ArticlePDF Available

Essential Oils of Persian Musk rose (Rosa moschata Herrm.) as Influenced by Drying and Harvest Times

Authors:

Abstract and Figures

Persian musk rose (Rosa moschata Hermm.) is widely used in perfumes and cosmetics industries because of its medicinal properties and pleasant odour. Since synthesis and accumulation of volatile compounds affected by flower harvest time, the current study was conducted to evaluate and monitor the changes of volatiles in the essential oil (EO) of Persian Musk Rose petals harvested at different dates (May 11, May 21 and June 01). GC and GC-MS determined the compositions of EO. In addition, the EOs obtained from fresh and dried flowers harvested at different dates were compared to maximize yield and quality of EO. The highest EO yield was observed in the fresh and dried petals harvested at May11, which was significantly higher than the June samples; however, there was no significant difference between May 11 and May 21 samples. The EO composition at different harvest dates was significantly different in the fresh petals, and the highest phenyl ethyl alcohol (14.3%) was observed at the second harvest date. Monoterpenes increased from 2.4% in the first harvest to 8.5% in the third harvest. Aliphatic hydrocarbons showed an increasing pattern in the petals harvested at May 11 (78.6%) to June (86.4%). Concentration of oxygenated monoterpenes significantly reduced in the EO of the dried petals. After drying, phenylpropanoids reduced at the first and the second harvest dates and increased at the third harvest. However, the concentration of aliphatic hydrocarbons increased at the first and the second harvests and decreased at the third harvest date.
Content may be subject to copyright.
Nat. Volatiles & Essent. Oils, 2016; 3(2): 9-14 Karami and Jandoust
9
RESEARCH ARTICLE
Essential oils of Persian Musk rose (Rosa moschata Herrm.) as
influenced by drying and harvest times
Akbar Karami* and Samira Jandoust
Department of Horticultural Science, Faculty of Agriculture, Shiraz University, Shiraz, IRAN
*Corresponding author. Email: akbarkarami@shirazu.ac.ir, akarami2004@gmail.com
Abstract
Persian musk rose (Rosa moschata Hermm.) is widely used in perfumes and cosmetics industries because of its medicinal
properties and pleasant odour. Since synthesis and accumulation of volatile compounds affected by flower harvest time, the
current study was conducted to evaluate and monitor the changes of volatiles in the essential oil (EO) of Persian Musk Rose petals
harvested at different dates (May 11, May 21 and June 01). GC and GC-MS determined the compositions of EO. In addition, the EOs
obtained from fresh and dried flowers harvested at different dates were compared to maximize yield and quality of EO. The highest
EO yield was observed in the fresh and dried petals harvested at May11, which was significantly higher than the June samples;
however, there was no significant difference between May 11 and May 21 samples. The EO composition at different harvest dates
was significantly different in the fresh petals, and the highest phenyl ethyl alcohol (14.3%) was observed at the second harvest
date. Monoterpenes increased from 2.4% in the first harvest to 8.5% in the third harvest. Aliphatic hydrocarbons showed an
increasing pattern in the petals harvested at May 11 (78.6%) to June (86.4%). Concentration of oxygenated monoterpenes
significantly reduced in the EO of the dried petals. After drying, phenylpropanoids reduced at the first and the second harvest dates
and increased at the third harvest. However, the concentration of aliphatic hydrocarbons increased at the first and the second
harvests and decreased at the third harvest date.
Keywords: Rosa moschata, drying, essential oils, harvest date
Introduction
Rosa has sixteen wild species in Iran of which R. moschata Herrm. with the common names of Persian Musk
rose, Nastrane Shiraz and Rose Anbar is one of the most strongly scented rose species with characteristic
floral scent molecules such as terpenoids, phenylpropanoids/benzenoids and fatty acid derivatives
(Mozaffarian 2013; Jandoust & Karami, 2015). Persian Musk rose is distributed in many local regions of Iran;
its wild origins are uncertain but are suspected to lie in the western Himalayas (Khosh-Khui 2014, Honarvar
et al., 2011). As, Persian Musk rose has not been confirmed clearly in history, but the supposition is that it
is a parent of Damask rose (Jandoust & Karami, 2015). In traditional medicine, hydrosol of Persian Musk
rose has been used to strengthen heart muscles, stomach, liver, spleen, nerves, and gums and to
strengthen intelligence (Honarvar et al., 2011; Jandoust & Karami, 2015). The quantity and composition of
the rose oil distilled from the rose petals are strongly affected by the genotypes, the climatic conditions,
diurnal variability, storage conditions, the time of rose petals harvesting, and the technology used for
processing and distillation (Baydar & Baydar 2005; Carvalho-Filho et al., 2006; Baydaret al., 2008; Barbosa
et al., 2011; Sharmaet al., 2012; Karami et al., 2013; Kumar et al., 2013; Jandoust & Karami, 2015).
