Secrets of aromatic oils. Methods for obtaining essential oils

Aroma oils (or essential oils) are liquids that have a strong smell and taste, an oily structure, and light color shades. They are able to volatilize, therefore they do not leave traces of fat on the skin, they practically do not dissolve in water. Their active properties are more pronounced when room temperature.

The aromatic properties of oils are due to the action of a mixture of a number of individual compounds that are isolated at the level of chemical composition. In addition, the quality depends on the storage conditions of the product.

source essential oils with strong physiological and pharmacological properties are only plants. Oils perform important physiological functions for plants:

• due to aromatic and terpenoid compounds, they activate metabolic processes;
• evaporating, they create a heat-resistant “cushion” around the plant, regulating the process of heat transfer;
• promote pollination of plants, attracting insects with the aroma;
• protect against disease and destruction by animals.

Plants containing essential oils are widely distributed in nature. Them beneficial features found application in many areas of human life.

Localization of oils in various parts of the plant

Depending on the species, essential oils are located differently in the body of the plant. Most often, roots, leaves, buds, flowers, rhizomes, and fruits are processed to obtain oil.

There may also be a different percentage of the final product in the raw material (from thousandths to 20% of total weight). It can be dispersed throughout the cells, be in cell sap or accumulate in special entities, which can be glandular spots, receptacles of oils, tubules with an oily substance.

How to receive

Useful properties of essential oils, their active use have led to the fact that the raw material base is depleted. World production today it has been launched to produce such products as turpentine, followed by oils of lemon, orange, mint.

When these substances are isolated from plant materials, their ability to dissolve in certain organic compounds, fats and alcohols is used.

Essential oils, whose properties and applications are very diverse, are produced by the following methods:

• Distillation with water. One of ancient ways to extract oil from the plant. Its essence is that two immiscible liquids are heated together. The mixture boils faster than if the liquids were heated separately. The resulting vapors of water with oil enter the refrigerator, where they condense and are collected in a receiver. For this method, simple equipment is taken, the yield of the final product is small, its quality is average.
• Steam distillation. This is a complex process using a distillation apparatus. The product of such distillation is mainly used in various fields of medicine, in the manufacture of perfumery products and in the food industry. Both fresh and dried plants are used.
• Cold pressing. This method is well suited for obtaining oil from the peel of various fruits. The raw material is first sent under the press (product yield 70%), then crushed and the process is completed by distillation (the remaining 30%).
• Maceration or enfleurage. The essence of the method is that oil is removed from raw materials by sorbents, which are solid fat or activated carbon. Then, through complex chemical reactions, the oil is separated from the sorbent.
• Extraction with selective solvents. The prepared raw material is mixed with the extractant, which is then distilled off in special devices. The result is a "tar" (perfume). This is how cloves, hops, lavender, chamomile, ginger and other plants are processed.

Each type of oil then finds its use.

Aromatic oils, depending on the composition, can have different impact and be used for different purposes.

There are many types of oils. This information compiled on the basis of their properties:

• Cleansing: Geranium, Lemongrass, Lavender, Sweet Orange, Rosemary, Tuberose, Lemon, Sage
• Excitement: bergamot, geranium, cardamom, bigardia, sandalwood, ylang-ylang, jasmine, mandarin, rose
• Tone: basil, clove, bay, lemon, nutmeg, lemon balm, mint, palmarosa, rosemary, cinnamon, citronella, sage, thyme, fir, ginger.
• Relaxation: valerian, lavender, oregano, frankincense, juniper, myrrh, chamomile, jasmine.
• Harmony: geranium, oregano, jasmine, marjoram, orange, mimosa, mandarin, rose, sandalwood.
• Strengthening: angelica, lemon balm, lavender, basil, nutmeg, cajuput, mint, verbena, rosemary, cedar, lemon, vetiver.
• Freshness: fir, mint, immortelle, lavender, orange, mandarin, lemon.
• Stimulus: immortelle, black pepper, coriander, lavender, clove, nutmeg, eucalyptus, rosemary, mint, verbena, hyssop, juniper, lemon.
• Peace: dill, jasmine, geranium, chamomile, vanilla, lemon balm, bigardia.

This shows that any essential oil can manifest itself in different ways. When composing aroma compositions, substances with opposite properties cannot be mixed.

Chemical composition

The composition of essential oils is very complex. There are elements that are included in the work of all systems of the human body. chemical names many elements are sometimes completely unfamiliar, but the benefits of their impact are obvious.

Esters contain aromatic mixtures, aldehydes, terpenoids, terpenes; saturated and unsaturated hydrocarbons are allocated; present organic acids, esters, alcohols; there are amines, oxides, organic sulfides, phenols, heterocyclic compounds.

The composition is also affected by the type and chemotype of the plant, weather conditions during the period of growth and collection, conditions for keeping and transporting raw materials, the method of producing oil and storing it.

Plants that provide raw materials for aromatic oils mainly grow in the tropics and in temperate climates. One type of plant grown in different conditions, may contain oil of different characteristics. It can be liquid and solid. His main characteristic- does not mix with water.

According to the structure and chemical composition, concretes, absolutes, resinoids, lipsticks are distinguished.

Basic properties

One of most valuable properties essential oils - their biological activity. At the same time, the range of effects of the product is very wide.

The information below shows some examples of the use of essential oils.

Fight against microbes and bacteria, purification and disinfection:

• eucalyptus;
• poplar;
• carnation;
• pine;

At the same time, leaves, buds and rhizomes are used to produce essential oil.

Fight against inflammatory processes:

• camphor;
• pharmaceutical camomile;
• yarrow;
• elecampane.

In the course are flowers and rhizomes.

Removal of spasms:

• peppermint;
• pharmaceutical camomile;
• coriander;
• dill.

Leaves, flowers, fruits, as well as seeds are used.

• wild rosemary;
• fennel;
• anise;
• elecampane;
• thyme;
• oregano.

It is worth using shoots, fruits and rhizomes.

The ability to remove mucus from the bronchi and lungs:

• wild rosemary;
• fennel;
• anise;
• elecampane;
• thyme;
• oregano.

Use shoots, fruits and rhizomes.

Ability to calm the nervous system:

• valerian;
• lemon balm;
• lavender.

The rhizome and flowers are used to make oil.

Cleansing the kidneys and bladder:

• Birch;
• juniper.

Oil is made from leaves, buds, and fruits.

Chamomile is used to rejuvenate body cells. Flowers are used to produce oil.

Based on the foregoing, it is easy to determine what effect an essential oil can have on the human body. Its action is manifested in:

• increased blood flow to the affected area;
• activation of the secretion of the pancreas, glands of the stomach and gallbladder;
• vasodilatation of the kidney filtration system;
• cleansing the body of toxins;
• destruction of bacteria.

When using essential oils, you need to be careful. An overdose may lead to backfire. Oils are used especially carefully in the treatment of gynecological diseases and in pregnant women. In addition, for mixing oils in complex treatment, it is desirable to choose agents that are close to each other in action.

Applications

Essential oils are used very widely. They are able to treat, are the prevention of many diseases, are used for hair and skin care. A special place belongs to aromatherapy with the use of essential agents.

Pictures on packages with bottles of essential oils attract attention with the unusualness of the plants depicted on them. But every oil has its uses. You need to know about this before purchasing a vial of this miraculous remedy.

The most commonly used oils are conifers, citrus, mint, ylang-ylang, various turpentine.

In the food industry, essential oils are used to make various additives that have a strong taste and nutritional value.

In the medical industry, esters are added to preparations and medicines.

In perfumery production, the use of aromatic oils is used as components of many cosmetics and perfumes.

Rules for use in complex treatment

Aromatherapy has a beneficial effect on human health. It is not able to completely replace drugs, but it can enhance their effect in the treatment and prevention of various diseases. There are a number of rules, the observance of which will give a positive result.

Aromatic oils should be applied with care to the skin and especially to the mucous membranes. Applied in pure form, they can leave a burn, so it is better to dilute them. For the base, you can take olive oil, salt, honey. The exceptions are lavender and tea tree. Means from these plants are safe for the skin.

