ESSENTIAL OIL PLANTS
Despite the sharp increase in the production of synthetic fragrant substances widely used in various industries in recent years, natural essential oils have not lost their significance. They are still widely used in perfumery, medicine, food, and flavoring industries.
A particularly large amount of natural essential oils is consumed in the production of toothpaste, tooth powder, powder, cologne, perfumes, and other similar products.
The liquor industry also widely uses natural essential oils for the preparation of liqueurs, wines, and tinctures. The fish canning industry also relies on essential oils.
Essential oils are widely used in the confectionery, baking, dairy, and other industries.
Naturally, the demand for essential oils increases every year.
In the USSR, more than 1500 hectares are used annually for the cultivation of essential oil plants. However, despite this, the demand for essential oils is not fully met, although the Soviet Union holds a leading position in the world in the production of coriander and sage oils. The USSR accounts for 90% of the world's coriander oil production, 75% of sage oil, and over 60% of rose oil.
In total, our country produces more than 1000 tons of essential oils from forty different species. Nevertheless, the demand for them, as mentioned, is still very high. This is why studying essential oil plants in nature, identifying the conditions under which they accumulate the most essential oils, and developing scientific foundations for their rational use is currently a relevant issue.
It should be noted that currently, only about 90 species of essential oil plants have been studied in detail, while only about 30 species are used in industry. In nature, there are over 1500 species of such plants.
In Kyrgyzstan alone, there are more than 100 species. It should also be noted that more than 50% of the world's essential oil plants are concentrated in the tropics and subtropics. In the temperate zone, there are almost half as many. Therefore, to eliminate the import of essential oils from other countries, it is necessary to study domestic essential oil plants and develop industrial production based on them.
The fact that Kyrgyzstan is rich in essential oil plants is facilitated by the overall ecological conditions favorable for their growth and development. Furthermore, the abundance of essential oil plant species in Kyrgyzstan is due to the unique situation of flora genesis.
Our research on the flora and vegetation of Kyrgyzstan shows that essential oil plants belong to the following families: Lamiaceae — 60 species, Asteraceae — 25 species, Apiaceae — 10 species, Cupressaceae — 4 species, Rosaceae — 2 species, Brassicaceae — 1 species, Myriapodaceae — 1 species, Rutaceae — 1 species.
Thus, the largest number of essential oil plant species belongs to the Lamiaceae family.
At the same time, not all species of this family growing in Kyrgyzstan have been studied for their essential oil content. Further study of them will undoubtedly increase the number of essential oil plant species not only in the Lamiaceae family but also in other families.
It is necessary to note that essential oil plants in Kyrgyzstan, with few exceptions, are almost not used at all. It is essential to utilize plant resources more widely for the needs of our country, especially now, when more products of high quality are being produced. When using essential oils, it should be remembered that in various phases of development, a plant can produce essential oils that differ in composition. This phenomenon is characteristic of species in the Apiaceae family, as well as some species from the Lamiaceae family, such as mint, among others. Below is a description of several essential oil plants of Kyrgyzstan.
Artemisia santolina. Widely distributed in almost all regions of Kyrgyzstan. It is even considered a weedy species. It is found in steppes and meadow-steppes, on rocky slopes.
Externally, it appears as a semi-shrub up to 80 cm tall with a thick woody root. The stems are numerous, branched, with brown-gray bark at the base; the herbaceous shoots have a brownish-purple hue. The leaves are dark green, twice or thrice pinnately dissected. The flower heads are located on short branches in paniculate or racemose inflorescences.
It contains up to 2.288% of yellow essential oil in air-dry grass. When cooled to -10°C, the oil begins to crystallize.
Artemisia late. A grayish semi-shrub up to 65 cm tall. The root is taproot, powerful, woody.
The stems are woody at the base and herbaceous at the top, with tufts of leaves. In spring and early summer, the stems are hairy; by the end of summer, they are bare with a straw-brown hue. The leaves are twice pinnately dissected. The flowers are yellow or red. The flower heads are collected in a broad panicle.
