Table 1.
Volatile compounds at different processing stages of Daokou braised chicken.
| NO. | Compounds | Relative Percentage Content (%) | |||
|---|---|---|---|---|---|
| L1 | L2 | L3 | L4 | ||
| 1 | (Z)-3-Nonen-2-ol | - | 0.02 ± 0.00 b | 0.07 ± 0.01 a | 0.06 ± 0.01 a |
| 2 | 1-Penten-3-ol | 0.05 ± 0.01 b | 0.09 ± 0.00 b | - | 0.52 ± 0.58 a |
| 3 | 3-Methyl-1-butanol | 0.34 ± 0.04 b | 0.28 ± 0.06 b | 1.89 ± 0.52 a | - |
| 4 | 1-Pentanol | 1.84 ± 0.13 | 3.37 ± 0.79 | 2.78 ± 0.86 | 2.16 ± 0.47 |
| 5 | 1-Hexanol | 8.59 ± 0.35 b | 7.88 ± 0.74 b | 11.57 ± 1.05 a | 7.92 ± 2.17 b |
| 6 | 1-Octen-3-ol | 7.20 ± 0.05 b | 11.80 ± 0.34 a | 7.65 ± 1.32 b | 9.25 ± 0.01 a,b |
| 7 | 1-Heptanol | 2.39 ± 0.23 a | 2.00 ± 0.08 a | 0.85 ± 0.02 b | 0.63 ± 0.27 b |
| 8 | 2,6-Dimethyl-4-heptanol | - | 0.24 ± 0.01 | 0.77 ± 0.18 | 0.29 ± 0.25 |
| 9 | 2,4-Dimethyl-cyclohexanol | 0.35 ± 0.14 b | 0.91 ± 0.12 a | 0.84 ± 0.06 a | 0.38 ± 0.06 b |
| 10 | 1-Octanol | 3.82 ± 0.49 a | 2.88 ± 0.21 b | 1.07 ± 0.08 c | 0.81 ± 0.00 c |
| 11 | (E)-2-Octen-1-ol | 1.22 ± 0.04 b | 2.50 ± 0.47 a | 1.18 ± 0.05 b | 1.52 ± 0.13 b |
| 12 | 1-Nonen-4-ol | 0.55 ± 0.00 c | 2.10 ± 0.49 a | 1.92 ± 0.31 a,b | 1.20 ± 0.06 b,c |
| 13 | 1-Nonanol | 0.74 ± 0.17 b | 1.25 ± 0.27 a | 0.66 ± 0.06 b | 0.31 ± 0.02 b |
| 14 | 2-Ethyl-1-hexanol | 0.17 ± 0.05 | - | - | - |
| 15 | (E, Z)-2,4-Decadien-1-ol | 0.06 ± 0.01 c | 0.21 ± 0.01 a | - | 0.15 ± 0.03 b |
| Total alcohols | 27.28 ± 0.23 b | 35.50 ± 3.34 a | 31.21 ± 4.34 a,b | 25.16 ± 1.96 b | |
| 16 | 2-Butanone | - | - | - | 0.14 ± 0.02 |
| 17 | 2,3-Butanedione | - | - | 2.52 ± 0.10 | 2.86 ± 0.72 |
| 18 | 2,3-Pentanedione | - | 0.06 ± 0.01 b | 0.29 ± 0.02 a | 0.30 ± 0.04 a |
| 19 | 2,3-Heptanedione | 0.48 ± 0.52 | 0.10 ± 0.03 | 0.47 ± 0.11 | 0.81 ± 0.04 |
| 20 | 6-Methyl-2-Heptanone | 0.07 ± 0.04 | 0.11 ± 0.06 | - | - |
| 21 | 3-Hydroxy-2-butanone | 0.27 ± 0.08 b | 1.45 ± 0.21 b | 7.06 ± 0.43 a | 5.97 ± 1.51 a |
| 22 | 4-Octen-3-one | 0.17 ± 0.02 | 0.13 ± 0.02 | 0.21 ± 0.03 | 0.25 ± 0.05 |
| 23 | 2,3-Octanedione | 3.42 ± 0.78 c | 5.24 ± 0.49 b | 6.24 ± 0.02 b | 10.19 ± 0.18 a |
| 24 | 2-Nonanone | 0.06 ± 0.01 b | 0.13 ± 0.01 b | 0.37 ± 0.11 a | 0.11 ± 0.04 b |
