## 3 Results and Discussion
### Aroma Recombination and Emission Experiments  
Aroma recombination and omission experiments are general methods to validate the critical aroma compounds [11]. On a quantitative basis, various aroma compounds at different concentrations are added into certain medium to produce an overall aroma [22; 23]. In addition, sensory analysis has also been used to study the relationship between flavor substances in the liquor and the liquor flavor. The 32 compounds with OAVs \(\geq\) 1 were recombined, and the aroma was compared with that of the base liquor. Figure 2 shows that the recombination solution had rich aroma, particularly fruity aroma, grain aroma, and distiller's grain aroma. A comparison of the aroma properties in the original liquor and recombination sample showed that they had highly similar aroma profiles with only very slight differences. These slight differences could be due to that the recombination sample did not undergo the aging process of the original liquor, and the reactions among compounds did not fully occur because of the short time of establishment, or the medium for the recombination did not contain some non-volatile compounds that interact with the aroma compounds. Although there were slight differences in aroma properties between the two samples, the statistical results showed that there were no significant differences in the eight properties analyzed in the aroma profiling, indicating that the simulation system of Xiaoqu liquor was successfully established. These results also imply the high accuracy and reliability of the aroma compound extraction method, AEDA combined with GC-O, \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**No.** & **Compounds** & **OAV** & **No.** & **Compounds** & **OAV** & **No.** & **Compounds** & **OAV** \\ \hline
1 & Ethyl octanoate  & 427.57 & 12 & \(N\)-propanol  & 9.65 & 23 & Ethyl lactate  & 3.46 \\
2 & Acetaldehyde  & 126.65 & 13 & Ethyl myristate  & 9.57 & 24 & Acetic acid  & 3.29 \\
3 & Isoamyl acetate  & 75.59 & 14 & Phenylacetaldehyde  & 9.05 & 25 & Sec-butanol  & 2.78 \\
4 & 1,1-diethyloxyethane  & 45.95 & 15 & Butyric acid  & 8.91 & 26 & Propionic acid  & 2.42 \\
5 & Ethyl hexanoate  & 41.28 & 16 & Isovaleric acid  & 7.52 & 27 & N-butanol  & 2.22 \\
6 & Valeric acid  & 30.21 & 17 & Ethyl laurate  & 7.07 & 28 & Phenethyl acetate  & 2.12 \\
7 & Dimethyl trisulfide  & 23.44 & 18 & Ethyl valerate  & 6.74 & 29 & Hexanoic acid  & 1.96 \\
8 & 1-octen-3-ol  & 20.8 & 19 & Ethyl butyrate  & 6.58 & 30 & \(\gamma\)-nonalactone  & 1.57 \\
9 & Ethyl acetate  & 16.5 & 20 & Isoamyl alcohol  & 5.6 & 31 & Caprylic  & 1.4 \\
10 & Isobutanol  & 15.1 & 21 & Ethyl caprate  & 5.02 & 32 & Phenethyl alcohol  & 1.15 \\
11 & Ethyl isovalerate  & 12.89 & 22 & 1-nonanol  & 3.76 & & \\ \hline \hline \end{tabular} Note: 1. \({}^{\text{a}}\) stands for the identification of the quantitative analysis results of SBSE-GC-MS. 2. \({}^{\text{b}}\) refers to the quantitative analysis results of GC-FID.  
\end{table} 
Table 4: Odor activity values (OAVs) of the key flavor compounds in JPXQL. quantitative analysis of complementary aroma active compounds, and the method for identifying the key aroma components based on OAV calculation used in this study. Table 5 shows the results of the omission experiments. Among the 11 scenarios of omission experiments, six scenarios of omission would lead to significant differences in aroma profiles (\(p\leq 0.05\)). The omission of all the ester compounds resulted in extremely significant differences in aroma profile, indicating the dominant role of ester compounds in the flavor of Xiaoqu liquor. Besides, omission of ethyl octanoate showed that this compound has great contribution to the aroma of Xiaoqu liquor. When ethyl acetate and ethyl lactate were omitted at the same time, there were obvious changes in the aroma profile, implying that these two compounds contribute greatly to the aroma of the liquor.