It is widely distributed in the Chui Valley, on the foothills of the northern slope of the Kyrgyz Ala-Too, in Ketmen-Tube, along the slope of the Chatkal Range, in the Fergana Valley, and in other places.
The yield of essential oil from late Artemisia is 0.4% (L. I. Popova and T. A. Proskurnikova), and in the vicinity of Frunze city — 0.9%.
The oil is light yellow.
The oil can be used in perfumery for soap making and in the liqueur industry.
Artemisia ferghana. A grayish semi-shrub with a thick woody root. The stems reach up to 70 cm in height, branched at the top. The leaves are twice pinnately dissected. The flowers are yellow in oval-elongated flower heads. The overall inflorescence is a sprawling panicle. It blooms in September and bears fruit in October.
It grows on clay-stony foothills and in valleys in the Chatkal and Fergana ranges and in the Fergana Valley.
It contains essential oil, the yield of which (according to L. I. Popova and T. A. Proskurnikova) from air-dry material is 0.762% in the budding phase. The oil contains pinene, myrcene, and other substances. It can serve as raw material for extracting camphor.
Artemisia annua. A weedy green plant with a pleasant smell of ripe apples. The stem is 15—150 cm tall, green or reddish. The leaves are light green, twice or thrice pinnately dissected. The flower heads are collected in a paniculate inflorescence. It blooms in July — August and bears fruit in August — September. It grows in gardens and vegetable gardens, in fields, in squares and parks, throughout the agricultural zone of Kyrgyzstan. Near ditches and in fields, it forms thickets.
According to M. I. Goryaev, the essential oil content is 0.06—0.04%; light yellow with a greenish tint, with a pleasant smell. The oil is used in soap making.
The raw material reserves of Artemisia annua are enormous. In Kyrgyzstan, it is possible to organize the production of essential oils from this species for the perfumery and chemical-pharmaceutical industries.
Overall, in the conditions of Kyrgyzstan, Artemisia forms valuable raw material resources for the perfumery and pharmaceutical industries. They can also be used for obtaining camphor.
Ziziphora clinopodioides. A low branching semi-shrub up to 40 cm tall. The leaves are broadly elliptical. The flowers are light lilac, collected in head-like inflorescences. It blooms in June and bears fruit in July — August.
Ziziphora is widely distributed in Kyrgyzstan, but does not form dense thickets. It is found in small patches or as single specimens on rocky-stony slopes of mountains, in the Central Tien Shan, on the ridges of Terkey Ala-Too, Kunghey Ala-Too, and along the northern slopes of Kyrgyz Ala-Too.
Ziziphora contains a large amount of essential oil. During the flowering of the plant, it is mowed and used in its entirety for processing.
The oil from the flowering grass is a yellow liquid with a smell reminiscent of heart mint oil. The yield from the plant is 0.49—0.71%.
The oil is mainly used for flavoring tooth powders.
Ziziphora bungei. A fragrant perennial plant up to 12—30 cm tall. The stems are numerous, almost erect. The leaves are narrow-lanceolate, and the flowers are pink. The inflorescences at the top of the stems are head-like. It blooms from June to August and bears fruit in August — September.
It is abundant in the Central Tien Shan (Jumgal, Kochkor Valley), the basin of Lake Issyk-Kul, the basins of the Big and Small Kemin rivers, and in southern Kyrgyzstan — in the Chatkal and Fergana ranges. In Ziziphora bungei, the highest amount of oil is observed in the phase of full flowering — up to 2.49%.
Ziziphora bungei in fresh form has a pleasant smell and a pungent taste. The essential oil is produced in the glands of the leaf, on the calyx, and in the parenchyma cells of the leaf. When dried, the oil does not change color. The smell and taste are well preserved in the dry material. The weight loss during drying is 50—60%. In Kyrgyzstan, this Ziziphora forms significant raw material reserves.
Thyme, or Thymus (in Kyrgyz, kekemeren). This is another important essential oil plant. In the USSR, 136 species grow, six of which are found in Kyrgyzstan. All species of this genus growing in Kyrgyzstan contain essential oils.
