Essential oils produced in Madagascar, are, in most cases, obtained by steam distillation of water. Methods vary, however, depending on the material available to the producer:
- Steam distillation of water at low pressure (or atmospheric pressure):
This is the method used by all farmers, producers of Clove leaf oil, in the Analanjirofo and Atsinanana regions. The farmer makes fire directly under the still made of iron or rarely made of aluminum
o The raw material is directly poured into the still, filled with water to ¾ full, or placed on a grid that separates water poured in the bottom of the cucurbit.
o By heating, the water evaporates and dilates plant cells that leave and when it breaks, escaping the vapors of contained volatile (essential oil), entrained by the steam.
o The mixture of water vapor and Essential Oil is then led to the gooseneck which directs it to the condenser (or cooling)
o The vapor mixture is cooled, in the condenser, and is liquefied.
o The mixture of essential oil and water is collected in a separator, wherein the separation is carried out of the water and the essential oil itself, as the relative density of the product with water. We must therefore adapt the separator with the essential oil to produce
§ If the essential oil is heavier than water, it sinks to the bottom of the separator (EO of Clove, Cinnamon, etc.).
§ If the essential oil is lighter than water, it will float to the top of the separator (EO of Niaouli, Geranium, pepper, etc.).
§ Sometimes the density of the oil is close to that of water.
This simple method allows farmers to make a regular production, although at times the yield and quality are poor.
- The steam distillation of water under pressure:
It is mostly used by industrial distilling large-scale raw materials from their own plantations or collected in large quantities from farmers. The still is separated from the boiler which produces water vapor at a pressure which must remain stable throughout the distillation.
§ The raw material is placed on a grid, suspended about twenty centimeters from the bottom of the still (usually conical or domed).
§ Steam under pressure is injected through the bottom of the still. As and when it arrived, it gradually heats the plant material to be distilled from the bottom to the top and acts exactly like in the previous method at low pressure on it.
§ The rest of the process follows exactly the same steps as in the method at low pressure above.
Using pressurized steam helps to regulate the distillation and get optimum performance and quality, in a shortened time.
1. Essential Oils of Clove
The Clove tree provides 3 types of essential oils including:
· Essential oil of Clove Leaf, commonly known as Clove leaf Oil (or, sometimes Crude Eugenol in trading). It results from the distillation of the leaves Clove. It is mainly produced by farmers in hand-made stills (mostly built of sheet metal, often aluminum) scattered throughout Analanjirofo and Antsinanana regions. The yield is 1 to 2%. The specification provides a rate of Eugenol greater than 80%. Trimeta Agro Food exports mainly to Europe, China, Indonesia and India (whose minimum rate of Eugenol is set at 82%). Main destination: Chemical Industry and cosmetics.
· Essential oil of Clove Stem (Clove Stem Oil). It results from the distillation in steam of clove Stems (peduncle), from cleanings lots of cloves for export. The yield varies from 4.5 to 6%. The specification is determined by a rate of Eugenol above 85%, and eugenyl acetate rate at 5%. Production is done exclusively at the distillery plant owned by Trimeta Agro Food in Tamatave (production capacity: 400kg / month). Main destination: pharmaceutical and cosmetics industry.
· Essential Oil Clove Bud (Clove Bud Oil). It results from the steam distillation of Clove. Premium, it is mainly for Fine Fragrances. It contains more than 80% eugenol and 10% of eugenyl acetate. Although clove contains up to 20% of essential oil, performance rarely reaches 15% for distillation.
Main destination: Perfumery, cosmetics and pharmaceutical industries. Production is done exclusively at the distillery owned by Trimeta Agro Food in Tamatave (production capacity: 1000 kg / month).
2. Black pepper oil, obtained by the distillation of dry mature fruit of black pepper. It is intended for Fine Fragrances (spicy note).
Yield: 2 to 2.5%. Trimeta Agro Food has a production capacity of 300kg per month.
3. Essential Oils of Cinnamon
The cinnamon gives two types of essential oils that are:
- Essential oil of cinnamon barks (containing mainly of cinnamaldehyde more than 50%) for fine fragrances.
- Essential Oil Cinnamon Leaf (containing more than 80% eugenol) for the chemical industry.