Therefore, in this research, the seasonal variations of EOs of fresh and dried flowers were studied by GC
and GC/MS techniques.
Nat. Volatiles & Essent. Oils, 2016; 3(2): 9-14 Karami and Jandoust
10
Materials and Methods
Plant material
The fresh flowers of Persian Musk rose were collected from College of Agriculture gardens (Shiraz 59°
35´E, 29°43´ N, Altitude 1810 m) during their flowering period (May 11, May 21 and June 01, 2014). A
specimen (Collector Number: PC 87-23) has been deposited in the Herbarium of the Faculty of Sciences,
Shiraz University.
Analysis of the oil
The aerial parts were air-dried at ambient temperature in the shade and air-dried and fresh flower
hydrodistilled by using a Clevenger-type apparatus for 3 h. It was dissolved inn-hexane (Merck), dried over
anhydrous sodium sulphate and stored at 4°C ± 2°C.GC analysis was performed using an Agilent gas
chromatograph series 7890-A with a flame ionization detector (FID). The analysis was carried out on fused
silica capillary HP-5 column (30 m × 0.32 mm i.d.; film thickness 0.25 mm). The injector and detector
temperatures were kept at 250 C and 280 C, respectively. Nitrogen was used as carrier gas at a ow rate
of 1 ml/min; oven temperature program was 60-210 C at the rate of 4C/min and then programmed to 240
C at the rate of 20 C/min and nally held isothermally for 8.5 min; split ratio was 1:50. GC-MS analysis was
carried out by use of Agilent gas chromatograph equipped with fused silica capillary HP-5MS column (30 m
× 0.25 mm i.d.; film thickness 0.25 m) coupled with 5975-C mass spectrometer. Helium was used as carrier
gas with ionization voltage of 70 eV. Ion source and interface temperatures were 230 C and 280 C,
respectively. Mass range was from 45 to 550 amu. Oven temperature program was the same given above
for the GC.
Identification of Compounds
The constituents of the essential oil were identified by calculation of their retention indices under
temperature-programmed conditions for n-alkanes (C8-C25) and the essential oil on a HP-5 column under
the same chromatographic conditions. Identification of individual compounds made by comparison of their
mass spectra with those of the internal reference mass spectra library or with authentic compounds and
confirmed by comparison of their retention indices with authentic compounds or with those of reported in
the literature. For quantification purpose, relative area percentages obtained by FID were used without the
use of correction factors.
Results and Discussion
In general, seasonal variation and drying had a significantly effect on the EOs contents and composition of
Persian musk rose as discussed more below.
Essential oil content
The EO content of both fresh and dried Persian musk rose flowers extracted during their flowering period
(May 11, May 21 and June 01). The highest EO content was observed in the fresh and dried petals
harvested at May 11, which was significantly higher than the June samples; however, there was no
significant difference between May 11 and May 21 samples.
Nat. Volatiles & Essent. Oils, 2016; 3(2): 9-14 Karami and Jandoust
11
GC-MS analysis
Seasonal variation
In the current study, at the selected time, EOs were collected for periods of 3hrs and analyzed by GC/MS.
