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Composition of the essential oil of dill, celery, and parsley from Estonia/Eestis kasvatatud tilli, selleri ja peterselli eeterliku oli koostis.
Abstract:
The qualitative and quantitative composition of the essential oil of dill, celery, and parsley growing in Estonia was studied using the simultaneous distillation/extraction micro-method for oil isolation and capillary gas chromatography for analysing the extracts. The yields of the oils from dried aromatic plants after two hours distillation were 2.9-4.3 mg/g. Forty-eight compounds were identified representing over 96% of the total oil. [alpha]-Phellandrene (75.1-75.8%), [beta]-phellandrene (7.4-7.9%), dill ether (2.2-3.9%), and limonene (2.8-2.9%) were the principal components of dill oil. p-1,3,8-Menthatriene (40.0-44.6%), [beta]-phellandrene (15.1-16.9%), myristicin (13.0-13.1%), and myrcene (6.5-7.0%) were characteristic constituents in oil from parsley leaves, but apiole (34.5%), myristicin (28.8%), and terpinolene (13.2%) predominated in parsley root oil. Celery oil contained in high quantities limonene (62.4-70.3%), (Z)-[beta]-ocimene (10.1-10.5%), and phthalide isomers (total 13.4-16.6%). Drying of aromatic plants for four weeks at room temperature did not significantly change the chemical composition of their essential oil.

Key words: Anethum graveolens, Petroselinum crispum, Apium graveolens, Apiaceae, essential oil composition, effect of drying.

Eestis kasvatatud tilli, selleri ja peterselli eeterlik oli eraldati samaaegse destillatsiooni ja ekstraktsiooni mikromeetodil ning analuusiti kapillaargaasi-kromatograafilisel meetodil. Oli saagised kuiva taimmaterjali kohta jaid vahemikku 2,9-4,3 mg/g. Tilli Oli pOhikomponentideks olid alfa-fellandreen (75,1-75,8%), beeta-fellandreen (7,4-7,9%), limoneen (2,8-2,9%) ja tilli eeter (2,2-3,9%). Peterselli lehtede olis domineerisid p-1,3,8-mentatrieen (40,0-44,6%), beeta-fellandreen (15,1-16,9%) ja muristitsiin (13,0-13,1%), peterselli juurikate olis aga leiti rohkesti apiooli (34,5%), muristitsiini (28,8%) ja terpinoleeni (13,2%). Selleri oli iseloomustas suur limoneeni (62,4-70,3%), (Z)-beeta-otsimeeni (10,1-10,5%) ja ftaliidide (13,4-16,6%) sisaldus. Uuritud maitsetaimede kuivatamine uhe kuu jooksul toatemperatuuril ei avaldanud oli koostisele olulist moju.

Authors:
Orav, Anne
Kailas, Tiiu
Jegorova, Anna
Pub Date:
12/01/2003
Publication:
Name: Estonian Academy of Sciences: Chemistry Publisher: Estonian Academy Publishers Audience: Academic Format: Magazine/Journal Subject: Chemistry Copyright: COPYRIGHT 2003 Estonian Academy Publishers ISSN: 1406-0124
Issue:
Date: Dec, 2003 Source Volume: 52 Source Issue: 4
Accession Number:
198707084
Full Text:
INTRODUCTION

Aromatic plants include a broad range of species that are used for their aroma characteristics as flavoring in foods and beverages and as fragrances in pharmaceutical and industrial products. They are marketed fresh, which is best, frozen and dried, which makes them available year round. Today aromatic plants are incredibly popular and the volume of their production is increasing for both processing and fresh markets.

The chemical composition of essential oil of aromatic herbs has been the subject of several studies [1-21]. The content of the main components of oils has been found to vary according to the geographical origin, harvesting time, growth conditions, isolation method, and so on. The essential oils of aromatic plants growing in Estonia have not been studied by capillary gas chromatography earlier.

The aim of the present work was to identify the compounds that constitute the essential oils of aromatic plants growing in Estonia and to determine the effect of drying process of plant material on the chemical composition of their oils. Dill, celery, and parsley as the most widely used aromatic plants in Estonia were chosen as objects for this research.

