Used in perfumery and aromatherapy, 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, oily mixtures extracted from plants. Whereas essential oils are produced by distillation,

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, 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 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. 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, mimosa, boronia,

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, clary sage, violet, oakmoss, tonka bean. Rose oil,

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 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 aromatherapy.

References

{{reflist Aromatherapy Perfumery

Production

Character and use

See also

References