| Total ketones | 4.43 ± 0.27 c | 7.21 ± 0.83 c | 17.13 ± 0.39 b | 20.58 ± 1.98 a | |
| 25 | 3-Methyl-butanal | - | - | - | 0.20 ± 0.02 |
| 26 | Pentanal | 1.53 ± 0.02 | 1.31 ± 0.06 | - | - |
| 27 | Hexanal | 26.62 ± 0.16 a | 17.21 ± 1.10 b | 9.36 ± 2.78 c | 18.71 ± 2.76 b |
| 28 | Heptanal | 4.30 ± 0.52 a | 2.02 ± 0.33 b | 2.12 ± 0.23 b | 2.07 ± 0.08 b |
| 29 | Octanal | 6.12 ± 0.29 a | 2.39 ± 0.22 b | 0.86 ± 0.02 c | 1.19 ± 0.45 c |
| 30 | Nonanal | 15.18 ± 0.22 a | 6.31 ± 0.53 b | 3.86 ± 0.05 b | 5.12 ± 1.75 b |
| 31 | 2-Octenal | 0.57 ± 0.14 | 0.79 ± 0.26 | 0.54 ± 0.09 | 0.56 ± 0.03 |
| 32 | Decanal | 0.70 ± 0.01 | 0.68 ± 0.13 | - | - |
| 33 | Benzaldehyde | 0.21 ± 0.04 | 0.19 ± 0.05 | 0.37 ± 0.04 | 1.18 ± 0.61 |
| 34 | 2-Nonenal | 0.32 ± 0.07 | 0.32 ± 0.10 | 0.26 ± 0.06 | 0.34 ± 0.06 |
| 35 | Z-4-Decenal | - | - | - | 0.44 ± 0.05 |
| 36 | Undecanal | 0.06 ± 0.01 b | 0.14 ± 0.01 b | 0.67 ± 0.23 a | 0.32 ± 0.13 a,b |
| 37 | (E, E)-2,4-Nonadienal | 0.10 ± 0.01 | 0.11 ± 0.01 | - | - |
| 38 | Trans-2-undecenal | 0.27 ± 0.06 | 0.13 ± 0.02 | - | - |
| 39 | (E, E)-2,4-decadienal | 0.33 ± 0.00 b | 0.43 ± 0.03 a | 0.24 ± 0.03 c | 0.27 ± 0.02 c |
| 40 | Tetradecanal | 0.47 ± 0.07 | - | 0.58 ± 0.29 | 1.00 ± 0.35 |
| Total aldehydes | 56.76 ± 0.35 a | 32.02 ± 2.34 b | 18.82 ± 2.93 c | 31.51 ±6.13 b | |
| 41 | Decane | - | - | 0.11 ± 0.01 | 0.08 ± 0.01 |
| 42 | Methyl-benzene | 0.23 ± 0.15 c | 0.60 ± 0.08 b | 1.05 ± 0.17 a | 1.02 ± 0.04 a |
| 43 | Undecane | 0.07 ± 0.01 b | 0.13 ± 0.04 a,b | 0.22 ± 0.04 a | - |
| 44 | Ethylbenzene | 0.06 ± 0.01 c | 0.12 ± 0.01 c | 0.36 ± 0.04 a | 0.24 ± 0.03 b |
| 45 | 1,3-Dimethyl-benzene | - | - | - | 0.21 ± 0.01 |
| 46 | (Z)-3-Dodecene | - | - | 1.15 ± 0.57 | - |
| 47 | Dodecane | - | 0.12 ± 0.02 b | 0.42 ± 0.02 a | 0.32 ± 0.05 a |
| 48 | 1-Ethyl-4-methyl-benzene | - | - | - | 0.20 ± 0.01 |
| 49 | 1-Ethyl-2-methyl-benzene | - | - | 0.17 ± 0.04 | - |
| 50 | 1-Ethyl-3-methyl-benzene | - | - | - | 0.11 ± 0.01 |
| 51 | 4,7-Methano-1H-indene, octahydro- | - | - | 0.19 ± 0.01 | 0.21 ± 0.01 |
| 52 | 1,2,3-Trimethyl-benzene | - | - | 0.12 ± 0.01 | 0.07 ± 0.01 |
