Table 2.
Mean concentration (μg/L) of volatile compounds detected in the wines fermented by four yeast strains
| Code | Compounds | Odour descriptiona | D254 | VIC | BV818 | CECA | Mean value |
|---|---|---|---|---|---|---|---|
| Alcohols | |||||||
| A1 | 2-Methyl-1-propanol | Wine, solvent, bitter | 212.9 | 164.4 | 21.2 | 319.3 | 179.5 |
| A2 | 3-Methyl-1-butanol | Whiskey, malt, burnt | 1505.4 | 1041.0 | 1771.4 | 1189.0 | 1376.7 |
| A3 | 2-Methylbutan-1-ol | Wine, onion | 1236.6 | 727.8 | 519.0 | 626.5 | 777.5 |
| A4 | 2,3-Butanediol | 19.5 | 183.9 | 410.5 | 20.7 | 158.7 | |
| A5 | Trans-3-hexen-1-ol | Moss, fresh | 3.7 | 2.1 | – | 1.9 | 1.9 |
| A6 | Heptan-1-ol | Chemical, green | – | – | 8.4 | – | 2.1 |
| A7 | 2-Ethylhexan-1-ol | Rose, green | 1.5 | 0.5 | – | – | 0.5 |
| A8 | 1-Octanol | Chemical, metal, burnt | 8.6 | 3.2 | 1.5 | 2.0 | 3.8 |
| A9 | 2-Phenylethanol | Honey, spice, rose, lilac | 2387.1 | 1572.2 | 1238.1 | 2120.5 | 1829.5 |
| A10 | 3,7-Dimethyl-6-octen-1-ol | – | – | 8.0 | 2.0 | 2.5 | |
| Subtotal | 5357.3 | 3695.1 | 3978.1 | 4281.9 | 4332.6 | ||
| Esters | |||||||
| E1 | Ethyl acetate | Pineapple | 309.7 | 237.2 | 111.4 | 242.2 | 225.1 |
| E2 | Ethyl propionate | Fruit | 3.8 | 3.5 | – | 2.5 | 2.5 |
| E3 | Methyl butyrate | Ether, fruit, sweet | 11.0 | 16.9 | – | – | 7.0 |
| E4 | Ethyl isobutyrate | Sweet, rubber | 12.2 | – | – | – | 3.1 |
| E5 | Isobutyl acetate | Fruit, apple, banana | 8.3 | 6.7 | – | 1.2 | 4.1 |
| E6 | Ethyl butyrate | Apple | 97.8 | – | 27.1 | – | 31.2 |
| E7 | Isoamyl acetate | Banana | 1967.7 | 1207.0 | 463.8 | 162.0 | 950.1 |
| E8 | 2-Methylbutyl acetate | Fruit | – | 900.0 | – | – | 225.0 |
| E9 | Ethyl 3-hydroxybutyrate | Marshmallow | – | – | 1.9 | 2.0 | 1.0 |
| E10 | Ethyl hexanoate | Apple peel, fruit | 128.0 | 80.6 | 157.1 | 31.9 | 99.4 |
| E11 | Ethyl benzoate | Camomile, flower, celery, fruit | 0.7 | – | – | – | 0.2 |
| E12 | Diethyl succinate | Wine, fruit | 1.0 | 0.5 | 0.7 | – | 0.6 |
| E13 | Ethyl octanoate | Fruit, fat | 329.0 | 172.2 | 504.8 | 135.5 | 285.4 |
| E14 | 2-Phenethyl acetate | Rose, honey, | 120.4 | 125.6 | 115.2 | 86.7 | 112.0 |
| E15 | Ethyl decanoate | Grape | 58.7 | 32.0 | 76.5 | 42.9 | 52.5 |
| E16 | Ethyl laurate | Leaf | 22.3 | 7.2 | 32.4 | 20.9 | 20.7 |
| E17 | Ethyl myristate | Ether | 1.1 | 1.0 | 4.3 | 0.8 | 1.8 |
| Subtotal | 3071.7 | 2790.4 | 1495.2 | 728.6 | 2021.5 | ||
| Acids | |||||||
| AC1 | Acetic acid | Sour | 210.6 | 123.3 | 98.1 | 134.3 | 141.6 |
| AC2 | Isobutyric acid | Rancid, butter, cheese | 11.3 | – | – | – | 2.8 |
| AC3 | Isovaleric acid | Sweat, acid, rancid | 12.7 | 2.0 | 3.6 | 10.4 | 7.2 |
| AC4 | 2-Methylbutyric acid | Cheese, sweat | 16.0 | 22.8 | 15.8 | 27.1 | 20.4 |
