Essential oil extraction from lavender, medicinal properties, chemical composition

do you know the chemical composition of EO lavender

what is the extraction principle EO from the lavender leaves

general definition of EO

The essential oil is an aromatic and volatile extract, highly concentrated, of complex composition, obtained by distillation or by expression from plants.

Often only one part of the plant is used (the leaf in the Tea Tree, the flower heads in fine lavender, the bark in the Cannellier de Ceylon …). Different parts of the same plant can produce essential oils, which will then have different properties and names. For example :

The bitter orange blossom gives Neroli essential oil.

The leaf gives the essential oil of Petit Grain Bigaradier.

The zest gives the essential oil of Orange.

Essential oils are considered as “preparations” herbal.

They are “odorous products, generally of complex composition, obtained from a botanically defined plant raw material, either by entrainment by steam, or by dry distillation, or by a suitable mechanical process without heating”.

o An essential oil is most often separated from the aqueous phase by a physical process that does not lead to a significant change in its composition (definition of the European Pharmacopoeia).
o Depending on their use and claim, essential oils are subject to the regulation of cosmetics, biocides (sanitizing sprays), or herbal medicines.
o An essential oil is considered a drug if it is presented as having properties to cure or prevent human diseases or when it has a pharmacological, immunological or metabolic action.
o It can also be used as an excipient (flavoring for example) in the formula of a drug.
o In pharmacy, the essential oils can be delivered in the form of magistral preparations or as such.

Medicinal properties associated with lavender

Lavender is one of the essential oils with the most medicinal active ingredients. We will list and explain each medicinal property.
Calming: sedative substance with generalized action.
Sedative: a substance that moderates the abnormal exitability of the nervous system and reduces general sensitivity.
Hypotensive: substance capable of lowering blood pressure by vasodilator effect on vessels.
Antispasmodic: a substance intended to eliminate the spasms, cramps and involuntary contractions of the smooth muscles, whatever their seat.
Antiseptic: substance capable of destroying the germs at the origin of many affections. Their antimicrobial activity can be tested by an aromatogram, equivalent to the antibiogram, commonly used in the laboratory.
Anti-inflammatory: substance that controls the inflammatory reaction, resulting in redness, heat and pain, that accompanies a number of conditions.
We have seen that there are several modes of absorption of the essential oils so that they cure either in local area or the whole body.

Chemical composition

After performing the chromatography with linalool and linalyl acetate to reveal the presence of certain chemical species, we can say that lavender essential oils contain mainly linalool (25% to 38%) and linalyl acetate (25% to 45%). Depending on the species of lavender, less chemical species are found: geraniol, pinene, camphor, cineol, coumarine lavandulyl acetate and ethylmamylketone (origin of the refreshing odor).
Monoterpene Alcohols:
Monoterpenes are a class of terpenes consisting of two molecules of isoprene C5H8 and have the basic formula (C5H8) 2.
Monoterpenes are with sesquiterpenes, one of the main elements of aromatic vegetable essences (essential oils). Monoterpenes can be found in more than two thousand plants of sixty different families. Monoterpenes are emitted by plants. They increase the clarity of the clouds and cool the climate. They are one of the main vectors of the rapid spread of forest fires.
Linalool is a terpenic alcohol. It is found in a majority of essential oils including lavender, bergamot, rosewood, which is the major component. C (CH3) 2 = CH-CH2-CH2-COH (CH3) CH = CH2
Camphor is a solid aromatic compound from the camphor tree. It complements the family of monoterpenes and its chemical formula is C10H16O. From this base, we synthesize the borneol and camphene found also in lavender  

Extraction – Distillation

The cut is made from the month of July when flowering ends and the color turns gray. The cutting machines then come into action, the harvest is carried out either in bulk or in sheaves according to the equipment used by the operators.
A short drying time, called pre-wilting can be performed before the distillation.

The process
Flower heads are introduced into a large capacity vase or container.
Once filled and tightly packed, they are closed with leakproof lids and distillation can begin.
The water vapor will cross them by driving the essential oil.
Water vapor will then flow through the mass of lavender.
This steam loaded with fine droplets of essential oil will then follow a conduit immersed in cold water, a coil: the gooseneck.
This difference in temperature will cause condensation and fluid flow in an essencier where it settles.

                      extraction process

The essential oil less dense than water floats (average density of 0.888 to 0.894).
The essential oil is thus recovered on the surface of the water by a system of overflow.
The distilled water, very slightly flavored, is evacuated and is little used.
It is improperly that the essential oil obtained is called “essence”.
The principle of extraction over the ages has changed little in itself but the appliances or stills have evolved well.
In chemical engineering, this process is called “steam training”.