Aromatherapy is also called essential oil therapy and involves the administration of essential oils via different methods. The benefits of aromatherapy are based on the fact that the application of essential oils stimulate the body into releasing certain hormones which produce a benevolent effect.
Four methods of administering aromatherapy are:
- Massage
- Direct inhalation
- On the skin application through lotions and bath salts
- Indirect inhalation
Essential oils trigger the release of the endorphins and oxytocin hormones. Lowering stress and pain is the natural action of endorphins. Oxytocin is related to social behaviour habits such as trust, recognition, and anxiety.
As a result of such healing properties of essential oils, aromatherapy makes use of them for better dealing with:
- Stress
- Insomnia
- Alopecia areata
- Agitation
- Burn Scars
- Respiratory and Cardiovascular Disorders
- Cough and Cold
- Immunity Boosting
- Healing Wounds
Essential oil extraction is carried out using the following methods:
- Carbon dioxide Supercritical Fluid Extraction (CO2 SCFE)
- Hydrodistillation
- Solvent Extraction
- Cold Press Extraction
- Maceration
- Resin Tapping
Carbon dioxide extraction of essential oils i.e. CO2 SCFE is preferred over most alternative methods. This is because the method delivers a relatively pure extract. Now, essential oils can produce the described effects only if they are applied in their pure form.
Hydrodistillation was used earlier for essential oil extraction. The process dissolves the raw material in hot water or passes steam through it. The required molecule (called target molecule - essential oil molecule in this case) boils off at a certain temperature and is condensed at a separate location. Since each molecule has a specific boiling point, only that molecule is boiled off and condensed at that temperature. The target molecule so obtained should be poor. However, heat used in hydrodistillation can thermally distort the target molecule i.e. change its composition.
Hexane (solvent) was also used in seed oil extraction - seed oil being an essential oil. This is an example of solvent extraction wherein hexane first dissolves the essential oil molecule. Later, hexane is evaporated or purged. This leaves behind the target molecule i.e. the seed oil molecule. However, after first associating with the seed oil molecule when dissolving it, hexane does not completely disassociate from the target molecule, thus altering its composition.
Carbon dioxide extraction of essential oils uses pressure difference to dissolve and separate the essential oil molecule (target molecule). At higher pressure, the essential oil molecule dissolves in supercritical carbon dioxide (sCO2). The essential oil molecule separates out from the sCO2 at lower pressure. sCO2 does not get attached to essential oil molecule, thereby maintaining its purity.
Supercritical fluids are those at a pressure and temperature respectively above their critical pressure and critical temperature. In this state, their solvent power i.e. capacity to dissolve can be customized by small changes in pressure. This is because their solvent power depends on density which gets modified with pressure alterations. The solvent power of sCO2 can be customized to dissolve one particular essential oil molecule, making producers prefer the carbon dioxide extraction of essential oils.
