Table 2.
Composition of volatiles identified at different harvest periods in essential oils of olive leaves from cvs. Leccino and Frantoio.
| Compound | KI | Leccino | Frantoio | ||||
|---|---|---|---|---|---|---|---|
| 22 August | 12 September | 25 October | 22 August | 12 September | 25 October | ||
| (Z)-3-hexen-1-ol | 849 | 1.32 ± 0.35 | 2.13 ± 0.17 | 1.61 ± 0.24 | 3.87 ± 0.25 | 2.50 ± 0.17 | 4.11 ± 0.53 |
| heptanal | 902 | 0.31 ± 0.02 a,b | 0.48 ± 0.05 a,c | 0.82 ± 0.04 b,c | 0.30 ± 0.06 | 0.22 ± 0.22 | 0.55 ± 0.1 |
| benzaldehyde | 977 | 0.23 ± 0.002 | 0.28 ± 0.04 | 0.40 ± 0.03 | 0.35 ± 0.05 b | 0.50 ± 0.05 c | 0.89 ± 0.05 b,c |
| pyridne-3-ethnyl | 986 | - | 1.78 ± 0.23 | 0.59 ± 0.32 | - | 3.43 ± 0.21 | - |
| (E,Z)-2,4-heptadienal | 1008 | 1.18 ± 0.23 | 2.47 ± 0.18 | 3.15 ± 0.04 | 1.23 ± 0.19 | 1.05 ± 0.19 | 1.98 ± 0.24 |
| (E,E)-2,4-heptadienal | 1027 | 0.74 ± 0.1 a,b | 1.19 ± 0.09 a,c | 1.91 ± 0.07 b,c | 0.54 ± 0.08 b | 0.5 ± 0.002 c | 2.81 ± 0.56 b,c |
| phenylacetaldehyde | 1063 | 0.84 ± 0.01 | 1.62 ± 0.27 | 1.11 ± 0.12 | 1.24 ± 0.15 | 1.73 ± 0.09 | 1.23 ± 0.27 |
| cis-linalool oxide (furanoid) | 1079 | 0.16 ± 0.02 | - | tr | - | - | - |
| octanol | 1087 | 1.09 ± 0.1 | 0.92 ± 0.13 | 0.98 ± 0.07 | 0.51 ± 0.06 b | 0.96 ± 0.03 c | 0.17 ± 0.03 b,c |
| trans-linalool oxide (furanoid) | 1092 | - | - | - | - | - | - |
| p-cymenene | 1100 | 0.24 ± 0.01 | 0.16 ± 0.01 c | 0.25 ± 0.03 c | 0.26 ± 0.04 | tr | tr |
| nonanal | 1107 | 6.08 ± 0.87 b,c | 7.46 ± 1.26 c | 24.80 ± 2.85 b | 7.88 ± 0.67 a | 3.67 ± 0.28 a,c | 11.15 ± 2.47 c |
| 1,4-dimethyl-δ-3-tetrahydroacetophenone | 1158 | 0.97 ± 0.14 | 1.21 ± 0.14 c | 0.70 ± 0.06 c | 1.15 ± 0.23 | 0.71 ± 0.17 | 0.62 ± 0.07 |
| limonen-4-ol | 1193 | 0.79 ± 0.16 | 0.81 ± 0.14 | 0.73 ± 0.02 | 0.61 ± 0.17 | 0.39 ± 0.07 | 1.09 ± 0.14 |
| decanal | 1200 | 0.88 ± 0.15 | 0.69 ± 0.03 | 0.66 ± 0.1 | 0.76 ± 0.09 | 0.64 ± 0.57 | 1.36 ± 0.43 |
| α-terpineol | 1210 | 0.81 ± 0.29 | 1.52 ± 0.26 | 0.86 ± 0.01 | 0.22 ± 0.07 | 0.39 ± 0.07 | 0.56 ± 0.09 |
| methyl salicylate | 1210 | 0.49 ± 0.18 | 0.42 ± 0.04 | 0.65 ± 0.09 | 1.01 ± 0.09 | 0.58 ± 0.07 | 0.32 ± 0.09 |
