## 2 Results and Discussion
### Volatile Compounds Identified in Doubanjiang

Table 1: _Cont._ \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**No.**} & \multicolumn{2}{c}{**RI 1a**} & \multirow{2}{*}{**Compounds b**} & \multirow{2}{*}{**Odor Description c**} & \multirow{2}{*}{**Identification d**} \\ \cline{2-2} \cline{5-5}  & **DB-5 ms** & & & & \\ \hline \multicolumn{5}{c}{_Aldehydes (8)_} \\
134 & \(<\)800 & \(<\)1000 & 3-methylbutanal 2 & cocoa, malt, pungent & MS, RI, Std, O \\
135 & 1364 & - & 4-methyl-2-phenyl-2-pental 2 & cocoa & MS, RI \\
136 & 1050 & 1668 & phenylacetaldehyde 3 & berry, honey, nut, pungent & MS, RI, Std, O \\
137 & 1106 & 1403 & nonanal 1 & citrus, paint, pungent & MS, RI, Std, O \\
138 & 1493 & 2098 & 5-methyl-2-phenyl-2-hexenal 3 & cocoa & MS, RI \\
139 & - & 1089 & hexanal 1 & green, beauty & MS, RI \\
140 & - & 1508 & decanal 1 & floral, fried, orange peel & MS, RI, Std, O \\
141 & - & 1547 & benzaldehyde 3 & burnt sugar, roasted pepper & MS, RI \\ \hline \multicolumn{5}{c}{_Lactones (7)_} \\
142 & 915 & 1660 & \(\gamma\)-butylrolactone 3 & caramel, fruit, roasted nut & MS, RI \\
143 & 956 & 1638 & \(\gamma\)-valerolactone 1 & herb, sweet & MS, RI \\
144 & 963 & - & tetrahydro-2-pyrano 1 & west & MS, RI \\
145 & 1046 & - & panololactone 1 & burnt, roasted bread & MS, RI \\
146 & 1367 & 2058 & \(\gamma\)-nonalactone 1 & apricot, cocoa, coconut & MS, RI \\
147 & 1541 & - & dihydroactinolide 2 & - & MS, RI \\
148 & - & 1698 & lavender lactone 1 & - & MS, RI \\ \hline \multicolumn{5}{c}{_Furans (6)_} \\
149 & 858 & 1672 & furfuryl alcohol 3 & burnt, caramel, cooked & MS, RI, Std, O \\
150 & 965 & 1593 & 5-methylfurral 1 & caramel, roasted garlic, spice & MS, RI \\
151 & 1070 & - & cis-linalool oxide 2 & earth, flower, nut, root & MS, RI \\
152 & 1169 & 2186 & sotolome 3 & savory, spice, soy sauce & MS, RI, Std, O \\
153 & - & 1484 & furfurral 2 & baked potatoes, bread & MS, RI \\
154 & - & 1523 & 2-acetylfuran 1 & balsamic, cocoa, coffee & MS, RI \\ \hline \multicolumn{5}{c}{_Sulfur-containing compounds (5)_} \\
155 & 911 & 1473 & methional 1 & cooked potato, soy & MS, RI, Std, O \\
156 & 986 & 1732 & methionol 1 & cooked potato, earth, soy & MS, RI \\
157 & 1529 & - & 2,5-bis(2-methylpropyl)thiophene 1 & - & MS, RI \\
158 & - & 1083 & dimethyl disulfide 2 & garlic, onion, putrid & MS, RI, Std, O \\
159 & - & 1403 & dimethyl trisulfide 2 & onion, sulfur, sweat & MS, RI \\ \hline \multicolumn{5}{c}{_Ethers (5)_} \\
160 & 1004 & 1631 & 2-(2-ethoxy)ethanol 1 & - & MS, RI \\
161 & 1320 & - & Theaspirane (A or B) 2 & honey & MS, RI \\
162 & - & 1207 & 1,8-cineole 2 & eucalypt, mint, sweet & MS, RI \\
163 & - & 1581 & methyl carbitol 1 & - & MS, RI \\
164 & - & 1167 & cyclohexene epoxide 1 & - & MS, RI \\ \hline \multicolumn{5}{c}{_Miscellaneous compounds (1)_} \\
165 & 1571 & - & p-chloronaniline 1 & - & MS, RI \\ \hline \hline \end{tabular}  
* Retention indices (RI) were determined on DB-5 ms and DB-wax column with C\({}_{8}\)–C\({}_{20}\) and C\({}_{10}\)–C\({}_{22}\) as external reference, respectively. “-” Not determined. b Superscript numbers “1” and “2” indicates that the corresponding volatile compound is identified by SAFE and HS-SPME, respectively, “3” means that the corresponding volatile compound is identified by both methods. c.d. Order descriptions are based on VCF database ([[http://www.vcf-online.nl/vcffHome.cfm](http://www.vcf-online.nl/vcffHome.cfm)]([http://www.vcf-online.nl/vcffHome.cfm](http://www.vcf-online.nl/vcffHome.cfm))). “-” means not reported. d MS, compounds identified by MS spectra; RI compounds identified by comparison with the retention indices (RIs) on DB-5 ms and/or DB-wax column in the NIST Chemistry WebBook ([[http://webbook.nist.gov/](http://webbook.nist.gov/)]([http://webbook.nist.gov/](http://webbook.nist.gov/))); Std, confirmed by authentic compound. O, compounds identified by the odor confirmation. eNumbers in each group given in parentheses indicate the number of identified compounds.  
\end{table} 
Table 2: Relative quantification analysis of chemical groups after SAFE in three doubanjiang samples.