Essential oils are extracted from grasses, flowers, herbs, shrubs, trees (like Eucalyptus), resins and spices. The essential oils are located in tiny secretory structures found in various parts of plants; leaves (eucalyptus), berries (juniper), grasses (palmarosa), flowering tops (lavender), petals (rose), roots (angelica), zest of fruit (orange), resins (frankincense) and wood (cedar).
 Why should I be aware of this?
Essential oils are extremely beneficial for us as they penetrate the cells and disperse throughout the body very quickly. Since everyone responds differently to the type and amount of essential oils, it is important to what benefits each offer and how much is needed to give the desired results.
 Essential oils and health
Many cultures have used essential oils for a variety of health reasons, promoting healing of both the mind and the body. Each oil, with its distinct qualities, aromas, and fragrances, can be used in conjunction with others to create specific results, such as soothing anxiety and stress, easing nausea, or relieving headaches. Though essential oils are expensive due to the elaborate process of extraction, very few drops of oils are used at a time to achieve the most positive results.
Essential oils have an immediate impact on many of our olfactory cells, which control the sense of smell. As we breathe in the fragrance from the oils, Our receptor cells are instantly stimulated as we breathe in the oils and messages are sent to the brain’s sensitive limbic system. The limbic system is linked to certain parts of the brain that control a variety of vital functions, including breathing and circulation, memory, our emotions, as well as the endocrine system, which is essential for controlling hormone levels.
 All about essential oils
With the use of a technique called distillation, the essence is extracted from the plant. The process involves placing the flowers or plants on a screen. Steam is passed through the area and becomes "charged" with the essence. The steam is then moved to another area where it cools and condenses. This mixture of water and essential oil is separated and bottled. Since plants contain such a small amount of this precious oil, production is a very costly process.
The process of extracting these oils takes a considerable amount of time, knowledge, and the right type of equipment, including a large quantity of plants, which can be rather expensive. For example, to create a mere four teaspoonfuls of rose oil, approximately 200 pounds of rose petals will be needed.
The following processes are used to extract oils fro various plants. Though a number of new methods have come up, distillation is still the most common method of extracting essential oils.
 Steam Distillation
In steam distillation, fresh, or sometimes dried, botanical material is placed in the plant chamber. Pressurized steam is generated in a separate chamber and circulated through the plant material. The heat of the steam opens and releases the intercellular pockets that hold the essential oils.
High temperature is required to open the pouches, but it should not be so high that it destroys the plants or burns the essential oils. On release the tiny droplets of essential oil evaporate and, together with the steam molecules, travel through a tube into the condensation chamber, where it condenses into water on cooling.
The essential oil forms a film on the surface of the water. This film is then shinned off the top and the water that remains is called floral water, distillate, or hydrosol. As it retains many of the therapeutic properties of the plant, it is valuable in skin care for facial mists and toners.
 Cold Pressing
Cold-pressed expression, or scarification, is another method of extracting essential oils. This process is used for obtaining citrus fruit oils such as bergamot, grapefruit, lemon, lime, mandarin, orange, and tangerine oils.
The process involves rolling the fruits over a trough with sharp projections that penetrate the peel. This pierces the tiny pouches containing the essential oil. Then juice is squeezed out of the whole fruit from the pulp to release the essential oil from the pouches. The essential oil rises to the surface of the juice and is separated from the juice by centrifugation.
A process called enfleurage is sometimes used to remove the essential oils from some flowers, such as jasmine or tuberose, which are very delicate and have such low contents of essential oil that heating them would destroy the blossoms before releasing the essential oils.
In this process the flower petals are placed on trays of odorless vegetable or animal fat, which absorb the essential oils of the flowers. After each process of absorption the depleted petals are removed and replaced with fresh ones. This procedure continues until the fat or oil becomes saturated with the essential oil. Alcohol is then added to separate the essential oil from the fatty substance. The alcohol later evaporates and only the essential oil remains.
 Solvent Extraction
Solvent extraction is another method used on delicate plants, wi the use of, a chemical solvent such as hexane to saturate the plant material and pull out the aromatic compounds. This renders a substance called a concrete. The concrete can then be dissolved in alcohol to remove the solvent. Although more cost-efficient than enfleurage, in solvent extraction residues of the solvent may remain in the absolute and can cause side effects..
 Turbo Distillation Extraction
For hard-to-extract or coarse plant material, such as bark, roots, and seeds, turbo distillation is suitable. In this process, the plants soak in water and steam is circulated through this plant and water mixture. The entire process involves recycling the same water continually through the plant material.
 Hydrodiffusion Extraction
In this process steam at atmospheric pressure is dispersed through the plant material from the top of the plant chamber. The steam can saturate the plants more evenly and in less time than with steam distillation. This method is also less harsh than steam distillation and the resulting essential oils smell much more like the original plant.
 Carbon Dioxide Extraction
Carbon dioxide extraction is a critical process which uses carbon dioxide under extremely high pressure to extract essential oils. Carbon dioxide is injected into a stainless steel tank where the plants are kept and pressure allowed to build. Under high pressure, the carbon dioxide turns into a liquid and acts as a solvent to extract the essential oils from the plants.
 What can I do?
We should always buy essential oils from long established and trusted aromatherapy suppliers who specialise in clinical grade oils and not the more common commercial grade.
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