| β-cyclocitral | 1228 | 0.71 ± 0.06 a | 0.95 ± 0.02 a | 0.81 ± 0.02 | 0.71 ± 0.03 | 0.84 ± 0.16 | 0.58 ± 0.08 |
| chrysanthenyl acetate | 1243 | 1.05 ± 0.23 | 1.23 ± 0.16 | 1.23 ± 0.1 | 0.67 ± 0.26 | 0.63 ± 0.29 | 1.32 ± 0.24 |
| α-ionene | 1262 | 1.14 ± 0.01 a,b | 0.50 ± 0.02 a | 0.57 ± 0.1 b | 0.27 ± 0.12 | 0.14 ± 0.004 | 0.18 ± 0.03 |
| (E)-2-decenal | 1276 | 0.57 ± 0.09 b | 0.68 ± 0.04 c | 1.14 ± 0.09 b,c | 0.58 ± 0.18 | 0.19 ± 0.03 | 0.15 ± 0.06 |
| vitispirane | 1283 | 0.72 ± 0.09 a | 0.49 ± 0.01 | 0.45 ± 0.04 a | 1.11 ± 0.08 a,b | 0.67 ± 0.05 a | 0.55 ± 0.05 b |
| dihydroedulan II | 1294 | 0.24 ± 0.02 | 0.29 ± 0.03 | 0.22 ± 0.02 | 0.12 ± 0.02 | tr | tr |
| dihydroedulan I | 1299 | 0.51 ± 0.01 b | 0.38 ± 0.03 c | 0.27 ± 0.02 b,c | 0.85 ± 0.04 a | 0.28 ± 0.11 a | 0.51 ± 0.06 |
| theaspirane a # | 1303 | 3.60 ± 0.59 | 4.02 ± 0.36 | 3.26 ± 0.55 | 13.54 ± 0.39 | 10.76 ± 0.09 | 10.68 ± 1.01 |
| theaspirane b # | 1321 | 3.80 ± 0.71 | 4.55 ± 0.34 | 3.52 ± 0.73 | 11.69 ± 0.24 | 12.65 ± 0.2 | 8.62 ± 1.49 |
| cyclosativene | 1373 | - | - | tr | 0.21 ± 0.01 | 0.24 ± 0.02 | 0.35 ± 0.08 |
| α-copaene | 1382 | 0.22 ± 0.06 | tr | 0.63 ± 0.08 | 0.55 ± 0.06 | 0.84 ± 0.04 | 0.68 ± 0.11 |
| (E)-β-damascenone | 1384 | 36.77 ± 0.12 b | 33.66 ± 2.62 c | 21.16 ± 1.52 b,c | 22.97 ± 1.17 | 23.78 ± 0.55 | 13.90 ± 2.42 |
| tetradecane | 1400 | 5.79 ± 0.01 b | 4.65 ± 0.06 | 2.86 ± 0.68 b | 4.17 ± 0.14 | 4.18 ± 0.65 | 7.93 ± 2.71 |
| (E)-β-damascone | 1417 | 1.29 ± 0.16 | 1.78 ± 0.02 | 1.44 ± 0.23 | 0.91 ± 0.05 | 1.32 ± 0.29 | 1.22 ± 0.13 |
| β-caryophyllene | 1427 | 4.06 ± 0.06 | 4.48 ± 0.58 | 3.88 ± 0.19 | 6.44 ± 0.14 | 7.95 ± 1.34 | 2.99 ± 0.98 |
| dihydrodehydro-β-ionone | 1431 | 7.75 ± 0.48 a,b | 3.53 ± 0.32 a | 3.73 ± 0.42 b | 1.91 ± 0.2 | 2.34 ± 0.36 | 2.34 ± 0.43 |
| (E)-geranyl acetone | 1461 | 0.87 ± 0.02 | 0.98 ± 0.02 | 0.89 ± 0.1 | tr | 0.67 ± 0.57 | 0.38 ± 0.2 |
| α-humulene | 1464 | 1.33 ± 0.04 b | 1.40 ± 0.02 c | 2.00 ± 0.17 b,c | 0.7 ± 0.05 | 1.04 ± 0.14 | 0.87 ± 0.25 |
| β-ionone | 1488 | 4.4 ± 0.29 | 5.14 ± 0.46 | 3.32 ± 0.4 | 4.66 ± 0.49 | 4.75 ± 0.1 | 4.92 ± 0.18 |
| α-muurolene | 1512 | 0.18 ± 0.06 | - | 0.20 ± 0.03 | tr | tr | tr |
