Rose Oil
Rose
oil,
meaning either rose otto (attar of rose) or rose absolute,
is the essential oil extracted from the petals of various types of rose. Two major species of rose are
cultivated for the production of rose oil:
- Rosa damascena, the damask rose, which is widely grown in Bulgaria, Turkey, Russia, Pakistan, India, Uzbekistan, Iran and China
- Rosa centifolia, the cabbage rose, which is more commonly grown in Morocco, France and Egypt
Bulgaria produces about 70% of all rose oil
in the world. Other significant producers are Morocco, Iran and Turkey.
Recently, China has begun producing rose oil as well.
Rose
oil contains usually as its major components geraniol, citronellol, nerol, β-phenethyl
alcohol, geranic acid, and eugenol, which together make up 55–75% of the oil,
with citronellol up to 60%. These components are found in free and bound forms
in ratios specific to individual species or cultivars. Other components present
include terpene hydrocarbons (especially α- and β-pinenes, myrcene, etc.),
esters, C14 to C23 n-paraffins making up the
so-called stearoptenes (accounting for 15–23% of the oil), nerol oxide, and
others.
Important fragrance
components of rose oil include (4R)-cis-rose oxide, (4R)-trans-rose
oxide, (±)-nerol oxide, 3-(4-methyl-3-pentenyl)-2-buten-4-olide,
3-methyl-4-(3-methyl-2-butenyl)-2-buten-4-olide, cis- and trans-2-(3-methyl-2-butenyl)-3-methyl
tetrahydrofuran, β-damascenone, 3-hydroxy-β-damascenone, and β-damascone.
Rose
absolute contains mainly phenethyl alcohol, with lesser amounts of citronellol,
geraniol, and nerol. Other compounds present include eugenol esters, and
others.
Production
Due to the
labor-intensive production process and the low content of oil in the rose
blooms, rose oil commands a very high price. Harvesting of flowers is done by
hand in the morning before sunrise and material is distilled the same day.
There are three main
methods of extracting the oil from the plant material:
- Steam distillation, which produces an oil called rose otto or attar of roses.
- Solvent extraction, which results in an oil called rose absolute.
- Supercritical carbon dioxide extraction, yielding an essential oil that may be marketed as either an absolute or as a CO2 extract.
Distillation
In the process of
distillation, large stills, traditionally of copper, are filled with roses and water. The still is fired for 60–105 minutes. The vaporized
water and rose oil exit the still and enter a condensing apparatus and are then
collected in a flask. This distillation yields a very concentrated oil, direct
oil, which makes up about 20% of the final product. The water which condenses
along with the oil is drained off and redistilled, cohobation, in order to obtain the water-soluble fractions of
the rose oil such as phenethyl alcohol which are a vital component of the aroma and which
make up the large bulk, 80%, of the oil. The two oils are combined and make the
final rose otto.
Rose otto will form white crystals at normal room temperature which disappear when the oil is gently warmed. It
will tend to become more viscous at lower temperatures due to this crystallization of some of its components.
Attar of roses was once made in India, Persia, Syria, and the Ottoman Empire. The Rose Valley in Bulgaria, near the town of Kazanlak, is among the major producers of attar of roses in
the world.
The hydrosol portion of the distillate is known as rosewater. This inexpensive by-product is used widely as a food
flavoring as well as in skin care.
Solvent
extraction
In the solvent
extraction method, the flowers are agitated in a vat with a solvent such as hexane, which draws out the aromatic compounds as well as other soluble substances such as
wax and pigments. The extract is subjected to vacuum processing which
removes the solvent for re-use. The remaining waxy mass is known as a concrete.
The concrete is then mixed with alcohol which dissolves the aromatic constituents, leaving
behind the wax and other substances. The alcohol is low-pressure evaporated,
leaving behind the finished absolute. The absolute may be further processed to
remove any impurities that are still present from the solvent extraction.
Carbon dioxide
extraction
A third process, supercritical carbon dioxide extraction, combines the best aspects of the other
two methods. When carbon dioxide is put under at least 72.9 atm of pressure and
at a temperature of at least 31.1°C (the critical point), it becomes a
supercritical fluid with the permeation properties of a gas and the solvation
properties of a liquid. (Under normal pressure CO2 changes directly
from a solid to a gas in a process known as sublimation.) The supercritical fluid CO2 extracts the
aromatics from the plant material.
Like solvent
extraction, the CO2 extraction takes place at a low temperature,
extracts a wide range of compounds rendering an essence more faithful to the
original, and leaves the aromatics unaltered by heat. Because CO2 is
gas at normal atmospheric pressure, it
leaves no trace of itself in the final product. The equipment for CO2
extraction is expensive, which is reflected in the price of the essential oils
obtained from the process.
