# Effect of Seasoning Addition on Volatile Composition and Sensory Properties of Steved Pork
## 3 Results and Discussion
### Volatile Compounds Profiling in the Fresh and Stewed Pork  
A total of 139 volatile compounds of the fresh and stewed pork were extracted and identified by GC-MS/O and GC \(\times\) GC-TOFMS, including 30 aldehydes, 23 alcohols, 19 ketones, 25 hydrocarbons, 13 esters, five ethers, three phenols, four acids, and 17 heterocyclic and sulphur-containing compounds (Table 2). Most of these compounds have been reported in several pork products [24; 25]. Aldehydes are mainly derived from the lipid oxidation and degradation reaction, and Strecker degradation of amino acids [21; 26], which are considered as the major contributions to the overall flavour of meat products [20; 27] due to their lower odour thresholds. Among seven stewed pork samples, the content of aldehydes was the most abundant, with the total mean amounts of 719.6-3326.1 ug\(\cdot\)kg\({}^{-1}\). Obviously, the content of aldehydes in heated pork samples (SP\({}_{1}\), SP\({}_{2}\), SP\({}_{3}\), SP\({}_{4}\), SP\({}_{5}\), and SP\({}_{6}\)) were significantly greater (\(p<0.001\)) than those in the fresh pork. This indicated that the thermal \begin{table}
\begin{tabular}{c c c c c c c c c c c c c c c} \hline \hline \multicolumn{1}{c}{\multirow{2}{*}{**Group**}} & \multicolumn{10}{c}{**GC-MS/O**} & \multicolumn{10}{c}{**GC \(\times\) GC-TOFMS**} \\ \cline{3-14}  & **FP** & **SP\({}_{1}\)** & **SP\({}_{2}\)** & **SP\({}_{3}\)** & **SP\({}_{4}\)** & **SP\({}_{5}\)** & **SP\({}_{6}\)** & **FP** & **SP\({}_{1}\)** & **SP\({}_{2}\)** & **SP\({}_{3}\)** & **SP\({}_{4}\)** & **SP\({}_{5}\)** & **SP\({}_{6}\)** \\ \hline \multirow{10}{*}{Quantities} & Aldehydes & 5 & 12 & 12 & 11 & 11 & 11 & 20 & 22 & 22 & 20 & 19 & 21 & 22 \\  & Alcohols & 3 & 5 & 5 & 6 & 7 & 7 & 8 & 14 & 13 & 16 & 17 & 19 & 16 & 18 \\  & Ketones & 0 & 0 & 0 & 3 & 3 & 3 & 3 & 8 & 10 & 12 & 13 & 11 & 14 & 13 \\  & Hydrocarbons & 6 & 11 & 13 & 11 & 13 & 13 & 14 & 6 & 11 & 12 & 18 & 13 & 15 & 13 \\  & Esters & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 1 & 8 & 10 & 11 & 10 & 11 & 11 \\  & Ethers & 1 & 2 & 1 & 3 & 4 & 4 & 4 & 1 & 1 & 2 & 5 & 5 & 5 & 5 \\  & Phenols & 0 & 0 & 0 & 2 & 2 & 2 & 2 & 1 & 0 & 0 & 2 & 2 & 2 & 2 \\  & Acids & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 3 & 0 & 2 & 2 & 2 & 2 & 2 \\  & Heterocyclic and & & 0 & 2 & 2 & 1 & 1 & 1 & 1 & 3 & 7 & 10 & 12 & 13 & 13 & 13 \\  & sulfur compounds & & & & & & & & & & & & & & & \\  & Total & 15 & 32 & 33 & 37 & 41 & 41 & 43 & 57 & 72 & 86 & 100 & 94 & 99 & 99 \\ \hline \multirow{10}{*}{Ratios (\%)} & Aldehydes & 37.8 & 66.8 & 63.7 & 34.9 & 40.2 & 37.8 & 43.2 & 43.1 & 30.6 & 38.9 & 20.0 & 17.9 & 18.5 & 19.9 \\  & Alcohols & 9.1 & 11.8 & 12.1 & 26.3 & 21.1 & 21.4 & 18.5 & 13.5 & 13.3 & 6.2 & 15.8 & 7.8 & 8.1 & 6.6 \\  & Ketones & 0.0 & 0.0 & 0.0 & 6.0 & 3.6 & 4.6 & 3.2 & 23.5 & 9.0 & 16.5 & 11.1 & 11.4 & 7.3 & 11.8 \\  & Hydrocarbons & 48.4 & 12.3 & 16.7 & 18.9 & 24.6 & 23.7 & 25.4 & 16.8 & 29.1 & 19.7 & 40.7 & 50.1 & 47.3 & 48.9 \\  & Esters & 0.0 & 0.0 & 0.0 & 0.0 & 0.0 & 0.0 & 0.0 & 0.1 & 2.8 & 5.2 & 2.5 & 3.7 & 9.1 & 4.4 \\  & Ethers & 4.8 & 1.2 & 1.0 & 6.2 & 3.7 & 4.6 & 3.6 & 0.2 & 0.2 & 0.2 & 2.4 & 0.8 & 0.9 & 0.5 \\  & Phenols & 0.0 & 0.0 & 0.0 & 2.9 & 3.8 & 4.5 & 2.7 & 0.01 & 0.0 & 0.0 & 0.5 & 0.5 & 0.7 & 0.2 \\  & Acids & 0.0 & 0.0 & 0.0 & 0.0 & 0.0 & 0.0 & 0.0 & 2.7 & 0.3 & 0.5 & 0.4 & 0.3 & 0.6 & 0.5 \\  & Heterocyclic and & & & & & & & & & & & & & & & \\  & sulfur compounds & & & & & & & & & & & & & & & \\  & Total & 100.0 & 100.0 & 100.0 & 100.0 & 100.0 & 100.0 & 100.0 & 100.0 & 100.0 & 100.0 & 100.0 & 100.0 & 100.0 & 100.0 \\ \hline \hline \end{tabular} Note: FP, fresh pork; SP1, stewed pork with water; SP2: stewed pork with water and salt; SP3: stewed pork with water, salt and spices; SP4: stewed pork with water, salt, spices and soy sauce; SP5: stewed pork with water, salt, spices, soy sauce and sugar; SP6: stewed pork with water, salt, spices, soy sauce, sugar and cooking wine.  
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