EXPERIMENTAL

Materials

Commercial plant material of Estonian origin was used. Each plant species was bought fresh. All fresh material was divided into two parts, and essential oils were directly isolated from one part. The other part of the material was dried during 4 weeks at room temperature in accordance with all requirements of an air drying method. Characterization of the plant material and the yields of essential oils are given in Table 1.

It is a fact that the water content in fresh plant material is very variable.

Carefully dried plant material consists practically only of dry matter. Therefore the yields of oil calculated for dry material are more accurate and more suitable for comparison than those for fresh material. The highest oil yield from dried plants was obtained from dill (4.3 mg/g) and the lowest from parsley leaves (2.9 mg/g).

Isolation of essential oil

The simultaneous distillation and extraction (SDE) method was chosen for essential oil isolation using Marcusson's type micro-apparatus with n-hexane (500 [micro]L) as solvent and n-tetradecane (2 [micro]L) as internal standard. Distillation time was 2 h. For the isolation procedure 10-20 g of plant material was used.

Capillary gas chromatography

n-Hexane extracts (1-5 [micro]L) of the essential oils were analysed using a Chrom-5 gas chromatograph with FID on two fused silica capillary columns (50 m x 0.20 mm i.d.) with bonded stationary phases (OV-101, film thickness 0.50 [micro]m and SW-10, film thickness 0.25 [micro]m). Helium with a flow rate 0.4-0.6 mL/min was used as the carrier gas with the split ratio of 1: 150. The column temperature was programmed from 50 to 250[degrees]C (OV-101) and from 70 to 230[degrees]C (SW-10) at 2[degrees]C/min. The injector temperature was 200[degrees]C.

The identification of the oil components was based on the comparison of their retention indices RI on two columns with the corresponding data of our RI data bank and with RI data presented in the literature. The results obtained were confirmed by GC/MS.

The quantitative composition of the essential oils was calculated using the internal normalization method. The yields of the oil isolated by the SDE method from aromatic plants were calculated by the internal standard method using pure n-tetradecane (> 99.9%) as internal standard.

Gas chromatography-mass spectrometry

The mass spectra of the compounds were recorded at 70 eV on a Hewlett Packard GC/MS 5988A instrument, the mass number (m/z) range 30-350. The fused silica capillary column (10 m x 0.20 mm) with HP-17 as stationary phase was used. The oven temperature program was from 50 to 250[degrees]C at 8[degrees]C/min. The injector temperature was 280[degrees]C.

RESULTS AND DISCUSSION

Common dill oil

The components of dill oil are listed in Table 2 together with their RI data on two columns and with their percentage amounts. We identified 29 compounds. Analysis indicated that the principal aroma compounds in Estonian dill oil were [alpha]-phellandrene (75.1-75.8%), [beta]-phellandrene (7.4-7.9%), dill ether (2.2-3.9%), and limonene (2.8-2.9%). [alpha]-Pinene, (E)-[beta]-ocimene, myrcene, and p-cymene were found in the oils in quantities from 0.6 to 2.0% and the other oil components constituted below 0.5%.

The concentration of [alpha]-phellandrene, the principal component of Estonian dill oil, was too high compared to those reported by other investigators [4-7]. Carvone (14-58%), found to be one of the main components in Cuban [5, 6], Romanian and Kazakhstan [4], and Hungarian [7] dill oils, occurred in trace amounts in the Estonian dill oil analysed. Such a divergence can be explained by differences in growth stages of plants used for analysis. Dill herb tested in the present work was harvested before flower formation, but the other studied dill samples [4-7] were harvested at the time of flowering or during the fruit formation period. In the essential oil of dill herb from Finland [3] harvested before bud formation large amounts of dill ether (37%) and [alpha]-phellandrene (32%) were found.

The chemical composition of essential oils obtained from fresh and dry materials was almost identical. Only the content of dill ether decreased from 3.9% to 2.2% on drying.