Apply the oil strictly according to the instructions. Excess can lead to allergies or burns. It is advisable to carry out the first sessions of aromatherapy with a smaller dose of oil in order to avoid unpleasant consequences.

Before including a new tool in complex treatment, you need to do a test to rule out allergic manifestations.

For an aroma lamp, you need to take hot water, place it over a candle, then add essential agent(1-3 drops). The room must be closed, the session lasts no more than 20 minutes.

The reaction of the body to aroma sessions will be an indicator of such treatment. The aroma must be pleasant, otherwise there will be no improvement.

Methods for Using Essential Oils

Due to their therapeutic and preventive properties, various types of aroma oils are widely used to improve health and preserve the beauty of the face, hands, hair.

The following methods are available for using this tool:

• Cold inhalations. The aroma is carefully inhaled for 5 minutes. Breathing should be even, slow, deep, eyes closed.
• Aromavanna. Fill the bath with warm (not hot, otherwise the esters will evaporate quickly) water, stir the aromatic oil in it and enjoy the procedure until the water cools down.
• Massage with aroma oils. They must first be diluted in the base. It is desirable to combine such massage with aromatherapy. The result of the procedure will be an improvement in breathing, blood circulation, lymph flow, and the functioning of internal organs.
• Essential oils can be introduced as an additional component in ready-made creams, as well as masks for the face, hair, hands. They are added before use. cosmetic product to enhance its action.

Any way to use the ether will bring pleasure and improve health.

Safety Precautions When Using Essential Oils

Aromatic oils have a very strong effect and therefore must be handled with great care. There are a number of rules for use in various areas of human life.

When using essential oils in medicinal purposes we must remember that their ingestion is fraught with severe poisoning. The eyes can also be affected if the oil gets on the mucous membrane. It is necessary to purchase oils only in places authorized for the sale of such goods, it is also necessary to carefully read the instructions and follow them.

In industry, aromatic oils are used for the manufacture of various products. In enterprises, they are available in large volumes. Remembering that oil can quickly evaporate and ignite at low temperatures, you must strictly observe safety precautions when working with it.

Inside, aromatic oils can only be taken as part of food (drinks, pastries, etc.), and some medicines also have them in their composition (validol, etc.).

In everyday life, essential oils are actively used as part of such aromatic products as sticks, amulets, incense burners, candles and others. When burned, they may form carcinogens. Accumulating in the body, they can cause considerable harm to health. Therefore, do not abuse such sessions of aromatherapy.

How to store

All essential oils are highly volatile, so the product container must be kept tightly closed to prevent evaporation. In addition, the air, in contact with the oil, causes a chemical reaction in it: the oil becomes rancid, its color changes and unpleasant odor notes appear.

The shelf life of oils is different: from a year to several years. Moreover, the opened bottle is stored less.

If all these requirements are met, the oil will bring considerable benefits.

Video: The history of aromatherapy and its mechanisms of action

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10.2. METHODS FOR OBTAINING ESSENTIAL OILS

The above properties of fragrant oils have been used in various methods obtaining from ether-bearing plants and their subsequent purification. Essential oils in most cases are produced from fresh raw materials (green mass of geranium, lavender flowers). But some oils are obtained from dried (mint), dried (calamus and iris roots) or pre-fermented (rose flowers, iris roots, oakmoss) raw materials.

There are many different ways to obtain essential oils. Some of them have been used since time immemorial, others are more modern and therefore much more productive. Preference should be given to gentle methods, since aromatic oils are very “sensitive” and easily volatilize. With careless and improper handling, their quality deteriorates noticeably, so careful adherence to technology is necessary condition upon receipt of oils. If essential oils are contained in the form of glycosides, then they must be released by enzymatic cleavage to a free state, otherwise it cannot be obtained. For this, enzymes contained in the plant itself are used. First, the raw materials are crushed and triturated with water. Then at a temperature of 50-60ºС insist for several hours: in this time runs breakdown of glycosides and fragrant substances are formed.

Depending on the nature of the raw materials and the basic properties of the oils, one or another method is used to extract them, which makes it possible to obtain the highest yield and best quality.

1. If the essential oil is in large quantities in large containers (for example, in the pericarp of citrus fruits), then they use pressing or squeezing method, i.e.mechanical way.

2. If there is a relatively large amount of fragrant oil in the raw material and the oil is thermostable, then use distillation methods, namely:

a) water distillation method; b) steam distillation method;

c) steam distillation method at elevated pressure; d) steam distillation method at reduced pressure.

3. If the components of the oil are thermolabile and undergo degradation, then use extraction methods. Distinguish:

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a) extraction with low-boiling solvents (ethyl ether, methylene chloride, petroleum ether, acetone, etc.);

b) extraction liquefied gases(propane, butane, carbon dioxide); c) extraction with fats (maceration of flower raw materials with fatty oil with

heating and without it).

4. For heat-labile oils, the so-called absorption methods which can be divided into:

- enfleurage - the essential oil released from freshly harvested raw materials (mainly from flowers) is absorbed by solid high-quality fats;

– dynamic sorption– absorption of oils by sorbents (activated carbon, silica gel).

The final products obtained in the first two methods are called essential oils, in the third - extractive essential oils.

and at the fourth - flower lipsticks.

mechanical way. Using this method, only fragrant oils of citrus fruits (lemon, orange, mandarin, bergamot) are obtained, where the oils are concentrated only in their peels in fairly large receptacles. Until 1930, they were obtained by pressing the peel into a sponge. At present, it is common to remove the skins, pass them through toothed rollers, mix them with a small amount of water, and then press them on hydraulic presses. The essential oil remaining (about 30%) in the peel is further extracted by steam distillation. In this case, the heating of the product must not be allowed, since this will destroy important volatile compounds. The yield of oils with this method (out of 1000 fruits, g):

distillation method. Steam distillation is the most common way to obtain essential oils. This method is used when the raw material contains a relatively high oil content and when the distillation temperature (about 100° C) does not affect the quality of the finished product. The distillation method is quite simple, but for each type of raw material it requires the selection of conditions - temperature, pressure, process duration. Cro-

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In addition, additional separation of oils from distillation waters is possible. During hydrodistillation, the source of water vapor is water poured into the apparatus along with the processed material: essential oil or essential oil.

romaine raw materials. But in most cases, getting aromatic oils use water vapor supplied to the apparatus from the steam generator (the so-called steam distillation).

The boiling point of individual components of essential oils ranges from 150 to 350 ° C. For example, pinene boils at 160 ° C, limonene at 177 ° C, geraniol at 229 ° C, thymol at 233 ° C. However, all these substances distilled below 100°C in the presence of water vapor.

The theoretical foundations of the steam distillation process follow from Dalton's law of partial pressures, according to which a mixture of liquids (mutually insoluble and not chemically acting on each other) boils when the sum of their vapor pressures reaches atmospheric pressure.

According to Dalton's law total pressure mixture is equal to the sum of the partial pressures of the components. As a result, the vapor pressure of the mixture reaches atmospheric pressure even before the water boils. So, for example, a mixture of fir oil and water at atmospheric pressure will distill at 95.5°C (instead of 160°C for pinene, the main component of fir oil).

Steam distillation is carried out in continuous or batch distillation apparatuses, container-type distillation apparatuses, etc.

Often, in order to avoid decanting the raw material and destroying the components of the oil (saponification of esters, etc.), the raw material is placed on perforated nets, the lower of which is above the condensate level, and distilled off with live steam. The distillate (a mixture of water and essential oil) is cooled in a refrigerator and the so-called decanted oil is separated, and the distillation water is distilled again, heated with dull steam or subjected to additional treatment with activated carbon and volatile solvents. With this method, fragrant water is simultaneously obtained.

On fig. 10.1 shows a diagram of a batch distillation plant, which consists of a cube 4, a condenser 15 and a receiver 19. The cube is protected by a steam jacket 3, equipped with a perforated bubbler coil 6 for starting live steam; has a drain cock 7 and is closed from above with a lid 1 with

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steam pipe 2, through which it is connected to the condenser.

