## 3 Results and Discussion
### Analysis of Baijiu Samples
 } \\ \hline
**Estees** & & & & & & & \\ Isoamyl acetate & 94 & 5339.58 \(\pm\) 951.27 & 56.80 & 6423.77 \(\pm\) 922.57 & 68.34 & 9176.91 \(\pm\) 250.18 & 97.63 \\ Ethlylynlynlynacetate & 407 & 189.57 \(\pm\) 26.6 & 0.47 & 688.71 \(\pm\) 32.78 & 1.69 & 568.87 \(\pm\) 27.91 & 1.40 \\ Phenently acetate & 909 & 146.62 \(\pm\) 32.39  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Volatile Compounds**} & \multirow{2}{*}{**Odor Thresholds**} & \multicolumn{2}{c}{**Fenju**} & \multicolumn{2}{c}{**Wuliangye**} & \multicolumn{2}{c}{**Guotai**} \\ \cline{2-7}  & & **Concentration** & **OAV** & **Concentration** & **OAV** & **Concentration** & **OAV** \\ \hline
**Alcohols** & & & & & & & \\ \hline
**Phenyl alcohol** & 28,900 & \(3256.13\pm 237.93\) & 0.11 & \(3049.82\pm 12.37\) & 0.11 & \(7868.06\pm 49.55\) & 0.27 \\ Benzyl alcohol & 40,900 & \(123.76\pm 8.78\) & 0.00 & \(144.44\pm 5.59\) & 0.00 & \(1145.19\pm 89.22\) & 0.03 \\ Hexanol & 5370 & \(547.29\pm 16.92\) & 1.02 & \(71913.75\pm 111.52\) & 13.39 & \(120.164\pm 294.94\) & 1.90 \\ Heptanol & 26,600 & \(262.14\pm 12.37\) & 0.01 & \(12218.44\pm 7.3\) & 0.05 & \(779.65\pm 7.08\) & 0.03 \\ Octanol & 1100 & \(70.9\pm 14.14\) & 0.06 & \(261.84\pm 3.25\) & 0.24 & \(684.62\pm 1.55\) & 0.62 \\ Nonanol & 50 & \(54.29\pm 10.27\) & 1.09 & \(633.44\pm 0.61\) & 1.27 & \(33.14\pm 0.2\) & 0.66 \\
1-Octen-3-cl & 6.12 & \(98.79\pm 4.68\) & 16.14 & \(197.71\pm 3.23\) & 32.31 & \(92.95\pm 5.78\) & 1.519 \\
2-Heptanol & 1430 & \(12.62\pm 8\) & 0.01 & \(1273.52\pm 7.73\) & 0.89 & \(391.19\pm 419.99\) & 0.27 \\
3-Octanol & 393 & nd & — & \(30.99\pm 2.27\) & 0.08 & \(173.23\pm 4.44\) & 0.44 \\
2-Nonanol & 75 & \(43.4\pm 4.37\) & 0.58 & \(69.37\pm 15.35\) & 0.92 & \(41.14\pm 2.25\) & 0.55 \\ Pentanol & 4000 & \(562.71\pm 7.22\) & 0.14 & \(1556.27\pm 537.43\) & 0.39 & \(1462.39\pm 176.97\) & 0.37 \\
**Acids** & & & & & & & \\ \hline Pentanoic acid & 389 & \(349.62\pm 10.85\) & 0.90 & \(6631.68\pm 1004.73\) & 17.05 & \(3336.22\pm 318.74\) & 8.58 \\ Heptanoic acid & 13,300 & \(1024.96\pm 86.08\) & 0.08 & \(17,513.91\pm 569.26\) & 1.32 & \(5403.77\pm 75.02\) & 0.41 \\ Octanoic acid & 2700 & \(918.51\pm 97.38\) & 0.34 & \(6827.55\pm 704.09\) & 2.33 & \(4896.17\pm 15.58\) & 1.81 \\ Decanoic acid & 500 & \(441.33\pm 41.32\) & 0.83 & \(2248.13\pm 52.02\) & 4.50 & \(864.62\pm 3.32\) & 1.73 \\
3-Methylbutanoic acid & 1050 & \(970.4\pm 40.16\) & 0.92 & \(6946.24\pm 76.03\) & 6.62 & \(2629.44\pm 181.79\) & 2.50 \\
4-Methylbutanoic acid & 144 & \(147.63\pm 15.04\) & 1.03 & \(1028.92\pm 293.65\) & 7.15 & \(766.3\pm 58.65\) & 5.32 \\
**Aldehydes and ketones** & & & & & & & \\ Decanal & 12 & \(61.26\pm 0.78\) & 5.11 & \(581.48\pm 13.79\) & 48.46 & \(316.29\pm 66.61\) & 26.36 \\ \((E)\)-2-Heptenal & 0.0046 & \(18.56\pm 0.08\) & \(4034.78\) & \(2.45\pm 0.07\) & 532.61 & \(20.53\pm 0.75\) & 446304 \\ \((E)\)-2-Nonneal & 51 & \(16.58\pm 0.47\) & 0.33 & \(71.87\pm 8.2\) & 1.41 & \(51.29\pm 12.93\) & 1.01 \\ \((E)\)-2-Octenal & * & nd & — & \(26.98\pm 8.16\) & — & \(587.1\pm 1.83\) & — \\
2-3-Butanedione & 5 & nd & — & — & \(877.35\pm 183.183\) & 175.47 \\
3-Hydrooxy-2-butanone & 259 & \(2102.04\pm 1637.78\) & 8.12 & \(15,734.59\pm 322.84\) & 60.75 & \(52.964\pm 487.69\) & 21.79 \\
2-Methylproponal & 1300 & \(657.74\pm 16.75\) & 0.51 & \(5540.37\pm 620.42\) & 2.72 & \(7700.86\pm 884.05\) & 5.92 \\
2-Methylhyuanat & 16 & \(161.22\pm 62.68\) & 10.08 & \(5350.9\pm 148.34\) & 38.871 \(\pm 9.04\) & 58.45 \\ Benzaldehyde & 4200 & \(496.91\pm 33.56\) & 0.12 & \(1102.29\pm 94.87\) & 0.26 & \(9456.166\pm 198.02\) & 0.23 \\
2-Octanone & 50 & \(47.32\pm 11.86\) & 0.95 & \(276.17\pm 526.65\) & 5.52 & \(271.72\pm 7.27\) & 4.34 \\ Phenylacetaldehyde & 262 & \(4799.96\pm 240.2  
The odor activity values (OAVs) of volatile compounds in different types of Baijiu samples are also presented in Table 3. The OAV was calculated by dividing the concentration by the respective reported odor threshold, which can be used to measure the aroma contribution of volatile compounds in the Baijiu samples [35].