## 3 Results
### Identification of the Odor-Active Compounds in Braised Pork
\begin{tabular}{c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**RI \({}^{\bullet}\)**} & \multirow{2}{*}{**Compounds**} & \multirow{2}{*}{**Odor Description \({}^{\text{b}}\)**} & \multirow{2}{*}{**Odor Threshold (\(\text{\text{\text{\text{\text{\text{\text{\text{\text{\text{\text{\text{\text{\text{\text{\text{\text{\text{\text{ \text{ \text{ \text{ \text{ \text{    }}}}}}}}}}}}}\) & \multicolumn{2}{c}{**A**} & \multicolumn{2}{c}{**B**} \\ \cline{5-12}  & & & **CN \({}^{\text{c}}\)** & \multicolumn{1}{c}{**FD \({}^{\text{d}}\)**} & **OAV \({}^{\text{e}}\)** & **CN** & **FD** & **OAV** \\ \hline \multicolumn{12}{c}{Esters and lactones} \\ \hline
2245 & \(\gamma\)-Undecalactone & flower, wax & 0.042 & 1.2843 & 3 & 31 & 6.2292 & 27 & 148 \\
2158 & Ethyl cinnamate & cinnamon, honey & 0.04 & 0.0734 & 27 & 2 & & & \\ \hline \multicolumn{12}{c}{Phenols} \\ \hline
2072 & Phenol & phenol & 5.9 & 3.6822 & 9 & \textless{}1 & & & \\ \hline \multicolumn{12}{c}{Ethers} \\
1218 & 1,8-Cineole & mint, sweet & 0.012 & 0.4129 & 27 & 34 & 0.5122 & 27 & 43 \\
1821 & Anethe & anise, slight sweet & 0.16 & 8.3842 & 81 & 52 & 4.5618 & 243 & 29 \\ \hline \multicolumn{12}{c}{Nitrogenous compounds} \\ \hline
2037 & 2-Acetylpyrrole & nut, walnut, burnt & 170 & 0.0934 & 9 & \textless{}1 & & & \\ \hline \multicolumn{12}{c}{Oxygen-containing heterocycles} \\ \hline
1278 & 2-Methyltetrahydroofuran-3-one & sweet, caramel & - & 0.0937 & 3 & & & & \\
1511 & 2-Acetylfuran & butter, meaty & 0.01 & 0.0429 & 27 & 4 & 0.0419 & 27 & 4 \\
1647 & Furfuryl alcohol & sauce-flavor & 2 & 0.3126 & 243 & \textless{}1 & & \\
2465 & Coumarin & green, sweet & 0.33 & 0.1622 & 9 & \textless{}1 & 1.2419 & 27 & 4 \\ \hline \multicolumn{12}{c}{Unknown} \\ \hline
1570 & Unknown1 & almond, caramel, loasty & - & & & & & 243 & \\
1656 & Unknown2 & licorice, anise & - & & & & 27 & \\ \hline \hline \end{tabular}  \(\hat{\text{\text{\text{\text{\text{\text{\text{\text{\text{\text{\text{\text{\text{\text{\text{ \text{\text{ \text{ \text{ \text{      \text{ }}}}}}}}}}}}}}}}\) Linear retention indices calculated of unknown compounds on a HP-Wax (60 m x 0.25 mm \(\times\) 0.25 \(\mu\)m) with a homologous series of n-alkanes (C-C30), b: Odor description: odor description detected and described by panelists during diceometry. c: Concentration. Results are as pg/g, calculated by the standard curves in Table 4. d: FD factor is the highest dilution of the extract at which an odorant is determined by aroma extract dilution analysis. c: OAV (odor activity values), concentration divided by odor threshold. f: Odor thresholds were unavailable. CN: concentration; FD: Flavor Dilution factor. AEDA: aroma extract dilution analysis. \end{table 3: _Cont._For sample A, furfuryl alcohol (sauce-flavor) was the most intense aroma-active compound owning the highest aroma intensity (FD = 243). Pentanal (almond, pungent), limonene (fruity, orange), furfural (bread, almond, sweet), and anethole (anise, light sweet aroma) had the higher FD factor (FD = 81) which also suggested them to be the key contributors to the overall flavor. Besides, there were 12 kinds of substances with FD = 27, such as \(\alpha\)-pinene, \(\delta\)-3-carene, 1,8-cineole, 2-acetylfuran, ethyl cinnamate and so forth. Moreover, compounds with FD \(<\) 27 were considered to make only