What Is Supercritical CO2 Extraction?
Do you know what the terms supercritical or C02 extracted mean? A supercritical fluid has unique properties that allow it to selectively extract a desired compound while leaving other compounds behind. This results in a supercritical oil that is highly concentrated and free of impurities.
Supercritical can be thought of as the “fourth state” of a material. It’s not a solid, a liquid, or a gas–and appears as something like a vapor. So, to picture supercritical water, think about a familiar example: the vapor that rises as water boils on the stove.
Supercritical oils have a wide range of applications, including aromatherapy, cosmetics, and food flavoring. They are also used in medical research and are being investigated as potential treatments for cancer and other diseases.
We all want to use the purest products. Merchants realize this and as technology improves, they find ways to give us what we want. Traditionally, cold-pressed oils are oils made by first grinding the vegetable, seed, or nut into a paste. The resulting paste is then pressed to force the oil out.
Sometimes, the merchant will use heat to extract more oil as in steam distillation, but this changes the color and chemical makeup of the oil. Since heat is used, the oil may not be 100 percent identical to its source. In other words, some components are destroyed or altered in the process.
Using solvents is another option, but that requires lots of processing as well as chemicals. In solvent extraction, plant materials are mixed with a solvent which pulls out the oil together with any impurities. Then another process removes the solvent, and the oil is mixed with alcohol and purified. Yet another process removes the alcohol and any remaining contaminants.
Supercritical Fluid Extraction Demo
This method is gaining in acceptance because it combines the best of the other two extraction methods and produces very pure oil. The best explanation I can find, is from the book Aromatherapy for Beginners—
Supercritical carbon dioxide extraction uses carbon dioxide under extremely high pressure to extract essential oils. Plants are placed in a stainless steel tank and, as carbon dioxide is injected into the tank, pressure inside the tank builds. Under high pressure, the carbon dioxide turns into a liquid and acts as a solvent to extract the essential oils from the plants.
When the pressure is decreased, the carbon dioxide returns to a gaseous state, leaving no residues behind. Many carbon dioxide extractions have fresher, cleaner, and crisper aromas than steam-distilled essential oils, and they smell more similar to the living plants. Scientific studies show that carbon dioxide extraction produces essential oils that are very potent and have great therapeutic benefits. This extraction method uses lower temperatures than steam distillation, making it more gentle on the plants. It produces higher yields and makes some materials, especially gums and resins, easier to handle.
Many essential oils that cannot be extracted by steam distillation are obtainable with carbon dioxide extraction. In the future, many botanicals that are not now available may possibly be obtained through carbon dioxide extraction.
What Are the Benefits of Using CO2 Over Other Methods?
Scientific studies show that carbon dioxide extraction produces essential oils that are very potent and have great therapeutic benefits. This extraction method uses lower temperatures than steam distillation, making it more gentle on the plants. It produces higher yields and makes some materials, especially gums and resins, easier to handle.
Now that you’re up to speed on supercritical fluids, are you ready to try some? Here is a list of some popular supercritical oils.
List of Supercritical Oils
Are There Any Side Effects of Supercritical Oils?
While supercritical oils are generally safe to use, there are a few potential side effects that you should be aware of. The most common side effect is skin irritation. If you experience any irritation, discontinue use, and wash the affected area with soap and water.
In addition, supercritical oils should be stored in a cool, dark place to prevent them from going rancid. When used properly, supercritical oils can be an incredibly powerful tool for promoting health and well-being.