Celery oil

We identified 26 compounds in the celery oil (Table 2). The main group of compounds forming celery oil consisted of monoterpenoid hydrocarbons, among them limonene (62.4-70.3%), (Z)-[beta]-ocimene (10.1-10.5%), [gamma]-terpinene (1.6-2.3%), and myrcene (1.3%). The quantities of other monoterpenes and sesquiterpenes in the celery oil were below 0.5%. Phthalide isomers (total 13.4-16.6%) were the second major group present in celery oil. These compounds appear to be most important in the aroma of celery [9-15]. The total amount of phthalides in Belgian celery oils was 6-11% [12]. By the data of Van Wassenhove et al. [11, 12] the main phthalide isomers in celery oils of Belgium are butylphthalide, trans-neocnidilide, and senkyunolide. MacLeod et al. [15] found 3-butylphthalide and sedanolide in high quantities in celery oil from Libya.

The analysis of oils obtained from fresh and dried materials indicated some changes in the oil composition. As it can be seen in Table 2, the percentage of limonene was reduced by the drying from 70.5% to 62.4% and the content of phthalides increased by 3.2%.

Parsley oil

In the essential oil of parsley leaves, stems, and roots 36 compounds were found (Table 2). These made up over 96% of the total oil. The oil from parsley leaves (with stems) contained mostly monoterpenes (76.1-78.8%). Aromatic compounds were found to form from 16.1% to 18.4% and oxygenated terpenes only from 1.0% to 1.2%. The oil from parsley roots contained a 3.3 times lower amount of monoterpenes (23.6%) and 2.7 times higher amount of aromatic compounds (64.5%) than the aboveground plant did.

Compounds present in greatest concentrations in parsley leave oil were p-1,3,8-menthatriene (40.0-44.6%), [beta]-phellandrene (15.1-16.9%), myristicin (13.0-13.1%), and myrcene (6.5-7.0%). Terpinolene, [beta]-phellandrene, limonene, 1-methyl-4-isopropenylbenzene, [beta]- and [alpha]-pinene were found in quantities from 0.6% to 4.2% and the other constituents below 0.8%. The main compounds of parsley root oil were apiole (34.5%), myristicin (28.8%), terpinolene (13.2%), and [beta]-phellandrene (4.6%).

The same compounds were found in the parsley leaves and roots as the main components by other investigators [16-21]. The intensity of odours was measured for each identified compound in oils from parsley leaves by researchers from Sweden [17]. No single compound was described as being uniquely parsley-like; however, the aromas of p-1,3,8-menthatriene, [beta]-phellandrene, myristicin, and apiole were found to have very strong odour intensities. It was considered that the aroma of parsley leaves was caused by a mixture of at least these naturally occurring volatile compounds. Myrcene, terpinolene, and p-cymenene, reported to have strong intensities, could also influence the aroma of parsley [17-21].

The oils obtained from fresh and dried materials did not have great differences in their chemical composition. Decreasing of the amount of p-1,3,8-menthatriene by 4.6% and of the amount of [beta]-phellandrene by 1.8% occurred in parsley leave oil by drying. The content of 1-methyl-4-isopropenylbenzene, [beta]-phellandrene, and [alpha]- and [beta]-pinene increased after drying by 0.6-1.8%. Variations in the amounts of other components were insignificant.

CONCLUSION

The analysis of the essential oils produced from aromatic plants growing in Estonia demonstrated good aroma characteristics of Estonian aromatic plants. Drying, which was carried out for four weeks at room temperature, did not change the chemical composition of essential oils from dill, parsley, and celery significantly.

ACKNOWLEDGEMENT

Financial support for the work reported here was provided by the Estonian Science Foundation (grant No. 4028).

REFERENCES

[1.] Simon, J. E. Essential oils and culinary herbs. In Advances in New Crops (Janick, J. & Simon, J. E., eds.). Timber Press, Portland, OR., 1990, 472-483.

[2.] Lawrence, B. New trends in essential oils. Perf. Flav., 1980, 5, 6-16.

[3.] Huopalahti, R., Lahtinen, R., Hiltunen, R. & Laakso, I. Studies on the essential oils of dill herb, Anethum graveolens L. Flavour Fragr. J., 1988, 3, 121-125.

