## Results and Discussion  
### Volatile components in fresh Jinchen fruit juice and peel oil  
In the analysis of volatile components present in Jinchen fruit juice, a total of 49 compounds were identified including 20 hydrocarbons, 10 aldehydes, nine esters, nine alcohols, and one ketone (Table 1). Limonene, followed by linalool, terpinen-4-ol, \(\beta\)-myrcene, \(\alpha\)-terpineol, octanal, and \(\gamma\)-terpinene were the components found in greatest proportions. \begin{table}
\begin{tabular}{r c c c c c} \hline \hline
**RI** & \multirow{2}{*}{**RIL**} & \multirow{2}{*}{**Compound name**} & \multicolumn{2}{c}{**Peak area (\%) \(\pm\) SD**} & \multirow{2}{*}{**Identification**} \\ \cline{4-5}
**(HP-5)** & & & **Fruit juice** & & **Peel oil** & \\ \hline
600 & 613 [29] & Ethyl acetate & 0.02\(\pm\)0.00 & n.d. & MS, RT \\
710 & 712 [29] & Ethyl propanoate & 0.01\(\pm\)0.01 & n.d. & MS, RI \\
725 & 724 [29] & Methyl butanoate & trace & n.d. & MS, RI \\
794 & 806 [29] & Hexanal & 0.07\(\pm\)0.06 & n.d. & MS, RT \\
796 & 800 [11] & Ethyl butanoate & 0.24\(\pm\)0.03 & n.d. & MS, RT \\
847 & 848 [11] & _trans_-2-Hexenal & 0.05\(\pm\)0.00 & n.d. & MS, RT \\
900 & 910 [29] & Heptanal & trace & n.d. & MS, RI \\
924 & 923 [30] & \(\alpha\)-Thujene & 0.03\(\pm\)0.02 & 0.04\(\pm\)0.00 & MS, RI \\
930 & 934 [11] & \(\alpha\)-Pinene & 0.61\(\pm\)0.10 & 0.76\(\pm\)0.02 & MS, RT \\
958 & 968 [29] & Benzaldehyde & 0.04\(\pm\)0.01 & n.d. & MS, RT \\
971 & 974 [11] & Sabinene & 0.02\(\pm\)0.01 & 0.49\(\pm\)0.01 & MS, RI \\
973 & 990 [11] & \(\beta\)-Pinene & 0.07\(\pm\)0.01 & n.d. & MS, RI \\
991 & 994 [11] & \(\beta\)-Myrcene & 2.38\(\pm\)0.33 & 1.88\(\pm\)0.04 & MS, RT \\
1004 & 1005 [15] & Octanal & 1.36\(\pm\)0.13 & 0.34\(\pm\)0.09 & MS, RT \\
1010 & 1012 [11] & \(\delta\)-3-Carene & n.d. & 0.14\(\pm\)0.07 & MS, RI \\
1007 & 1039 [15] & Limonene & 77.8\(\pm\)4.86 & 90.85\(\pm\)0.11 & MS, RT \\
1053 & 1036 [10] & _cis_-\(\beta\)-Ocimene & 0.28\(\pm\)0.02 & 0.26\(\pm\)0.03 & MS, RI \\
1063 & 1074 [11] & \(\gamma\)-Terpinene & 0.92\(\pm\)0.23 & 1.21\(\pm\)0.03 & MS, RI \\
1074 & 1074 [11] & 1-Octanol & 0.04\(\pm\)0.02 & n.d. & MS, RT \\
1089 & 1096 [11] & Terpinolene & 0.18\(\pm\)0.02 & 0.08\(\pm\)0.00 & MS, RI \\
1104 & 1107 [11] & Linalool & 3.9\(\pm\)0.82 & 0.92\(\pm\)0.02 & MS, RT \\
1106 & 1109 [11] & Nonanal & n.d. & 0.08\(\pm\)0.01 & MS, RT \\
1133 & 1133[29] & Ethyl 3-hydroxy- & 0.08\(\pm\)0.01 & n.d. & MS, RI \\  & & hexanoate & & & \\
1135 & & (\(\pm\))-4-Acetyl-1-methyl- & 0.03\(\pm\)0.01 & n.d. & MS \\  & & cyclohexene & & & \\
1139 & 1147 [11] & _trans_-Limonene oxide & n.d. & 0.01\(\pm\)0.00 & MS, RI \\
1149 & 1159 [11] & \(\beta\)-Terpineol & 0.15\(\pm\)0.11 & n.d. & MS, RI \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Volatile components identified in fruit juice and peel oil of Jinchen fruit by GC-MS. In peel oil extracts, a total of 32 compounds were identified in the volatile fraction, including 16 hydrocarbons and eight aldehydes, three esters, three alcohols, one ketone and one terpenic oxide (Table 1). Among these components, limonene was the one found in greatest concentrations, representing 90.85% of all volatiles. Other predominant components were \(\beta\)-myrcene, \(\gamma\)-terpinene, lanalool and \(\alpha\)-pinene. In both samples the major compounds were monoterpenes and sesquiterpenes. The peel oil contained terpen at higher levels than those of the fruit juice, except for _cis-_\(\beta\)-ocimene, \(\beta\)-myrcene, terpinolene, \(\delta\)-amorphene and valencene. Three sesquiterpenes which could not be found in peel oil were detected in small quantity in fruit juice: \(\alpha\)-cubebene, \(\beta\)-elemene, and \(\alpha\)-caryophyllene. Bicyclogermacrene, which had been reported in lime oils by [PERSON] _et al_. [9] and [PERSON] _et al_. [31] was found in Jinchen peel oil in minor amounts (0.01%), but was not found in Jinchen fruit juice. It is interesting to note the large difference between the numbers of alcohols and esters found in the fruit juice and peel oil.