Rice. 10.1. Installation for the production of essential oils by steam distillation

With the help of winch 13 lift the cube cover. In a cube on a false bottom 5 and a layer of cloth 18, vegetable raw materials are placed, which, if necessary, are soaked with water. The lid is then lowered and hermetically connected to the body using bolts or a clamping device. Steam 12 is let in through valve 9 into the steam jacket, and exhaust steam and condensate are released through valve 10, which pass through the steam trap 11 into the sewer. After sufficient heating of the plant material through the valve 8 and the bubbler 6, live steam is let into the cube, which evenly passes through the plant mass and entrains the essential oil. Vapors of ethereal condensate enter the receiver. The cooled water enters the condenser from below through valve 16, and the waste water exits from above through valve 17. After the distillation is completed, valves 8 and 9 are closed, the cube is allowed to cool, the liquid is drained through tap 7, the lid is lifted and the cube is unloaded, overturning it using a gear mechanism fourteen.

The receiver is the so-called Florentine bottles with drain pipes for water. They are arranged in such a way that if oil is lighter than water, then it is collected in a layer from above, and water flows out through a drain pipe, which is fixed in a tube at the bottom of the bottle (Fig. 10.2). If the essential oil is heavier than water, then it sinks to the bottom, and the water is removed through a tube fixed at the top of the bottle.

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Fig.10.2. Florentine bottles:

1 - for essential oils lighter than water, 2 - for essential oils heavier than water

In cases where distillation (running) waters obtained after separating the oil contain a lot of valuable essential oil in a dissolved or emulsified state (for example, when receiving rose oil), the latter is isolated from it using cobation. The cobation process consists in the fact that distillation waters are distilled a second time, while most of the retained oil is distilled off with the first portions.

Continuously operating distillation apparatuses are used to process large quantities of raw materials. Steam distillation can be carried out not only at atmospheric pressure, but also under pressure with superheated steam. In this case, the ratio of water and oil favorably changes in favor of increasing the distilled oil. This is because the decrease in vapor pressure water is coming stronger, not proportional to the change in the vapor pressure of the essential oil.

When obtaining fragrant oil by steam distillation, individual parts of plants (flowers, leaves, seeds, stems, roots) can be used both in raw and dried form. It is better to use dried leaves as they are easier to grind and provide a fuller extraction. The duration of distillation is about 2 hours. The distillation should not be carried out too quickly, since part of the steam is used involuntarily, and the oil is emulsified.

The yields of essential oils (in %) during steam distillation vary greatly depending on their content in the fragrant parts of plants:

Due to the cheapness and simplicity of the equipment in this way,

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tea most oils. However, significant disadvantages should be noted:

– relatively high distillation temperature for some aromatic substances included in this essential oil, which sometimes causes their decomposition;

– the solubility of some aromatic substances in water during its condensation from water vapor, and therefore, these aromatic substances are absent in the composition of the oil after settling;

– insufficiently high distillation temperature for some of the hardly volatile aromatic substances that make up this essential oil, as a result of which these substances are not distilled off from plant materials and, therefore, are absent in the composition of the distilled oil;

– the presence in most aromatic oils of terpenes and sesquiterpenes, which reduce their solubility in alcohol, and in some cases their smell. So, for example, sesquiterpenes have a special, specific camphor smell, which differs from the main smell of the essential oil, but often harmonizes with it.

Thus, the oils obtained by steam distillation do not have such a natural smell as the essential oil directly in the plant. So, for example, it has not yet been possible to obtain satisfactory oils from such flowers as lily of the valley, jasmine, lilac, etc. by this method. The last drawback can be eliminated by the so-called detoxification method (distillation in a vacuum or hydrovacuum, hydrodistillation, treatment with alcohol of reduced strength).

In the distillation of essential oils, terpenes are distilled off first and therefore can be easily separated from the constituents that cause the odor characteristic and are distilled at a higher temperature. Sesquiterpenes are most often distilled off last. During distillation, a certain amount of the main odor carrier is carried along with terpenes, depending on the method of distillation and fraction. Sterpenic oils are characterized by:

1) greater solubility in water and alcohol; 2) greater strength, that is, the concentration of the main smell;

3) the property to immediately give transparent and remaining transparent alcohol solutions.

These benefits of such oils are used in perfumery. So in

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alcohol can completely dissolve only non-terpene citrus oils. When designating such oils, the prefix D (for perfumes) is used. However, very often there is some change in the smell in such an oil, which does not match the freshness and integrity of a natural oil containing terpenes. Sterpenic oils should not be used in medicine, since the desired therapeutic effect is observed only when using essential oils with the maximum at full strength, i.e. contain as many active ingredients as possible.

Extraction Method began to be used from the second half of the nineteenth century. Unlike the previous ones, this method requires more sophisticated equipment. A well-purified solvent is also required.

Essential oils are soluble in many organic solvents. This property is used in cases where the components of the oil are thermally labile and undergo degradation during steam distillation.

The following solvents are used: ethyl alcohol, benzene, chloroform, methyl alcohol, acetone, liquid or gaseous butane, carbon dioxide. But the most commonly used petroleum ether (liquid petroleum product, a mixture of light hydrocarbons).

The equipment used is very diverse. Basically, it consists of an extractor, a distillation cube with a refrigerator, into which a solvent with oil comes from the extractor.

During extraction, the raw material is poured one or several times with a solvent, which, after saturation with aromatic substances, is drained from the raw material. From the drained extract, called a micelle, the solvent is removed under pressure, then under vacuum. The resulting essential oils are called extraction or "odorous waxes" (Essences concretes) and in their smell they are closer to the essential oils found in plants than oils obtained by steam distillation. This is especially true for raw materials pleasant smell, which, when distilled with water vapor, gives too little oil (rose, daffodil, violet, carnation).

However, the solvent extracts from plants not only aromatic oils, but also waxes, paraffins, gums and fats, so the primary extraction products have a solid consistency and are not completely soluble in alcohol. Such oils are called concretes.

For release from ballast substances of specific oils, the latest

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are extracted again with ethyl alcohol, and after its distillation and filtration with cooling, secondary extraction products are obtained, called absolute oils or absolute. Absolute oils are completely soluble in alcohol; they are also devoid of terpenes and sesquiterpenes. When ethyl alcohol is used as the extractant, this form is referred to as rhizinoid. This type of extraction is used in the production of essential oils from various plants:

the yield of specific oils is from 0.08 (tuberose) to 0.98% (ylang-ylang); the yield of absolute oils is from 0.18 (tuberose) to 80% (ylang-ylang). Generally, essential oils extracted with organic solvents do not

used internally to avoid manifestation allergic reaction and weakening immune system due to the fact that solvents are highly toxic, and their separation from the essential oil is incomplete. For ingestion, essential oils extracted with ethanol are allowed, the admixture of other solvents is allowed in an amount of not more than 5 parts per million parts of the main substance.

The extraction methods for obtaining fragrant oils should also include maceration with fats. To do this, raw materials in fabric bags are immersed in a container with fat for 24-48 hours at a temperature of 50-70 ° C. This operation is repeated 10-15 times until a smell of a certain strength is obtained. Usually animal fats are used - beef or pork, and from vegetable - olive oil. Sometimes paraffin with a melting point of 60 ° C is used. Fats and oils must be clean, odorless and prepared according to a special recipe. Next, the oil is extracted with alcohol (see enfleurage).

AT recent times developed and widely used for the extraction of essential oils cryogenic method using pressurized gases.

The enfleurage method (from the French enfleurer - to convey a floral aroma) is the most ancient. In this way, jasmine, lily of the valley, tuberose (raw materials with a low content of essential oils) are usually processed.