[4.] Jirovetz, L., Buchbauer, G. & Nikiforov, A. Vergleichende Inhaltsstoffanalyse verchiedener Dillkraut und Dillsamenole mittels GC/FID und GC/MS. Ernahrung/Nutrition, 1994, 18, 534-536.

[5.] Pino, J. A., Roncal, E., Rosado, A. & Goire, I. Herb oil of dill (Anethum graveolens L.) grown in Cuba. J. Essent. Oil Res., 1995, 7, 219-220.

[6.] Pino, J. A., Rosado, A., Goire, I. & Roncal, E. Evaluation of flavor characteristic compounds in dill herb essential oil by sensory analysis and gas chromatography. J. Agric. Food Chem., 1995, 43, 1307-1309.

[7.] Simandi, B., Kery, A., Lemberkovics, E., Oszagyan, M., Ronyai, E., Mathe, I., Fekete, J. & Hethelyi, E. Supercritical fluid extraction of medicinal plants. In Process Technology Proceedings, 12. High Pressure Chemical Engineering. Proceedings of the 3rd International Symposium of High Pressure Chemical Engineering, Zurich, Switzerland, October 7-9, 1996 (von Rohr, Ph. R. & Trepp, Ch., eds.). Elsevier, Amsterdam, 1996, 357-362.

[8.] Wilson, C. W. III. Terpene and sesquiterpene hydrocarbons in the essential oil from fresh celery. J. Food Sci., 1969, 34, 521-523.

[9.] Uhlig, J. W., Chang, A. & Jen, J. J. Effect of phthalides on celery flavor. J. Food Sci., 1987, 52, 658-660.

[10.] MacLeod, G. & Ames, J. M. Volatile components of celery and celeriac. Phytochemistry, 1989, 28, 1817-1824.

[11.] Van Wassenhove, F. A., Dirinck, P. J., Schamp, N. M. & Vulsteke, G. A. Effect of nitrogen fertilizers on celery volatiles. J. Agric. Food Chem., 1990, 38, 220-226.

[12.] Van Wassenhove, F., Dirinck, P., Vulsteke, G. & Schamp, N. Aromatic volatile composition of celery and celeriac cultivars. Hort. Sci., 1990, 25, 556-559.

[13.] Bartschat, D., Wust, M. & Mosandl, A. Stereoisomeric flavor compounds LXXVII: 3-butyl-hexahydrophthalides: simultaneous enantioselective analysis, structure elucidation, and sensorial properties of the stereoisomers. J. High Resol. Chromatogr., 1997, 20, 251-256.

[14.] Dauksas, E., Venskutonis, P. R., Sivik, B. & Nillson, T. Effect of fast CO2 pressure changes on the yield of lovage (Levisticum officinale Koch.) and celery (Apium graveolens L.) extracts. J. Supercrit. Fluids, 2002, 22, 201-210.

[15.] MacLeod, A., MacLeod, G. & Subramanian, G. Volatile aroma constituents of celery. Phytochemistry, 1988, 27, 373-375.

[16.] Paju, A., Raal, A. & Tamkivi, K. Ravimtaimed ja tervis III. Ravimtaimed erituselundite haiguste ravis. Eesti Rohuteadlane, 1991, 2, 99-107.

[17.] Kasting, R., Andersson, J. & von Sydow, E. Volatile constituents in leaves of parsley. Phytochemistry, 1972, 11, 2277-2282.

[18.] Freeman, G. G., Whenham, R. I., Self, R. & Eagles, J. Volatile flavour components of parsley leaves (Petroselinum crispum (Mill.) Nyman). J. Sci. Food Agric., 1975, 26, 465-470.

[19.] MacLeod, A. J., Snyder, C. H. & Subramanian, G. Volatile aroma constituents of parsley leaves. Phytochemistry, 1985, 24, 2623-2627.

[20.] Nitz, S., Kollmannsberger, H. & Drawert, F. Analysis of flavours by means of combined cryogenic headspace enrichment and multidimensional GC. In Bioflavour '87 (Schreier, P., ed.). Walter de Gruyter & Co., Berlin, New York, 1988, 123-135.

