Table 3.
Concentrations (µg/L) determined of volatile compounds in beers by HSSE–GC–MS.
| Beer Sample | Lager (N = 8) | Wheat (N = 4) | Stout (N = 4) | Ale (N = 4) | ||||
|---|---|---|---|---|---|---|---|---|
| Volatile Compound | Mean | SD | Mean | SD | Mean | SD | Mean | SD |
| isobutyl acetate | <LOQ a | - | 128.05 b | 67.07 | <LOQ a | - | <LOQ a | - |
| ethyl butyrate | 107.85 a | 25.26 | 88.81 a | 8.32 | 103.94 a | 29.18 | 145.21 a | 44.62 |
| ethyl isovalerate | 4.08 a | 4.59 | <LOQ | - | 4.01 a | 2.46 | 2.04 a | 0.96 |
| hexanal | ND | - | ND | - | ND | - | ND | - |
| ethyl pentanoate | 13.24 a | 7.66 | 40.78 b | 18.46 | 13.74 a | 1.99 | 6.33 a | 4.96 |
| isopentyl acetate* | 2.61 b | 0.45 | 4.31 c | 0.87 | 0.75 a | 0.26 | 1.47 a | 0.78 |
| 3-methyl-1-butanol* | 51.32 a | 12.37 | 39.82 a | 17.15 | 38.94 a | 8.18 | 64.89 a | 24.07 |
| ethyl hexanoate | 307.14 a | 259.04 | 64.90 a | 8.01 | 284.65 a | 247.13 | 361.33 a | 97.23 |
| hexyl acetate | 7.33 b | 3.07 | 6.86 ab | 1.46 | 3.43 a | 0.75 | 3.74 ab | 0.87 |
| octanal | 5.54 a | 3.02 | <LOQ | - | 8.39 a | 6.14 | 5.02 a | 4.07 |
| 6-methyl-5-hepten-2-one | 6.36 a | 5.12 | <LOQ | - | 26.22 a | 27.64 | 12.72 a | 12.32 |
| ethyl heptanoate | <LOQ | - | <LOQ | - | 12.25 a | 12.74 | 6.02 a | 4.80 |
| 1-hexanol | 11.26 a | 2.97 | 12.45 a | 9.50 | 56.79 a | 57.27 | 33.79 a | 19.39 |
| heptyl acetate | <LOQ | - | 1.13 a | 0.06 | 3.41 b | 0.23 | 2.13 ab | 1.79 |
| nonanal | ND | - | ND | - | ND | - | ND | - |
| ethyl octanoate | 139.08 a | 52.82 | 103.08 a | 20.90 | 529.03 a | 514.51 | 762.58 a | 655.03 |
| heptanol* | ND | - | ND | - | 1.25 a | 1.09 | 4.12 b | 0.71 |
| isopentyl hexanoate | 0.35 a | 0.21 | 0.53 a | 0.12 | 0.49 a | 0.65 | 1.35 b | 0.26 |
| octyl acetate | 5.49 b | 0.62 | 5.25 b | 0.21 | 4.16 a | 0.04 | 4.37 a | 0.21 |
| benzaldehyde | 7.87 a | 3.12 | ND | - | ND | - | 5.80 a | 2.32 |
| linalool | <LOQ | - | ND | - | 100.13 a | 3.45 | 106.42 a | 26.66 |
| isobutyric acid | 6.05 a | 3.28 | 5.66 a | 0.11 | <LOQ | - | 17.81 b | 3.00 |
| octanol | 5.47 a | 2.55 | 8.64 a | 0.27 | 6.76 a | 0.41 | 15.83 b | 8.10 |
| 2,3-dihydrobenzofurane | 3.48 a | 1.66 | 3.23 a | 0.98 | 3.01 a | 0.62 | ND | - |
| ethyl decanoate | 50.07 a | 47.31 | 57.11 ab | 5.72 | 66.44 ab | 44.73 | 154.61 b | 87.21 |
| benzenoic acid ethyl ester | 5.87 a | 0.49 | 5.95 a | 0.25 | 6.43 ab | 0.53 | 7.17 b | 0.46 |
| 1-decanol | 47.28 a | 23.98 | <LOQ | - | 64.99 a | 46.59 | <LOQ | - |
| phenylethyl acetate | 360.93 b | 98.68 | 378.90 b | 26.03 | 31.31 a | 20.49 | 141.57 a | 76.76 |
| β-damascenone | 4.63 a | 0.10 | 4.84 a | 0.12 | 7.37 b | 0.11 | 6.99 b | 1.91 |
| guaiacol | 22.92 a | 22.80 | ND | - | 69.46 b | 5.14 | ND | - |
| ethyl dodecanoate | 17.38 a | 19.98 | 2.36 a | 0.51 | 19.13 a | 11.48 | 11.99 a | 11.93 |
| benzopropanoic acid ethyl ester | 8.51 a | 3.12 | 4.30 a | 2.40 | 5.77 a | 3.39 | 15.17 b | 4.94 |
| hexanoic acid 2-phenylethyl ester | <LOQ | - | ND | - | 4.87 a | 5.03 | 3.63 a | 2.13 |
| isobutyric acid phenethyl ester | 12.20 ab | 2.73 | 9.09 a | 0.79 | 10.26 a | 2.47 | 15.58 b | 3.57 |
| nerolidol | 380.29 ab | 179.77 | 172.73 a | 54.20 | 192.11 a | 119.94 | 621.57 b | 174.28 |
| octanoic acid | 199.88 ab | 118.62 | 88.90 a | 10.53 | 95.84 a | 68.18 | 288.87 b | 69.42 |
| β-phenylethyl-2-methylbutyrate | 3.83 a | 4.76 | 2.69 a | 1.20 | <LOQ | - | <LOQ | - |
* mg/L; SD: standard deviation; ND: not detected; <LOQ: below limit of quantitation; For each compound, different letters indicate significant differences according to Tukey’s test (α = 0.05).