The highest amount of essential oils is observed during flowering, and it is during this time that the plant should be harvested. For harvesting, the above-ground mass is cut, dried to an air-dry state, and sent for processing. The shrinkage can be up to 70%.
Thyme essential oil is mainly used for obtaining thymol.
The yield of essential oil ranges from 0.1 to 0.6% of air-dry material.
Thyme essential oil contains 51.7% thymol.
Different species of thyme have oils with different scents. The essential oil has a lemony, thyme-like, and other smells. The oil is used in the perfumery, soap-making, liquor, and confectionery industries.
Thymus marschallii. A perennial plant with a woody stem at the base. The stems are raised at the base. The plant reaches 12—37 cm in height. The leaves are sessile, elongated-elliptical. The flowers are pale lilac and small. The inflorescences are up to 15 cm long. It blooms in May — June and bears fruit in August.
It grows in the foothills among meadow-steppes, meadows, in forest clearings, and in juniper groves in the Kyrgyz Ridge, in the basin of Lake Issyk-Kul, in the basins of the Big and Small Kemin rivers, in the Chui Valley, and Terkey Ala-Too. It contains essential oil.
Oregano (Origanum vulgare). A perennial plant widely distributed in meadows, forests, forest clearings, and meadow-steppes. The stems are up to 60 cm tall, erect. The leaves are opposite and elongated. The flowers are pinkish-lilac or lilac-rosy, collected in a corymbose panicle. It blooms in June — July and bears fruit in August — September.
It grows in almost all regions of Kyrgyzstan.
It is an excellent honey plant, medicinal, vitamin-rich, and essential oil plant. In oregano, as well as in marjoram, the essential oil content ranges from 0.3 to 0.57%.
Valuable essential oil plants include catnip. In the USSR, there are 82 species of catnip; 18 of them grow in Kyrgyzstan. All of them contain essential oils.
In some catnip species (Bukhara, cat, and footed), there is very little essential oil. Since catnip is widely distributed in Kyrgyzstan and creates large raw material reserves, it should also be used for obtaining essential oils.
Catnip (Nepeta cataria). A large perennial plant up to 120 cm tall. The stems are four-sided. The leaves are elongated-ovate, elongated-elliptical. The flowers are pale violet, pink, and white. The inflorescences are arranged in spaced semi-umbels at the ends of the stems. It blooms from June to August and bears fruit in August — September.
It grows in tall grass meadows, meadow-steppes, forest clearings, and even in steppes.
It is widespread in all regions of Kyrgyzstan.
Perovskia abrotanoides. It grows as a semi-shrub up to 1 m tall. The stem branches significantly at the top and forms a panicle. The leaves are twice pinnately dissected, elongated-ovate, covered with hairs and glands. The flowers are bright violet. The inflorescence is up to 40 cm long. It blooms in June — August and bears fruit in August.
It grows along dry gravel riverbeds, in rocky-stony places in the Central Tien Shan, especially in the Jumgal Valley, in the basin of Lake Issyk-Kul, on the northern slope of the Chatkal Range.
The above-ground part (in vegetative shoots) contains essential oil. In the flowering phase, the oil content in the leafy parts of the shoots is lower. It is even lower in the inflorescences, which may be explained by the quantitative difference in glands on the leaf and calyx.
The yield of essential oil is 2.5% on absolutely dry weight. The oil obtained from Perovskia abrotanoides is used for extracting camphor and for technical purposes.
Perovskia abrotanoides is very decorative and can be used in artificial plantings in the gardens and parks of Central Asia.
Perovskia angustifolia. It grows as a semi-shrub over 1 m tall. The leaves are broad-lanceolate, serrated at the edges, bare, green with glands, and wedge-shaped at the base, elongated into a petiole. The inflorescence is up to 30 cm long, loose. The flowers are purple, on hairy pedicels. It blooms in June — July and bears fruit in August.
It grows along dry riverbeds, in rocky-stony places, in the foothills of the Fergana Range (the basin of the Kutart River) and in the Chatkal Range.
Perovskia angustifolia contains essential oil. The yield of the latter is 0.62%. The oil is colorless and contains almost the same components as the oil from Perovskia atriplicifolia.