The method is based on the ability of essential oils released by plants (mainly from flowers) to pass into the gas phase and then be absorbed by fats and sorbents. This process is carried out in special frames-chassis (size 5×50×50), hermetically assembled by 30-40 pieces (one on top of the other) into a battery. In the middle of such a frame is a glass plate, on which

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adsorbent is applied on both sides. On an adsorbent (activated carbon or a mixture of pork and beef fat, etc.) with a thickness of about 3-5 mm, spread flowers (without cups) up to 3 mm thick, and the edges of the plate remain uncovered by 4 cm. To increase the fat absorption surface, grooves are made with a spatula. Within 1-3 days, the evaporating essential oils are absorbed by the adsorbent. Then the raw materials are removed and fresh raw materials are placed on the frames. This operation is carried out repeatedly (up to 30 times) until the adsorbent is completely saturated with essential oil. Since the waste raw material still contains a certain amount of essential oil (heavy fractions), it is additionally processed by extraction. And the fat saturated with essential oil is then scraped off the glass.

This product with a sufficiently high odor quality is marketed under the name flower lipstick. Fragrant oil is extracted from flower lipstick with alcohol. The alcohol extract is frozen and the precipitated impurities are removed by filtration. Then the alcohol is distilled off in a vacuum and pure essential oil is obtained.

At present, the enfleurage method is rarely used. This is primarily due to high price final product (for example, 700 g of essential oil is obtained from 1 ton of rose petals).

Method dynamic sorption is essentially an improved method of enfleurage. Raw materials (flowers picked early in the morning) are placed in the chamber on the nets. Then the chamber is hermetically sealed and heated air is blown through it, which, capturing the vapors of essential oils, passes through activated carbon or silica gel, where the absorption (sorption) of the aroma oil vapors of the loaded flowers takes place. By extracting the sorbent (silicone or activated carbon), the essential oil is isolated, after which the ether is distilled off from the solution and a pure essential oil is obtained, close to the absolute oil. This method is promising and is becoming more widespread.

Raw essential oils obtained by various methods can be subjected to various technological processing. To improve the quality of aromatic oil, it is purified to remove some unwanted compounds from it. This purification is carried out by distillation of the oil under reduced pressure and is called vacuum distillation. In the case of removing mono- and/or sesquiterpene hydrocarbons, this process may be referred to as "deterpenization". Sometimes volatile components are distilled off (fat aldehydes,

Essential oils are clear, colorless or colored liquids. They are distinguished from vegetable oils by the property of volatility. Their density is usually less than 1. They are practically insoluble in water, but readily soluble in alcohol and other organic liquids, as well as in fats, waxes and other oils. These properties are used in various methods for obtaining essential oils. Certain parts of plants from which essential oils are derived, especially flowers, are prone to quick loss quality, so should be used as soon as possible after harvest. Other parts, including roots and seeds, can be stored for a long time. They are transported to different parts of the world. Basically, aromatic oils are obtained in five ways (we will not mention artisanal methods, since they do not guarantee quality).

Distillation is the main method for extracting essential oils from plants. According to authoritative experts, this is the only method by which it is possible to obtain substances that fully meet the definition of "essential oil". Substances obtained by other methods are called essences or absolutes.

In distillation, the plant material is either immersed in water, which is then brought to a boil, or placed on a grid placed over boiling water so that steam passes through it. Leaves, roots, fruits, flowers, branches, trunks, bark and resins can be used as raw materials. When raw materials are placed in water, the process of obtaining oil is called direct distillation, and if steam is passed through it, then this is called steam distillation.

In both cases, hot water and steam rupture the glands of the plant and the essence contained in them is released in the form of steam. This steam, together with the steam involved in the distillation process, is collected in a tube passing through the cooling units, after which it again acquires liquid form and drained into a sump. The steam turns into a water distillate and the essence of the plant into an essential oil. Since oil is lighter than water, it collects on the surface of sedimentation tanks and is easily separated from the water fraction. Sometimes the water distillate is also a valuable product and is sold as flower or herbal water.

From some plants, only a very small amount of essential oil can be obtained by distillation, and then it is considered by-product in the production of, for example, rose or orange water. To obtain essential oil from more delicate, delicate plants that do not tolerate exposure to steam - jasmine, rose, orange flowers - a different technology is used, namely: enfleurage or solvent extraction.

The distillation process as a method for extracting essential oils from plants has been known since at least the 10th century AD. e. It is assumed that this method was invented in Persia, where essential oils were highly valued for their wonderful aroma and used as perfumes. However, recent archaeological excavations in Italy have unearthed distillers of simple construction. This suggests that the ancient Romans already knew this technology, and the Persians simply perfected it.

Some distillers in use today, especially in less developed countries, differ little from those of the old distillers, but where there is large-scale production of essential oils, such plants are much larger and often made of stainless steel, although they use the same technology. .

Enfleurage is a traditional method used to extract the highest quality plant essences from delicate flowers such as rose and jasmine. This is a laborious and expensive process, so the resulting product - the absolute - has a high price.

The enfleurage process proceeds as follows. Glass sheets are coated with fat, usually refined pork or beef. Lay the petals of freshly cut flowers on top. Fat actively absorbs volatile essential oils. Withered petals are removed and fresh ones are put in. The process takes several days, and for jasmine it takes as long as three weeks, until the fat can no longer absorb the oil.

Then the fat is collected, cleaned of stale petals or stems. The product obtained at this stage is called lipstick. It is then dissolved in alcohol and shaken vigorously for twenty-four hours to separate the fat from the essential oil.

The oil obtained by this method is called "absolute". The absolute is usually a highly concentrated viscous liquid, but sometimes it has a solid or semi-solid consistency, such as rose absolute. It hardens at room temperature, and if you hold a bottle of absolute in your hand for a while, then, when heated, it acquires a liquid consistency. The absolute has a strong smell and strong therapeutic properties. To achieve the same effect, much less absolute is required than the essential oil obtained by distillation.

There is another method of enfleurage. Gauze sheets are stretched over wooden frames, impregnated olive oil and arrange the flower petals, changing them daily, until the oil can no longer absorb the plant essence. The resulting product is used in its natural form as a fragrant body oil or subjected to an alcohol extraction to separate the absolute.

These two methods have traditionally been used in the perfume industry, especially for the production of high quality essential oil. But now with last method get no more than 10% of all absolutes, because the process is too long and expensive. Approximately 80% of rose and jasmine absolutes are currently extracted with volatile solvents, with the remaining 10% being aromatic oils extracted by distillation.

Absolute is a term describing substances that are obtained from a plant through enfleurage or solvent extraction. Archaeological finds indicate that distillation existed even before the time of Avicenna, but it is likely that he significantly improved its technique by adding a cooling system to the main still. Enfleurage extracts a substance called lipstick, a mixture of fat and essential oil. During extraction with solvents, a concrete is obtained, consisting of fats, waxes, essential oils and other plant substances. Absolute is extracted from lipstick or concrete with the help of alcohol. These methods are used to extract the essence from flower petals where distillation would distort their delicate fragrance. Three absolutes are mainly used in aromatherapy - rose, jasmine and orange blossom (neroli). Other floral absolutes, notably carnation, gardenia, mimosa, hyacinth, are used in high-end perfumery but are only rarely used medicinally.

Absolutes differ from essential oils (obtained by distillation) in that they have an exceptionally strong aroma and high healing power and should be used in low concentrations. Absolutes are usually colored highly concentrated liquids, more viscous than essential oils. When stored in a bottle at room temperature, rose absolute may solidify, but if held in the hand, it quickly reverts to a liquid state.

Some aromatherapists believe that absolutes should not be used in aromatherapy because they may contain traces of solvents such as acetone, ethanol, or hexane used to extract the absolute from lipstick or concrete. The exception is cases where natural ethanol is used. In practice, however, many aromatherapists use absolutes in small amounts.

Extraction

Some of the highest quality flower absolutes are obtained through solvent extraction. This method was tested in the 30s of the XIX century, and after sixty years it was widely used.

The flowers are placed in perforated racks in airtight containers, which can be connected to each other in a row. At one end is a reservoir containing liquid solvent, and at the other is a vacuum distiller. The liquid solvent slowly seeps through the flowers, dissolving the essential oils. The solvent is then separated for later use, and the result is a semi-solid aromatic substance called "concrete". It contains essential oil, fats and waxy substances. Twenty-five grams of concrete is equivalent to a kilogram of the best quality enfleurage lipstick.

Like lipstick, concrete is vigorously shaken in alcohol to remove vegetable waxes, resulting in a high-quality absolute.

