl-9H-carbazole & & C\({}_{\rm H}\)H\({}_{\rm N}\)N & 0.55 \(\pm\) 0.05 & - & - & - \\  & 62 & 3,5-Dimethyl-9H-carbazole & & C\({}_{\rm H}\)H\({}_{\rm N}\)N & – & 2.65 \(\pm\) 0.42 & - & 0.64 \(\pm\) 0.01 \\  & 63 & 2,7-Dimethyl-9H-carbazole & & C\({}_{\rm H}\)H\({}_{\rm N}\)N & & 4.21 \(\pm\) 0.69 & - & - \\  & 64 & Caffe & & C\({}_{\rm H}\)H\({}_{\rm N}\)H\({}_{\rm N}\)O\({}_{2}\) & & 0.30 \(\pm\) 0.01 & - & - \\ \hline  & 12 & 2-Pentylfuran & & C\({}_{\rm H}\)H\({}_{\rm N}\)O & 1.43 \(\pm\) 0.50 & 1.27 \(\pm\) 0.06 & 0.67 \(\pm\) 0.13 & 0.41 \(\pm\) 0.12 \\  & 13 & 2-Acetylfuran & & C\({}_{\rm H}\)H\({}_{\rm N}\)O\({}_{2}\) & - & - & - & 0.82 \(\pm\) 0.50 \\ others & 32 & 1,2-Dimethoxybenzene & & C\({}_{\rm H}\)H\({}_{\rm N}\)O\({}_{2}\) & - & 1.59 \(\pm\) 0.02 & - & - \\  & 38 & 1,3-Dimethoxybenzene & & C\({}_{\rm H}\)H\({}_{\rm N}\)O\({}_{2}\) & 2.00 \(\pm\) 0.63 & 5.04 \(\pm\) 0.01 & - & - \\  & 56 & 5-Metoxy-6-7- & & C\({}_{\rm H}\)H\({}_{\rm N}\)O\({}_{2}\) & - & 2.13 \(\pm\) 0.07 & - & - \\  & & dimethylbenzofuran & & C\({}_{\rm H}\)H\({}_{\rm N}\)O\({}_{2}\) & - & 2.13 \(\pm\) 0.07 & - & - \\ \hline \hline \end{tabular}
\end{table} 
Table 2: _Cont._The relative contents of the volatile compounds in samples with different aging times were significantly different from each other, disregarding those of CK. The relative contents of ketones in the HAS, MAS, and LAS samples were 19.29%, 21.09%, and 31.22%, respectively, while those of aldehydes were 17.72%, 20.00%, and 21.35%, respectively, with the content of both compounds tending to decrease with increasing aging time. This was consistent with the decreasing trend in the aldehyde content reported for aged Pu'er tea [18].