Drying of medicinal raw materials.dry yield factors
Jun 09, 2018
fresh form of medicinal raw materials is rarely used. To obtain juices, fresh leaves of aloe, plantain of large and some other plants are used. They are recycled immediately after collection.
Basically, medicinal plants are dried, they remain physiological in the dry state for a long time. In a living plant, active substances are accompanied by enzymes - biological catalysts of protein nature, which are separated from each other. A living cell has the ability to retain enzymes, but when wilted, they cause the cleavage of biologically active substances into simpler organic compounds. That's why you need to dry medicinal raw materials immediately after collection and quickly. When water is removed from the cells, the enzymatic processes cease. If the curative substances of medicinal raw materials do not change when heated above 60-70 ° C, drying is carried out at this temperature. Dried thus dried medicinal raw material usually does not lose its properties, even during brief dampening during storage. If the medicinal raw material is dried at a lower temperature, then during dehydration, the action of the enzymes resumes, and its activity decreases.
Sometimes counted on the action of enzymes, if the active on the body are not the primary substances of living plants, but the products of their splitting. Then dried medicinal raw materials not immediately, but after wilting it. This is the case, for example, with the preparation of valerian.
The optimum drying temperature is different and depends on the chemical composition of the raw material and some properties of the biologically active substances.
The raw material containing essential oils is dried slowly, spreading it in a thick layer, at a temperature of 25-30 °.At the same time, the formation of the essential oil continues, and in the dried raw material it will be greater than in the fresh plant. Birch buds, collected with branches, are dried outdoors or in well-ventilated cold rooms, as they can dissolve in the warmth.
The raw material containing glycosides and alkaloids is dried at 50-60 °, part of the nightshade plants containing alkaloidhisciamine( belladonna, henbane, dope, etc.) - at 40 °, since at a higher temperature this alkaloid passes into atropine, whichacts 2 times weaker. Leaves of bearberry and cowberry can be dried at a higher temperature, because the glycoside arbutin contained in them can withstand heating to 150 °.Rapid high-temperature drying of this raw material prevents the oxidation of tannins and, in connection with this, a change in the color of the raw materials.
Raw materials - containing vitamins, especially vitamin C, are dried quickly at 80-100 ° to avoid oxidation of ascorbic acid. But this temperature regime is not always applicable. So, for example, in fruits of black currant, in addition to vitamin C, there is an essential oil, so they are dried at 50-60 °.
Drying characteristics are given when describing individual species, but there are general rules.
Before drying, the raw material is sorted by removing accidentally fallen parts of other plants or the same plant that are not provided for the billet( for example, leaves in flowering material, insect damaged parts, browned, etc.).
Dry raw materials using natural and artificial heat. Natural drying is done outdoors, in good weather, in the wind. At night, the raw materials are transferred to a room or under a canopy. In closed premises it is better to dry in an attic under an iron roof or in a ventilated shed. The room should be equipped with racks with sliding frames, covered with gauze or net. You can dry the raw materials on gauze hammocks, hanging them between the rafters, making struts of thin wooden slats or narrow strips of plywood that are nailed from two hundred
ron at a distance of 80-100 cm. With this drying, raw materials are ventilated not only from above and from the side, but alsobelow, why drying is faster.
Medicinal raw materials are laid out on shelves or hammocks in a thin layer and periodically turned over.
Raw materials in need of high temperature, dried in dryers, and in the absence of them - in a Russian oven or on it. The furnace should not be very hot, otherwise the raw material will burn. When drying in the oven, the damper should be ajar. Drying raw materials, especially berries, can also be done in the oven of the gas stove, and the flame of the gas burner should be minimal, and the door of the cabinet is ajar. With larger blanks, vegetable dehumidifiers are used.
Leaves, flowers and grasses are dried, protecting them from sunlight, so that leaves do not yellow, flowers do not burn out, do not lose their natural color. However, in good sunny weather, you can dry the flowers of a cornflower while preserving their natural color. Slow drying them in the shade leads to the discoloration of many flowers.
Fruits, seeds and many underground organs can be dried in the sun.
Kidneys of plants dry in a well ventilated room, scattering them with a thin layer and often mixing or not removing from the branches. In a warm room they start to blossom.
The bark is dried in good weather outdoors or in a well-ventilated room. Correctly dried bark becomes brittle.
Leaves are dried in lofts or in a ventilated room, spread out in 2-3 layers and often inverted. Leaves with thin leaf blades dry unevenly. First, dry leaf blades become, and veins and petioles remain soft. Dry them until they become brittle. After drying, the leaves are raked into a pile and left for a few days. Due to their hygroscopicity, they attract moisture from the air and are less crumbled when packed.
Flowers are laid out in a thinner layer, so as not to turn over during drying. You can stir up the baskets of Compositae( tansy, chamomile, arnica, etc.).
Herbs are dried in the same way as the leaves. In well-dried grass, not only the leaves, but also the stems should break, and not bend.
You can dry the grass by tying them into small bundles and hanging them on the ropes.
Dry fruits and seeds lose moisture even before threshing, so they do not have to be dried. If necessary, they are dried in the air or indoors. Juicy fruits are dried before sunbathing and dried at 70-90 ° C in ovens or dryers, well-dried fruits do not stain hands and do not stick together in compression.
Roots and rhizomes that do not contain essential oils can be dried in the sun. Flavoring rhizomes of calamus, valerian are dried in the shade or in a well-ventilated room. In bad weather, this raw material is dried at elevated temperature or in ventilated premises. This drying, thick roots and rhizomes are cut into parts along, and long across to pieces, a very thick circleWhen drying whole roots, use a low temperature to allow the internal parts to dry out. Dry roots and rhizomes must break down
Recently, many harvesting stations accept from collectors not only dry but also raw raw materials. In this case, it is dried using specialdryers of various designs. To determine the mass of dry raw materials, use the output coefficients. Recreasing the mass of raw raw materials by a factor, you get a lot of dry raw materials.