CO2 extracts, also known as supercritical CO2 extracts or supercritical fluid CO2 extracts, are extremely pure plant extracts produced from a relatively new and highly efficient extraction process. CO2 extraction produces superior herbal extracts that find wide use in the flavoring and herbal medicine industries. CO2 extracts are oils similar to distilled essential oils that can be used in aromatherapy and natural perfumery to great benefit. Essential oils have traditionally been derived using either steam or hydro distillation, or extracted using chemical solvents such as hexane, heptane or ethanol. The supercritical CO2 extract and its process have many benefits over the traditional distillation processes, which should be taken into consideration when choosing a natural aromatic oil for use in body care products, aromatherapeutic blend, natural perfume or similar product. Eden Botanicals was one of the original essential oils companies in the USA to embrace the concept of using CO2 extracts like essential oils in the aromatherapy and natural perfumery field. Read below to find out more about this interesting process or please click here to view a list of the 30 or so CO2 extracts that we sell, including certified organic CO2 extracts.
The CO2 extraction process consists of pumping pressurized carbon dioxide into a chamber filled with plant matter. When carbon dioxide is subjected to pressure it becomes "supercritical" and has liquid properties while remaining in a gaseous state. Because of the liquid properties of the gas, the CO2 functions as a solvent, pulling the oils and other substances such as pigment and resin from the plant matter. Thus, the difference between CO2, or supercritical, extraction and traditional distillation is that CO2 is used as a solvent instead of heated water or steam. The temperature involved in the supercritical extraction process is around 95 to 100 degrees F as opposed to 140 to 212 degrees F in steam distillation.
Steam distillation is typically considered the best way to obtain essential oils for use in aromatherapy - simply because CO2 extracts were not available when aromatherapy was becoming popular and being written about. However, the steam distillation method produces varying oil qualities dependent upon the temperature, pressure and time used for distillation. The CO2 extraction process, or supercritical extraction process, will in some cases produce a superior oil in that it has not been altered by the high heat associated with steam distillation. Another important difference between CO2 extracts and distilled essential oils is that CO2 extracts typically contain more constituents found in the plant than just the essential oil portion. In this way they more closely resemble the original plants chemical make up, and could be considered to contain a fuller spectrum of constituents from the plant than essential oils do.
An important point regarding steam distillation of essential oils is that the temperature involved in the process changes the molecular composition of the plant matter. The use of heat in the distillation process changes the molecular composition of the essential oil. (Remember from chemistry class - heat is a great potentiator of chemical reactions). An excellent case in point is that of German chamomile (Matricaria recutita). In the distillation of German chamomile, the matricin (the chemical in the plant that functions as an excellent anti-inflammatory) changes to chamazulene with the addition of high temperatures during steam distillation. Thus, after the distillation process of German Chamomile, the matricin has been lost and chamazulene is found. The blue color of German chamomile oil is evidence of this chemical change as chamazulene is a dark blue color. However, when German Chamomile flowers are extracted using CO2 technology, the resulting extract is green. The chemical reaction due to the addition of heat did not occur and the extract is more similar in composition to the original flowers than the distilled essential oils is.
There are a few positive aspects of the supercritical CO2 extraction process and the resultant supercritical CO2 extract over some aromatic extracts such as absolutes. The CO2 supercritical extraction process eliminates the need for potentially harmful solvents like hexane that is often used in the manufacture of absolute oils, avoiding unnecessary environmental pollution and potential human bodily harm. Another positive aspect to the CO2 distillation process is the aroma of the extract. A CO2 supercritical extract often will exhibit a more genuine aroma of the actual herb, spice or plant than a distilled essential oil. The aroma of the CO2 extracts of ginger, cardamom and other spices, for instance, are more alive, active and spirited than the aroma of the same plants that have been steam distilled.
At Eden Botanicals, we recognize and respect the many considerations involved in the selection of essential oils and extracts. While we consider some of the CO2 extracts to be superior to steamed distilled essential oils, we do not believe this is always the case. For instance we love the spice oils derived using CO2 technology, and believe that they are in general superior to most steam distilled spice oils. This is not necessarily the case with all essential oils however. If you compare patchouli essential oils derived from CO2 and steam distillation, you will find quite different oils, with very different aroma profiles. In these cases, some people will prefer the more earthy, woody patchouli derived from steam distillation to the fresher, greener aroma of the patchouli CO2 extract. For patchouli it comes down to personal preference, and we do not feel one is better than the other. In order to offer you the greatest variety and the best quality of essential oils, we carry many of the CO2 supercritical extracts in addition to the traditional essential oils. In some cases, we only offer the CO2 extract due to its superior quality.