| α-farnesene | 1514 | tr | 0.35 ± 0.06 c | 0.98 ± 0.22 c | 0.22 ± 0.05 b | 0.36 ± 0.001 | 0.56 ± 0.1 b |
| δ-cadinene | 1527 | 0.28 ± 0.07 | 0.56 ± 0.02 | tr | 0.31 ± 0.02 | 0.29 ± 0.04 | 0.27 ± 0.01 |
| kessane | 1542 | - | - | - | 0.16 ± 0.02 | 0.25 ± 0.02 | 0.20 ± 0.05 |
| liguloxide | 1547 | 0.86 ± 0.02 b | 0.82 ± 0.01 c | 0.59 ± 0.02 b,c | 1.80 ± 0.09 a,b | 2.60 ± 0.03 a | 2.95 ± 0.12 b |
| (E)-nerolidol | 1575 | 0.55 ± 0.07 | 0.94 ± 0.28 | 1.79 ± 0.19 | 0.36 ± 0.03 a,b | 1.47 ± 0.22 a | 2.24 ± 0.57 b |
| caryophyllene oxide | 1594 | 1.52 ± 0.01 | 1.29 ± 0.09 | 1.24 ± 0.09 | 0.36 ± 0.02 b | 0.56 ± 0.12 | 0.74 ± 0.13 b |
| (E)-2-hexenyl benzoate | 1599 | 0.92 ± 0.02 a | 0.22 ± 0.02 a | - | 0.57 ± 0.15 | 0.39 ± 0.06 | 0.65 ± 0.08 |
| hexadecane | 1606 | 1.55 ± 0.25 | 0.75 ± 0.13 | 1.12 ± 0.42 | 1.42 ± 0.14 | 1.51 ± 0.004 | 3.60 ± 1.31 |
| Alcohols | 2.41 | 3.05 | 2.58 | 4.39 | 3.46 | 4.27 | |
| Aldehydes | 11.55 | 15.83 | 34.79 | 13.58 | 9.34 | 20.70 | |
| Ketones | 52.05 | 46.30 | 31.25 | 31.69 | 33.58 | 23.38 | |
| Esters | 2.46 | 1.87 | 1.89 | 2.25 | 1.60 | 2.29 | |
| Aromatic hydrocarbones | 1.39 | 0.66 | 0.82 | 0.53 | 0.18 | 0.27 | |
| Saturated hydrocarbons | 7.34 | 5.40 | 3.98 | 5.59 | 5.69 | 11.53 | |
| Monoterpenes | 2.46 | 3.28 | 2.49 | 1.54 | 1.62 | 2.23 | |
| Sesquiterpenes | 9.08 | 9.90 | 11.43 | 11.21 | 15.70 | 11.96 | |
| Heterocyclic compounds | 8.87 | 9.72 | 7.71 | 27.30 | 24.45 | 20.43 | |
| Pyridines | - | 1.78 | 0.59 | - | 3.43 | - | |
| Total identified (%) | 96.90 | 96.86 | 96.73 | 97.37 | 98.21 | 96.47 | |
Results are expressed as mean ± SE. Kovats indices (KI) are determined on the VF-5MS capillary column; -, not detected; tr, traces (<0.01%). Compounds are identified by mass spectra and KI comparison with NIST and Wiley libraries, as well as literature values [34,35,36,37]. Statistical analyses are performed by one-way ANOVA analysis, with or without Welch corrections. Means were compared by Tukey’s test if equal variance could be assumed or by Dunett T3’s test if equal variance could not be assumed. Mean values with the same letter differ significantly (p ≤ 0.05). theaspirane #—correct isomer could not be determined.