## 3 Results and Discussion
### Analysis of GC-MS
#### 3.1.1 Volatile Compounds in Different Processing Stages
** & **Compounds** & \multicolumn{4}{c}{**Relative Percentage Content (\%)**} \\  & & **L1** & **L2** & **L3** & **L4** \\ \hline
1 & (Z)-3-Nonen-2-ol & - & 0.02 \(\pm\) 0.00 \({}^{\mathrm{b}}\) & 0.07 \(\pm\) 0.01 \({}^{\mathrm{a}}\) & 0.06 \(\pm\) 0.01 \({}^{\mathrm{a}}\) \\
2 & 1-Penten-3-ol & 0.05 \(\pm\) 0.01 \({}^{\mathrm{b}}\) & 0.09 \(\pm\) 0.00 \({}^{\mathrm{b}}\) & - & 0.52 \(\pm\) 0.58 \({}^{\mathrm{a}}\) \\
3 & 3-Methyl-1-butanol & 0.34 \(\pm\) 0.04 \({}^{\mathrm{b}}\) & 0.28 \(\pm\) 0.06 \({}^{\mathrm{b}}\) & 1.89 \(\pm\) 0.52 \({}^{\mathrm{a}}\) & - \\
4 & 1-Pentanol & 1.84 \(\pm\) 0.13 & 3.37 \(\pm\) 0.79 & 2.78 \(\pm\) 0.86 & 2.16 \(\pm\) 0.47 \\
5 & 1-Hexanol & 8.59 \(\pm\) 0.35 \({}^{\mathrm{b}}\) & 7.88 \(\pm\) 0.74 \({}^{\mathrm{b}}\) & 11.57 \(\pm\) 1.05 \({}^{\mathrm{a}}\) & 7.92 \(\pm\) 2.17 \({}^{\mathrm{b}}\) \\
6 & 1-Octen-3-ol & 7.20 \(\pm\) 0.05 \({}^{\mathrm{b}}\) & 11.80 \(\pm\) 0.34 \({}^{\mathrm{a}}\) & 7.65 \(\pm\) 1.32 \({}^{\mathrm{b}}\) & 9.25 \(\pm\) 0.01 \({}^{\mathrm{a}}\) \\
7 & 1-Hephenol & 2.39 \(\pm\) 0.23 \({}^{\mathrm{a}}\) & 2.00 \(\pm\) 0.08 \({}^{\mathrm{a}}\) & 0.85 \(\pm\) 0.02 \({}^{\mathrm{b}}\) & 0.63 \(\pm\) 0.27 \({}^{\mathrm{b}}\) \\
8 & 2,6-Dimethyl-4-heptanol & - & 0.24 \(\pm\) 0.01 & 0.77 \(\pm\) 0.18 & 0.29 \(\pm\) 0.25 \\
9 & 2,4-Dimethyl-cyclohexanol & 0.35 \(\pm\) 0.14 \({}^{\mathrm{b}}\) & 0.91 \(\pm\) 0.12 \({}^{\mathrm{a}}\) & 0.84 \(\pm\) 0.06 \({}^{\mathrm{a}}\) & 0.38 \(\pm\) 0.06 \({}^{\mathrm{b}}\) \\
10 & 1-Octanol & 3.82 \(\pm\) 0.49 \({}^{\mathrm{a}}\) & 2.88 \(\pm\) 0.21 \({}^{\mathrm{b}}\) & 1.07 \(\pm\) 0.08 \({}^{\mathrm{c}}\) & 0.81 \(\pm\) 0.00 \({}^{\mathrm{c}}\) \\
11 & (E)-2-Octen-1-ol & 1.22 \(\pm\) 0.04 \({}^{\mathrm{b}}\) & 2.50 \(\pm\) 0.47 \({}^{\mathrm{a}}\) & 1.18 \(\pm\) 0.05 \({}^{\mathrm{b}}\) & 1.52 \(\pm\) 0.13 \({}^{\mathrm{b}}\) \\
12 & 1-Nonen-4-ol & 0.55 \(\pm\) 0.00 \({}^{\mathrm{c}}\) & 2.10 \(\pm\) 0.49 \({}^{\mathrm{a}}\) & 1.92 \(\pm\) 0.31 \({}^{\mathrm{a,b}}\) & 1.20 \(\pm\) 0.06 \({}^{\mathrm{b,c}}\) \\
