METHODS OF DRYING MEDICINAL PLANT RAW MATERIALS

АННОТАЦИЯ

В данной статье исследуются изучение методов сушки лекарственных растений. Рассмотрены процессы сушки, а также сушка различных групп лекарственного сырья

ABSTRACT

This article explores the study of methods of drying medicinal plants. Drying processes, as well as drying of various groups of medicinal raw materials are considered.

Ключевые слова: гликозиды, полисахариды, сырье, корнеплоды, термообработка, лекарственная растения.

Keywords: glycosides, polysaccharides, raw materials, root crops, heat treatment, medicinal plants.

INTRODUCTION. The flora of Uzbekistan is extremely rich and diverse. Deserts and steppes, mountains and foothills, plains and river deltas coexist side by side and form an amazing landscape. This may seem incredible, but in reality, compared to the neighboring regions of Central Asia, the number of plants per unit area in the foothill and mountainous regions of Uzbekistan is many times greater.

In recent years, drying of medicinal plants has been developed especially intensively in the republic.

LITERATURE REVIEW. Drying can be considered as the simplest and most economical method of preserving medicinal raw materials, ensuring the safety of biologically active substances [3].

In freshly harvested vegetable raw materials, the water content is 60-80%. Removing moisture to only 20% already reduces the rate of biochemical reactions and enzyme activity, and with a moisture content of 10... 14%, the activity of enzymes completely stops, that is, intracellular processes leading to the decomposition of active substances stop. In addition, a decrease in moisture in the plant mass leads to a delay and cessation of the development of various mold fungi and microorganisms in it, which also reduce the quality of raw materials.

Most medicinal plants should be dried in the shade, because under the influence of direct sunlight they lose their natural color, and the active substances contained in them are destroyed [1].

In some cases, drying is preceded by drying of the collected raw materials. Sometimes this procedure helps to increase the content of active substances or speeds up the process of subsequent dehydration.

MATERIAL AND METHODS. Methods of drying medicinal plant raw materials are divided into two groups.

1. Without artificial heating:

- air-shade, carried out outdoors, but in the shade, under canopies, attics, in special drying sheds and air dryers;

- sunny, outdoors or in solar dryers.

2. With artificial heating or thermal. In experiments, the effectiveness of using microwave ovens for drying medicinal plant raw materials has been proven.

The duration of the drying process and the performance of drying plants are influenced by the morphological features of the raw material, its initial humidity, the total surface of the dried material, as well as humidity, temperature and speed of the coolant.

In farms, drying of raw materials is carried out in floor, convective, conveyor and other dryers of periodic and continuous operation under strictly regulated modes.

Currently, steam conveyor dryers (SPK-90, KSK-90) have become the most widespread in our country. They consist of a drying chamber, inside which mesh belts are arranged sequentially, one above the other, raw materials are moved from one belt to another [2,6].

Vitamin flour aggregates of various modifications (AVM-0.4, AVM-0.75, AVM-1.5) are also used for drying raw materials of medicinal crops. Before drying, the raw materials are crushed so that the particle size does not exceed 10 mm.

The most simple, versatile and require relatively low costs in the construction and operation of floor or frame dryers of active ventilation. Serial heat generators (TG-2,5, TG-3,5, TAU-0,25) or air heaters (VAC-400, VAC-600) are used as a coolant [4].

For drying medicinal plant raw materials, carousel dryers SCM-1 are used. They consist of a circular drying chamber with a diameter of 11 m rotating around a vertical axis. The chamber is equipped with systems for feeding, dosing and unloading dried raw materials [6].

The optimal drying mode is given in the instructions for harvesting and drying specific types of medicinal plant raw materials. The optimal drying regime should be based on experimental data on the effect of drying and its specific methods on the content of certain groups of biologically active substances.

During natural drying, the raw materials should be spread out in a thin layer on sieves or racks (with a distance of 40-60 cm) in well-ventilated areas protected from direct sunlight and moisture access (canopies, attics). For the first two days, the raw materials are periodically mixed [1].

The general rules of drying are as follows:

- raw materials containing essential oils are dried at a temperature no higher than 40°C with a fairly thick layer of 10-15 cm to prevent the evaporation of essential oil.

- raw materials containing glycosides, flavonoids, polysaccharides are dried at a temperature of 50-60°C. Raw materials containing glycosides should be dried as quickly as possible, this allows you to quickly inactivate enzymes that destroy glycosides.

- raw materials containing alkaloids are dried at a temperature of up to 50 ° C.

- raw materials containing vitamins and bitterness are dried at a temperature of 60-70 ° C.

- raw materials containing ascorbic acid are dried at a temperature of about 80°C.

