Essential oils are chemical components of plants that give them their characteristic smell and are commonly thought to be part of the plant defence properties. Commonly used in aromatherapy, there are numerous claimed medicinal uses for essential oils including relaxation, antisepsis and decongestion to name a few. Essential oils have been used for centuries and the most famous person using them was Cleopatra, who used them when bathing in asses’ milk to keep her hygienically clean, as well as smelling good. The chemistry of essential oils has been well described and all oils are a complex mixture of organic volatile compounds consisting of carbon, hydrogen and oxygen. Their volatile nature (the ability to change state from solid to vapour) gives them their characteristic aroma (smell) and the individual components generating this aroma are widely used in the fragrance industry, food preparation (peppermint oil), beauty products and health care.
Essential oils can be extracted from any part of the plant: the leaves, bark, berries, flowers, root, seeds and the roots, most commonly by steam distillation, cold pressing or by organic solvents. The essential oil yield is effected by environmental conditions and distillation processes. Some of the most well-known essential oils are Tea Tree, Lavender, and Clove, although over 500 have been identified. Each essential oil has a characteristic fingerprint of major and minor aromatic organic components which determines the nature of the essential oil. A change in the unique ratios of components will lead to a different essential oil. Significant differences in chemical composition of oils from the same species of plant can give rise to chemotypes, which biological variations are caused by the effects of soil, temperature, weather conditions and light. The plants can be botanically identical but their chemical components can differ, it is therefore very important to have the chemistry of the essential oils authenticated, especially when used in an essential oil blend.
Essential oils are Nature’s antiseptics and are gaining more scientific status as researchers prove their ability to combat certain pests, infections and other minor ailments with them.