This species of Perovskia is very beautiful; it can be used not only as an essential oil plant but also as an ornamental plant.
The essential oils of Perovskia have a large sesquiterpene fraction (20—25%), containing azulene-forming sesquiterpenes, so they can be used for the industrial production of azulenes. Perovskia is of interest for obtaining camphor. Therefore, it is recommended to introduce it into cultivation.
Among essential oil plants, there are many Ferulas. When using them, it should be remembered that most of them have immense anti-erosion significance. Ferulas should be used in such a way as not to disrupt the natural biocomplex.
Ferula kugitanskaya (Ieshke). A powerful perennial plant up to 180 cm tall. The stem is thick, reddish-brown, wrapped at the base with remnants of leaves, branching at the top into a broadly oval panicle. The leaves are soft, quickly wilting, thrice dissected, with terminal lobes elongated — up to 15 cm long and 5 cm wide.
The umbels are different; the central ones are sessile, the lateral ones are sterile. The flowers are yellow. It blooms in May — June and bears fruit in July.
It grows on grassy gravel slopes and river terraces in the mid-mountain and subalpine zones of the Internal Tien Shan, in the basin of Lake Issyk-Kul, along the northern slope of the Kyrgyz Ala-Too.
Essential oil is contained in the roots and fruits of Ferula. In the extract from the fruits, the oil yield is 3.5% and 19% of dark yellow resin. The yield of essential oil from fresh root weight ranges from 0.425 to 0.714%. The yield of oil from the resin is 11.7%. The oil is light green, with a peculiar strong smell; it can be used as a source for obtaining pure α-pinene, which has wide applications in the chemical and paint industries.
Ferula pseudo-oreoselinum. A perennial plant with a single stem, up to 2—3 m tall, purple-brown. At the top, the stem branches into a shield-like panicle. The leaves are soft, green on top, bare, pale underneath, slightly hairy; the basal leaves are on long thick petioles, dissected. The stem leaves are reduced to membranous sheaths. The umbels are different: the central ones have 8—20 rays and the lateral ones. The umbels have 15 flowers. The flowers are yellow. It blooms in July and bears fruit in July. It grows in the forests and shrubs of the Chatkal Range. It is endemic. The large roots contain 2—5% of essential oil. From the hardened milky juice of the roots, resin is obtained, which is used in medicine.
Thus, both species of Ferula contain valuable resins and essential oils, which are used in medicine, perfumery, and the paint industry.
Ferula is abundantly found over significant areas and forms large raw material reserves, so it deserves the utmost attention as a raw material for obtaining essential oils.
Juniperus semiglobosa or Juniper. The branches and berry cones contain 0.64—1.6% essential oil. The oil is yellowish, with a strong persistent smell, easily separable from water. It is used to produce coniferous essence and for flavoring toilet soaps. The bark and berries are used for tanning and dyeing.
Juniperus turkestanicus. It grows as a tree up to 18 m tall and as a shrub in the subalpine zone. The bark is brownish-gray. The crown is usually dense, broadly conical, with lower branches spreading along the ground. The leaves are scale-like, fleshy.
The berry cones are fleshy, soft, and sweet, black, shiny, spherical or elongated. The seed is single, large, up to 9 mm long.
It grows in the subalpine zone on rocky-stony slopes, where it develops as a low shrub.
Lower down, in the forest zone, it forms juniper forests, sometimes mixed with other species of juniper and deciduous trees.
It is widely distributed in Chatkal, the Fergana Range, Alai, as well as in the Central Tien Shan, Kyrgyz Ridge, and Talas.
Fresh foliage contains 0.73—0.87%, while the berry cones contain 1.19—1.32% essential oil, which is light yellow. The oil predominately contains pinene (71%), cendrol (up to 12%), and some other products.
The oil is used as a wound healer. Interestingly, the yield of oil from the cushion-like shrub form of juniper is lower than from the tree form. The oil of this juniper species has healing properties and is used in medicine.
Juniperus zaravshanicus. A small tree 5—10 m tall with reddish peeling bark. The crown is dense and rounded. The leaves are scale-like. The berry cones are large, 8—12 mm in diameter, spherical, dark burgundy, almost black with a light bloom, fleshy, resinous, and multi-seeded.
