Ask an Aromatherapist: What is a CO2 Extract and How Do I Use Them?
Originally developed for the food and flavor industry (for things such as spices, hops, teas, and vegetable oils) CO2 extracts are now being employed for fragrances and aromatherapy. It may sound a bit far out but read on to find out about their benefits.
Essential oils come from aromatic plants. Essential oils are found in specialized oil sacs, glands, or vesicles which are located in different plant parts. For example, essential oils can come from flowers (such as rose, lavender, or neroli), peels (such as sweet orange), bark (such as cinnamon bark), wood or twigs (fir or spruce oils for example), roots (such as ginger or vetiver), seeds (such as carrot seed or coriander), leaves (basil, peppermint, or clary sage for example), and resins (such as frankincense or elemi).
Essential oils are typically steam distilled, cold pressed, or solvent extracted. CO2 extraction is a newer method. In steam distillation steam, as you may have guessed, is passed through large amounts of plant material and used to extract the extract the volatile essential oils from the plant matter. The mixture is cooled and the water and essential oils separate.
In cold pressing the essential oils are pressed from the fruit and collected.
Delicate plants such as rose and jasmine can't withstand steam distillation or pressing and a solvent is employed to extract the essential oils. The oils are attracted to the solvent. The solvent and oils are separated and the result is called an absolute.
CO2 extraction was initially developed for the food and fragrance industry. It is a more expensive process but it has several advantages.
CO2 extraction employs a supercritical state of carbon dioxide as the solvent. Thus harmful solvents such as hexane are avoided. CO2 extraction yields oils products with excellent odor quality, although the chemistry of the CO2 extract and essential oil can be significantly different.
The parameters during a CO2 extraction can be altered to allow extraction of a wider range of components according to the characteristics desired in the final product.
CO2 select oils are typically more similar to the essential oil (although they can have a significantly different aroma and chemistry), while CO2 total extracts contain a lower percentage of essential oil but more of the lipids and waxes present in the plant. Often a CO2 extract will have more of the general aroma of the actually herb, spice, or plant than a distilled essential oil.
For example CO2 extracts of ginger, cardamom, and other spices are active and spirited than the steam distilled essential oil.
So CO2 extracts are oils produced using carbon dioxide under pressure to extract the oils. CO2 select extracts are produced under lower pressure and are similar to steam extracted essential oils but contain even more volitive components that steam distilled oils.
CO2 total extracts are produced under higher pressure and contain all the CO2 soluble lipophilic components making the extracts more like the plant itself. CO2 total extracts are typically quite thick or can even be pasty.
CO2 extracts can be used in ways similar to essential oils. Since they were developed initially for the food and fragrance industry they can also be employed in cooking or creating natural fragrances. CO2 extracts can be used when an aroma more like that of the actual plant is desired.
If you have questions about CO2 extracts, essential oils, or aromatherapy contact Tricia.