Table 2.
| Compound | Aroma |
Aroma
Threshold |
Example of Concentrations
(±SD *) in Dry-Hopped Beer (the Methods Used for Analysis) |
Reference |
| Hydrocarbons | ||||
| α-humulene (29) | spicy and woody | 450 µg/L, 120 µg/L | 5.2 (±0.5) µg/L (Trap GC-MS) 0.4 (±0.04)–1.2 (±0.41) μg/L (HS-GC-MS) |
[51,52,53,54] |
| β-myrcene (1) | herbaceous, resinous, green, balsamic, fresh hops |
350 µg/L, 30–200 µg/L, 9.5 µg/L | 79.7 (±2.8) μg/L (Trap GC-MS) 0.3 (±0.12)–15.9 (±2.58) μg/L (HS-GC-MS) 117.4–863.6 μg/L (HS-SPME-GC-MS) |
[51,52,53,54,55,56] |
| β-pinene (2) | turpentine odor with a dry, woody, or resinous aroma |
140 µg/L | 15.4 (±3.3)–89.4 (±19.7) μg/L (HS-GC-SPME) |
[50,57,58] |
| (E)-caryophyllene (30) | spicy and woody | 230 µg/L | 2.3 (±0.2) μg/L (Trap GC-MS) 0.2 (±0.06)–0.3 (±0.12) μg/L (SPE-GC-MS) |
[51,52,53,54] |
| Terpene Alcohols | ||||
| α-terpineol (7) | lilac odor with a sweet taste reminiscent of peach on dilution |
330 μg/L, 450 μg/L | 25.4 (±6.4) μg/L (Trap GC-MS) 0.2 (±0.07)–2.8 (±0.15) μg/L (HS-GC-MS) |
[36,54,55,57,59] |
| β-citronellol (6) | lemon/lime-like | 8 μg/L, 40 μg/L | 26.3 (±3.5) μg/L (Trap GC-MS) 1.2 (±0.05)–1.8 (±0.29) μg/L |
[36,42,54,55] |
| geraniol (4) | floral/rose-like | 4–5 μg/L, 40 μg/L | 265 (±45.8) μg/L (Trap GC-MS) 30.9 (±0.92)–72.8 (±0.17) μg/L (HS-GC-MS) |
[36,41,54,55] |
| linalool (3) | floral/lavender/coriander/citrus-like flavor |
8 μg/L | 155 (±8.0) μg/L (Trap GC-MS) 33.4 (±0.80)–36.4 (±0.87) μg/L (HS-GC-MS) |
[42,54,55] |
| nerol (5) | fresh, sweet, rose-like | 300 μg/L, 80 μg/L | 5.2 (±0.10)–7.7 (±0.25) μg/L (SPME-GC-MS) |
[36,57,59] |
| Sulfur Compounds | ||||
| 3-mercaptohexanol (3MH) (34) | rhubarb and grapefruit |
55 ng/L | 29–475 ng/L (LC-MS/MS) | [55,60] |
| 3-mercaptohexyl acetate (3MHA) (35) | passion fruit and grapefruit | 4 ng/L | 4–10 ng/L (LC-MS/MS) | [55,60] |
| 4-mercapto-4-methylpentan-2-one (4MMP) (36) | blackcurrant and passion-fruit-like |
1.5 ng/L | 31–40 ng/L (LC-MS/MS) | [55,60] |
| Esters | ||||
| ethyl 2-methyl- butanoate (16) |
green-fruity, apple-like | 1.1 μg/L | 1.1–1.9 μg/L (SPME-GC-MS) | [56,57] |
| ethyl 3-methyl- butanoate (17) |
fruity, vinous, apple-like | 2 μg/L | 1.5–1.8 μg/L (SPME-GC-MS) | [56,57] |
| ethyl 2-methyl- propanoate (18) |
fruity | 6.3 μg/L | 11.8–18.7 μg/L (SPME-GC-MS) | [56,57] |
| ethyl 4-methyl- pentanoate (19) |
fruity | 1.0 μg/L | 0.6–0.9 μg/L (SPME-GC-MS) | [56,57] |
| ethyl heptanoate (20) | fruity, reminiscent of cognac, wine/brandy | 400 μg/L | 1.6–8.8 μg/L (SPME-GC-MS) | [57,61,62] |
| isoamyl acetate (21) | fruity, banana, sweet, fragrant | 1200 μg/L | 275 (±54.6)–(330 (±11.6) μg/L (Trap GC-MS) |
[54,55,57,63] |
| isoamyl isobutyrate (22) | fruity, apricot, pineapple |
N/A ** | 0.6–16.5 μg/L (SPME-GC-MS) | [57,62] |
| isobutyl isobutyrate (23) | pineapple | N/A | 0.4–54 μg/L (SPME-GC-MS) | [57,61] |
| 2-methylbutyl isobutyrate (2-methylbutyl 2-methylpropanoate) (24) |
fruity | 78 μg/L | 1.6–103.6 μg/L (SPME-GC-MS) 41–198 μg/L (GC-FID) 24–87 µg/L (HS-SPME-GC-MS) |
[57,61,63,64,65] |
| 2-methylbutyl 2-methylbutyrate (25) | fruity, floral, banana and pineapple | N/A | 0.13–0.3 μg/L (SPME-GC-MS) | [66] |
| methyl geranate (26) | fruity, floral, waxy, herbal, citrus/sweet, candy | N/A | 1.3–7.6 µg/L (SPME-GC-MS) 8–192 µg/L (HS-SPME-GC-MS) |
[1,65,66] |
| 2-methylbutylpropanoate (27) | sweet, fruity, rum-like | N/A | 41–198 µg/L (SPME-GC-MS) | [66] |
| isoamyl butyrate (28) | fruity, green apple-like, and apricot | N/A | N/A | [66] |
| Ketones | ||||
| 2-nonanone (10) | rue, rose and tea-like | 5–200 μg/L | 6.9 (±0.30) μg/L (Trap GC-MS) 0.1–2.7 µg/L (SPME-GC-MS) |
[54,56,57] |
| 2-undecanone (11) | rue odor with a sweet flavor reminiscent of peach |
7 μg/L, 400 μg/L | 4.4 (±0.30) μg/L (Trap GC-MS) 0.1–6.0 µg/L (SPME-GC-MS) |
[54,56,57] |
| β-ionone (12) | violet-like, fruity, woody | N/A | ≤0.1 μg/L (SPME-GC-MS) | [57,61] |
* Standard deviations presented in the parentheses where stated by the authors. ** N/A—no available data and n.d.—not detected.