RU2381245C1 - Method of production of concentrated colouring agent - Google Patents

Abstract

FIELD: food industry.

SUBSTANCE: method involves cleaning the vegetable raw material, extracting it with 0.1 hydrochloric acid solution, filtration, sorption by means of sorbent with clay content of 10% minimum. After sorption the sorbent with anthocyanins from the mother solution is centrifugally separated, the mother solution is removed and the following desorption is performed with a solvent which is 1% hydrochloric acid solution in ethanol centrifugally separating re-extract from the sorbent.

EFFECT: invention enables to simplify the method, improve the target product quality and increase storage stability.

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Description

The invention relates to methods for producing concentrated dye from plant materials, in particular anthocyanin.

The invention can be used in the food and medical industries.

The role of anthocyanins as medicinal substances has long been recognized by medicine all over the world [L.A. Deineka, A.A. Shaposhnikov, V.I. Deineka, V.N. Sorokopudov. “Anthocyanins: natural dyes and not only” // Scientific statements of BelSU. A series of medicine and pharmacy. No. 3, issue 4, p. 92-100].

When anthocyanins are extracted from plant materials, a number of concomitant extractive substances are released along with anthocyanins: proteins, carbohydrates, tannins, lipids, and others, which reduce the quality and shelf life of crude anthocyanins and products with anthocyanin dyes.

The known "Method for the isolation of biologically active anthocyanins" according to the patent of the Russian Federation No. 2302423, published June 10, 2007. According to this method, anthocyanins are isolated from an aqueous-alcoholic extract of red grape cake and sorbed anthocyanins on talcum powder, followed by elution with an aqueous-alcoholic solution. In this case, the effect of purification of anthocyanins is achieved. The disadvantages of this method are the low sorption activity of talc in relation to anthocyanins, and the concentration of anthocyanin dye does not occur.

The closest in technical solution is the "Method for the production of flavonoid dye from plant materials" according to the patent of the Russian Federation No. 2134280, published August 10, 1999. According to this method, plant materials are extracted with hot water, sorption of coloring substances with an inorganic sorbent at a ratio of solid and liquid phases of 1 : 18 to 1: 100 in a continuous stream at 70-80 ° C. Then, desorption is carried out in a continuous countercurrent with an alcoholic solution of citric acid with a mass fraction of 5-10% at 80-85 ° C. As the sorbent, active alumina is used - aluminum grade A-I gel. The resulting secondary extract was concentrated in vacuo. The disadvantage of this method is that sorption and desorption are carried out at high temperatures, i.e. technology is energy intensive.

The objective of the present invention is to develop a method for deep purification of anthocyanin dyes isolated from plant materials, with simultaneous concentration, using a simple and reliable technology.

The technical effect that allows us to solve the problem is to simplify the method of obtaining concentrated dye, improving the quality of the finished product and its shelf life.

The problem is solved by the proposed method for producing concentrated dye, including: purification of plant materials, extraction, filtration, sorption and subsequent desorption, characterized in that the extraction is carried out by 0.1 N. hydrochloric acid solution, and a sorbent with a clay content of at least 10% is used for sorption, moreover, after sorption, the sorbent with anthocyanins is separated from the mother liquor by centrifugation, and the mother liquor is removed, subsequent desorption is carried out with a solvent - 1% hydrochloric acid in ethanol with separation of the extract from sorbent by centrifugation.

To obtain a dry concentrate of anthocyanin dyes, the solvent is removed by any known method.

The advantages of the proposed method are that they simultaneously purify and concentrate the anthocyanin dyes using cheap and technologically advanced sorbents, significantly reduce energy consumption, and the resulting dyes practically do not contain any accompanying extractive substances. Due to the use of hydrochloric acid in the extraction and desorption processes, the maximum extraction of anthocyanin dyes from any plant (natural) raw material occurs.

Anthocyanin dyes obtained from blackcurrant and blackberry berries can be characterized by the following indicators.

Indicators Blackcurrant dye Blackberry dye Appearance Syrupy liquid Thick liquid Color Dark red Red purple Smell Specific, blackcurrant aroma is felt. Specific, blackberry aroma is felt.

20-40 ml of the obtained extracts were added to the bottles with mineral water "May Crystal", "Fertile Spring" and others (0.5 l). In this case, complete dissolution of the dyes in water was observed. The resulting solutions were transparent, without precipitate and without turbidity, which positively characterizes the dyes.

When untreated anthocyanin dyes were used for tinting mineral waters after 14-20 days, mold appeared on the surface of mineral water tinted with anthocyanin dye. When using purified anthocyanin dyes for tinting mineral waters, mold was not observed even after storage for more than 6 months.

