Table 2.
Concentrations of volatile compounds in different fermentation trials.
| Compounds | Concentration (mg/L) 1 | |||
|---|---|---|---|---|
| Sf | SP | SS | SSP | |
| Alcohols | ||||
| 2-Butanol | 6.60 ± 0.80 a | – b | – b | – b |
| 1-Butanol | 0.33 ± 0.06 b | 0.17 ± 0.04 c | 1.04 ± 0.11 a | 0.45 ± 0.05 b |
| 3-Methyl-1-butanol | 31.56 ± 1.15 a | 13.82 ± 2.94 c | 14.41 ± 1.18 c | 22.69 ± 3.84 b |
| 1-Pentanol | – c | 0.12 ± 0.02 b | 0.15 ± 0.05 b | 0.36 ± 0.06 a |
| 2-Heptanol | – c | – c | 0.13 ± 0.02 b | 0.37 ± 0.09 a |
| 1-Hexanol | 0.46 ± 0.04 bc | 0.36 ± 0.05 c | 0.55 ± 0.05 b | 0.87 ± 0.17 a |
| 2-Octanol | – c | – c | 0.14 ± 0.01 b | 0.24 ± 0.04 a |
| 1-Octene-3-ol | 1.41 ± 0.33 a | 0.20 ± 0.06 b | 0.16 ± 0.02 b | 0.21 ± 0.07 b |
| Heptanol | 0.20 ± 0.02 c | 0.25 ± 0.04 bc | 0.38 ± 0.10 b | 0.54 ± 0.11 a |
| Octanol | 0.46 ± 0.04 a | – b | – b | – b |
| 2-Ethylcyclopentane methanol | 0.19 ± 0.02 c | 0.22 ± 0.04 bc | 0.31 ± 0.04 b | 0.61 ± 0.08 a |
| 2-Octene-1-ol | 0.74 ± 0.21 a | – b | – b | – b |
| Diethylene glycol monoethyl ether | 2.10 ± 0.35 b | 1.47 ± 0.27 bc | 1.14 ± 0.08 c | 3.16 ± 0.92 a |
| Furfuryl alcohol | 0.11 ± 0.04 c | 0.69 ± 0.17 b | 0.28 ± 0.04 c | 0.98 ± 0.11 a |
| Phenethyl alcohol | 27.75 ± 0.99 a | 8.08 ± 1.80 b | 7.98 ± 0.11 b | 9.86 ± 0.80 b |
| Esters | ||||
| Ethyl acetate | 1.32 ± 0.08 a | 0.67 ± 0.04 b | 0.33 ± 0.05 c | 0.42 ± 0.07 c |
| Ethyl hexanoate | 1.07 ± 0.07 a | 0.31 ± 0.04 b | 0.11 ± 0.04 c | 0.19 ± 0.05 c |
| Ethyl heptanoate | 0.42 ± 0.07 a | 0.16 ± 0.02 b | – c | – c |
| Ethyl lactate | – d | 0.19 ± 0.02 b | 0.07 ± 0.04 c | 0.30 ± 0.05 a |
| Ethyl octanoate | 0.39 ± 0.03 a | 0.26 ± 0.05 b | 0.09 ± 0.02 d | 0.16 ± 0.02 c |
| Ethyl citrate | 0.37 ± 0.02 a | 0.12 ± 0.02 b | – c | – c |
| Ethyl caprate | 0.06 ± 0.02 a | – b | –b | – b |
| Hexanoic acid 2-phenylethyl ester | – c | 0.50 ± 0.05 a | 0.19 ± 0.02b | 0.30 ± 0.05 b |
| Phenethyl acetate | 1.02 ± 0.17 a | – b | – b | – b |
| Ethyl 3-phenylpropionate | 0.12 ± 0.02 a | – b | – b | – b |
| γ-Nonanoic lactone | – c | – c | 1.62 ± 0.00b | 2.27 ± 0.05 a |
| Ethyl cinnamate | 0.40 ± 0.06 a | 0.21 ± 0.01b | 0.07 ± 0.01c | – d |
| γ-Decalactone | 0.18 ± 0.07 a | – b | – b | – b |
| Ethyl palmitate | 2.55 ± 0.30 a | 0.84 ± 0.07 b | 0.51 ± 0.02 c | 0.65 ± 0.11 bc |
| Ethyl oleate | 0.88 ± 0.15 a | 0.49 ± 0.12 b | 0.12 ± 0.02 c | 0.39 ± 0.09 b |
| Ethyl linoleate | 0.83 ± 0.16 a | 0.39 ± 0.04 b | 0.16 ± 0.02 c | 0.16 ± 0.02 c |
| Acids | ||||
| Isobutyric acid | 0.14 ± 0.04 b | 0.09 ± 0.02 b | 0.45 ± 0.06 a | 0.39 ± 0.09 a |
| Butyric acid | – c | – c | 0.11 ± 0.04 b | 0.29 ± 0.08 a |
| Caproic acid | 0.22 ± 0.09 b | 0.07 ± 0.03 b | 0.65 ± 0.13 a | 0.82 ± 0.11 a |
| Aldehydes and Ketones | ||||
| 2-Octenal | 0.70 ± 0.13 a | 0.28 ± 0.07 b | – c | – c |
| 2,5-Dimethylbenzaldehyde | 0.67 ± 0.07 c | 0.69 ± 0.13 c | 1.30 ± 0.10 b | 1.66 ± 0.32 a |
| Octadecanal | – c | 1.11 ± 0.30 a | 0.17 ± 0.04 b | – c |
| 5-Methyl-3-heptanone | 0.32 ± 0.09 a | 0.16 ± 0.02 b | – c | – c |
| 2-Heptanone | –b | –b | 0.12 ± 0.02 a | –b |
| 2-Octanone | 0.24 ± 0.04 ab | 0.19 ± 0.05 b | 0.13 ± 0.02 b | 0.28 ± 0.04 a |
| 1-Octene-3-one | 0.71 ± 0.15 a | 0.16 ± 0.02 b | – c | – c |
| Geranyl acetone | –b | –b | 0.15 ± 0.05 a | 0.15 ± 0.04 a |
| alpha-Ionone | –b | –b | 0.14 ± 0.04 a | – b |
| Aromatics | ||||
| Naphthalene | 0.19 ± 0.05 b | 0.07 ± 0.03 c | 0.23 ± 0.02 b | 0.50 ± 0.11 a |
| 4-Ethyl-2-methoxyphenol | 27.75 ± 2.56 a | 2.40 ± 0.31 b | – c | – c |
| 4-Ethylphenol | 9.83 ± 1.15 a | 0.71 ± 0.14 b | 0.10 ± 0.04 b | 0.11 ± 0.06 b |
| 4-Hydroxy-3-methoxystyrene | 1.55 ± 0.40 b | 0.63 ± 0.07 b | 7.55 ± 1.27 a | 13.00 ± 2.86 a |
| 2,4-di-tert-butylphenol | 4.78 ± 1.29 b | 2.46 ± 0.59 c | 4.32 ± 0.78 b | 7.29 ± 1.48 a |
| 2,3-Dihydrobenzofuran | 1.99 ± 0.09 c | 0.78 ± 0.04 c | 4.09 ± 0.48 b | 7.13 ± 1.81 a |
1 Values listed includes the mean ± standard deviation from triplicate analysis and triplicate fermentation; a,b,c,d Statistical analysis by a one-way ANOVA (p < 0.05) with same letters showing no significant difference; – = not detected.