| 53 | Tridecane | - | 0.56 ± 0.18 | 0.38 ± 0.25 | 0.44 ± 0.01 |
| 54 | Tetradecane | - | 0.66 ± 0.06 | 0.57 ± 0.04 | 0.53 ± 0.07 |
| 55 | 3-Ethyl-2-methyl-1,3-hexadiene | 0.16 ± 0.07 b | 0.37 ± 0.04 a | 0.17 ± 0.01 b | 0.18 ± 0.02 b |
| 56 | Nonadecane | - | - | 1.25 ± 0.06 | - |
| 57 | (2RS,3SR,4RS.5RS)-2,3: 4,5-Diepoxyhexan | - | 2.13 ± 0.05 | 1.80 ± 0.22 | 1.60 ± 0.19 |
| 58 | Heptadecane | 0.04 ± 0.01 b | 0.07 ± 0.01 b | 0.39 ± 0.13 a,b | 0.23 ± 0.06 a |
| 59 | 4-Decene, 2,2-dimethyl-, (E)- | - | - | - | 0.26 ± 0.10 |
| 60 | Octadecane | - | - | 0.16 ± 0.06 | 0.10 ± 0.01 |
| Total hydrocarbons | 0.55 ± 0.09 c | 4.73 ± 0.25 b | 8.47 ± 1.10 a | 5.62 ± 0.12 b | |
| 61 | Limonene | - | - | 0.73 ± 0.01 | 0.72 ± 0.11 |
| 62 | 1,8-Cineole | - | 1.05 ± 0.11 c | 11.28 ± 0.45 a | 4.38 ± 1.49 b |
| 63 | Trans-p-mentha-1(7),8-dien-2-ol | - | - | - | 0.06 ± 0.01 |
| 64 | Linalool | - | - | - | 0.23 ± 0.06 |
| 65 | 3-Cyclohexen-1-ol, 4-methyl-1-(1-methylethyl)- | - | - | 0.13 ± 0.01 | 0.21 ± 0.01 |
| 66 | α-Terpineol | - | - | 0.08 ± 0.00 | 0.10 ± 0.01 |
| 67 | β-Fenchol | - | - | 0.80 ± 0.11 | 0.60 ± 0.15 |
| 68 | Anethole | - | - | 0.23 ± 0.04 | 0.14 ± 0.02 |
| 69 | Trans-geraniol | - | - | 0.42 ± 0.02 | 0.25 ± 0.01 |
| 70 | (E)-Cinnamaldehyde | - | - | 0.43 ± 0.01 | 0.28 ± 0.01 |
| Total terpenes | - | 1.05 ± 0.18 c | 14.07 ± 0.07 a | 6.93 ± 0.31 b | |
| 71 | Acetic acid, hexyl ester | - | 0.27 ± 0.07 | 0.28 ± 0.04 | 0.20 ± 0.06 |
| Total esters | - | 0.27 ± 0.07 | 0.28 ± 0.04 | 0.20 ± 0.06 | |
| 72 | 2-Pentyl-furan | 0.29 ± 0.08 d | 1.09 ± 0.12 c | 1.38 ± 0.07 b | 1.98 ± 0.18 a |
| 73 | 2-Furanmethanol, 5-ethenyltetrahydro | - | 0.27 ± 0.07 b | 1.32 ± 0.21 a | 2.10 ± 0.47 a |
| 74 | Oxime-,methoxy-phenyl- | 0.66 ± 0.49 a | 0.14 ± 0.01 b | 0.21 ± 0.07 b | 0.19 ± 0.03 b |
| 75 | N,N-Dibutylformamide | - | 0.07 ± 0.01 | - | - |
| Total heterocycles | 1.20 ± 0.25 d | 1.54 ± 0.26 c | 2.94 ± 0.52 b | 4.22 ± 0.45 a | |
1 a–d: Means within the same row with different letters differ significantly (p < 0.05); 2 RI: the retention index calculated using n-alkanes C6–C26 as external standard; 3 MS: identification by comparison with mass spectra.