It grows on rocky, gravelly slopes up to 2500 m above sea level. It sometimes forms pure juniper forests, more often mixed forests in the Central Tien Shan (western part), Fergana, Alai, and Turkestan ranges.
In fresh green twigs, it contains 0.45—0.75% essential oil, in which pinene predominates — 79%, myrcene — 6%, cendrol — 6%.
For harvesting raw materials, it is advisable to take short branches of juniper, no more than 50 cm long. In this case, the tree is less damaged. Juniper requires particularly careful exploitation due to its slow growth.
The essential oil composition includes: 76—79% α-pinene, about 5% myrcene, 6—7% cendrol. During drying, the oil losses are small. The weight loss of green branches during drying is 52%. Therefore, it is possible to organize the harvesting of raw materials in summer and process it in winter.
The oil of Zaravshan juniper in the USSR is used to produce immersion oil, which is widely used in microscopy. The oil has bactericidal properties and is used in medicine.
Juniper is an economically important tree species. It can serve as a source of oils containing cendrol, pinene, sabinene, and myrcene. It provides valuable wood, which is an excellent building and craft material, as well as good pencil wood.
Essential oils of juniper are used for preparing spicy and pickled fish, liqueurs, and distilled products.
The berry cones of juniper are included in the recipes for making tinctures "Juniper" and "Mountain Dubnyak," among others.
The aroma and taste of the tinctures are determined by the essential oils contained in the juniper berries.
Essential oils of juniper are one of the components for flavoring export tobacco "Dunza." They are also used in technology and optics.
The raw material base of juniper in the republic is enormous. The area of juniper forests and shrubs reaches approximately 563,000 hectares.
The exploitation of these natural resources should be rational and should not harm the natural complex.
It should be noted that on dry, grassy slopes, juniper shows particularly slow growth, while on more humid northern slopes, the growth of juniper improves.
In addition to wild-growing plants, Kyrgyzstan also has cultivated essential oil plants. These include nutmeg sage, peppermint, coriander, ajwain, common fennel, medicinal hyssop, lemon balm, Moldavian dragonhead, Canadian small-leaved, and many others.
Among food flavorings, dill occupies a primary place.
Nutmeg sage. It is not only cultivated but also widely distributed in the so-called savanna-like steppes of Kyrgyzstan, preferring rocky slopes and elevations.
It is mainly sown in the collective farms of the Chui Valley. The raw material is processed at the "Efironos" factory.
Annually, about 2.5 thousand tons of inflorescences are harvested, and more than 4 tons of essential oil are extracted.
In the USSR, 78 species of sage grow, but only 2 are used: nutmeg sage and medicinal sage.
Currently, many cultivated varieties have been developed. This biennial plant has large leaves and a panicle of two-lipped whitish-lilac flowers. The flowering stems of sage contain 0.11—0.18% essential oils. However, the amount of oils fluctuates throughout the day. At night, it reaches 0.24%, while during the day, it is only 0.12%.
Peppermint. It does not occur in the wild. This is a cultivated perennial plant up to 80 cm tall. The leaves are elongated-ovate. The flowers are pale lilac, collected in false whorls, forming spike-like inflorescences. There are many varieties.
The essential oil has a pleasant smell and is widely used in medicine and the perfumery industry.
Coriander. Coriander is not only cultivated as an essential oil plant, but it also goes wild and grows as a weed in fields and gardens, near dwellings.
In the USSR, up to 700 tons of essential oil are obtained from coriander annually.
This annual plant reaches 50—90 cm in height with pinnately dissected leaves. The flowers are pink, white, and purple, collected in a complex umbel.
The yield of essential oil fluctuates significantly from 0.174 to 0.325%. The oil is used for confectionery products, in perfumery, and in soap making.
In conclusion, it should be emphasized once again that essential oil plants are of great importance in the national economy. Natural essential oils are used in perfumery and pharmaceuticals, the fish and canning industries, in confectionery, baking, dairy, liquor, and tobacco production, as well as in technology and optics.