In this study, a total number of 79 EOs compounds were detected by GC/MS from FW and DW of R.
moschata at different season (Table 1). In overall, identified components in the subsequent season was
representing 97.499.9 % of total EOs. The major compounds at different season were identified as 1-
nonadecene (5.90-34.80%), n-heneicosane (18.8-53.8 %), n-nonadecane (9.5-34.4) and phenyl ethyl alcohol
(0.1-14.27 %). The EO composition at different harvest dates was significantly different in the fresh petals,
and the highest phenyl ethyl alcohol (14.27 %) was observed at the second harvest date. Monoterpenes
increased from 2.39% in the first harvest to 8.54% in the third harvest. Aliphatic hydrocarbons showed an
increasing trend in the petals harvested at May 11 (78.6%) to June (86.4%). The yield and chemical
composition of essential oils (EO) from medicinal plants are related to a variety of internal and external
factors such as harvest time and postharvest processing, due to spontaneous conversions and their
unstable nature. The effect of harvest time on yield and quality of EO has been widely investigated. Baydar
& Baydar, 2005 reported that yield and EO composition of R. damascena flowers was significantly different
on May 8 and 24. They obtained more EO on May 24, which was about 0.04%. Kumar et al., 2013 showed
that harvesting R. damascena at different times might affect its EO composition and yield. The highest EO
yield in Thymus vulgaris have been reported on December. However, the monoterpenic phenols, thymol
and carvacrol were higher after blooming on summer (McGimpsey et al., 2006).
Effects of drying
The EO composition of dried petals was significantly dissimilar than the fresh ones at different harvest
dates. Concentration of oxygenated monoterpenes significantly reduced in the EO of the dried petals (Table
1). After drying, phenylpropanoids reduced at the first and the second harvest dates and increased at the
third harvest. However, the concentration of aliphatic hydrocarbons increased at the first and the second
harvests and decreased at the third harvest date. Number of components and composition of the EO
obtained from fresh and dried flowers harvested at different times were different. The GC-MS analyses
revealed that Persian Musk rose EO is mainly rich of aliphatic hydrocarbons such as n-nonadecane, n-
heneicosane, 1-nonadecane, n-tricosene; however, components such as geraniol, citronellol, nerol,
comprise lower proportion of the EO. Aliphatic hydrocarbons in fresh petals of EO were about 78.6%,
75.3%, and 86.4% in May 11, May 21 and June. Therefore, aliphatic hydrocarbon increased from first
harvest to third harvest. On the other hand, the highest phenyl ethyl alcohol (14.2%), which causes the
odor of the rose flowers, was obtained from the fresh tissues harvested in May 21. Hence, it can be
concluded that efficiency of EO extraction and quality of EO obtained from flowers harvested on May 21 is
significantly higher. Although phenyl ethyl alcohol, or 2-phenylethanol, is the major scent compound of the
fresh flower, its content is around 1% in the hydrodistilled rose oil due to the high solubility in residue
water or rose water, by-products of hydrodistillation (Baydar et al., 2008). It appears that such
investigations are useful for optimizing EO extraction and obtain products with established composition as
a market demand. On the other hand, postharvest processing and preserving methods may also influence
amount and composition of EO of the harvested material. Drying is widely used for controlling microbial
infections, insect pest management and preserving the medicinal plant tissues for long time (Schweiggert
et al., 2007). However, drying may influence the amount and composition of essential oil. Barbosa et al.,
2006 reported that the citral level in Lippia alba dried leaves was significantly increased, however nerol
Nat. Volatiles & Essent. Oils, 2016; 3(2): 9-14 Karami and Jandoust
12
content showed a significant decrease and geraniol oxidized into geranial after drying. Carvalho-Filho et al.,
2006 showed significant changes in the Ocimum basilicum L. EO composition during drying.
Table 1. Seasonal changes in essential oil compounds (%) of Rosa moschata Herrm.