13 & 1-Nonanol & 0.74 \(\pm\) 0.17 \({}^{\mathrm{b}}\) & 1.25 \(\pm\) 0.27 \({}^{\mathrm{a}}\) & 0.66 \(\pm\) 0.06 \({}^{\mathrm{b}}\) & 0.31 \(\pm\) 0.02 \({}^{\mathrm{b}}\) \\
14 & 2-Ethyl-1-hexanol & 0.17 \(\pm\) 0.05 & - & - & - \\
15 & (E, Z)-2-4-Decadien-1-ol & 0.06 \(\pm\) 0.01 \({}^{\mathrm{c}}\) & 0.21 \(\pm\) 0.01 \({}^{\mathrm{a}}\) & - & 0.15 \(\pm\) 0.03 \({}^{\mathrm{b}}\) \\  & Total alcohols & 27.28 \(\pm\) 0.23 \({}^{\mathrm{b}}\) & 35.50 \(\pm\) 3.34 \({}^{\mathrm{a}}\) & 31.21 \(\pm\) 4.34 \({}^{\mathrm{a,b}}\) & 25.16 \(\pm\) 1.96 \({}^{\mathrm{b}}\) \\
16 & 2-Butanone & - & - & - & 0.14 \(\pm\) 0.02 \\
17 & 2,3-Butanedione & - & - & 2.52 \(\pm\) 0.10 & 2.86 \(\pm\) 0.72 \\
18 & 2,3-Pentanedione & - & 0.06 \(\pm\) 0.01 \({}^{\mathrm{b}}\) & 0.29 \(\pm\) 0.02 \({}^{\mathrm{a}}\) & 0.30 \(\pm\) 0.04 \({}^{\mathrm{a}}\) \\
19 & 2,3-Heptanedione & 0.48 \(\pm\) 0.52 & 0.10 \(\pm\) 0.03 & 0.47 \(\pm\) 0.11 & 0.81 \(\pm\) 0.04 \({}^{\mathrm{a}}\) \\
20 & 6-Methyl-2-Heptanone & 0.07 \(\pm\) 0.04 & 0.11 \(\pm\) 0.06 & - & - \\
21 & 3-Hydroxy-2-butanone & 0.27 \(\pm\) 0.08 \({}^{\mathrm{b}}\) & 1.45 \(\pm\) 0.21 \({}^{\mathrm{b}}\) & 7.06 \(\pm\) 0.43 \({}^{\mathrm{a}}\) & 5.97 \(\pm\) 1.51 \({}^{\mathrm{a}}\) \\
22 & 4-Octen-3-one & 0.17 \(\pm\) 0.02 & 0.13 \(\pm\) 0.02 & 0.21 \(\pm\) 0.03 & 0.25 \(\pm\) 0.05 \\
23 & 2,3-Octanedione & 3.42 \(\pm\) 0.78 \({}^{\mathrm{c}}\) & 5.24 \(\pm\) 0.49 \({}^{\mathrm{b}}\) & 6.24 \(\pm\) 0.02 \({}^{\mathrm{b}}\) & 10.19 \(\pm\) 0.18 \({}^{\mathrm{a}}\) \\
24 & 2-Nonanone & 0.06 \(\pm\) 0.01 \({}^{\mathrm{b}}\) & 0.13 \(\pm\) 0.01 \({}^{\mathrm{b}}\) & 0.37 \(\pm\) 0.11 \({}^{\mathrm{a}}\) & 0.11 \(\pm\) 0.04 \({}^{\mathrm{b}}\) \\  & Total ketones & 4.43 \(\pm\) 0.27 \({}^{\mathrm{c}}\) & 7.21 \(\pm\) 0.83 \({}^{\mathrm{c}}\) & 17.13 \(\pm\) 0.39 \({}^{\mathrm{b}}\) & 20.58 \(\pm\) 1.98 \({}^{\mathrm{a}}\) \\
25 & 3-Methyl-butanal & - & - & - & 0.20 \(\pm\) 0.02 \\
26 & Pentanal & 1.53 \(\pm\) 0.02 & 1.31 \(\pm\) 0.06 & - & - \\
27 & Hexanal & 26.62 \(\pm\) 0.16 \({}^{\mathrm{a}}\) & 17.21 \(\pm\) 1.10 \({}^{\mathrm{b}}\) & 9.36 \(\pm\) 2.78 Ketones are generally associated with creamy and fruity flavor characteristics [17], which have little contribution to meat flavor owing to their high odor threshold.