With all drying methods, medicinal raw materials, with the exception of essential oil, are laid out in a thin layer and regularly turned over, while, however, they tend not to increase the degree of grinding.

Based on experimental studies, weight losses during drying were established for various morphological groups of medicinal raw materials: buds - 65-70%; flowers, buds - 70-80%; leaves - 55-90%; herbs - 65-90%; roots and rhizomes - 60-80%; bark - 50-70%; tubers - 50-70%; fruits - 30-60%; seeds - 20-40%.

Drying of various groups of medicinal raw materials has its own characteristics.

The kidneys are dried carefully, for a long time, in a cool place at a temperature no higher than 20 ° C, spreading a thin layer. During drying, the kidneys are often mixed in order to avoid their caking and mold formation, after which they are cleaned of impurities.

The bark is dried by heat drying, but drying is also allowed in the open air, in the sun. Pieces of bark (tubes, gutters) are laid out separately and periodically turned over.

Leaves with thin plates dry unevenly: after the leaf blades dry, the veins and petioles are still soft, so they are dried until the petioles become brittle. After drying, the leaves are not cleaned for several days - due to their high hygroscopicity, they are slightly moistened and crumble less during storage. Large leaves (mother and stepmother, datura, etc.) are laid out separately from each other when drying, when the upper part dries, they are turned over to the other side.

Flowers and inflorescences must be dried quickly, without access to sunlight with good ventilation, laying them out in a layer of 1 cm on grids, frames covered with gauze. The flowers and inflorescences are turned over and stirred carefully so that they do not crumble and crumple.

Grass can be dried like leaves and flowers.

Juicy fruits are cleaned of impurities before drying, spoiled and polluted are separated, dried in the open air, in the sun. After drying, the raw material must be kept indoors so that it absorbs moisture from the air and becomes air-dry, since in the oven or oven the raw material is often over-dried, and this is undesirable.

Dry fruits and seeds lose moisture before threshing and almost do not need drying. If necessary, they are dried outdoors or indoors.

The roots and rhizomes are cut lengthwise or crosswise into pieces before drying, the bark is removed from some plants (marshmallow, licorice). To preserve the healing substances, the roots and rhizomes are first dried in the open air, and then dried in the sun or in a dryer. Drying is optimal to start at a temperature of 30-40 ° C, and finish at 50-60 ° C. Under such conditions, uniform drying of all parts of the roots is ensured, their color is preserved, and decomposition of active substances is prevented. During the drying process, the roots are turned over several times a day. Small roots are dried whole without cutting.

Orchid root tubers are dipped into boiling water for a few minutes before drying to prevent their germination during storage, as well as to reduce the bitter taste [5].

CONCLUSION. The end of drying can be judged by the following signs: roots, rhizomes and bark do not bend when bent, but break with a bang; leaves and flowers are ground into powder; juicy fruits, squeezed in the hand, do not stick together into lumps and do not smear. The raw materials dried in this way are considered to be full-fledged, ready for storage and use.

Thus, the improvement of the technology of drying medicinal plant raw materials is very promising.

References:

1. Gorchakova N.K., Safronich L.N., Bobkova N.V. Medicinal plants and medicinal plant raw materials containing alkaloids (educational and methodical manual), M., "Russian doctor", 2000
2. Kuzmenko A.I., Pashkova E.B., Pirogov A.V. et al. The study of the composition of herbal medicinal collection by gas-liquid chromatography with chromato-mass spectrometric detection. Bulletin of the Moscow University. Series 2. Chemistry. - 2010. - vol.51. - No. 2. - pp. 132-138.
3. Lyagin JI.A. Comparative evaluation of the effectiveness of various methods of drying, medicinal raw materials /S. N. Lubatkin, L. A. lyagin // Vasilevskii read -2009 : proceedings of the international. nauch.-pract. Conf. — Saratov : Nauchnaya kniga, 2009. P. 296-297.
4. Ostrikov A. N. Processes and apparatuses of food production: textbook. for universities: in 2 books / A. N. Ostrikov, Yu. V. Krasovitsky, A. A. Shevtsov, etc. - St. Petersburg: GIORD, 2006. - Book 1.-632 p.
5. Pronchenko G.E., Rendyuk T.D., Markaryan A.A. Medicinal plants and medicinal plant raw materials. containing phenolic compounds (textbook), M., "Russian doctor", 2006, 158s.
6. Rybalko L.A. Combined method of drying medicinal raw materials / S.N. Lyubaykin, L.A. Rybalko // Young scientists agro-industrial complex of the Volga region. - Saratov: SSAU, 2003 - pp. 178-179.