Components RI
May 11 May 21 June
FW DW FW DW FW DW
α-Pinene 930 t t - - t -
Myrcene 988 t - - - - -
n-Octanal 1001 - - - - t -
p-Cymene 1021 - t - - t 0.2
trans-Rose oxide 1124 - - - - t -
Limonene 1025 t t - - t 0.2
1,8-Cineole 1028 - t - - - -
(Z)-β-Ocimene 1033 t - - - - 0.3
Benzene acetaldehyde 1040 t 0.2 - - t -
(E-Ocimene 1044 t - - - - -
dihydro-Tagetone 1048 - - - - - 3.1
γ-Terpinene 1055 - t - - - -
n-Octanol 1066 t t - - t -
Linalool 1066 0.1 0.2 - - 0.1 -
n-Nonanal 1097 0.2 0.7 - - 0.5 -
Terpinene-4-ol 1174 - - - - t -
Phenylethyl alcohol 1110 1.9 1.3 14.3 1.7 0.1 0.8
Camphor 1141 - t - - - -
(2E)-Nonen-1-al 1155 - 0.3 - - t -
n-Nonanol 1167 t 0.1 - - t 0.7
α-Terpineol 1187 t t - - t -
n-Dodecane 1196 - - - - t -
n-Decanal 1202 0.1 0.5 - - 0.1 0.5
Citronellol 1225 0.9 0.2 4.1 - 7.6 5.4
Pulegone 1235 - 0.1 - - - -
Neral 1237 0.1 - - - t -
Geraniol 1251 1.1 0.2 0.4 - 0.7 -
2-Phenylethyl acetate 1253 0.3 0.1 0.3 - 0.2 -
Geranial 1267 0.1 - - - t -
Nonanoic acid 1267 - - - - - 6.4
Undecanal 1303 0.1 0.4 - - 0.1 1.4
Methyl geranate 1320 - - - - t -
Citronellyl acetate 1350 - - - - 0.1 -
Eugenol 1353 2.2 1.5 1.2 - 0.4 3.0
Geranyl acetate 1381 - - - - 0.1 -
β-Elemene 1388 - - - - t -
n-Decanoic acid 1364 - 0.9 - - - 3.0
n-Tetradecane 1396 - - - - t -
Nat. Volatiles & Essent. Oils, 2016; 3(2): 9-14 Karami and Jandoust
13
Methyl eugenol 1401 - - - - 0.4 -
Dodecanal 1405 0.1 0.4 - - t 0.5
(E)-Caryophyllene 1415 0.8 0.3 - - 0.2 -
dihydro-β-Ionone 1434 0.5 - 1.1 - - -
α-Guaiene 1434 - - - - 0.1 -
α-Humulene 1449 - - - - 0.2 -
Geranyl acetone 1449 0.4 0.7 - - - 0.8
(E)-β-Farnesene 1453 0.5 - - - - -
Germacrene D 1476 - - - - 0.1 -
(E)-β-Ionone 1482 - 2.0 - - 0.1 -
n-Pentadecane 1495 - 0.5 - - 0.4 -
(E,E)-α-Farnesene 1505 - - - - 0.1 -
Tridecanal 1506 - 0.2 - - - 1.2
(E)-Nerolidol 1560 - - - - 0.1 -
Caryophyllene oxide 1577 - 0.2 - - t 2.8
2-Phenylethyl tiglate 1581 - - - - t -
n-Hexadecane 1595 0.1 0.2 - - 0.1 -
Tetradecanal 1608 - - - - t -
β-Eudesmol 1645 - - - - 0.1 -
α-Eudesmol 1648 - - - - 0.1 -
1-Heptadecene 1695 2.4 1.1 1.2 - 0.4 2.7
(6Z,9E)-Heptadecadiene 1719 1.2 - - - - -
n-Heptadecane 1695 2.7 4.1 1.6 1.0 3.2 -
(Z,Z)-Farnesol 1717 - - - - 0.4 -
Benzyl benzoate 1758 - 0.9 - 0.3 0.3 -
n-Octadecane 1795 - 0.4 - 0.1 0.6 -
Phenylethyl octanoate 1846 - 2.7 - 2.5 0.4 -
1-Nonadecene 1868 34.8 19.6 21.3 7.6 8.6 5.9
n-Nonadecane 1892 12.7 16.6 13.0 9.5 27.4 30.4
2-Phenylethyl phenyl acetate 1902 - 0.8 - 0.5 - -
1-Eicosene 1970 0.7 0.3 0.7 - 0.5 -
Ethyl palmitate 1995 - - - - 0.3 -
n-Eicosane 1999 0.8 1.4 - 0.9 4.5 2.1
n-Octadecanol 2073 6.1 2.8 3.0 1.7 1.4 -
n-Heneicosane 2103 21.1 32.7 30.9 53.9 26.1 18.8
n-Docosane 2197 0.3 0.6 0.4 1.8 1.5 -
1-Tricosene 2287 0.2 0.2 - 0.5 0.8 -
n-Tricosane 2296 1.6 2.7 5.1 10.5 7.8 -
n-Tetracosane 2400 - - - 0.5 0.5 -
n-Pentacosane 2500 0.2 0.4 0.7 1.9 2.9 -
Total 97.4 98.5 99.3 98.9 99.9 99.8
*RI: Retention indices analysed on HP-5; ““: not detected; t: trace amount; DW: Dry weight; FW: Fresh
weight
Nat. Volatiles & Essent. Oils, 2016; 3(2): 9-14 Karami and Jandoust
14
Conclusion
In general, it is clear that during seasonal variation and emission timing, Persian musk rose EOs varied
significantly over time. GC/MS analysis was performed to define both similarities and differences across
different seasons and fresh and dried flower in Persian Musk rose. Therefore, drying of plant material and
seasonal variations of EOs has essential function and application in agriculture. Consequently, it can be
concluded that efficiency of EO extraction and quality of EO obtained from flowers of this plants harvested
on May 21 is significantly higher than other harvest times.
