## 2 Results and Discussion
### Volatile Composition
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Compounds**} & \multirow{2}{*}{**RI**} & \multirow{2}{*}{**Threshold (mg/L)**} & \multirow{2}{*}{**Sensory properties**} & \multicolumn{3}{c}{**Concentration (ug/L)**} \\ \cline{5-6}  & & & & **F-Land** & **LS-Land** & **HS-Land** \\ \hline Esters & & & & & & \\ \hline Ethyl acetate & 877 & 7.5 [5] & Fruity, sweet & 64571.6 \(\pm\) 298.4 \({}^{\circ}\) & 107130.0 \(\pm\) 889.6 \({}^{\circ}\) & 123756.8 \(\pm\) 928.3 \({}^{\circ}\) \\ Ethyl butanoate & 1032 & \(2\times 10^{-2}\) [5] & Sour fruit, fruity & nd & 265.8\(\pm\)23.0 \\ Ethyl hexanoate & 1232 & \(5\times 10^{-3}\) [5] & Furity, arise & 51090.6 \(\pm\) 64.0 \({}^{\circ}\) & 63860.7 \(\pm\) 36.7 \({}^{\circ}\) & 64627.6 \(\pm\) 501.9 \({}^{\circ}\) \\ Phenethyl acetate & 1830 & \(2.5\times 10^{-1}\) [5] & Pleasant, floral & 8.1 \(\pm\) 03 \({}^{\circ}\) & 31.8 \(\pm\) 1.7 \({}^{\circ}\) & 36.9 \(\pm\) 4.4 \({}^{\circ}\) \\ Isoamyl acetate & 1122 & \(3\times 10^{-2}\) [5] & Banana & 2238.0 \(\pm\) 113.8 \({}^{\circ}\) & 1569.5 \(\pm\) 29.3 \({}^{\circ}\) & 20651.5 \(\pm\) 59.5 \({}^{\circ}\) \\ Heyl acetate & 1287 & 6.7 \(\times\) 10 [35] & Pleasant fruity, pear & 178.1 \(\pm\) 3.1 \({}^{\circ}\) & 125.1 \(\pm\) 6.6 \({}^{\circ}\) & 154.9 \(\pm\) 10.7 \({}^{\circ}\) \\ Ethyl lactate & 1363 & 14 [40] & Lactic, raspberry & 42037.2 \(\pm\) 124.4 \({}^{\circ}\) & 4477.4 \(\pm\) 20.9 \({}^{\circ}\) & 5646.6 \(\pm\) 100.1 \({}^{\circ}\) \\ Herbyl acetate & 1051 & 1.4 [36] & Almond, pear & 1.1 \(\pm\) 02.0 \({}^{\circ}\) & 2.1 \(\pm\) 03 \({}^{\circ}\) & 1.5 \(\pm\) 01.0 \({}^{\circ}\) \\ Methyl octanoate & 1111 & \(2\times 10^{-1}\) [36] & Intense citrus & \(2.2\pm 0.0\) & nd & 3.1 \(\pm\) 0.1 \\ Ethyl octanoate & 1429 & \(2\times 10^{-3}\) [5] & Pineapple, pear, floral & 43839.9 \(\pm\) 77.5 \({}^{\circ}\) & 62635.5 \(\pm\) 139.8 \({}^{\circ}\) & 5741.8 \(\pm\) 44.2 \({}^{\circ}\) \\ Isoamyl hexanoate & 2044 & NA & NA & tr & tr & tr \\ Ethyl decanoate & 1637 & \(2\times 10^{-1}\) [5] & Fruity, fatty, pleasant & 861.8 \(\pm\) 2.8 \({}^{\circ}\) & 1148.7 \(\pm\) 45.6 \({}^{\circ}\) & 1200.5 \(\pm\) 77.0 \({}^{\circ}\) \\ Diebly succinate & 1682 & 200 [41] & Light fruity & 7662.2 \(\pm\) 33.4 \({}^{\circ}\) & 1456.9 \(\pm\) 89.6 \({}^{\circ}\) & 1123.0 \(\pm\) 100.5 \({}^{\circ}\) \\ Ethyl dodecanoate & 1848 & 1.5 [36] & Flowery, fruity & 698.5 \(\pm\) 2.9 \({}^{\circ}\) & 1672.4 \(\pm\) 59.9 \({}^{\circ}\) & 3375.1 \(\pm\) 77.7 \({}^{\circ}\) \\ Subtotal (ug/L) & & & 129003.8 & 18773.8 & 207985.1 \\ Proportion (\%) & & & 56.1 & 54.6 & 56.6 \\ \hline Acids & & & & & \\ \hline Isoburric acid & 1607 & 200 [5] & Fatty & nd & 24.7 \(\pm\) 1.3 & nd \\ Hexanoic acid & 1855 & 3 [5] & Cheese, rancid, fatty & 1737.4 \(\pm\)54.2 \({}^{\circ}\) & 4113.2 \(\pm\) 231.0 \({}^{\circ}\) & 3961.0 \(\pm\) 37.1 \({}^{\circ}\) \\ Heptanoic acid & 1990 & 3 [42] & Fatty, dry & tr & \\ Octanoic acid & 2075 & \(5\times 10^{-1}\) [5] & Rancid, harsh, cheese, fatty acid & 1834.4 \(\pm\) 137.8 \({}^{\circ}\) & 4094.4 \(\pm\) 97.8 \({}^{\circ}\) & 3875.1 \(\pm\) 233.4 \({}^{\circ}\) \\ Decanoic acid & 2292 & 15 [5] & Fatty, unpleasant & 501.0 \(\pm\) 100.8 \({}^{\circ}\) & 1483.5 \(\pm\) 30.8 \({}^{\circ}\) & 14041.1 \(\pm\) 74.5 \({}^{\circ}\) \\ Subtotal (ug/L) & & & 4072.8 & 9715.8 & 9240.2 \\ Proportion (\%) & & & 1.8 & 2.8 & 2.5 \\ \hline Acids & & & & & \\ \hline Isoburric acid & 1607 & 200 [5] & Fatty & nd & 24.7 \(\pm\) 1.3 & nd \\ Hexanoic acid & 1855 & 3 [5] & Cheese, rancid, fatty & 1737.4 \(\pm\)54.2 \({}^{\circ}\) & 4113.2 \(\pm\) 231.0 \({}^{\circ}\) & 3961.0 \(\pm\) 37.1 \({}^{\circ}\) \\ Heptanoic acid & 1990 & 3 [42] & Fatty, dry & tr & & \\ Octanoic acid & 2075 & \(5\times 10^{-1}\) [5] & Rancid, harsh, cheese, fatty acid & 1834.4 \(\pm\) 137.8 \({}^{\circ}\) & 4094.4 \(\pm\) 97.8 \({}^{\circ}\) & 3875.1 \(\pm\) 233.4 \({}^{\circ}\) \\ Decanoic acid & 2292 & 15 [5] & Fatty, unpleasant & 501.0 \(\pm\) 100.8 \({}^{\circ}\) & 1483.5 \(\pm\) 30.8 \({}^{\circ}\) & 14041.1 \(\pm\) 74.5 \({}^{\circ}\) \\ Subtotal (ug/L) & & & 4072.8 & 9715.8 & 9240.2 \\ Proportion (\%) & & & 1.8 & 2.8 & 2.5 \\ \hline \hline \end{tabular}
\end{table}