What is a chemotype?

The chemotype of an E.H. is defined by the percentage of the molecule most present in the E.H..

For example,thyme E.H. contains 50% thymol, which defines its chemotype. A molecule is generally only included in an E.H. if it exceeds 10%. All E.H.s whose percentage of molecules is not mentioned are present only in trace amounts.

The chemotype used in aromatherapy makes it possible to identify chemical variations in secondary metabolites within the same species, due to environmental factors (altitude, sunshine, temperature, humidity, etc.). This means that the essence produced by two plants of the same species, despite their very similar genotype and morphology, may vary greatly in chemical composition. This is a very important concept in aromatherapy.

An essence can be extracted from any organ as long as it has the structures to produce it. Many E.H.s come from flowers, leaves, seeds, fruits, rhizomes and so on. The same plant from the same biotope (living environment characterized by a certain number of characteristics such as temperature, humidity, etc.) can synthesize essences with very different compositions and odors, depending on the producing organ in question. The best-known example is the bitter orange tree, from which 3 distinct E.O.s can be extracted. The leaves givepetit grain bigarade E.O., the flowers giveneroli E.O., while the fruit rind gives bitter orange zest essence.

The plant from which the raw material is extracted can be cultivated or harvested in the wild. The conditions of cultivation, harvesting, drying, storage, etc. determine the quality of the plant and therefore the quality of the essence produced. If the plant is obtained by cultivation, it must, at the very least, be ecologically sound, and therefore do without chemicals (pesticides, weedkillers, etc.) likely to pollute the soil. The plant must also grow in its natural biotope, or one very close to it.

Essential oil extraction

There are various methods for extracting the essence produced by aromatic plants. Of these, the European Pharmacopoeia selects only three to obtain a product that can be called an essential oil:steam distillation, dry distillation for stems and barks in a suitable apparatus, or by a suitable mechanical process without heating for citrus fruits.

Steam distillation: Aromatic plants are placed in a still, where steam formed in a separate generator flows through them. As the steam passes through the plant, it carries away the aromatic molecules that form the essential oil. The vapors then pass through a refrigerator with cold water circulation to condense and be collected in the essencier, where the E.O. is separated from the water. The duration of distillation is crucial to obtaining a quality essential oil, and varies according to the plant. Quality also depends on the size of the plant. An industrial-scale production will be of lower quality than that obtained by a producer working with small stills (< 1500 liters).
Dry distillation is the heating of stems or barks at high temperature, without the use of water (unlike hydrodistillation or steam distillation). The result is a viscous, blackish, tar-like distillate. Today, this method is used to obtain Cade EO and birch bark EO.
Mechanical expression: Also known as cold expression, this consists in breaking the essence pockets contained in the pericarp of citrus fruits (oranges, lemons, mandarins, bergamots, etc.), either in a press, or manually by scraping the pericarp with a spoon (the latter technique produces a high-quality product). In this case, we obtain an essence rather than an E.O., as there is no modification of the plant product.

Other techniques: There are other methods for extracting essences, but the product obtained cannot be defined as an essential oil.

Percolation: This process involves passing water vapour from top to bottom. This technique is faster and therefore less likely to modify aromatic molecules, but the extract obtained contains non-volatile substances. These are known as percolation essences.
Supercritical CO2 extraction: a high-pressure stream of CO2 is passed through the plant material, dissolving the essence, which is then easily separated. The technique uses a maximum temperature of 40°C, ensuring minimum degradation of the essence. This modern but costly method ensures a product very close to the original gasoline.
Enfleurage: This is used for flowers, which are then brought into contact with fats that impregnate with the essence to produce an ointment. The ointment can be used as is for cosmetics, or exhausted with absolute alcohol to obtain alcoholic flower extracts.
Volatile solvent extraction (mainly ether and benzene): Giving flower or leaf concretes, transformed into absolutes by exhaustion with ethanol, then into concrete essences by evaporation of the ethanol.

Composition of essential oils

Unlike vegetable oils, E.O.s are volatile, which means they can be extracted with steam. With rare exceptions (cinnamon bark, cloves), their density is lower than that of water. They are immiscible in aqueous media, but soluble in the usual organic solvents. E.H.s are also active under polarized light, a property used to control their quality. The rotatory power of an E.H. also makes it possible to identify pure, natural oils. Finally, their refractive index " n " is high. Of varying degrees of color, the entire spectrum is represented: from the blood-red of certain savories, to the blue of Chamomilla recutita, to the pale green of Citrus bergamia. You can even observe the ultraviolet of mandarin orange under a UV lamp.

E.H.s are complex substances, and may contain :

Terpene derivatives: 10-carbon hydrocarbon monoterpenes, sesquiterpenes, diterpenes.
Amino acid derivatives: Isobutanol from valine, iso-amyl alcohol from leucine, angelic acid and tiglic acid from isoleucine. And sulfur-containing amino acid derivatives.
Fatty acid derivatives: for example, linoleic acid yields jasmone, methyl jasmonate and macrocyclic lactones.
A wide variety of other molecules.

However, composition can vary greatly depending on the plant producing the essence, its geographical origin, climate, altitude, extraction method, the skill of the handler, etc.

What essential oils can I find on the Soin-et-Nature website?

Soin-et-Nature offers a complete range of essential oils to meet many health and well-being needs. Here are the categories available:

To guarantee the quality and effectiveness of essential oils, chemotyped HECT and HEBBD essential oils ensure a pure, certified composition.
For the needs of professionals, large-volume essential oils are available for widespread, economical use.
To fight acne naturally, targeted essential oils help purify the skin and reduce blemishes.
To reduce the appearance of cellulite, firming and draining essential oils support skin tone.
To promote healing, essential oils with regenerating properties help repair skin tissue.
To soothe the respiratory tract, specific essential oils offer optimal respiratory comfort.
To boost natural defenses, certain essential oils stimulate the immune system and protect the body.
To relieve cramps and muscle pain, soothing essential oils promote relaxation and recovery.
To naturally ward off insects, repellent essential oils provide effective protection against bites.
To alleviate headaches, specific essential oils offer fast, natural relief.
To support slimming programs, draining and toning essential oils facilitate weight management.
To combat colds and winter ailments, decongestant essential oils relieve the respiratory tract.
To soothe muscular pain, relaxing essential oils contribute to muscle comfort.
To improve sleep quality, relaxing essential oils help you fall asleep and get a good night's rest.
To limit excessive sweating, certain essential oils regulate perspiration while providing a cooling action.
To eliminate warts naturally, specific essential oils help treat these skin conditions.
To reduce stress and regain serenity, relaxing essential oils act on the nervous system to promote emotional well-being.

These essential oils available on Soin-et-Nature allow you to take advantage of the benefits of plants to treat everyday ailments naturally, while favouring a gentle and effective approach.