Used in

perfumery Perfume (, ) is a mixture of fragrance, fragrant essential oils or aroma compounds (fragrances), Fixative (perfumery), fixatives and solvents, usually in liquid form, used to give the human body, animals, food, objects, and living-spaces an agre ...

and

aromatherapy Aromatherapy is a practice based on the use of aromatic materials, including essential oils and other aroma compounds, with claims for improving psychological well-being. It is used as a complementary therapy or as a form of alternative medic ...

, absolutes are similar to

essential oil An essential oil is a concentrated hydrophobic liquid containing volatile (easily evaporated at normal temperatures) chemical compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetheroleum, or simply as the ...

s. They are concentrated, highly

aromatic In organic chemistry, aromaticity is a chemical property describing the way in which a conjugated system, conjugated ring of unsaturated bonds, lone pairs, or empty orbitals exhibits a stabilization stronger than would be expected from conjugati ...

, oily mixtures extracted from plants. Whereas essential oils are produced by

distillation Distillation, also classical distillation, is the process of separating the component substances of a liquid mixture of two or more chemically discrete substances; the separation process is realized by way of the selective boiling of the mixt ...

boiling Boiling or ebullition is the rapid phase transition from liquid to gas or vapor, vapour; the reverse of boiling is condensation. Boiling occurs when a liquid is heated to its boiling point, so that the vapour pressure of the liquid is equal to ...

, or pressing, absolutes are produced through

solvent extraction A solvent (from the Latin language, Latin ''wikt:solvo#Latin, solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a Solution (chemistry), solution. A solvent is usually a liquid but can also be a solid, a gas ...

, or more traditionally, through enfleurage.

Production

First, plant material is extracted with a hydrocarbon solvent, such as

hexane Hexane () or ''n''-hexane is an organic compound, a straight-chain alkane with six carbon atoms and the molecular formula C6H14. Hexane is a colorless liquid, odorless when pure, and with a boiling point of approximately . It is widely used as ...

, to yield

concrete Concrete is a composite material composed of aggregate bound together with a fluid cement that cures to a solid over time. It is the second-most-used substance (after water), the most–widely used building material, and the most-manufactur ...

. The concrete is then extracted with

ethanol Ethanol (also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound with the chemical formula . It is an Alcohol (chemistry), alcohol, with its formula also written as , or EtOH, where Et is the ps ...

. The ethanol extract is cooled (e.g., to −15 °C) to solidify waxes, and cold filtered to yield a liquid extract. When the ethanol evaporates, an oil—the absolute—is left behind. Traditionally, the absolute was obtained by enfleurage, where the resulting

pomade Pomade is a greasy, waxy, or water-based substance that is used to style hair. It generally gives the user's hair a shiny, slick appearance. It lasts longer than most hair-care products, and often requires repeated washes for complete remov ...

was extracted with ethanol to yield the absolute.

Character and use

Some raw materials are either too delicate or too inert to be steam-distilled and can only yield their aroma through solvent extraction. Examples of these are

jasmine Jasmine (botanical name: ''Jasminum'', pronounced ) is a genus of shrubs and vines in the olive family of Oleaceae. It contains around 200 species native to tropical and warm temperate regions of Eurasia, Africa, and Oceania. Jasmines are wid ...

and

beeswax Bee hive wax complex Beeswax (also known as cera alba) is a natural wax produced by honey bees of the genus ''Apis''. The wax is formed into scales by eight wax-producing glands in the abdominal segments of worker bees, which discard it in o ...

. Absolutes in demand include

rose A rose is either a woody perennial plant, perennial flowering plant of the genus ''Rosa'' (), in the family Rosaceae (), or the flower it bears. There are over three hundred Rose species, species and Garden roses, tens of thousands of cultivar ...

tuberose ''Agave amica'', formerly ''Polianthes tuberosa'', the tuberose, is a perennial plant in the family Asparagaceae, subfamily Agavoideae, extracts of which are used as a Note (perfumery), note in perfumery. Now widely grown as an ornamental plant, ...

, jonquil,

ylang-ylang ''Cananga odorata'', known as ylang-ylang ( ) or cananga tree, is a tropical tree that is native to the Philippines, Malaysia, Indonesia, New Guinea, the Solomon Islands, and Queensland, Australia. It is also native to parts of Thailand and Vie ...

mimosa ''Mimosa'' is a genus of about 600 species of herbs and shrubs, in the mimosoid clade of the legume family Fabaceae. Species are native to the Americas, from North Dakota to northern Argentina, and to eastern Africa (Tanzania, Mozambique, and ...

boronia ''Boronia'' is a genus of about 160 species of flowering plants in the citrus family Rutaceae. Most are endemic to Australia with a few species in New Caledonia, which were previously placed in the genus ''Boronella''. They occur in all Australi ...

lavender ''Lavandula'' (common name lavender) is a genus of 47 known species of perennial flowering plants in the sage family, Lamiaceae. It is native plant, native to the Old World, primarily found across the drier, warmer regions of the Mediterranean ...

, lavandin,

geranium ''Geranium'' is a genus of 422 species of annual, biennial, and perennial plants that are commonly known as geraniums or cranesbills. They are found throughout the temperate regions of the world and the mountains of the tropics, with the gre ...

, clary sage, violet, oakmoss, tonka bean.

Rose oil Rose oil (rose otto, attar of rose, attar of roses, or rose essence) is an essential oil that is extracted from the petals of various types of rose. ''Rose ottos'' are extracted through steam distillation, while ''rose absolutes'' are obtained t ...

absolute,

tobacco Tobacco is the common name of several plants in the genus '' Nicotiana'' of the family Solanaceae, and the general term for any product prepared from the cured leaves of these plants. More than 70 species of tobacco are known, but the ...

absolute,

orris root Orris root (''Rhizoma iridis''; etymology possibly an alteration of ''iris (plant), iris'') is the root of ''Iris germanica'' and ''Iris pallida''. It had the common name of Queen Elizabeth Root. It is commonly used as a fixative (perfumery), fi ...

oil, ambrette seeds oil, angelica root oil, and orange flower oil are valuable and expensive fragrance and flavor ingredients. Residual solvents may remain in the absolutes. Therefore, some absolutes are considered undesirable for

References

{{reflist Aromatherapy Perfumery

Production

Character and use

See also

References