RU2323765C2 - Process to manufacture extracts from plant raw materials - Google Patents

Abstract

FIELD: CHEMISTRY.

SUBSTANCE: crushed plant raw material with addition of ethanol modifier is extracted in two stages. At the first stage, supercritical carbon dioxide is used, which results in carbon dioxide extract further dissolved in ethanol by bubbling the extraction agent at atmospheric pressure. At the second stage, solvent cake is extracted with ethanol solution, which results in ethanolic extract.

EFFECT: invention increases grade of extraction of biologically active substances.

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Description

The invention relates to a technology for the extraction of plant materials by gases in a supercritical state and can be used in chemical-pharmaceutical, food, perfumery and cosmetic and other industries for the production of various aromatic and essential oil additives and drugs.

Known methods for extracting plant materials, which include contacting with a gas stream in a supercritical state, adding modifiers to control the polarity of the extractant, isolating extractives by lowering temperature and pressure, and passing the extract stream through a gas-dynamic ultrasound system (see Supercritical fluid chromatography / Ed. R. Smith, Moscow: Mir, 1991, p. 246 and RF Patent No. 2031103 of 10/20/92. // Bull. Image No. 8 of 03/20/95).

The disadvantages of these methods are the difficulty of implementation and the low reliability of the separation of extractives from the gas phase of the extractant.

There is also known a method of processing wax, in which the extraction is carried out in two stages, in the first stage with liquefied carbon dioxide with the release of carbon dioxide extract, in the second stage, the carbon dioxide extract is treated with alcohol and an alcohol extract is obtained from which alcohol-soluble and insoluble parts are isolated.

The disadvantage of this method is the partial loss of useful biologically active components during separation in the first stage of extraction, as well as losses with post-extraction meal, which is not used in the process.

Closest to the proposed invention in terms of essential features is a method of complex processing of spicy aromatic raw materials, including two-stage extraction of crushed raw materials in the first stage with liquefied carbon dioxide with the release of carbon dioxide extract and dissolving it in alcohol, and at the second stage, extraction with 40-96% ethyl alcohol at 20-40 ° C post-extraction meal with the release of an alcohol extract containing various biologically active substances.

The disadvantage of this method is the low degree of extraction of volatile biologically active components in the first stage of extraction.

The objective of the invention is to increase the degree of extraction of volatile biologically active components.

This problem is solved due to the fact that in the method of producing extracts from plant materials, which consists in the fact that the crushed raw materials are subjected to two-stage extraction, in the first stage - liquefied carbon dioxide with the release of carbon dioxide extract and dissolution of the latter in ethanol, and in the second stage after extraction the meal is extracted with ethyl alcohol with the release of the alcohol extract, and the extraction in the first stage is carried out with carbon dioxide in a supercritical state, in a crushed vegetable Ethyl alcohol is added as a modifier before extraction, and the carbon dioxide extract is isolated and dissolved in alcohol by sparging the extractant at atmospheric pressure.

When solving this problem, a technical result is created, which consists in the fact that it becomes possible to extract more volatile biologically active substances by increasing the dissolving ability of carbon dioxide in the supercritical state, and adding a small amount of modifier alcohol to plant materials increases the degree of extraction of extractive substances for by changing the polarity of the extractant. In addition, the loss of extractive substances with a gas phase is reduced, since the bubbling method is used to isolate and dissolve the carbon dioxide extract in alcohol at low (atmospheric) extractant pressure.

Examples of specific performance of the method

The extraction of plant materials in the first stage was carried out with carbon dioxide. Crushed plant material in an amount of about 10 g was placed in a thermostatically controlled extractor, the inlet and outlet of which were connected using shut-off valves to a thermostatically controlled carbon dioxide cylinder and to two Rychter bubblers in series with alcohol. The extraction time is selected 90 minutes. In front of the bubblers, a pneumatic resistance was installed, made in the form of a segment of a capillary, which ensured a decrease in the pressure of the extractant and a setting of its flow rate through the bubblers in the range of 10–40 cm ³ / min to extract the carbon dioxide extract after extraction.