REFERENCES
Barbosa, F.F., Barbosa, L.C.A., Melo, E.C., Botelho, F.M. & Santos, R.H.S. (2006). Influence of drying air temperature on
the content and chemical composition of essential oil of Lippia alba (Mill) N. E. Brown. Quim Nova, 29, 1221-1225.
Baydar, H. & Baydar, N.G. (2005). The effects of harvest date, fermentation duration and Tween 20 treatment on
essential oil content and composition of industrial oil of Damask rose (Rosa damascena Mill.). Industrial Crops and
Products, 21, 251-255.
Baydar, H., Schulz, H., Kruger, H., Erbas, S. & Kineci, S. (2008). Influences of fermentation time, hydro-distillation time
and fractions on essential oil composition of Damask rose (Rosa damascena Mill.). Journal of Essential Oil Bearing
Plants, 11, 224-232.
Carvalho-Filho, J.L.S., Blank, A.F., Alves, P.B., Ehlert, P.A., Melo, A.S., Cavalcanti, S.C. & Silva-Mann, R. (2006). Influence
of the harvesting time, temperature and drying period on basil (Ocimum basilicum L.) essential oil. Brazilian Journal of
Pharmacognosy, 16, 24-30.
Honarvar, M., Javidnia, K. & Khosh-Khui, M. (2011). Essential oil composition of fresh and dried flowers of Rosa
moschata from Iran. Chemistry of Natural Compounds, 47, 826-828.
Jandoust, S. & Karami, A. (2015). Seasonal variation in floral scent of Persian Musk rose (Rosa moschata Hermm.).
Journal of Medicinal Plants and By-products, 4, 243-247.
Karami, A., Khosh-Khui, M., Salehi, H. & Saharkhiz, M.J. (2013). Headspace analysis of floral scent from two distinct
genotypes of Iranian Damask rose (Rosa damascena Mill.). Journal of Essential Oil Bearing Plants, 16, 489-498.
Khosh-Khui, M. (2014). Biotechnology of scented roses: a review. International Journal of Horticultural Science and
Technology, 1, 1-20.
Kumar, R., Sharma, S., Sood, S., Agnihotri, V.K. & Singh, B. (2013). Effect of diurnal variability and storage conditions on
essential oil content and quality of damask rose (Rosa damascena Mill.) flowers in north western Himalayas. Scientia
Horticulturae, 154, 102-108.
McGimpsey, J.A., Douglas, M.H., VanKlink, J.W., Beauregard, D.A. & Perry, N.B. (2006). Seasonal variation in essential
oil yield and composition from naturalized Thymus vulgaris L. in New Zealand. Flavour and Fragrance Journal, 9, 347-
352.
Mozaffarian, V. (2013). Identification of Medicinal and Aromatic Plants of Iran. Farhang Moaser Publishing, IR.
Sharma, B., Singh, B., Dhyani, D., Verma, P.K. & Karthigeyan, S. (2012). Fatty acid composition of wild growing rose
species. Journal of Medicinal Plants Research, 6, 10461049.
ResearchGate has not been able to resolve any citations for this publication.
