Essential Oils 101: What is it, How is it Made and its Functions
Aromatic plants, defined as the plants that produce and exude aromatic substances (largely essential oils), and it have been used for thousands of years for religious rituals, perfumery, cosmetics, food manufacture and preservation, as well as for aromatherapy and disease control .
The first records of essential oils come from ancient India, Persia, and Egypt. In recent history their benefits outlook became very promising. Lavender oil became famous for its skin healing when René-Maurice Gattefossé, the 1930s French chemist, burned his hand in his laboratory. He applied lavender oil to treat the burn and was so impressed by the quick healing process.
What is essential oil?
Essential oil is aromatic, volatile liquids obtained from plant material through distillation and named after the plant from which they are derived. They are called volatile or ethereal oils as they evaporate when exposed to air at ordinary temperatures. It is highly concentrated, low volume, high value products. Sometimes it is referred to as the soul of a plant.
Labender Essential Oil
The synthesis of essential oils:
The synthesis and accumulation of essential oils occur either outside the plant, in the glandular trichomes (such as Asteraceae, Geraniaceae, Laminaceae, etc.) and in the papillae, either inside the plant, in the secretory cells, in the intercellular spaces (secretory channels) or secretory bags (such as Anacardiaceae, Rutaceae, Myrtaceae).
Credits: Emma Guo
All parts of aromatic plants may contain essential oils in varying amounts. The essential oil can contain within different parts of a plant, including:
Flowers : for example, orange, lavender, and the clove flower bud or ylang-ylang bracts,
Leaves: for example mint, thyme, oregano, bay leaf
Roots, for example vetiver roots, ginger root, sweet flag
Seeds, for example carvi, coriander, Nigella sativa
Fruits, for example fennel, anise, litsea cubeba
Wood and bark, for example cinnamon, sandalwood, rosewood
The functions of essential oils:
The role of essential oil is not yet fully understood by science. Some specialists consider them to be true plant hormones, fluid manifestations of the immune system of plants, in the sense that they contribute to the removal of pests, instead, attracting pollinating agents, which are some insects and birds. They are the ones who give the fragrance of the aromatic plant and have, this fragrance is used for the improvement of the mood and as the depression release.
The practice of using essential oils may take some research but it's worth the time and effort for living more natural lifestyle. its extraction is a delicate process requiring knowledge, experience and constant supervision.
Characters of essential oils:
Color: Most of essential oils are clear, but some oils such as blue tansy, patchouli, orange and lemongrass are amber, yellow, green or even dark blue in color such as chamomile oil.
Smell: Most of essential oils have a pleasant aroma and rarely have an unpleasant pungent odor. It is possible to distinguish between volatile essential oils by their smell, as each aromatic plant has its distinctive one.
Volatilization: The vast majority of essential oils completely evaporate or volatilize under normal and ordinary conditions, except for a few such as lemon oil.
Dissolving: All essential oils are insoluble in water, but they are soluble in 95% alcohol and ether.
Relative density: The relative density of essential oils varies in value according to their plant sources.
Optical rotation: The optical rotation of essential oils is a quickly measured, easily generated polarimetric quality parameter. Moreover, it helps to differentiate between different essential oils and to analyze the purity of it.
Chemistry of Essential Oils:
Many thousands of compounds belonging to the family of terpenes have so far been identified in essential oils , such as functionalized derivatives of alcohols (geraniol, α-bisabolol), ketones (menthone, p-vetivone) of aldehydes (citronellal, sinensal), esters (γ-tepinyl acetate, cedryl acetate), and phenols (thymol).
Classification of Essential Oil’s aroma “note”
George Wilson Septimus Piesse, an English chemist and perfumer, classified the odor of essential oils according to musical notes on diatonic scales as seen in the following Figure :
This Essential Oil’s aroma “note” is the feature that distinguishes how long its scent will last, and according to (Lavabre, 1997) it can be grouped into one of the following three categories:
Top notes
Essential oils that are classified as top notes normally evaporate very fast and normally also have anti-viral properties. They tend to be light, fresh and uplifting in nature and are generally highly volatile and fast acting.
Middle notes
The bulk of essential oils are considered as middle notes and normally give body to the blend and have a balancing effect. The smells of middle notes are not always immediately evident and may take a couple of minutes to come into their own effect and are normally warm and with soft fragrances.
Base note
Essential oils that are classified as base notes are normally “heavy” oils with their fragrance evident, but are also slowly evolve and be present for a long time and slows down the evaporation of the other oils. These fragrances are normally intense and heavy. They are normally rich and relaxing in nature.
Processes of manufacturing and extracting essential oils:
Cleaning Step: The aromatic plants, seeds or fruits are thoroughly cleaned of dust, insects and exotic parts that may be present with the original plants and all other types of impurities. Then they are washed with running water, and finally the water is filtered out.
Preparing Step: The plants are prepared by chopping or grinding the material into fine particles, the wooden branches can also be cut into thin slices, minced or crushed into small pieces.
Extraction Step: The extraction process is the basic and important step in essential oil manufacturing . There are several methods depends on the type of plant, its sensitivity and heat tolerance. Distillation is considered as the only way to make oil and hydrosol.
Making Fresh Lavender Essential Oil and Hydrosol with LETIME LT3000 Essential oil distiller
For ages, aromatic plants have been used for the treatment of various ailments in traditional and folklore medicine. They are processed by different distillation techniques and yield distinct products such as essential oil and hydrosol. Interest has grown in the therapeutic power of them, So attention need to be drown in collecting, processing and trading these products to gain best oil yield and quality.
Having questions about essential oil or hydrosol? Leave your comments here or Contact Leo.