The final solution of extractive substances in alcohol after the first stage of extraction was obtained by mixing solutions of two bubblers.

In the second stage of extraction, the post-extraction meal was extracted with 70% ethyl alcohol at 25 ° C for one hour.

The first stage of extraction in the known method was carried out with liquefied carbon dioxide at a pressure in the extractor P = 7.5 MPa and a temperature T = 15 ° C, and in the proposed method used carbon dioxide in a supercritical state with parameters in the extractor P = 10.0 MPa and T = 50 ° C and the addition of alcohol as a modifier to the plant material before extraction. The increase in carbon dioxide pressure in the cylinder was provided by raising the temperature of the thermostat.

The amount of volatile components of the extractives in the alcohol solution after the first extraction stage was controlled by gas chromatography using a Crystal 2000M chromatograph with a flame ionization detector and a column with a non-polar stationary phase (Apieson L) with linear programming of the column temperature from 50 to 150 ° C at a rate of 5 ° C / min. From the obtained chromatograms, the total content of volatile components was determined using an external standard (a solution of butanol-1 in ethanol) and the fraction of volatile (in the temperature range of the column from 50 to 80 ° C) components in the total amount of volatile substances.

The amount of extractives after the second extraction stage was determined by the gravimetric method.

Example 1

10.2 g of the crushed medicinal plant, eucalyptus rod-like (Eucalyptus Viminalis L.) was subjected to extraction in a known manner. After the first stage of extraction in a solution of ethyl alcohol, 2.4% (0.24 g) of carbon dioxide extract was found, the fraction of volatile components being 31%.

According to the proposed method, when extracting 9.8 g of raw material with 15 wt.% Modifier, 5.3% (0.52 g) of the extract was obtained, and the proportion of volatile components was 72%.

The amount of modifier alcohol is selected for each specific medicinal plant according to the criterion of maximum extract yield. So, with an increase in the amount of modifier alcohol to 20 wt.%, Instead of 5.3% of the extract, 5.305% is obtained, i.e. almost the same value. Thus, a further increase in the amount of modifier in this example is not advisable.

At the second stage of extraction, the yield of extractives is 9.8% of the feedstock.

Example 2

After the first stage of extraction in a known manner, from 10.1 g of crushed herbs of Melissa officinalis (Melissa officinalis L.), 1.81% (0.18 g) of the extract was obtained, the fraction of volatile components being 91%.

The proposed method with the addition of 5 wt.% Modifier to the feedstock in an amount of 10.3 g provided after the first extraction 3.8% (0.39 g) of extractives, and the proportion of volatile components was 98.2%.

If instead of 5 wt.% Modifier to use 10 wt.% To the feedstock, the amount of extractives increases by only 0.1%, therefore, to increase the amount of modifier alcohol in this example is not necessary.

At the second stage of extraction, the yield of extractives to the feedstock was 9.8%, similarly to example 1.

From a comparison of the obtained results of examples 1 and 2 it is seen that the proposed method for producing extracts from plant materials allows for more efficient use of plant materials. So, the amount of volatiles isolated from rod eucalyptus increases compared with the known method 2.2 times, and isolated from Melissa officinalis 2.1 times.

Using the proposed method will increase the degree of extraction of volatile biologically active components to obtain additional aromatic and essential oil extracts, which can be used both in the form of various additives and compositions, and individually.

Claims (1)

A method of obtaining extracts from plant materials, in which the crushed raw materials are subjected to two-stage extraction, in the first stage - liquefied carbon dioxide with the release of carbon dioxide extract and dissolution of the latter in ethyl alcohol, and in the second stage - post-extraction meal is extracted with ethyl alcohol with the release of alcohol extract, characterized in that the extraction at the first stage is carried out with carbon dioxide in a supercritical state, ethyl is added to the crushed plant material before extraction alcohol, and the carbon dioxide extract is isolated and dissolved in alcohol by sparging the extractant at atmospheric pressure.