Research
Full-text available
Abstract The seasonal variation of volatile oil compositions (VOCs) from fresh flowers of Persian Musk rose was investigated by Combi PAL Headspace Techniques. In this study, a total number of 21 VOCs were detected by headspace on the Combi PAL System and gas chromatography-mass spectrometry (HS-GC/MS) from Rosa moschata Herrm. at different seasons which was representing 92.53-99.37 % of total VOCs. The analysis of VOCs at different seasons detected the major compounds: Phenyl ethyl alcohol (30.68-77.36 %), 1-Nonadecene (1.01-30.42 %), n-Nonadecane (4.61-14.04 %), n-Heneicosane (4.47-12.07 %) and 1-Tricosene (0-5.91 %). Phenylpropanoids content varied significantly over time, with a low level during September and maximum content in May. In contrast to phenylpropanoids contents, the high level of fatty acid derivatives was realized during September. In all of seasons a low level of terpenoids derivatives was emitted from Persian Musk rose flowers. The results of this research suggest that the fragrance characteristics of R. moschata resulted from its specific composition and can be manipulated by seasonal changes and environmental conditions.
Article
Full-text available
Leaves of Lippia alba were submitted to six different drying treatments, using air at ambient temperature and heated up to 80 °C. The essential oil was extracted by steam distillation and analyzed by GC-MS. For the dried leaves, the oil content was reduced by 12 to 17% whencompared with the fresh plant (0.66%). The major oil component was citral, representing 76% for the fresh plant, and varying from 82 to 84% for the dried material. These results showed that L. alba can be submitted to a drying process of up to 80 ºC without degradation and/or loss of the major, [LC1] active component.
Article
Full-text available
Damask rose (Rosa damascena Mill.) is known for its high quality oil, used in the perfumery industry. The aim of this study was to determine the influences of fermentation time, hydro-distillation time and fractions with sequential intervals on essential oil composition, particularly on methyl eugenol content of Damask rose. Essential oil of the rose flowers was produced by hydro-distillation using a Clevenger-type apparatus. Six fermentation times (6, 12, 18, 24, 30 and 36 h at 25°C in sack), 6 distillation times (30, 60, 90, 120, 150 and 180 min.) and 7 fractions (0–15, 16–30, 31–60, 61–90, 91–120, 121–180, and 181–240 min.) during a hydro-distillation were used. The components in the essential oils were analyzed by GC-FID and GC-MS. Rose oil was characterized by high percentage of acyclic monoterpene alcohols, represented particularly by citronellol, geraniol and nerol, and long-chain hydrocarbons represented particularly such as nonadecane, nonadecene and heneicosane. The oil yield started to decrease through the fermentation (from 0.055 to 0.025 %). Fermentation increased the citronellol and methyl eugenol contents in opposition to the content of geraniol and nerol. Each one of hydrocarbons increased their percentages nearly two times and more during the fermentation. Extending of distillation time up to 150 min increased the essential oil yield. The longer distillation time gave a higher methyl eugenol concentration, whose content increased steadily up to last distillation time (from 0.69 to 1.65 %). Contents of monoterpene alcohols decreased, whereas the hydrocarbons steadily increased up to late fractions.
Article
Full-text available
Ocimum basilicum L. essential oil with high concentration of linalool is valuable in international business. O. basilicum essential oil is widely used as seasoning and in cosmetic industry. To assure proper essential oil yield and quality, it is crucial to determine which environmental and processing factors are affecting its composition. The goal of our work is to evaluate the effects of harvesting time, temperature, and drying period on the yield and chemical composition of O. basilicum essential oil. Harvestings were performed 40 and 93 days after seedling transplantation. Harvesting performed at 8:00 h and 12:00 h provided higher essential oil yield. After five days drying, the concentration of linalool raised from 45.18% to 86.80%. O. basilicum should be harvested during morning and the biomass dried at 40ºC for five days to obtain linalool rich essential oil.
Article
The chemical compositions of floral scent from two distinct genotypes (G1 and G2) of Iranian Rosa damascena flowers were isolated at six stages of flower development using headspace extraction. The main floral headspace components were phenyl ethyl alcohol, β-citronellol, α-pinene, benzyl alcohol and geranyl acetate. In both genotypes, the relative percentage of phenyl ethyl alcohol increased as flowers were developed. However, the concentration of β-citronellol was highest in stage 4 (47 %) and stage 3 (45.1 %) in two genotypes under study. The first flower development stage of both genotypes had the lowest amount of this compound. Benzyl alcohol was highest and a major component in the G2 and increased with floral development while G1 had a trace amount of this compound. Geranyl acetate, an important contributors to the aroma, was highest in stage 4 (11.6 %) and stage 3 (22.7 %) in the G1 and G2, respectively. This compound was not found in early stages of flowers development (stages 1 and 2) of both genotypes.