| AC5 | Hexanoic acid | Sweat | 89.1 | 50.1 | 91.2 | 52.0 | 70.6 |
| AC6 | Octanoic acid | Sweat, cheese | 115.1 | 63.3 | 105.7 | 57.5 | 85.4 |
| AC7 | Decanoic acid | Rancid, fat | 4.3 | 2.3 | 11.6 | 5.3 | 5.9 |
| Subtotal | 459.1 | 263.8 | 326.0 | 286.6 | 333.9 | ||
| Aldehydes and ketones | |||||||
| AK1 | Acetaldehyde | Pungent, ether | 4.1 | 2.2 | 1.1 | 55.2 | 15.7 |
| AK2 | Acetal | Fruit, cream | 0.8 | 2.5 | – | 7.3 | 2.7 |
| AK3 | Benzaldehyde | Almond, burnt sugar | 1.0 | 0.7 | – | – | 0.4 |
| AK4 | Octanal | Fat, soap, lemon, green | – | – | – | 2.1 | 0.5 |
| AK5 | Phenylacetaldehyde | Honey, sweet | 3.4 | 1.4 | 2.0 | 0.0 | 1.7 |
| AK6 | Acetophenone | Must, flower, almond | – | – | 3.0 | 2.0 | 1.3 |
| AK7 | Nonanal | Fat, citrus, green | 2.6 | 7.7 | 15.2 | 17.7 | 10.8 |
| AK8 | Decanal | Soap, orange peel, tallow | 3.2 | 2.0 | 3.6 | 1.2 | 2.5 |
| Subtotal | 15.1 | 16.5 | 24.9 | 85.5 | 35.5 | ||
| Lactones | |||||||
| L1 | γ-Butyrolactone | Caramel, sweet | 36.9 | 34.0 | 107.6 | 46.6 | 56.3 |
| L2 | γ-Caprolactone | Coumarin, sweet | 18.8 | 4.3 | 16.8 | 9.6 | 12.4 |
| L3 | γ-Octanoic lactone | Coconut | 7.0 | 3.4 | 4.5 | 3.9 | 4.7 |
| L4 | 1,5-Octalactone | Peach | 7.8 | 3.9 | 10.4 | 2.6 | 6.2 |
| Subtotal | 70.5 | 45.6 | 139.3 | 62.7 | 79.5 | ||
| Sulphur compounds | |||||||
| S1 | 3-Methylthiopropanol | Sweet, potato | 368.8 | 55.0 | 350.5 | 250.0 | 256.1 |
| S2 | Methyl 3-methylthiopropionate | Vegetative, radish and horseradish | 163.4 | 58.3 | 62.0 | 39.9 | 80.9 |
| S3 | Ethyl 3-methylthiopropionate | Pineapple citrus | 92.2 | 99.4 | 101.9 | 69.9 | 90.9 |
| S4 | Dihydro-2-methyl-3(2H)-thiophenone | Cabbage, onion, must | – | – | – | 5.6 | 1.4 |
| Subtotal | 624.4 | 212.7 | 514.4 | 365.4 | 429.2 | ||
| Phenols | |||||||
| P1 | Chavicol | Medicine, phenol | 7.2 | 4.6 | 0.8 | 1.2 | 3.5 |
| P2 | 2-Methoxy-4-vinylphenol | Clove, curry | 3.1 | 1.9 | 1.8 | 1.1 | 2.0 |
| P3 | Eugenol | Clove, honey | 2.2 | 0.6 | – | – | 0.7 |
| Subtotal | 12.5 | 7.1 | 2.6 | 2.3 | 6.1 | ||
| Styryl derivatives | |||||||
| SD1 | Styrene | Balsamic, gasoline | 77.1 | 36.7 | 26.7 | 45.5 | 46.5 |
| SD2 | 2,4-Dimethylstyrene | 1.7 | – | 5.0 | 0.8 | 1.9 | |
| Subtotal | 78.8 | 36.7 | 31.7 | 46.3 | 48.4 | ||
| Furans | |||||||
| F1 | 2-Methylfuran | Ether | 0.9 | – | – | 1.6 | 0.6 |
| F2 | 2,4-Dimethylfuran | – | – | – | 4.0 | 1.0 | |
| F3 | 4-Hydroxy-2,5-dimethylfuran-3-one | Caramel | – | – | 15.1 | – | 3.8 |
| Subtotal | 0.9 | – | 15.1 | 5.6 | 5.4 | ||
| Terpenes | |||||||
| T1 | Limonene | Lemon, orange | 11.7 | 4.1 | 67.5 | 6.2 | 22.4 |
| Subtotal | 11.7 | 4.1 | 67.5 | 6.2 | 22.4 | ||
| Total | 9720.0 | 7072.0 | 6594.8 | 5871.1 | 7314.5 | ||
Values shown represent averages of triplicate samples (maximum SD: ± 10%)
– not detected