In the 19th century, petroleum ether was used as a solvent, and later benzene was used. In modern technological processes extractions can use liquid butane or liquid carbon dioxide, which produce excellent oil and do not spoil even the most delicate flavors.

cold pressing method

Essential oils of lemon, bergamot, orange and other citrus fruits are obtained by simple pressing. The essential oil of citrus fruits is found in their peel. Before extracting the oil, cut the flesh from the peel. For a long time this process was carried out manually in two ways: either by scraping inner part peel, or its outer part was cut off in thin strips.

Then the zest was squeezed out, and an essential oil was obtained with a small amount of juice. The resulting liquid was defended until the oil rose to the surface, and then it was removed.

Another traditional method was as follows: the fruit was rolled on a drum studded with spikes that pierced the rind, then the resulting liquid was collected and the oil was separated from the juice.

Now, different mechanisms are used to process citrus fruits, but the best citrus oil is still obtained by manual extraction.

At home, you can also get some lemon or orange oil. To do this, you can use a new garlic crusher (one that has not been used before). But first you need to make sure that the fruits are not coated with any compound that is sometimes used to prevent spoilage during long storage and which will make the oil from the zest of these fruits unfit for consumption.

Filtration

Filtration is a relatively recently invented method for extracting essential oil from plants. It is similar to the steam distillation method, but the difference is that in filtration, the steam generator is placed above the plant material and the steam passes through it from top to bottom. The essence released from the plants in the form of steam, together with the steam involved in the distillation, is collected in a tube passing through the cooling system, where each subsequent installation has more than low temperature than the previous one. At the end of the process, the essential oil is separated from the water fraction in exactly the same way as in the conventional steam distillation process.

This method is not as widely used, but it is convenient to extract essential oil from woody and hard plant materials, such as seeds of plants of the umbrella family (anise, dill, fennel, etc.). It takes 12 hours to extract the oils by conventional steam distillation, and the filtration method reduces the extraction time to 4 hours. The less time the plants are exposed to steam, the higher quality oil will result.

Obtaining essential oils DISTILLATION

Essential oils are extracted from many plants, and from various parts of them. The most common way to obtain oils is steam distillation, or distillation in another way.

Distillation plants are usually placed close to the breeding grounds so that the raw materials can be processed as fresh as possible. The desired plant parts: seeds, leaves, stems, flowers (or combinations of two or more parts) are packed tightly into the first container of the alembic. Then steam enters the cube, and then, together with this heated steam, the essential oil begins to evaporate. The evaporated oil rises and passes along with the water vapor through the condenser to the oil collecting vessel, where it is cooled. When the essential oil and water cool, the oil separates from the water, forming a layer on its surface. Now they can be separated using a special separating funnel.

Some plants, such as jasmine, are not amenable to steam distillation, since the high temperature in the apparatus destroys its most valuable substances. In such cases, the two methods described below for isolating the oil are used, which, strictly speaking, give not oil, but the so-called absolute.

ENFLERAGE

The enfleurage method is also practiced by some French perfumers, though mainly in order to demonstrate it to tourists and earn money from it. In general, it seems to be outdated. This is a laborious and very slow process, although jasmine oil obtained in this way is the highest grade strength and purity. Jasmine flowers are placed by hand on glass trays coated with a special fat. The baking sheets are placed one above the other and left for a while so that the essential oil has time to absorb into the fat. The process is repeated, and already used flowers are replaced with new ones until the fat is completely saturated with oil. Saturated fat is what perfumers call lipstick. When the lipstick is ready, it is treated with alcohol to extract the absolute. The fat remaining after the enfleurage is not thrown away: since it retains the aroma of jasmine, it is suitable for the production of soap.

SOLVENT EXTRACTION

Solvent extraction is another way to obtain jasmine absolute, as well as essential oils from other plants.

Flowers (or other plant parts containing oil) are soaked (macerated) in a container with a solvent such as hexane. The oils and vegetable wax contained in the raw material are dissolved in hexane and the resulting solution (extract) is drained. The extract is then heated to evaporate the solvent. What remains after removal of the solvent is called concrete, it is a mixture of pure oil with vegetable waxes.

After cooling, the concrete is treated with alcohol to separate the oil from the wax. Thus, an ethereal absolute is obtained.

EXTRACTION WITH CARBON DIOXIDE

This method is relatively new compared to the two described above, and may eventually replace the solvent extraction method. The fact is that during extraction with solvents, some part of the solvent still remains in the absolute, and using extraction with carbohydrate dioxide, this problem can be avoided.

Unfortunately, many of the oils cannot be synthesized with our simple equipment and reagent kit. But now we will be able to use our entire arsenal and, as if by magic, extract a rich set of fragrant substances from our glasses, flasks and retorts. Let's start with obtaining natural fragrant substances from plants.

Fragrances are found in plants usually in the form of small droplets in special cells. They are found not only in flowers, but also in leaves, in the peel of fruits, and sometimes even in wood.

The content of essential oils in those parts of plants that are used to obtain them ranges from 0.1% to 10%. The fact that they are called oils should not mislead us. Essential oils have nothing to do with ordinary vegetable oils: linseed, sunflower, corn, that is, with liquid fats. They are more or less complex mixtures of fragrant organic substances of various types.

Among them, esters, aldehydes and alcohols of saturated, unsaturated and aromatic series are especially common.

Terpenes and their derivatives are very important components of essential oils.

Consider the formulas of some representatives of this class of compounds: Terpinene is a cyclic hydrocarbon. It is found in trace amounts in many essential oils. Limonene is an important component of oil from lemon peel. Pinene - the main component gum turpentine. It serves as the starting compound for the production of synthetic fragrances.

Essential oils are usually very difficult to dissolve in water, but readily soluble in alcohol.

Therefore, alcohol is used in large quantities in the perfume industry as a solvent. Essential oils can be obtained, for example, by extracting them from plant parts with alcohol or other solvents.

The most valuable fragrant substances of flowers are obtained by placing alternately layers of solid animal fat and plant parts in a closed chamber on a wire mesh.

After a while, the flowers are replaced with new ones so that the fat is saturated with essential oil. With this method (in France it is called "enfleurage"), a fat is obtained containing essential oils dissolved in it, and this concentrate of aromatic substances is delivered to perfume factories (Then the essential oils are extracted from the fat with alcohol. This method is used, for example, to extract essential oils from jasmine and tuberose. - Approx. transl.).

We will apply the third, especially important method of extracting essential oils - steam distillation.

By themselves, essential oils are often volatile only at elevated temperatures, and their boiling is accompanied by decomposition. If, however, water vapor is passed through a mass consisting of plants or their parts, then the oils are removed along with it and then collected in the distillate in the form of droplets that have low density and therefore float on the surface of the water.

Get essential oils

We close the 0.5 liter flask with a rubber stopper with two holes. In one of them we insert a glass tube drawn at the end, which reaches almost to the bottom of the flask. This tube serves as a safety valve. It should be long enough (about 1 m).

Through another hole, we introduce a short elbow of a curved tube with an inner diameter of at least 5 mm (It is best to take a tube with an inner diameter of 8-10 mm.

The distance between the flasks should be as short as possible, but it is advisable to separate the tube between the flasks by inserting a glass tee in the middle of it and connecting it to both parts of the tube with short pieces of rubber hose. A piece of rubber hose with a clamp attached to it is attached to the free end of the tee. This allows you to quickly disconnect or connect both flasks during the experiment. If you have a metal steamer, you can replace the first flask with it. - Approx. transl.).

Insert the longer leg of the same tube through the hole in the cork into the second flask, so that the tube also reaches there almost to the bottom. In addition, with the help of a glass tube, we will connect the second flask with a direct refrigerator (Liebig or with an external lead coil). As a receiver, it is best to take a separating or dropping funnel.

First, we get cumin oil. To do this, we need 20 g of cumin.

Grind it in a mortar with the addition of sand or in an old coffee grinder. Place the cumin in the second flask and add a little water - so that it does not completely cover the mass of cumin. We fill the first flask one third with water and, in order for the boiling to be uniform, we add several pieces of porous ceramics (“boilers”) to the water.

