## 2 Results and Discussion
### Volatile Compounds Identified in Doubanjiang
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**No.**} & \multicolumn{2}{c}{**RI \({}^{\textbf{a}}\)**} & \multirow{2}{*}{**Compounds \({}^{\textbf{b}}\)**} & \multirow{2}{*}{**Odor Description \({}^{\textbf{c}}\)**} & \multirow{2}{*}{**Identification \({}^{\textbf{d}}\)**} \\ \cline{2-2} \cline{5-6}  & **DB-5 ms** & & & & \\ \hline
78 & - & 1466 & 6-methyl-5-hepten-2-ol 1  & - & MS, RI \\
79 & - & 1561 & octanol [1] & Orange peel & MS, RI \\
80 & - & 1621 & cyclooctyl alcohol [1] & - & MS, RI \\
81 & - & 1650 & levemontholl [1] & - & MS, RI \\
82 & - & 2027 & 2-hepten-4-ol 1  & - & MS, RI \\
83 & - & 2163 & 2-phenoxy-ethanol [1] & pleasant & MS, RI \\ \hline \multicolumn{6}{c}{_Ketones (19)_} & & & \\
84 & \(<\)800 & - & acetoin [3] & green pepper, rancid & MS, RI \\
85 & 937 & 1457 & 2-cyclohex-1-one [1] & solvent, unpleasant & MS, RI \\
86 & 1151 & 1716 & 4-oxoisophore [1] & citrus, honey, must & MS, RI \\
87 & 1226 & - & eucarone [2] & - & MS, RI \\
88 & 1246 & - & D-carone [2] & minty & MS, RI \\
89 & 1391 & 1803 & \(\beta\)-damascenone [3] & fruit, grape, sweet, floral & MS, RI, Std, O \\
90 & 1431 & - & \(\alpha\)-ionone [1] & floral, violet, wood & MS, RI \\
91 & 1441 & 1868 & geranyl acetone [3] & green, hay, magnolia & MS, RI \\
92 & 1488 & 1961 & \(\beta\)-ionone [1] & floral, raspberry, seaweed & MS, RI \\
93 & 1551 & \(>\)2200 & dihydroactinidiolide [1] & - & MS, RI \\
94 & 1715 & - & blumenol C [1] & - & MS, RI \\
95 & 1837 & - & hexahydrofamosyl acetone [3] & - & MS, RI \\
96 & - & 1262 & 3-octanone [1] & butter, herb, mold, resin & MS, RI \\
97 & - & 1306 & cyclohexanone [1] & bitter, peppermint & MS, RI \\
98 & - & 1314 & 1-hydroxy-2-propanone [1] & mushroom & MS, RI \\
99 & - & 1347 & 6-methyl-5-heptene-2-one [1] & mushroom, pepper, rubber & MS, RI \\
100 & - & 1418 & thujone [2] & - & MS, RI \\
101 & - & 1610 & 6-methylhepta-3,5-dien-2-one [1] & - & MS, RI \\
102 & - & 1819 & 2-ridecano [1] & harsh, herb, oil, spice & MS, RI \\ \hline \multicolumn{6}{c}{_Acids (13)_} & & & \\
103 & - & 1459 & acetic acid [2] & pungent, sour, vinegar & MS, RI, Std, O \\
104 & - & 1576 & 2-methylpropanoic acid [2] & burnt, cheese, rancid & MS, RI \\
105 & - & 1637 & butanoic acid [2] & butter, cheese, rancid & MS, RI \\
106 & - & 1678 & 3-methylbutanoic acid [2] & cheese, rancid, sweat & MS, RI, Std, O \\
107 & - & 1811 & 4-methylpentanoic acid [1] & floral, sour, sweat & MS, RI \\
108 & - & 1854 & hexanoic acid [1] & acid, pungent, rancid & MS, RI \\
109 & 1113 & 1956 & 2-ethylhexanoic acid [1] & soapy & MS, RI \\
110 & - & 1960 & heptanoic acid [1] & rancid, sour, sweat & MS, RI \\
111 & - & 2064 & octanoic acid [1] & acid, fat, rancid, sweat & MS, RI \\
112 & - & 2170 & nonanoic acid [1] & fat, green, sour & MS, RI \\
113 & - & \(>\)2200 & benzoic acid [2] & pungent, sour, urine & MS, RI \\
114 & - & \(>\)2200 & decanoic acid [1] & dust, fat, rancid, sweat & MS, RI \\
115 & - & \(>\)2200 & lauric acid [1] & fat, fruit, metal, wax & MS, RI \\ \hline \multicolumn{6}{c}{_Nitrogen-containing compounds (10)_} & & \\
116 & 886 & 1258 & 2,6-dimethylpyridine [1] & green, coffee, nutty & MS, RI \\
117 & 915 & 1345 & 2,6-dimethylplyrazine [2] & cocoa, coffee, roasted nut & MS, RI \\
118 & 1068 & 1996 & 2-acetylpyrrole [1] & herbal, nutty, anisic, & MS, RI \\
119 & 1087 & - & tetramethylpyrazine [1] & cocoa, coffee, roasted & MS, RI \\
120 & - & 1045 & 1-hexanamine [2] & - & MS, RI \\
121 & - & 1277 & methylpyrazine [1] & cocoa, popcorn, roasted & MS, RI \\
122 & - & 1396 & 2-ethyl-5-methylpyrazine [1] & fruit, roast, sweet & MS, RI \\
123 & - & 1421 & N,N-dimethylacetamide [1] & amine, burnt, oil & MS, RI \\
124 & - & 1510 & 3-isobutyl-2-methoxypyrazine [3] & bell pepper, green pepper & MS, RI, Std, O \\
125 & - & 1700 & N-methylpyproxidianone [1] & - & MS, RI \\ \hline \multicolumn{6}{c}{_Phenols (8)_} & & \\
126 & 1091 & 1883 & 2-methoxyphenol [3] & bacon, medicine, phenol & MS, RI, Std, O \\
127 & 1164 & 2193 & 4-ethylphenol [3] & medicine, phenol, stable & MS, RI \\
128 & 1197 & - & estragole [2] & anise, licorice & MS, RI \\
129 & 1280 & 2050 & 4-ethyl-2-methoxyphenyl [3] & medicine, phenol, smoke & MS, RI, Std, O \\
130 & 1294 & 1849 & anethole [3] & anise & MS, RI \\
131 & - & 1979 & 4-methylguajaaicol [1] & clove, phenol, smoke & MS, RI \\
132 & - & 2023 & phenol [2] & medicine, phenol, spice & MS, RI \\
133 & - & 2188 & 3-allyl-6-methoxyphenyl [1] & - & MS, RI \\ \hline \hline \end{tabular}
\end{table}