[21.] Simon, J. E. & Quinn, J. Characterization of essential oil of parsley. J. Agric. Food Chem., 1988, 36, 467-472.

Anne Orav *, Tiiu Kailas, and Anna Jegorova

Institute of Chemistry, Tallinn Technical University, Ehitajate tee 5, 19086 Tallinn, Estonia

Received 3 July 2003

* Corresponding author, aorav@chemnet.ee
Table 1. Characterization of the aromatic plant samples

          Material                 Plant part       Oil yield, mg/g

                                                     Fresh   Dried

Dill, Anethum graveolens L.     Leaves with stems     0.8     4.3
(collected before flower
formation)

Parsley, Petroselinum crispum   Leaves with stems     0.52    2.9
(Mill.) Nyman                   Roots                 0.42     --

Celery, Apium graveolens L.     Leaves with stems     0.37    3.8

Table 2. Identification data and percentage composition of
Essential oils of aromatic plants. The components identified
in the highest yields are in bold

Compound                    RI            Concentration, %

                         OV-    PEG    Dill   leaves   Celery
                         101    20M
                                      Fresh   Dried    Fresh

[alpha]-Thujene          921   1029     0.3     0.4      --
[alpha]-Pinene           928   1029     1.6     2.0      0.2
Camphene                 940   1074    tr.     tr.       --
Sabinene                 964   1125     0.1     0.1      0.2
[beta]-Pinene            967   1116     0.1     0.1      0.4
Myrcene                  982   1161     0.6     0.6      1.3
[alpha]-Phellandrene     995   1167    75.1    75.8      0.1
[alpha]-Terpinene       1008   1180     --      --       --
p-Cymene                1010   1273     0.6     1.2      0.1
Limonene                1020   1204     2.8     2.9     70.3
[beta]-Phellandrene     1020   1213     7.9     7.4      0.1
(Z)-[beta]-Ocimene      1028   1232     0.1     0.1     10.1
(E)-[beta]-Ocimene      1038   1250     1.3     1.2      0.3
[gamma]-Terpinene       1048   1246     --      --       2.3
[alpha]-p-Dimethyl-
  styrene               1070            0.4     0.4      --
1-Methyl-4-isopro-
  penylbenzene          1074   1428
Terpinolene             1077   1282     0.4     0.5      --
p-1,3,8-
  Menthatriene          1096   1387     --      --      tr.
1-Phenyl-2-butene       1152   1414     --      --       0.3
Dill ether              1164   1506     3.9     2.2      --
Myrtenal                1166   1617     --      --       --
[alpha]-Terpineol       1174   1693     --      --       --
Carvone                 1215   1725    tr.     tr.       --
Bornyl acetate          1268   1574    tr.      0.1      --
(E)-[beta]-Caryo-
  phyllene              1412   1589     --      --       0.1
[beta]-Farnesene        1450   1662     0.2     0.2      0.1
Sesquiterpene           1465   1675     --      --       --
Germacrene D            1467   1690     0.3     0.4      --
a Bergaptene            1477   1910     --       --      --
Myristicin              1500   2246     0.5     0.3      --
[beta]-Bisabolene       1504   1737     0.1     0.1      --
[delta]-Cadinene        1512   1749     --      --       --
[gamma]-Selinene        1517   1755     --      --       --
Elimicin                1526   2215     --      --       --
Germacrene B            1549   1813     --      --       --
Viridiflorol            1575   2069     --      --       0.1
Phthalide isomer *      1585            0.2     0.3     tr.
Phthalide isomer *      1600            --      --       0.3
Phthalide isomer *      1605            --      --       0.7
T-Cadinol               1624   2156     0.2     0.1      --
Apiole                  1645   2460     0.3     0.5      0.1
Farnesol *              1652   2275     0.1     0.3      0.1
Phthalide isomer *      1674            --      --       2.9
Phthalide isomer *      1684            0.1     0.1      9.4
Phthalide isomer *      1691            --      --       0.1
n-Heptadecane           1700   1700     0.1     0.2      0.1
n-Octadecane            1800   1800     0.2     0.2      0.1
n-Nonadecane            1900   1900     0.1     0.1      --

