“Essential oil” derived from the word “quintessence”. Based on Aristotelian idea, matter is composed of four elements: fire, air, earth, water; the fifth element, or quintessence, is the soul and spirit of the aromatic plants. Some even said it is the life force of the plants.
Of course, nowadays, we know that, essential oils are the aromatic essences extracted (distillation, cold pressing…) from roots, flowers, fruits, herbs or trees. It is the plant’s second metabolism developed over the centuries for survival, defense against microbial pathogens, adapting to the ever-changing environment and used for attracting pollinating insect.
This is why essential oils have therapeutic properties such antiseptic, anti-virus, anti-fungal, immune stimulating which is beneficial to our mankind.
Essential oils are highly concentration, volatile and fat-soluble. It differs from fixed oils which contain glycerides or fatty acids which will not leave a permanent stain on filter paper.
Nowadays, essential oils are used as raw materials in many industries, including aromatherapy, perfumes, toiletry and cosmetics, phytotherapy, spices and nutrition, insecticides.
What is Absolute?
Absolute is essences obtained by using chemical solvents. The solvents used are usually ethanol, methanol, benzene or hexane. All but the first of these are toxic chemicals. Compared with steam distillation essential oil, absolute is richer in fragrance and it also contains some non-volatile constituents such as waxes and plant dyes.
Absolutes are usually used as raw materials in fragrances rather than in aromatherapy.
Why Solvent Extraction?
This is because some of the aromatic essences of the plants cannot survive under the heat and hydration of distillation. Besides, for the aromatic plants such as jasmine and tuberose yield very low concentration of essential oils, to extract them as absolute and carbon dioxide extraction is alternative way to obtain them. But CO2 extraction is not economically feasible.
Rose Essential Oils Vs Rose Absolute
To produce 1 drop of the rose essential oil, it took about 2,000 petals to yield the oil, whereas, the yield of oil from a solvent extraction method is approximately 24% of the weight of the flowers. Comparison, solvent extraction method is more efficient.
However, the extraction method can impact the active constituents found in the final product. The main constituent in rose absolute is Phenylethyl alcohol (>60%), while citronellol and geraniol were the major compounds (>55%) of rose essential oil.
According to Opdyke (2013), phenylethyl alcohol was reported to be slightly irritating to the skin of guinea-pigs but when tested on human, it didn’t show any irritation reaction.
Baser, K. H. C & Buchbauer, G. (2010). Handbook of Essential Oil: Science, Technology and Applications. CRC Press
Battaglia, S. (2002). The Complete Guide to Aromatherapy (second edition). Brisbane: The International Centre of Holistic Aromatherapy
Petersen, P. (2014). A Rose by another Name. American College of Healthcare Sciences.
Opdyke D. L. J. (2013). Monographs on Fragrance Raw Materials: A Collection of Monographs Originally Appearing in Food and Cosmetics Toxicology, Elsevier.
Hamid, A.A., Aiyelaagbe, O.O. & Usman, L.A. (2011). Essential Oils: Its Medicinal and Pharmacological Uses. Vol. 33, Issue, 2, pp.086-098, International Journal of Current Research.