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Rose oil (rose otto,attar of rose,attar of roses, orrose essence) is anessential oil that is extracted from thepetals of various types ofrose.Rose ottos are extracted throughsteam distillation,[1] whilerose absolutes[2] are obtained throughsolvent extraction, theabsolute being used more commonly inperfumery. The production technique originated inIran.[3][4] Even with their high price and the advent oforganic synthesis, rose oils are still perhaps the most widely used essential oil in perfumery.
Two major species of rose are cultivated for the production of rose oil:[5]
Composition of rose oil and headspace vary, but the Rose international standard survey of 2003–2020 lists three components as the major components with a specific range specified in ISO 9842:2003.[6]
Heneicosane,eicosane,docosane,tricosane,tetracosane,pentacosane,hexacosane,heptacosane,nonacosane,dodecane,tetradecane,pentadecane,hexadecane,heptadecane,octadecane,nerol,linalool,phenyl ethyl alcohol,farnesol,α-pinene,β-pinene,α-terpinene,limonene,p-cymene,camphene,β-caryophyllene,neral,geranyl acetate,neryl acetate,eugenol,methyl eugenol,benzaldehyde,benzyl alcohol,octane andtetradecanol.[7]
Beta-damascenone's presence is considered as the marker for the quality of rose oil.Even though these compounds usually exist in less than 1% quantity of rose oil, they make up for slightly more than 90% of the odor content due to their lowodor detection thresholds.[8]
Rosa centifolia does not have a rose oil because of the delicate nature of its petals. TheRosa centifolia absolute is composed of more than 50%phenylethyl alcohol and the rest of the composition resembles aRosa damascena.[9]
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 beforesunrise, and the material is distilled the same day.
There are three main methods of extracting the oil from the plant material:
In the first part of the two-stage 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 of the whole process. 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 asphenethyl 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 attar.
Rose attar is mobile in room temperature and is usually clear, light yellow in color. It will form white crystals at normal room temperature which disappear when the oil is gently warmed. It will tend to become moreviscous at lower temperatures due to this crystallization of some of its components.
The essence has a very strong odor, but is pleasant when diluted and used for perfume. Attar of roses was once made in India, Persia, Syria, and the Ottoman Empire. TheRose Valley in Bulgaria, near the town ofKazanlak, is among the major producers of attar of roses in the world.[10]In India,Kannauj is an important city of fabrication of rose attar,Kannauj is nicknamed "The Grasse of the East" or "The Grasse of the Orient".Grasse (in France) is an important city of fabrication of rose fragrance.
Due to the heat required for distillation, some of the compounds extracted from the rosedenature or break down chemically. As such, rose attar does not smell very similar to "fresh" roses.
Thehydrosol portion of the distillate is known asrosewater. This inexpensive by-product is used widely as a food flavoring as well as in skin care.
In the solvent extraction method, the flowers are agitated in a vat with asolvent such ashexane, which draws out thearoma compounds as well as other soluble substances such aswax andpigments. The extract is subjected to vacuum processing which removes the solvent for re-use. The remaining waxy mass is known as aconcrete. The concrete is then mixed withalcohol 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.
Rose absolute is a deep reddish brown with no crystals. Due to the low temperatures in this process, the absolute may be more faithful to thescent of the fresh rose than the otto.
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 (73.9 bar) of pressure and at a temperature of at least 31.1 °C (88.0 °F) (thecritical point), it becomes a supercritical fluid with the permeation properties of a gas and the solvation properties of a liquid. (Under normal pressureCO
2 changes directly from a solid to a gas in a process known assublimation.) The supercritical fluidCO
2 extracts the aromatics from the plant material.
Like solvent extraction, theCO
2 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. BecauseCO
2 is gas at normalatmospheric pressure, it leaves no trace of itself in the final product. The equipment forCO
2 extraction is expensive, which is reflected in the price of the essential oils obtained from the process.
It takes a large amount of rosepetals to distill a small amount of essential oil. Depending on extraction method and plant species, the typical yield can be approximately 1:3,000.[11] To mitigate the cost, most dealers dilute rose oil withCitronellol,Geraniol,Geranium orPalmarosa (Cymbopogon martinii) essential oils, both of which are rich inGeraniol, the main constituent of rose oil. Some of these "rose oils" are up to 90% geranium or palmarosa to 10% rose. This is referred to asextending the rose fragrance. This may be done to compensate for chemotype, e.g. Bulgarian distilled rose oil is naturally low in phenylethanol, and Ukrainian or Russian rose oil is naturally high in phenylethanol. Pure rose oil should not be used directly on the skin, as it can cause allergic reactions such as red skin and spots.[medical citation needed]
Rosa ×damascena is a cultivated flower not found in the wild. Recent genetic tests indicate that it is a hybrid ofR. moschata xR. gallica crossed with the pollen ofRosa fedtschenkoana, which indicates a probable origin in the foothills ofcentral Asia[12] or Iran.[13] Rose oil likely originated inancient Iran where the production technique was invented.[14][15]
Bulgarian rose oil is generally characterized by the following qualities:[1]
{{cite encyclopedia}}:Missing or empty|title= (help)Rosa damascena Mill is the hybrid between R. gallica and R. Phoenicia and is the member of Rosaceae family with more than 200 species and 18,000 cultivars around the world. R. damascena as the king of flowers has been the symbol of love, purity, faith and beauty since the ancient times. It was originated from Iran and essential oil extracting from its flowers has been started since 7th century A.D.
The dictionary definition ofrose oil at Wiktionary