Plants are like small chemical laboratories, which produce very useful substances, for themselves, but also for us. These molecules can be extracted in many ways, depending on their chemical-physical characteristics, and their therapeutic uses. let's see how the essences are obtained and how a distiller works for essential oils.
Essential oils: what are they?
Essential oils are substances found in flowers (petals), fruits (peel), resin and bark of many plants. They are volatile, soluble in alcohol and oil, but not in water and this often makes their extraction and purification from impurities difficult. The most popular essential oils are: rosemary ( Rosmarinus Officinalis ), cypress ( Cupressus Sempervirens ), eucalyptus ( Eucaliyptus Globulus ), mint ( Peppermint ), lavender ( Lavendula Officinalis ), thyme ( Thymus Vulgaris ).
How to get essential oils
There are various methods of extracting natural essential oils.
The essential oils present in citrus fruits (for example: orange, bergamot, mandarin, lemon) are obtained from the pressing of the fruit peels.
Enfleurage is the method used to extract the essential oils present in the most delicate parts of plants, such as flower petals, which cannot be treated at high temperatures. It is a very ancient method. It consists of depositing the petals on a layer of fat, so that the fat absorbs the essential oils directly. The petals are changed frequently until the fat is saturated with perfumed oils. Finally the fat is dissolved and the essential oils are separated.
Solvent-based extraction is used for fine aromatic plants (for example rose and jasmine) whose oils do not resist heat. It consists in making the essential oils chemically bond with a solvent, and then removing them later and obtaining pure essential oils.
What is the distiller for essential oils
The steam current distiller is used for most aromatic plants, which contain essential oils that are poorly soluble in water and resistant to heat.
The operating principle of an essential oil distiller is simple: the vegetable is permeated by steam, the vegetable tissues break and release the essential oil ; steam carries essential oil. Finally the steam with the essential oil is cooled and consequently separated, as the steam cools and condenses and has a specific weight different from that of essential oils.
How the distiller works for essential oils
The distilling device is hermetically sealed to prevent the vapors from escaping. A fitting connects it with a water-cooled refrigerant to condense the vapors. Here are the steps in the distiller's process:
The parts of the plant (fresh or dried) are placed in a closed container ;
In the lower part of the container water vapor is made to flow, which passes through the vegetable parts and vaporizes the volatile oils they contain;
Steam and vaporized oil, together, pass through a cooled condenser ;
The essential oils are extracted from the water at the surface of the separator while the water is collected in the lower part.
The essential oils thus obtained with the distiller are not exactly identical to those contained in the plants. They are in fact modified by distillation processes and by temperature, but they are also purified from any substances present in the plant. It is therefore important to know the chemotype, that is the chemical composition of essential oils.
In this way, the distiller allows to obtain pure essential oils of high quality .