Now, with a Bunsen burner, heat the contents of the first and then the second flask to a boil. After that, we will again move the burner under the first flask and heat it as much as possible so that water vapor intensively passes through the second flask, which then enters the refrigerator and from it in the form of condensate to the receiver.

If there are two burners, then the second flask can be slightly heated at the same time so that the volume of liquid in it does not increase too much as a result of condensation of the vapor.

It is convenient to use a sand bath to heat the second flask, warming it up in advance, before the passage of water vapor. Let's run a distillation for at least an hour. During this time, about 100 ml of water is collected in the receiver, on the surface of which colorless drops of caraway oil float. We separate the water as completely as possible with the help of a separating funnel and as a result we get about 10 drops of pure caraway oil, together with a small amount of water. This amount would be enough to make several bottles of caraway liqueur!

The characteristic smell of caraway oil is due to carvone, which contains more than 50%. In addition, it contains limonene - the aromatic substance of lemons. Caraway oil is used primarily to perfume soaps and mouthwashes. It is also added in small quantities to some perfumes.

Using the same device, essential oils can be isolated from other plants. To do this, grind them and subject them to steam distillation for 1-2 hours. Of course, the yield will be different depending on the content of the essential oil. The most interesting are the following essential oils:

Peppermint oil. From 50 g of dried peppermint, we can extract 5-10 drops of peppermint oil. It contains, in particular, menthol, which gives it its characteristic odour. mint oil used in large quantities to make cologne, hair eau de toilette, toothpaste and elixirs. Currently menthol for the most part obtained by synthesis.

Anise oil is obtained from crushed anise. Mixed with peppermint oil and eucalyptus oil it is part of the tooth elixirs and pastes, as well as some soaps.

Clove oil is obtained by steam distillation of cloves, which are sold as spices. Important integral part his is eugenol. (Eugenol can be obtained from synthetic vanillin.) Clove oil is an additive to many perfumes and is also used in the manufacture of mouthwashes and soaps.

We get lavender oil from 50 g of dried and crushed lavender flowers. It is one of the most important fragrant substances, which, in addition to its use in the manufacture of lavender water and cologne, is used in the manufacture of perfumes, soaps, hair toilet waters, powders, creams, etc.

Spruce oil. We will collect at least 100-200 g of needles and young spruce shoots. Grind them and, while they are still wet, distill with water vapor without first adding water. Usually needles contain only a few tenths of a percent of this essential oil. It will delight us with a pleasant aroma in the room. In addition, spruce oil is a favorite flavoring agent for various bath preparations.

Let us leave it to the reader to obtain other fragrant substances from plants. For example, pine, cinnamon, chamomile flowers, or other fragrant garden flowers can be steamed. We will store the resulting products in securely closed test tubes - later we will need them as fragrant substances for the manufacture of cosmetics.

Unfortunately, we will have to give up on obtaining fragrant substances contained in perfumes with a delicate, delicate smell - bergamot oil, as well as oils from jasmine flowers and orange flowers - because we do not have the necessary starting materials for this.

However, an essential oil with a very delicate aroma is also obtained from lily of the valley flowers. If you manage to collect a lot of them, then, of course, it is worth isolating the essential oil from them.

SCENTED ETHERS Many well-known aromatic substances belong to the class esters. The latter are widely distributed in nature and give a wide variety of shades of smells, from the smell of tropical orchids to the characteristic aroma of fruits that are well known to us. We can synthesize these compounds. Esters are formed by the interaction of alcohols with carbolic acids. At the same time, water is split off

R-OH + HOOC- R1 R-OOC- R1 + H2O

alcohol + acid ester + water

The reaction proceeds rather quickly only in the presence of water-removing agents and catalysts. Therefore, a mixture of alcohol and carboxylic acid is boiled for a long time in the presence of sulfuric acid, which acts as a dehydrating agent and also catalyzes the reaction.

In addition, often the reaction mixture is saturated with gaseous hydrogen chloride. We can more easily achieve the same result by adding common salt, which forms hydrogen chloride with sulfuric acid.

Esters are also obtained in the presence of concentrated of hydrochloric acid or anhydrous zinc chloride, but with a lower yield.

We will use these additives in those cases where the original organic substances are decomposed by concentrated sulfuric acid, which can be detected by darkening of the reaction mixture and an unpleasant pungent odor.

Get esters

To obtain esters in small quantities, we use a simple device. Insert a narrow test tube into a wide test tube in such a way that one third of the wide test tube in its lower part remains empty.

The easiest way to strengthen a narrow test tube is with a few pieces of rubber cut from a hose or cork. At the same time, it should be taken into account that a gap of at least 1.5–2 mm must be left around a narrow test tube in order to exclude excess pressure during heating.

Now pour 0.5-2 ml of alcohol and approximately the same amount of carboxylic acid into a wide test tube, with thorough cooling (in ice water or cold running water), add 5-10 drops of concentrated sulfuric acid and, in some cases, a few more grains of table salt.

Insert the inner test tube, fill it with cold water or, even better, with pieces of ice, and fix the assembled device in a regular stand or in a test tube stand.

Then, on the smallest fire of the Bunsen burner, we will boil the mixture for at least 15 minutes (add "boiling"!). The longer the heating, the better the yield.

The inner tube filled with water serves as a reflux condenser. If its contents are too warm, then you need to stop the experiment, after cooling, fill the inner tube with ice again and continue heating (It is more convenient to continuously pass cold running water through the inner tube. To do this, you need to pick up a stopper with two glass tubes inserted into it. - Approx. transl.).

Even before the completion of the experiment, we can often smell the pleasant smell of the resulting ester, which is still superimposed with a pungent smell. hydrogen chloride(Therefore, you do not need to sniff the reaction mixture by bringing the opening of the test tube closer to you!).

After cooling, the reaction mixture is neutralized with a dilute soda solution. Now we can detect the smell of pure ether, and also notice many small oily droplets of ester that float on the surface. aqueous solution, while the unreacted starting materials are mostly contained in solution or form a crystalline precipitate.

According to the above recipe, we get the following esters:

Ethyl methanate (ethyl formate, formic ethyl ester), formed from ethanol (ethyl alcohol) and methane (formic) acid. This ether is added to some varieties of rum to give it a characteristic flavor.

Butyl ethanoate (butyl acetate, acetic butyl ether) - from butanol (butyl alcohol) and ethanoic (acetic acid).

Isobutyl ethanate (isobutyl acetate, acetic isobutyl ether) is formed respectively from 2-methylpropanol-1 (isobutyl alcohol) and ethanoic acid. Both latest broadcast have a strong fruity smell and are an integral part of perfume compositions with the aroma of lavender, hyacinths and roses.

Pentilethanate (amyl acetate, acetic amyl ether) - from pentanol, that is, amyl alcohol (Poison!), And ethanoic acid.

Isopentylethanate (isoamyl acetate, acetic isoamyl ether) - from 3-methylbutanol-1, that is, isoamyl alcohol (Poison!), And ethanoic acid. These two esters in dilute solution have a pear odor. They are part of fantasy perfumes and serve as solvents in nail polishes.

Methylbutanate (methnlbutyrate, oil methyl ether) - from methanol ( methyl alcohol) and butanoic (butyric) acid. Its smell is reminiscent of ranet.

Ethyl butanate (ethyl butyrate; butyric ethyl ether) - from ethyl alcohol and butanoic acid. It has a characteristic smell of pineapples.

Pentylbutanate (amyl butyrate, butyric amyl ether) - from pentanol (amyl alcohol) and butanoic acid (alcohol is poisonous!).

Isopentylbutanate (isoamylbutyrate, butysoamyl ether) - from 3-methylbutanol-1 (isoamyl alcohol) and butanoic acid (alcohol is poisonous!). The last two ethers have the smell of pears.

Among the esters of aromatic acids, there are also substances with a pleasant aroma. In contrast to the fruity odor of esters of the aliphatic series, they are dominated by balsamic, so-called animal odors or odors of exotic flowers. We synthesize some of these important fragrances.