Geraniol
PHYSICAL
AND CHEMICAL PROPERTIES
FORMULA
: (CH3)2CCH(CH2)2C(CH3)CHCH2OH
PHYSICAL STATE :
Clear to pale yellow oily liquid with sweet rose odor
MELTING POINT :
15 oC
BOILING POINT :
229 - 230 oC
SOLUBILITY IN WATER :
Insoluble (> 0.1g/100ml)
Geraniol is a monoterpenoid and an alcohol. It is the primary part of rose
oil, palmarosa oil, and citronella oil (Java type). It appears as a clear to
pale-yellow oil that is insoluble in water, but soluble in most common organic
solvents. It has a rose-like scent and is commonly used in perfumes.
Geraniol is one of the most widely used
aromatic isolates, indispensable in compounding of rose scents In fact, it
forms part of atmost any perfume compound. Thus Geraniol serves extensively in
the perfumes, cosmetics, soap and flavour industries.
One of the plants containing geraniol is
citronella oil. Production of Citronella oil in Indonesia is one of the biggest
crops in the world. It is because land in Indonesia supports for the plant
growth. Citronella oil is isolated from Java Citronella leaves (Cymbopogon
winterianus jowwit). Nowadays, Citronella oil is exported across the
country in its pure oil form so that only little foreign exchange will be
obtained from this manufacture. Therefore, efforts to increase its commercial
value are needed. In this research, isolation of geraniol, one of chemical
components contained in Citronella oil is carried out. This compound has been
widely used in field of cosmetics, breeding and health.
Geraniol also find an application as an insect
repellents or deterrants. The
results of the active fraction Citronella oil can be applied in various
industries such as cosmetics products with skin lotion mosquito repellent which
is a natural insecticide ingredients are cheap and effective in repel
mosquitoes and can be used safely and practically.
~forgiveness
if there are mistakes~
How to isolation and identification geraniol from citronella oil ? and how to increase the geraniol content from citronella leaves ?
BalasHapusgeraniol can be isolated from cittronela oil using steam distillation method. Geraniol distillate extracted with ether to separate it from the water. To improve the content of geraniolnya, citronella oil is hydrolyzed with NaOH in ethanol for 1 hour to hydrolyze geranil acetate into geraniol. Identification of compounds geraniol performed using gas chromatography-mass spectrometry (GC-MS).
BalasHapusThe method used in isolating from leaves of lemon grass lemongrass oil is steam distillation method. Enriching the content of geraniol in lemongrass oil is used reflux. Vacuum distillation fractionation to isolate geraniol from lemongrass oil. Lemongrass oil used in this study were isolated from 10 kg of leaves by steam distillation of lemongrass scented and citronella oil produced as 42.5 mL (0.373%) in yellow shiny clear distinctive smell of lemongrass.
BalasHapusCitronella oil was isolated from Citronella leaves by steam distillation. The distillate of Citronella oil was extracted with ether to separate it from water. To increase the geraniol content, Citronella oil was hydrolysed with NaOH in ethanol for 1 hour to convert geranil acetate to geraniol. Identification of geraniol was conducted by Gas Chromatography-Mass Spectroscopy (GC-MS) method.
Ten kilograms of Citronella leaves produced 42,5 mL (0,373%) of yellow-pale Citronella oil with refractive index of 1,4755. The data of GC chromatogram of Citronella oil showed that the geraniol content was about 65,34%. The enrichment of geraniol with NaOH in ethanol caused hydrolysis reaction of geranil acetate to geraniol, and therefore raised the geraniol content up to 81,96%.
why when carbon dioxide is put under at least 72.9 atm pressure and at a minimum temperature of 31.1 ° C (critical point) can be a supercritical fluid and gas permeation properties of the solvation properties of the liquid? and what will happen if it is done under a tipping point?
BalasHapusFirstly we have to know about critical point. The critical point, Tc, of a material is the temperature where the liquid and vapor phases are indistinguishable. When approaching the critical point temperature, gas and liquid properties become equal, this phase is called Supercritical Fluid. Above the critical point, the liquid can not be formed by adding the pressure.
HapusThe critical point of carbon dioxide is 72,9 atm at 31,1 oc. We have to reach supercritical fluid, so that CO2can extract the aromatics from the plant material. If it done far below the critical point, it will not be supercriticl fluid, so CO2 cannot extract the aromatics from the plant material
tiara i have question
BalasHapusin your material i read "like solvent extraction takes place at a low temperature, extracks a wide range compounds rendering an essence more faithful to the original, and leaves the aromatics unaltered by heat"
my question is :
why if the extraction takes place at high temperatures ?
whether the extraction process can run smoothly ?
thanks
tiara..
BalasHapusyour article explained that there are three main methods of extracting the oil from the plant material. Different products are produced from each methods.What is the difference among them ??
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BalasHapus