## 2 Results and Discussion
### Quantitative Analysis and OAV of Volatile Compounds  
As was shown in Table 2, a total of 44, 43 and 44 substances were detected in T1, T2 and T3, respectively. T1 included 13 alcohols, 9 nitrogen or sulfur-containing compounds, 11 aldehydes, 3 ketones, 3 esters, 2 acids, 2 hydrocarbons and 1 ester; T2 included 12 alcohols, 10 nitrogen or sulfur-containing compounds, 11 aldehydes, 3 ketones, 3 esters, 2 acids and 2 hydrocarbons; T3 included 12 alcohols, 9 nitrogen or sulfur-containing compounds, 14 aldehydes, 3 ketones, 2 esters, 2 acids and 2 hydrocarbons. +++ ==ERROR: No output for this page== \begin{table}
\begin{tabular}{c c c c c c c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**No.**} & \multirow{2}{*}{**Compounds A**} & \multirow{2}{*}{**Identification B**} & \multirow{2}{*}{**R** (**euclidean)**} & \multirow{2}{*}{**R (**ereference) C**} & \multicolumn{4}{c}{**Concentration (**log kg\({}^{-1}\)**)**} & \multicolumn{4}{c}{**Threshold C**} & \multicolumn{2}{c}{**OAV**} \\ \cline{3-14}  & & & & & & & & & & & & & & & & & \\ \cline{3-14}  & & & & & & & & & & & & & & & & & & & \\ \hline
**41** & 2-MethylButanoic acid & MS,R4D,8d & 885 & 1650 & 888 & 1652 & 15,13 ab & 2.9 & 16,85a & 1.77 & 11,72b & 2.98 & 20 & \(<\)1 & \(<\)1 & \(<\)1 \\
**42** & 3-MethylButanoic acid & MS,R4D,8d & 846 & 1684 & 875 & 1686 & 8,87b & 2.6 & 9,45a & 2.28 & 6,32b & 3.51 & 1 & 9 & 9 & 6 \\
**43** & 2-Acetylothiade & FP,R4D,8d & 1015 & 1652 & 1015 & 1662 & 5,84a & 2.47 & 471a & 3.58 & 3,43a & 1.27 & 4 & 1 & 1 & 1 & \(<\)1 \\
**44** & 2-Berenaceous1 dehyde & MS,R4D & 1051 & 1664 & 1051 & 1646 & 26,77b & 2.74 & 2.39a & 3.43 & 46,3a & 45.39 & 0.73 & 38 & 34 & 57b \\
**45** & 2-Doneyepitallative & FP,R4D,8d & 1326 & 1659 & 1326 & 1699 & 1288 & 6.19 & 28.0 & 6.18a & 28.27 & 5.57a & 2.45 & 4.23 & 2 & 1 & 1 \\
**46** & 3-Methylbitineineuronal & FP,R4D,8d & 998 & 1706 & 998 & 1706 & 18,19 ab & 25.6 & 11,84b & 1.25 & 23.19a & 1.79 & 500 & \(<\)1 & \(<\)1 & \(<\)1 \\
**47** & 2-Hexyl alcohol & MS,R4D,8d & 1088 & 1809 & 1035 & 1886 & -- & - & 0.97 & 0.08 & -- & 100 & \(--\) & \(<\)1 & \(--\) \\
**48** & 2-Doneylipid sulfence & FP,R4D,8d & 923 & 1912 & 925 & 1912 & -- & - & 5.88 & 1.43 & -- & 100 & \(--\) & \(--\) & \(--\) \\
**49** & 2-Methylalcohol & MS,R4D & 110 & 1923 & 1113 & 1923 & 2.25e & 1.29 & 1.26 & 2.35 & 211a & 37.89 & 80 & \(<\)1 & \(<\)1 & \(<\)1 \\
**50** & 2-Methylalcohol & MS,R4D & 1370 & 2012 & 1370 & 2012 & 11.32a & 1.43 & 9.54 ab & 2.98 & 8.7 bo & 2.63 & 2.5 & \(<\)1 & \(<\)1 & \(<\)1 \\
**51** & 2-Methylalcohol & 1425 & 2156 & 1425 & 2166 & -- & -- & -- & -- & 1.81 & 2.15 & 0.014 & \(--\) & \(--\) & \(129\) \\ \hline \hline \end{tabular}  
* A The volatile compounds detected in traffic samples. B The intention from the volatile compounds on D6-5 and HP-Innova columns [20] C. MS mass spectrum comparison using Wiley library; RI- intention index in agreement with literature value; Std: confirmed by authentic standards. P Values with different Roman letters (a–) in the same row are significantly different according to the Duncan test (\(p<0.08\)). E– no detected.
* The threshold of volatile compounds referred to in the literature. C Detection odor threshold in air according to ref [29,30].
* The OAV of the compounds.  
\end{table} 
Table 2: _Cont._Quantitative analysis based on external standard method (Table 3), the flavor substances with higher content (\(\mu\)g/kg) in T1 were as the following: dimethyl sulfide (1260), dimethyl disulfide (1139), 3-methylbutanal (2187), octanal (873), P-cresyl methyl ether (870.84) and 2-methylbutanol (734). Except for the characteristic aromatic substances of black truffle, T1 also contained a large amount of p-cresol methyl ether, which made the black truffles produced in Nanhua Yunnan have the fragrance [31] of Yang Yang(_Cananga adorata (Lank.) [PERSON]_) and violet (_Matthiola incana (L.) R. Br._  
The major volatile compounds in T2 were dimethyl sulfide (1156), 2-methylbutanol (1123), 3-octanone (6300), 1-octen-3-one (1034), 3-octanol (2157), 1-octen-3-ol (5849).