Methyl and ethyl benzoate are obtained from methyl or ethyl alcohol, respectively, and benzoic acid. We will conduct an experiment according to the above recipe and take alcohol and about 1 g of crystalline benzoic acid as starting materials. These esters are reminiscent of balms in smell and are part of perfume compositions with the smells of fresh hay, Russian leather (yuft), cloves, ylang-ylang and tuberose.

Pentyl benzoate (amyl benzoate, benzoic amyl ether) and isopentyl benzoate (isoamyl benzoate, benzoic amyl ether) smell like clover and ambergris - a kind of discharge from the whale's digestive tract. They are used for perfumes with oriental flavor.

To obtain these substances, we esterify benzoic acid with amyl or isoamyl alcohol (Poison!) in the presence of concentrated hydrochloric acid, because side reactions are possible in the presence of sulfuric acid.

Ethyl salicylate smells like periwinkle green oil, which we have already met before. However, it has a less pungent odor. It is used for the manufacture of cassia-scented perfumes and Chypre-type perfumes. We will get this ether from ethyl alcohol and salicylic acid when heated with common salt and sulfuric acid.

Pentyl salicylate (amyl salicylate) and isopentyl salicylate (isoamyl salicylate) have a strong smell of orchids. They are often used to create scents of clover, orchids, camellias and carnations, as well as fantasy scents, especially in soap perfumes. In these two cases, we will also carry out the esterification in the presence of hydrochloric acid.

Also noteworthy are benzyl methanate (benzyl formate), benzyl ethanate (benzyl acetate), and benzyl butanate (benzyl butyrate). All these esters are formed from aromatic benzyl alcohol and the corresponding carboxylic acids - methane (formic), ethanoic (acetic) or butanoic (butyric).

Since benzyl alcohol is hard to find commercially, we get it ourselves from commercial benzaldehyde, which is used in perfumery to create bitter almond scent.

In a water bath with continuous stirring for 30 minutes, we will heat 10 g of benzaldehyde with concentrated solution caustic potash. (Be careful, lye causes burns on the skin!)

As a result of the reaction, benzyl alcohol and the potassium salt of benzoic acid are formed:

2C6H5-CHO + KOH = C6H5COOK + C6H5-CH2-OH
benzaldehyde potassium benzoate benzyl alcohol

After cooling, add 30 ml of water. In this case, potassium benzoate dissolves, and benzyl alcohol is released in the form of an oil, forming upper layer. Let us separate it in a separating funnel and heat it in our simple esterification apparatus with the above carboxylic acids while adding sulfuric acid and common salt.

The resulting esters have strong smell jasmine and are used in the manufacture of many perfumes.

Let's make perfume

To create a leading smell, you will need, first of all, citrus oil, which we get from the peel of lemons or oranges. It is so rich in essential oils that it is very easy to isolate them. To do this, it is enough to mechanically destroy the membrane of the cells that contain the oil and collect the droplets released in the process. For this purpose, grate the peel, wrap it in a piece of durable cloth and carefully squeeze it out. At the same time, a cloudy liquid, consisting of water and droplets of oil, seeps through the fabric.

Let us mix approximately 2 ml of this liquid with 1 ml of the distillate obtained from the soap. The latter contains higher fatty aldehydes and has a refreshing odor slightly reminiscent of wax.

Now we need another flower shade. We will create it by adding 2-3 drops of lily of the valley oil or substances synthesized by us - isopentyl salicylate (isoamyl salicylate) or terpineol to the mixture.

A drop (literally) of methyl salicylate, cumin oil, and a little vanilla sugar enhance the flavor.

In conclusion, dissolve this mixture in 20 ml of pure (not denatured) alcohol or in last resort in an equal volume of vodka and our spirits will be ready. Although they have pleasant aroma, yet it is hardly worth wearing them, because it is difficult for them to compete with factory perfumes.

The reader can try to independently choose the composition of other perfumes, using the fragrant substances described above and obtained by him.

There are several ways to extract aromatic substances from plants, the main ones are described below. Some of them have been used since time immemorial, others are more modern and much more productive. However, strictly speaking, only those obtained by distillation or pressing can be called essential oils.

For essential oils, like wines, there are good and bad years, and like any crop, its quality reflects the characteristics of the soil. The therapeutic effect of the same oil may be weaker if it is extracted from a plant grown in poor soil. Some crops are harvested in the summer, such as lavender, while the jasmine flowers, from which the essential oil is made, are harvested at night, when their fragrance is strongest. Flower oils, such as those from jasmine or rose, require thousands of petals to make, since they contain only a small amount of oil. This is reflected in the price of such oils (they are the most expensive). Other oils, such as those based on tea tree or eucalyptus, both medicinal and refreshing, are produced in much greater quantities by evaporation from the leaves and sometimes from the stems of the plants. They, in turn, are less expensive.

Essential oils are clear, colorless or colored liquids. They are distinguished from vegetable oils by the property of volatility. Their density is usually less. They are practically insoluble in water, but readily soluble in alcohol and other organic liquids, as well as in fats, waxes and other oils. These properties are used in various methods for obtaining essential oils. Some parts of plants from which essential oils are derived, especially flowers, tend to lose quality quickly and should be used as soon as possible after harvest. Other parts, including roots and seeds, can be stored for a long time. They are transported to different parts of the world.

Each technology for the production of essential oil has secrets and features associated with the extraction of aroma from a particular plant and the purification of this aroma from hydrocarbons that have a free radical (deterpenization). Preference should be given to gentle methods, since essential oils are very "sensitive" and easily volatilize. With careless and improper handling, their quality noticeably deteriorates, therefore, careful observance of the technology is a necessary condition for obtaining essential oils.

Distillation (steam evaporation)

This is the most economical way to extract essential oils. Many historians attribute the discovery of distillation to the Persian physician and scientist Avicenna, who was mentioned in the first chapter. But there is an assumption that this process could be used in Ancient Egypt. Distillation must be carried out very carefully and correctly in order to avoid loss of valuable essential oils and possible changes in their chemical composition. Some plants are distilled immediately after harvest, others after several days. And some plants are first dried, and then the essential oil is extracted from them.

Plant mass (be it roots, petals, flowers) is placed in a container, then in water and heated, bringing to a boil, or exposed to steam under pressure. Heat and steam destroy the structure of plant cells, and the essential oil flows out of them, the oil particles and steam move through the tube to another container. There, the steam cools and turns into a liquid, which is a mixture of water and particles of essential oils contained in the plant mass. Water and essential oils are separated, essential oils are lighter than water, so they float, then they are collected. This is the most accepted distillation method for extracting aromatherapy oils, and purists believe that only an oil obtained in this way can be called an essential oil.

The water passing through the distilled plant is saturated with aromatic substance and reused, it can be used as an eau de toilette, like lavender or rose.

The first distillation gives the best quality. Re-distillation of the resulting oil is called rectification. Repeated and subsequent distillations produce cheap oils unsuitable for aromatherapy.

In this production technique, the selection of the optimal steam temperature is very important, since intensive heat treatment increases the yield of essential oil at the expense of its quality. That is why essential oils domestic production often do not match international standards.

Spin (pressing)

This method is used exclusively for citrus fruits: bergamot, grapefruit, lemon, real lime, tangerine, orange. Oil is secreted from small sacs located under the surface of the fruit. Initially, the oil was simply squeezed out, squeezing the fruit with your hands. The liquid was collected with a sponge and then squeezed into a glass. Indians, Chinese, Japanese do not disdain to work in such "old" ways. Why don't you squeeze the oil out of citrus fruit right in your kitchen?

However, given the labor costs, at present, citrus essential oil is extracted using special combines. A lot of orange essential oil is produced by fruit juice factories in the USA. This is not the best oil, because fruit growing uses pesticides and chemical fertilizers, and they can spoil the oil. The best aromatherapy oil is naturally grown fruit oil.

Unfortunately, some manufacturing factories citrus oils subjecting the pressed peel to distillation to effectively separate the oil. Obviously, such an essential oil will be of lower quality, but it is often added to the pressed oil to increase the yield of essential oil, and hence income.