Article
The essential oil of Rosa damascena Mill. is one of the most valuable and important base material in the flavor and fragrance industry. The aim of this study was to determine the effects of harvest date, fermentation duration and Tween 20 treatment on the essential oil content and composition of the rose petals. The essential oil content and composition were significantly different in the petals harvested at various dates (May 24, June 1, 8, and 15, 2002). The highest oil content was found on May 24 harvest (0.040%), and then a gradual decrease was observed up to last harvest date (0.032%). The highest percentages of geraniol, nerol, and phenylethyl alcohol were obtained from the petals harvested on May 24. However, the highest percentages of citronellol and linalool were found from the petals harvested on June 8. The petals collected freshly were fermented for various duration (0, 12, 24, and 36 h) at 25 °C in sacks. The highest essential oil content was found in the non-fermented petals. As fermentation duration increased, essential oil content gradually decreased. The most significant changes during the fermentation were observed in citronellol and geraniol contents. Citronellol/geraniol (C/G) ratio increased from 0.57 to 10.31 throughout the fermentation. In the other experiment, Tween 20 was added into the distillation water at various concentrations (0, 1000, 2500, and 5000 ppm). Although Tween 20 generally raised the contents of essential oil, it did not significantly influence the oil composition. The highest oil content (0.045%) was obtained from the distillation treated with 2500 ppm of Tween 20. Oil content had high positive correlations with geraniol and linalool contents (r=0.55 and 0.53, respectively), but high negative correlation with citronellol content (r=−0.48).
Article
Field experiments were conducted at CSIR-Institute of Himalayan Bioresource Technology, Palampur, India to study the effect of diurnal variability and storage conditions of flower on oil content and composition of damask rose (Rosa damascena Mill.) during 2011. In this study, the rose oil was obtained by hydrodistillation in Clevenger type apparatus and the components in the oil were analyzed by GC/MS. The essential oil content and composition were affected by harvest time and storage conditions. The highest essential oil content (0.043%, v/w) was obtained from the rose flowers which were harvested at 04:00 am and the lowest (0.017%, v/w) from the flowers harvested at 02:00 pm. The percentage of citronellol + nerol, main components of rose oil, increased with delay in harvesting. Geraniol content (26.3%) was maximum when the flowers were harvested at 10:00 am, but after that there was significant reduction in its concentration upto 06:00 pm. Storage duration of flowers at different temperature also affected the oil content and composition. There was 8.5% and 27.6% reduction in oil content when the flowers were stored for 24 h at 4 °C, and 18 ± 1 °C or 25 ± 1 °C, respectively. Parallel to the increase of the storage time citronellol + nerol content increased. The rates of hexadecane, nonadecane and methyl eugenol in the flowers distilled immediately were determined to be lower than the stored flowers. The percentage of geraniol in the flowers distilled immediately were between 27.4% and declined to 4.4%, 6.9% and 18.1% after 24 h of storage at 25 ± 1 °C, 18 ± 1 °C and at 4 °C temperature, respectively. The optimal results in terms of its oil content and components were obtained from the rose flowers distilled immediately after the harvest compared to the flowers stored at 25 ± 1 °C, 18 ± 1 °C. However, at 4 °C the flowers can be stored for 16 h without much effect in oil content and composition.
Article
The seasonal variation in essential oil yield and composition from naturalized Thymus vulgaris L. in Central Otago, New Zealand, is reported. Essential oil yield (l/ha), from replicated, pilot-scale distillations, was influenced by both the field production of herb and the essential oil content of the herb. The oil yield peaked at 22.8 l/ha in December, after flowering had finished. Essential oil composition also varied significantly during the 13-month sampling period. Levels of the phenolic components, thymol and carvacrol, peaked at a total of 37% after flowering in summer (December and January). p-Cymene was an important component of Central Otago thyme oils and ranged from 40% to 50% in winter and early spring (May to October), declining to 21% in January. To maximize yields and phenol content of the oil, naturalized thyme in Central Otago should be harvested after flowering has finished in December.