Essential oils are highly beneficial health care products. What distinguishes them from other medicinal products are their drug-free, side effects-free, safety properties. When you use an essential oil for a particular ailment, you can be sure of getting cured without hiccups. Essential oils do not interact with other oral medications too. On the whole, they are 100% safe irrespective of the person on whom they are administered.
Types of essential oils: Essential oils are differentiated or grouped by their extraction methods. Nowadays different methods are used in extraction, but the most common and prevalent methods are: Steam Distillation, Cold Pressing and Solvent Extraction. Based on these methods, essential oils can be classified into four different types: 1.Steam-distilled, 2. Expressed, 3. Solvent-extracted and 4. Absolutes or concretes.
1. Steam-distilled oils: Steam distillation is the oldest and traditional method of oil extraction. Pure aromatherapy oils are extracted through this process as it yields pristine oil, free from impurities. The process works like this: Plant material is placed in a container and steam is passed through it. Heat from the steam opens pockets of plant containing aromatic molecules and oils. When released, these molecules rise with the steam and pass through a closed system. After this, the aromatic steam is passed through a cooling process and is distilled with cold water. During this process, the essential plant oils condense and transform into liquid state. The liquid mixture is separated later into two – essential oils and aromatic water or hydrosol.
Steam distillation takes into account a variety of things, including the pressure of steam passed through plant material, the coolant used, the temperature of the closed system during production of oil etc. An oil’s quality and purity is based on all these factors and the skill of the distiller. Reputed distillers’ oils are rated high owing to the quality and purity of their extracts.
2. Cold-pressed or Expressed oils: This is a method used to extract oils from the citrus family of fruits. Oils are produced from the rind of fruits like tangerines, grapefruits, lemons, oranges and others. Though they should be known only as expressed oils, they are classified under essential oils due to their high therapeutic value. Using mechanical pressure, oils are forced out of the fruits in juice form. Since the juicy form of oils contain a lot of water, a separation process is carried out to separate oils from water. One downside to this method is, cold-pressed oils get spoilt quickly than other oils. So it is recommended that these oils are bought in small quantities and refilled whenever required.
3. Solvent Extracted Oils: Some plant material cannot tolerate heat (in steam form) or be subjected to cold-pressing. When they are subjected to any such method, the oil thus produced may be contaminated or impure in quality. To avoid this, some plants like Jasmine, Rose, Orange Blossom (Neroli), Tuberose and Oak are extracted through solvents. Solvents such as ethanol, ether, methanol, hexane, alcohol, and petroleum are used to extract essential oils.
The process works like this: Plant material is first passed on through hydrocarbon solvents. Then, the solvent mixture is filtered and distilled in low pressure to produce essential oils. A downside to this method is that, sometimes, solvent residues remain in the oils. This can cause allergic reactions in certain individuals.
4. Absolutes or concretes: Absolute oils are essences that are obtained by extraction of a concrete with alcohol. A concrete is generally the solid waxy residue that remains after extraction of oils by solvents (especially hexane).