Extraction from solution

Nowadays, chemical solvents are used in industries such as ethyl alcohol, petroleum ether, hexane, etc. In this method, heated solvents take oil from plant material, then the solvent is distilled off at low temperature, leaving only an odorous substance known as " flower mass. The extraction process from the solution does not produce essential oils. The resulting extract is called "concrete"; this thick waxy mass contains about 50% essential oil. This method is used for flowers, gums, resins and absolutes (thick highly concentrated liquids) and resinoids are obtained - fragrant extracts of resins.

If dry plants were subjected to extraction - resins, balsams, roots, seeds, moss, then the fragrant product remaining at the bottom of the vacuum is called a resinoid. It is a finished product for perfumery.

If flowers were subjected to extraction - violets, tuberoses, mimosa, roses, jasmine, this product is called concrete, and it is not the final product. The concretes are treated with alcohol to remove the wax, then the alcohol is removed.

The method is used to increase the yield or to obtain oils in the case when there are no other methods. However, jasmine, unlike other flowers, is processed hot water and ferry. This method is more suitable for the production of oils for perfumery, rather than aromatherapy. Absolute (absolu), although in small degree but always contains traces of solvent. Therefore, when using an essential oil for aromatherapy purposes, it must be carefully analyzed to prevent the presence of substances harmful to the body.

Absolutes

To obtain an absolute from aromatic plant material (flowers, leaves, etc.), hydrocarbon solvents are used - such as gasoline or hexane. The plant material is placed in a solvent and heated slowly to extract the aromatic molecules, which go into solution. The solution is then filtered to separate the concrete. Concrete is a hard, wax-like mass. It contains approximately 50% wax and 50% volatile essential oil such as jasmine.

To isolate the absolute from the wax-like mass of concrete, the latter is mixed with pure alcohol to dissolve the aromatic molecules, and then cool. The mixture is filtered to remove unwanted impurities and separate insoluble substances. Then, creating a vacuum, the alcohol is slowly evaporated. The result is a thick, sticky, colored liquid, which is called the absolute.

The described method is widely used for roses, jasmine, neroli. But, although to a small extent, traces of the solvent always remain. Therefore, the absolute will never have the purity that can be achieved by obtaining essential oils by distillation. Absolutes are expensive and are sometimes falsified. Purchase goods only from a reliable supplier.

Resinoids, fragrant resin extracts

The extraction of essential oils with solvents can be used for gums and resins in order to obtain fragrant extracts. At the site of damage to a tree or plant, a substance protrudes; when thickened, it becomes solid or plastic - this is the resin. For the needs of the production of resin is obtained by making cuts in the bark or trunk. The exposed resin hardens in air.

Natural fragrance resin extracts are obtained using hydrocarbon solvents such as petroleum ether*, hexane or alcohol. Solvents are removed by filtration followed by distillation. If a hydrocarbon solvent is used, the result is a resinoid, a fragrant resin extract (eg, benzoic resinoid). If the solvent was alcohol, then the absolute of the aromatic resin is obtained. For example, absolutes of aromatic resins of frankincense and myrrh can be extracted from resin - raw hardened plant juice that stands out on sections. However, both can be extracted by steam distillation, resulting in an essential oil.

Essential oils and scented extracts (resinoids) may contain small amounts of the solvent used in their extraction (eg ethyl alcohol). Resinoids are often used in the perfume industry to provide longevity.

Enfleurage (extraction of aromatic substances from flowers)

This method was used in ancient Egypt more than 5000 years ago. This ancient method, which allows you to get the absolute, and invented by our non-lazy ancestors, is used less and less, due to the significant duration and laboriousness, and hence the high cost. In our time of continuous commerce, they are mainly concerned not with quality, but with the cheapness of the cost of the product. Previously, the process was used to obtain fragrant extracts from delicate flowers such as jasmine, which continue to be fragrant even after they have been cut. The process uses purified cold fat odorless (pork or beef), applying it to sheets of glass in large rectangular wooden frames. The flowers are laid out on a layer of fat that absorbs the essential oil. About a day later, spent flowers are replaced with new ones. The process is repeated many times until the fat has absorbed enough essential oil. Fat rich in aromatic substance is called lipstick. Lipstick is dissolved in alcohol and then processed. The alcohol evaporates and a pure absolute is obtained.

Extraction with carbon dioxide

It's relative new way, it has been used only since the 80s of the XX century. The cost of the product is high due to the high cost of equipment. The process was developed for the perfume industry. The oils produced in this way are expected to be of high quality, purity and natural state, just like inside a living plant. And of course, they will be free of impurities and carbon dioxide.

The price of the currently available product is too high for an aromatherapist. However, as prices fall and production increases, the resulting oils will become more affordable. The new essential oils have a different chemical composition than those already used, and therefore more research will be needed to determine their therapeutic effects.

Hydrodiffusion/percolation

Hydrodiffusion, or percolation, is the most modern way to obtain an extract. The process is faster than distillation, and the equipment used is much simpler than carbon dioxide extraction. A scattered jet of steam (spray) is passed from top to bottom through the plant material placed on the grate. Then the resulting liquid, and it consists of a mixture of condensed vapor and essential oil, is cooled. As with distillation, essential oil and water can be easily separated from each other. Although this method is promising, research is still needed to determine the place of such oils in aromatherapy.

Maceration (soaking)

The maceration method is based on the dissolution of essential oils in vegetable fatty oils. The crushed plant (chamomile, yarrow, St. John's wort, calendula, etc.) is placed in a flask with warm vegetable oil, and kept in the light for seven days (the solution is shaken periodically), the cells with the aromatic substance are destroyed and the essential oil goes into solution. It is best to use a dried plant, which has less moisture. After filtering, the oil is poured into a tightly closed glass vessel and stored in a cold, dark place, it is ready for use for massage. This is how calendula, carrot, peach oils are obtained.

Why don't you make your own oil at home? Half fill glass jar selected plant material (for example, lemon balm). Add warm vegetable oil so that the jar is full. It will be very good to add a little (about 10 percent of the volume vegetable oil) common wheat oil to protect the entire mixture from spoilage. Close the jar with a lid and store for at least a week. Remember that the contents must be thoroughly shaken daily. Once the time has passed, filter the plant material, bottle and label.

Received different ways essential oils and their volatile functions are not exactly the same set of substances that are released by plants. This is due to the fact that under the action of, for example, hot steam, some constituents of the volatile components may change, volatilize. In addition, the source material for obtaining essential oil can be not only freshly cut, but in some cases also dried.

The big advantage is that the technologies for obtaining essential oils are quite simple and there is a raw material base for industrial essential oils. Essential oils can be quite easily obtained from waste accumulated during the harvesting of wood: spruce, pine, fir and trees of other species. And these wastes are huge. Research them component composition and standardization organizationally easily solvable.

The average yield of essential oil from 100 kg of vegetable raw materials is: eucalyptus - 3 kg, lavender - 2.9 kg, sage - 1.4 - 1.7 kg, chamomile - 0.7-1 kg, etc. To obtain 1 kg of rose essential oil, it is necessary to process 1-2 tons of plant petals, and only 50 g of essential oil is obtained from 100 kg of bitter orange flowers. The cost of an essential oil depends on the yield of oil per 1 kg of an ether-bearing plant. The lower the yield, the more expensive the essential oil, although there are exceptions.

Many fragrant oils formerly derived from flowers, such as carnation, gardenia, lily, are now produced almost entirely synthetically. In the pharmaceutical industry, these chemically synthesized products are referred to as "natural copies". Natural copies are not essential oils and cannot be used in aromatherapy.

It is believed that only natural oils (unrefined, undiluted) obtained directly from the distillation apparatus and having certificates of quality and compliance with international standards (ISO) have real and full aromatherapeutic properties.

The use of essential oils is quite common and has many followers. But it should be remembered that the quality of essential oils is an extremely important condition for the effectiveness and safety of aromatherapy. Only natural essential oils, unadulterated, undiluted and free of hazardous substances, have full volume medicinal properties and with proper use do not cause allergies and do not have a toxic effect.

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