COMPONENT GROUPS:
Monoterpenes                           90.3    91.1     85.3
Oxygenated
  monoterpenes                          3.9     2.3      --
Sesquiterpenes                          0.6     0.7      0.2
Oxygenated
  sesquiterpenes                        0.3     0.4      0.2
Aromatic compounds                      1.8     2.4      0.5
Phthalides                              0.3     0.4     13.4
n-Alkanes                               0.4     0.5      0.2

  Total, %                             97.6    97.8     99.8

Compound                             Concentration, %

                        leaves   Parsley   leaves   Parsley roots

                        Dried    Fresh     Dried        Fresh

[alpha]-Thujene           --       --        --           --
[alpha]-Pinene            0.2      1.0       2.8          0.2
Camphene                  --       0.1       tr.          0.1
Sabinene                  0.2      0.2       0.2          0.1
[beta]-Pinene             0.4      0.6       1.2          2.9
Myrcene                   1.3      7.0       6.5          0.9
[alpha]-Phellandrene      0.4      2.2       4.1          0.3
[alpha]-Terpinene         --       0.1       0.1          --
p-Cymene                  0.1      0.1       0.3          --
Limonene                 62.4      2.8       3.2          0.5
[beta]-Phellandrene       0.3     16.9      15.1          4.6
(Z)-[beta]-Ocimene       10.5      0.1      tr.           0.1
(E)-[beta]-Ocimene        0.2      0.2       0.2          --
[gamma]-Terpinene         1.6      0.1       0.1          0.2
[alpha]-p-Dimethyl-
  styrene                 --       --        --           --
1-Methyl-4-isopro-
  penylbenzene                     2.4       4.2          0.1
Terpinolene               --       2.9       2.6         13.2
p-1,3,8-
  Menthatriene           tr.      44.6      40.0          0.4
1-Phenyl-2-butene         0.3      0.4       0.3         tr.
Dill ether                --       --        --           --
Myrtenal                  --       0.5       0.4          --
[alpha]-Terpineol         --       0.2       0.3          0.1
Carvone                   --       0.1      tr.           --
Bornyl acetate            --       0.2       0.1          --
(E)-[beta]-Caryo-
  phyllene                0.2      0.3       0.2          --
[beta]-Farnesene         tr.       0.1       0.1          0.2
Sesquiterpene             --       0.8       0.6          1.5
Germacrene D              --       --        --           --
a Bergaptene              --       0.3       0.2          1.8
Myristicin                --      13.0      13.1         28.8
[beta]-Bisabolene         --       0.5       0.2          0.9
[delta]-Cadinene          --       0.1       0.1          --
[gamma]-Selinene          --      tr.       tr.           2.1
Elimicin                  --       --        --           1.1
Germacrene B              --      tr.        0.1          0.1
Viridiflorol              0.1      --        --           --
Phthalide isomer *        0.1      --        --           --
Phthalide isomer *        0.8      --        --           --
Phthalide isomer *        1.7      0.1      tr.           0.3
T-Cadinol                 --       0.1       0.1          0.1
Apiole                    0.7      0.2       0.5         34.5
Farnesol *                0.1      0.1       0.1          0.1
Phthalide isomer *        4.9      --        --           0.7
Phthalide isomer *        8.4      --        --           0.2
Phthalide isomer *        0.7      --        --           --
n-Heptadecane             0.3     tr.       tr.           0.1
n-Octadecane              0.3     tr.       tr.          tr.
n-Nonadecane              --       --        --           0.2

COMPONENT GROUPS:
Monoterpenes             77.5     78.8      76.1         23.5
Oxygenated
  monoterpenes            --       1.0       0.8          0.1
Sesquiterpenes            0.2      1.8       1.5          6.6
Oxygenated
  sesquiterpenes          0.2      0.2       0.2          0.2
Aromatic compounds        1.1     16.1      18.4         64.5
Phthalides               16.6      0.1      tr.           1.2
n-Alkanes                 0.6     tr.       tr.           0.3

  Total, %               96.2     98.3      97.0         96.4

--not found;
tr.--traces (< 0.05%);
* Specific isomer not identified.
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