## 3 Results and Discussion
### Analysis of ROAV Values of VOCs during the Ripening Process of R. roxburghii
At stage V, the total number of aroma types rose to 17, although mint and metal flavors were absent, featuring a distinctive lemon flavor contributed by \(\alpha\)-terpinene. Figure 3B,C further illustrates that during the ripening of _R. roxburghii_ fruits, both the categories of aroma and their relative concentrations increased. The primary characteristic aromas, which included green, fruit, grass, fat, flower, soap, and wood, accounted for over 85% of the aroma profiles at the first four stages and nearly half at stage V. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multicolumn{2}{c}{**Odor**} & \multirow{2}{*}{**Class**} & \multirow{2}{*}{**Compounds**} & \multicolumn{2}{c}{**Odor**} & \multicolumn{4}{c}{**ROAV**} \\ \cline{5-10} \multicolumn{2}{c}{**Descriptions**} & & & **Threshold** & **(mg/kg)** & **I** & **II** & **III** & **IV** & **V** \\ \hline \multirow{10}{*}{Fat} & \multirow{4}{*}{Aldehydes} & Octanal & 0.000587 & ND & ND & 35,446.06 & 16,981.53 & 98,386.72 \\  & & 1-Nonanal & 0.0011 & 11,982.85 & 17,551.64 & 70,171.81 & 51,494.71 & 93,581.44 \\  & & (E)-2-Nonneal & 0.0019 & 3919.81 & 2052.53 & 4809.00 & ND & ND \\  & & 1-Nonanol & 0.002 & 653.29 & 1427.64 & ND & ND & ND \\  & & \(\alpha\)-Terpine & 1.2 & ND & ND & ND & 2.49 & ND \\  & & Alkenes & p-Martha-1,3,8-treine & 0.015 & ND & ND & ND & 94.69 & ND \\  & & Decyl aldehyde & 0.003 & 778.21 & 754.34 & 1348.23 & ND & ND \\ Soap & & (E)-2-Heptenal & 0.04 & 413.38 & 246.49 & 282.08 & 236.53 & ND \\  & & 2-Heptanone & 0.14 & 2.65 & ND & 3.20 & ND & 5.10 \\  & & Alcohols & 1-Pentanol & 0.1502 & ND & ND & 2.37 & 1.41 & 21.28 \\  & & Alkenes & Styrene & 0.0036 & 12.91 & ND & 143.33 & 265.82 & ND \\ Mint & & Aldehydes & \(\beta\)-Cyclocitral & 0.003 & 218.73 & ND & ND & 579.84 & ND \\  & & 1-Hexanol & 0.0056 & 4706.37 & 4174.89 & 3924.12 & 1422.84 & 2572.79 \\  & & & \(\alpha\)-Terpine & 0.0011 & ND & 417.14 & 361.15 & ND & ND \\ Flower & & Phenols & Methyl eugenol & 0.775 & ND & ND & ND & 14.80 & ND \\  & & Ketones & \(\beta\)-Lonone & 0.000007 & 85,552.07 & ND & ND & 183,215.46 & 1,095,920.27 \\  & & & Phenethyl alcohol & 0.56423 & 1.83 & ND & ND & ND & ND \\  & & & Nernaiol & 0.68 & ND & ND & ND & 1.91 \\ Sweet & & Alkenes & (E)-\(\beta\)-Coimene & 0.034 & ND & ND & 643.42 & 59.67 & 73.85 \\  & & Caryophylene oxide & 0.41 & ND & ND & 1.35 & 2.45 & ND \\  & & Others & 4-Allylanisole & 0.0075 & ND & ND & ND & 2180.27 \\ Metal & & Alcohols & 1-Octanol & 0.1258 & 26.45 & 44.60 & 70.81 & 124.62 & ND \\  & & Ketones & \(\alpha\)-Jonone & 0.00378 & ND & ND & ND & 131.65 & 2452.49 \\ Wood & & & \(\alpha\)-Carophyllene & 0.16 & 1.87 & 5.36 & 22.47 & ND & 139.00 \\  & & & \(\beta\)-Caryophyllene & 0.064 & ND & 18.40 & 81.77 & 272.01 & 536.81 \\  & & Aldehydes & & Benzaldehyde & 0.75089 & 1.97 & ND & ND & ND & 3.01 \\  & & Ketones & 4-Methoxy-2,5-dimethyl- & 0.16 & ND & ND & 10.36 & 31.03 & 314.81 \\ Mushroom & & Ketones & 6-Methyl-5-hepten-2-one & 0.068 & ND & 42.48 & 95.68 & 39.79 & 104.31 \\ Pungent & Ketones & & Ethly vinyl ketone & 0.023 & ND & ND & 280.88 & ND & 891.90 \\ Sweat & & Acids & Octanoic acid & 3 & ND & ND & 4.08 & 3.28 & 89.64 \\  & & Hexanoic acid & 5 & ND & ND & ND & 1.59 \\ Lemon & Alkenes & & \(\alpha\)-Terpinene & 0.04 & ND & ND & ND & ND & 13.23 \\ \hline \hline \end{tabular} Note: Odor descriptions are sourced from Flavoort by [PERSON] and [PERSON] ([[https://www.flavvomet.org](https://www.flavvomet.org)]([https://www.flavvomet.org](https://www.flavvomet.org)), accessed on 15 April 2024) and the Flavor Ingredient Library ([[https://www.femflavor.org/flavor-library](https://www.femflavor.org/flavor-library)]([https://www.femflavor.org/flavor-library](https://www.femflavor.org/flavor-library)), accessed on 15 April 2024). The odor threshold refers to the concentration of substances in water as detailed in the database. I, II, III, IV, and V represent the different stages of fruit maturity. ND indicates not detected.  
\end{table}