Methods for obtaining essential oils

In ancient times one can find references to living tissue... Vital cells, drawn from plants, produce fibers that continue to live and form a living fatty substance, being an indispensable fuse. The people will greatly appreciate this remedy in the future Russia.

E. I. Roerich

Over many millennia of existence, humanity has come up with many ways to obtain precious essential oil. Yes, truly precious, since very little incense can be extracted from the total mass of flowers, leaves, rhizomes, fruits, grass, bark or wood. Oil yield varies among different crops. Thus, from 1 kg of dry nutmeg you can get up to 16 g of essential oil, and from 1 kg of acacia flowers - only 1.5-2 g.

When producing essential oils, it is important to take into account the prevalence, productivity of the plant, the complexity of obtaining raw materials, and their processing. The quality of essential oil depends not only on humans, but primarily on Nature. Just as wine tasters distinguish them not only by name, but also by the year of harvest, so the essential oil obtained from the same plant, depending on the climatic conditions and place of growth, can differ in its composition and, consequently, in its aromatic bouquet . All of the above conditions determine the high cost of essential oils. The price for them ranges from 20 USD. e. up to 10,000 USD e for 1 kg. Therefore, when large bottles of essential oil are displayed on store shelves at a low price, there is no doubt that this product has nothing to do with the product you are looking for. Compare the following facts. To obtain 1 kg of neroli essential oil, you need to manually collect and then process 850 kg of small fragrant flowers from orange trees. To produce the same amount of essential oil from delicate and capricious tuberose, it is necessary to collect 3.6 tons of flowers, and 5 tons of hyacinth. Essential oil authenticity is checked by chemical analysis in combination with gas-liquid chromatography.

The book “The Mind of Flowers,” written by the famous playwright Maurice Maeterlinck in 1904, gives an unusual figurative presentation of the methods of obtaining essential oils in the capital of French aromas, the city of Grasse: “It is known that some of them, roses for example, are full of pliability and meekness and give their fragrance with complete simplicity. They are enclosed in a heap in huge boilers, similar in size to the boilers of our locomotives, through which water vapor passes. Little by little their oil, more precious than molten pearls, seeps drop by drop into a glass tube, narrow as a goose feather, at the end of a retort that looks like some kind of monster that would give birth in agony to amber tears. But most flowers do not so easily surrender their souls...

The glass plates are covered with fat two fingers thick and everything is thickly covered with flowers. Thanks to what hypocritical smiles, what crafty promises does fat manage to force an irrevocable confession? Every morning they are removed, thrown out, and the treacherous bed is covered with a new layer of simple-minded flowers. Only after three months, having consumed ninety generations of flowers, the greedy and insidious fat, saturated with fragrant secrets and confessions, refuses to accept new victims. One violet is able to resist the temptations of cold fat; we have to add the torture of fire. Place the vessel with lard in hot water. She gives in, gives herself away; and her crafty executioner, before being satisfied, absorbs a quarter of the weight of her petals, as a result of which the torture lasts the whole season, while the violet blooms in the shade of the olives.

But the drama doesn't end there. We still need to make this greedy fat vomit back the swallowed treasure. This is not achieved without effort. Fat has low passions that destroy it. They treat him with alcohol, and he gives back what he took. Now alcohol has the secret. And he is tamed, evaporated. And now the liquid pearls, after so many adventures, are finally collected in a crystal bottle.”

Maurice Maeterlinck described two methods for obtaining essential oils: steam distillation and enfleurage. The latter is practically not used today. In the Ancient world, an aromatic extract was obtained by maceration using vegetable oils and animal fats.

Currently, the most common methods are distillation with water, steam, or both, and extraction with toluene, benzene, carbon dioxide, hexane, petroleum ether, and other solvents.

After distilling off the solvents, a solid mass is formed - concrete, which is treated with ethyl alcohol and an absolute, or absolute oil, is obtained. If after the initial extraction a viscous liquid is formed, during processing ^Withthey say, resin, balsams, etc., then this resinous mass is called “resinoid”. Resinoids are actively used in the perfume industry as fixatives for volatile odors.