## 3 Results
### Volatile Flavor Compounds Identified from the Braised Pork
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Compounds**} & \multirow{2}{*}{**ID X**} & \multirow{2}{*}{**RI Y**} & \multirow{2}{*}{**RI Z Z**} & \multicolumn{2}{c}{**Peak Area (\%)**} \\ \cline{5-6}  & & & & **A** & **B** \\ \hline \multicolumn{6}{c}{Hydrocarbons} \\ \hline \(\alpha\)-Pineineine & M & 1036 & 1032 m & 0.03 \(\pm\) 0.01 & 0.03 \(\pm\) 0.01 \\ \(\beta\)-Pineine & M & 1135 & 1116 m & nd & 0.17 \(\pm\) 0.04 \\ \(\delta\)-3-Carene & M & 1169 & 1148 m & 0.03 \(\pm\) 0.01 & 0.17 \(\pm\) 0.05 \\ \(\beta\)-Myrcene & M & 1171 & 1145 m & 0.07 \(\pm\) 0.01 & nd \\ Limonene & M & 1204 & 1201 m & 0.15 \(\pm\) 0.04 & 0.30 \(\pm\) 0.12 \\ \(\circ\)-Cymene & S & 1280 & & 0.01 \(\pm\) 0.00 & nd \\ Total & & & & 0.29 & 0.66 \\ \hline \multicolumn{6}{c}{Aldehydes} \\ \hline
3-Methylbutanal & M & 935 & 910 m & 0.01 \(\pm\) 0.01 & 0.01 \(\pm\) 0.01 \\ Pentanal & M & 942 & 935 m & 0.64 \(\pm\) 0.24 & nd \\ Hexanal & M & 1076 & 1084 m & 0.31 \(\pm\) 0.11 & 0.05 \(\pm\) 0.02 \\ Heptanal & M & 1174 & 1174 m & 0.23 \(\pm\) 0.04 & nd \\ Nonanal & M & 1385 & 1385 m & 0.12 \(\pm\) 0.03 & 0.14 \(\pm\) 0.01 \\ Benzaldehyde & M & 1522 & 1495 m & 0.06 \(\pm\) 0.03 & 1.18 \(\pm\) 0.05 \\ (E)-2-Decenal & S & 1635 & & 0.01 \(\pm\) 0.00 & 0.01 \(\pm\) 0.01 \\ Phenyl acetaldehyde & M & 1639 & 1625 m & 0.19 \(\pm\) 0.01 & 0.37 \(\pm\) 0.06 \\
2,4-Decedaienal & M & 1654 & 1632 m & nd & 0.01 \(\pm\) 0.01 \\ (E)-Cinnamaldehyde & M & 1666 & 1631 m & 0.23 \(\pm\) 0.08 & 0.11 \(\pm\) 0.04 \\ Neral & M & 1669 & 1667 m & 0.10 \(\pm\) 0.08 & 0.04 \(\pm\) 0.01 \\ Dodecanal & M & 1693 & 1722 m & 0.13 \(\pm\) 0.06 & nd \\ Benzenepropanal & S & 1775 & & 0.02 \(\pm\) 0.01 & 0.46 \(\pm\) 0.12 \\ (E,E)-2,4-Decadienal & S & 1854 & & 0.02 \(\pm\) 0.01 & nd \\
2-Methoxybenzaldehyde & S & 1977 & & nd & 0.28 \(\pm\) 0.05 \\
4-Methoxybenzaldehyde & S & 2042 & & 0.05 \(\pm\) 0.01 & 0.34 \(\pm\) 0.11 \\ (Z)-Cinnamaldehyde & S & 2053 & & 0.74 \(\pm\) 0.16 & 1.09 \(\pm\) 0.41 \\ (Z)-13-Octadecenal & S & 2383 & & nd & 0.39 \(\pm\) 0.11 \\
2-Methoxycinamaldehyde & S & 2401 & & nd & 0.34 \(\pm\) 0.09 \\ Total & & & & 2.85 & 4.80 \\ \hline \multicolumn{6}{c}{Alcohols} \\ \hline Allyl alcohol & S & 1105 & & 0.35 \(\pm\) 0.02 & nd \\
1,8-Cineole & M & 1218 & 1213 m & 0.08 \(\pm\) 0.01 & 0.13 \(\pm\) 0.02 \\
1-Pentanol & M & 1234 & 1255 m & 0.08 \(\pm\) 0.01 & nd \\ Linalool & M & 1530 & 1537 m & 0.07 \(\pm\) 0.02 & 0.44 \(\pm\) 0.11 \\
1-Terpinen-4-ol & M & 1589 & 1591 m & nd & 0.08 \(\pm\) 0.02 \\ \(\alpha\)-Terpineol & M & 1681 & 1688 m & 0.22 \(\pm\) 0.10 & 0.08 \(\pm\) 0.02 \\ \(\beta\)-Fenchyl alcohol & S & 1701 & & nd & 0.05 \(\pm\) 0.01 \\ Cinnamyl alcohol & M & 2330 & 2300 m & 0.15 \(\pm\) 0.06 & nd \\ (E)-2-Tetradecen-1-ol & S & 2356 & & nd & 0.26 \(\pm\) 0.08 \\ Total & & & & 0.96 & 1.04 \\ \hline \multicolumn{6}{c}{Ketones} \\ \hline
2,3-Pentanedione & S & 1057 & & 0.10 \(\pm\) 0.04 & nd \\
2-Heptanone & M & 1172 & 1170 m & 0.01 \(\pm\) 0.00 & nd \\
2-Octanone & M & 1267 & 1244 m & 0.04 \(\pm\) 0.01 & nd \\ Acetoin & M & 1270 & 1287 m & nd & 0.21 \(\pm\) 0.07 \\ Acetol & M & 1286 & 1287 m & nd & 0.09 \(\pm\) 0.02 \\
2-Tridecanone & S & 1804 & & 0.01 \(\pm\) 0.01 & nd \\
2-Pentadecanone & S & 2020 & & 0.06 \(\pm\) 0.01 & 0.35 \(\pm\) 0.11 \\
1-(4-Methoxyphenyl)-2-propanone & S & 2170 & & 0.01 \(\pm\) 0.00 & nd \\
2-Heptadecanone & S & 2208 & & 0.01 \(\pm\) 0.01 & nd \\ Total & & & & 0.24 & 0.65 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Identification of braised pork volatile compounds extracted using SDE-GC/MS. Comparing the volatiles extracted by the two techniques, it could be revealed that SDE extracted a higher number of aldehydes, ketones, acids and phenols than the SPME, while the SPME extracted more hydrocarbons, sulphur, and nitrogen compounds. It was worth noting that sulphur-containing compounds were not detected in SDE and only one nitrogenous compound (2-acetylpyrrole) was identified.