Thus, natural anthocyanin dyes obtained from blackcurrant, blackberry and other plant materials can be used for tinting mineral waters. [L. A. Deineka, I. I. Saenko, E. I. Shaposhnik, O. P. Syrtseva, V. I. Deineka. “Using Natural Anthocyanins for Tinting Mineral Waters”, Materials of the International Scientific and Technical Conference “Innovative Technologies for Processing Agricultural Raw Materials in Ensuring the Quality of Life: Science, Education, Production”, Voronezh, October 1-4, 2008]

The method is implemented as follows: 300 g of fresh or freshly frozen berries or waste after allocation of juice pour 300 ml of 0.1 N. hydrochloric acid solution, stirred using a mixer until smooth. The resulting mass is maintained as long as the color of the solution does not match the color of the crushed plant material. Then the mixture is filtered through a paper filter. To the filtrate add 10 g of sorbent (for example, any clay), mix for 10-15 minutes and centrifuged. The solution over the sorbent in the test tubes is drained and, without removing the sorbent from the test tube, a 1% solution of conc. HCl in ethanol. Separate the reextract from the sorbent by centrifugation.

The content of extractives is determined by the gravimetric method.

Example 1

Obtaining anthocyanin dye from frozen blackcurrant berries

300 g of frozen blackcurrant berries are poured into 300 ml of 0.1 N. hydrochloric acid solution and stirred using a mixer until smooth. The resulting mass can withstand 60 minutes, during which time the color of the solution is equal to the color of plant materials. Then the mixture is filtered through a paper filter. 300 ml of crude anthocyanin extract are obtained.

10 g of clay (producer of Stimul-color cosmetics LLC, St. Petersburg) is added to the filtrate and incubated for 15 minutes with periodic stirring.

The sorbent with anthocyanins is separated from the mother liquor by centrifugation for 10 minutes at a speed of 5000 rpm. The mother liquor is removed. To reextract the dye, 100 ml of reextractant (99 ml of ethanol and 1 ml of concentrated hydrochloric acid) are added to the sorbent, mix well and centrifuged again under the same conditions.

The re-extract is drained and repeated re-extraction is performed. The first reextract contains 51.0% anthocyanins in relation to the initial solution of anthocyanins. During the second reextraction (already used for the second and fifth reextractions, already 50 ml of the reextracting agent) another 26.2% of anthocyanins passes into the solution with respect to the initial concentration. In the third reextraction, another 7.3% of anthocyanins passes into the solution, in the fourth - another 7.3% of anthocyanins, and in the fifth - 2.1%.

Thus, during five consecutive reextractions, 94.0% of anthocyanins from the initial content pass into the solution. If we restrict ourselves to three cycles of reextraction, 84.6% of anthocyanins from the initial content will pass into the solution.

The mass of 1 ml of dry residue after purification amounted to 0.0090 g in the first reextract, 0.0038 g in the second, and 0.0022 g in the third. The mass of extract prior to purification was 0.0422 g. Thus, the dry matter mass decreased in the first reextract by 79.7%, in the second by 91.0%, and in the third by 94.8%.

Example 2

Obtaining anthocyanin dye from frozen blackberries

300 g of frozen blackberries are poured into 300 ml of 0.1 N. hydrochloric acid solution and stirred using a mixer until smooth. The resulting mass can withstand 60 minutes, during which time the color of the solution is equal to the color of plant materials. Then the mixture is filtered through a paper filter. 350 ml of crude anthocyanin extract are obtained.

10 g of clay (producer of Stimul-color cosmetics LLC, St. Petersburg) is added to the filtrate and incubated for 15 minutes with periodic stirring.

The sorbent with anthocyanins is separated from the mother liquor by centrifugation for 10 minutes at a speed of 5000 rpm. The mother liquor is removed. To reextract the dye, 100 ml of reextractant (99 ml of ethanol and 1 ml of concentrated hydrochloric acid) are added to the sorbent, mix well and centrifuged again under the same conditions. The re-extract is drained and repeated re-extraction is performed. The first reextract contains 67.1% of anthocyanins with respect to the initial solution of anthocyanins. During the second re-extraction (already 50 ml of the re-extractant are used for the second and fifth re-extraction), another 16.4% of anthocyanins passes into the solution with respect to the initial concentration. Thus, during five consecutive extractions, 83.5% of anthocyanins from the initial content pass into the solution.

The mass of 1 ml of dry residue after purification in the first reextract was 0.0051 g. The mass of 1 ml of extract before purification was 0.0222 g. Thus, the mass of dry residue decreased by 78%.

Claims (1)

A method of obtaining a concentrated dye, including purification of plant materials, extraction, filtration, sorption and subsequent desorption, characterized in that the extraction is carried out 0.1 N. hydrochloric acid solution, and for sorption using a sorbent with a clay content of at least 10%, and after sorption, the sorbent with anthocyanins is separated from the mother liquor by centrifugation, and the mother liquor is removed, subsequent desorption is carried out with a solvent - 1% hydrochloric acid in ethanol with separation reextract from the sorbent by centrifugation.