Scientific Aromatherapy

Knowing how to choose a high quality essential oil

The essential oils used within the framework of scientific aromatherapy meet strict quality criteria that must unconditionally be known and abided by :

Certified botanical species

High quality essential oils must unconditionally come from botanically certified plants, i.e. they must be identified by two Latin names, as Latin is the universally recognized language in botany. The first name designates the genus, for example Cupressus; and the second the species: sempervirens, ever green cypress.

Distilled part of the plant

The various parts of a single plant (flower, leaf, stem, bark, root etc.) can produce different essences. The plant organ therefore also needs to be specified.

Chemotypes

The aromatic components of a plant are not unchangeable. A single plant, growing in different places, can secrete very different essences as a function of a range of factors such as sunshine, climate, soil composition, altitude, etc.

Two chemotypes of the same essential oil may not only have different actions but also highly variable toxicity indices.

The guarantee of a high quality essential oil is also reflected in the packaging; the information that appears on it must be complete and rigorous.

Identity Card for an essential oil.

Pranarôm recommends using ChemoTyped Essential Oils.

Depending on the biotope (sunshine, climatic conditions, soil composition, altitude, neighbouring plant population…) a given aromatic plant can produce essential oils bio-chemically very different.
 Those variations in the biochemical composition of essential oils bring about the notion of “Chemotype”. Two chemotypes of the same essential oil will have not only different activities but also very different toxicities.

Exemple :

– Thymus vulgaris CT thujanol : well tolerated on the skin

.

– Thymus vulgaris CT thymol : dermocaustic.

Conventional, BIO certified or wild…

There are a number of different categories of essential oils.

100% pure, 100% natural and 100% complete or integral essential oils are rare and their price is higher if they meet all the quality criteria for a chemotyped essential oil.  

In general, we can distinguish several quality levels for essential oils :

• Industrial standard quality : the essential oil comes from a plant that is not botanically defined, is industrially cultivated and not necessarily harvested at a time that is particularly favorable. Distillation is very often incomplete or the essential oil is rectified and even chemically reconstituted.
  
• Chemotyped quality, 100% pure and 100% natural : the essential oil is obtained after full distillation of botanically identified plants that are harvested at the right time. The distilled aromatic plants can come from agriculture or wild production. The biochemical components of the essential oil are known and correspond to the desired quality profile.
• BIO certification : the essential oil is obtained from plants whose cultivation has been awarded BIO certification by an approved body.

   

What is the best essential oil ?

Whether or not it has BIO certification, the best essential oil is one which is chemotyped, 100% pure and 100% natural.

Certification labels : 

• Ecogarantie 

*Ingredient grown organically (audit Certisys BE-BIO-01) – ECOGARANTIE ® certified product in accordance with ECOGARANTIE specifications (audit CERTISYS)

• Organic Farming

*Ingredient from organic farming (audit Certisys BE-BIO-01) – BIO means: from organic farming (audit Certisys BE-BIO-01)

Distillation is a delicate process which calls for experience and constant supervision. To obtain a top quality essential oil, the following criteria must be met :

• The still : must be made of stainless steel, as copper and iron can form oxides.
  
• Low pressure : distillation needs to take place at low pressure, between 0.05 and 0.10 bar, with overoxidation occurring at high pressure. In this way, the color of the common thyme essential oil in full bloom varies from light red to reddy-brown when increasing the pressure. The pyrogenic reaction of wood with bark, which results from high pressure distillation at high temperature gives essential oils that are soiled with carcinogens.
  
• Duration of the distillation : it needs to be extended to allow the extraction of the totum from the aromatic molecules, i.e. all fractions that are referred to as “head”, “heart” or “tail”. For example, three quarters of the common thyme essential oil is extracted during the first thirty minutes, but you require between sixty and eighty-five additional minutes to extract all the phenols. Distillers are paid by the kilogram of essential oil, and that is why some producers distil at high pressure and stop distilling after the profitable 25 or 30 minutes. Very often, these essential oils are then “rectified”, i.e. re-distilled to purify them from undesirable components (higher boiling points) and to concentrate the most volatile components. This process produces discolored essential oils with a less refined odor, different properties and increased side effects. In this way, a rectified eucalyptus essential oil can contain up to 80% eucalyptol, but it will be more irritating for the bronchial tubes than a “complete” eucalyptus essential oil which only contains 60% eucalyptol.
  
• Water : the water used must be a non-calciferous spring water in order to avoid recourse to chemical descalers.
  
• Storage and keeping : after distillation, the essential oils must be filtered and then stored in immutable hermetic tanks stocked in a cool cellar. Their bottling must only take place in brown or blue opaque glass bottles to ensure they are kept away from light and oxygen.

Process for the expression of essential oils

Expression consists in mechanically breaking the “essence pockets” in the fresh zest of citrus fruits to extract the essences.

This method is the simplest but it is only possible with citrus fruits (orange, lemon, bergamot). The product obtained is called “essence” and not “essential oil”.

Other extraction methods :

Other extraction methods exist, which we will detail below.

• Percolation or hydrodiffusion : this method consists in sending steam downwards. It is faster and gives a higher quality of aromatic substances, but charges the essential oils with non-volatile substances. We then speak of “percolation essence”.
• Supercritical CO2 extraction : ultra-modern and highly expensive, this method consists in passing a current of CO2 at high pressure which bursts the essence pockets and brings out the aromatic substances.
• Enfleurage : enfleurage is normally reserved for flowers containing very low concentrations of essences (jasmine, mimosa etc.). The flowers are put into contact with absorbent fats that gradually become saturated with essence. The ointments thereby obtained are used as they are or exhausted by absolute alcohol. We thereby obtain alcoholic flower extracts referred to as “absolute”.
• Exhaustion procedure : the extraction of the essences can take place using volatile solvents (benzene). We obtain concretes of flowers and leaves which become absolute by alcohol exhaustion and then “concrete essences” after evaporation. Concretes generally contain 2 to 3% residual solvents. These essences are therefore only suitable for olfactory therapy.

To obtain 1 kg of essential oil, you will need :

• 7 kg of Clove floral buds – Eugenia caryophyllus.
• 50 kg of Lavendin – Lavandula x burnatii clone reydovan.
• 150 kg of True Lavender – Lavandula angustifolia ssp angustifolia.
• 1 ton of Everlasting (Italian Everlasting) – Helichrysum italicum ssp serotinum.
• 4 tons of Damask’s Rose petals – Rosa damascena.
• 5 to 10 tons of Melissa – Melissa officinalis.