RU2116313C1 - Method of preparing pectin and pectin-containing substances from beet pulp - Google Patents

Abstract

FIELD: chemical, food, pharmaceutical industry. SUBSTANCE: method involves preparing pulp, its hydrolysis, extraction and isolation pectins from extracts. Pulp is washed out with water, pressed out and dried at 120 C or below. Dried pulp is milled to meal and stored. Prepared meal is extracted with sulfurous acid hot solution at pH 3 or less. Extract is purified, evaporated and dried in sprayed state and pectin powder is obtained. Extracted pulp is subjected for additional extraction with alkali hot solution at pH 8-10 and this extract is kept at pH > 12 for 1-5 h, purified and treated with acid up to pH 6.5 or less at 70-100 C. Then precipitate is dried in sprayed state and pectic acids powder is obtained. Plant residue is washed out, pressed out and milled and beet food fibers are obtained. Except for, pectic acids precipitate (all or its part) is treated with ammonium concentrated solution and dried obtaining powder of pectic acid ammonium salts. EFFECT: improved method of preparing, increased quality, decreased cost. 2 cl, 1 tbl, 1 ex, 1 dwg

Description

 The invention relates to the chemical industry, namely to the production of plant material (beet pulp) pectin and pectin-containing substances that can be used in food, pharmaceutical and other industries.

 Known methods for producing pectin from plant materials by hydrolysis and extraction, followed by isolation of pectin from a solution using water-soluble organic solvents of alcohols or acetone (see book V. N. Golubev, N. P. Shelukhina. Pectin: Chemistry, technology of application, M Russian Academy of Technological Sciences, Institute of Human Ecology, 1995, pp. 200 - 203).

Closest to the proposed is a method for producing pectin from beet pulp (see the book L. V. Donchenko, N. S. Karpovich, E. G. Simkhovich "Production of pectin", edited by N. S. Karpovich, - Chisinau, 1994) . In this way, the pulp is processed, which has undergone high-temperature drying by flue gases at a temperature of more than 500 ^o C.

The method includes hydrolysis of the protopectin fraction and extraction of beet pectin from beet tissue, which is carried out at a hydrochloric acid concentration of 1-1.5%, a process hydromodule 1: (15-16), a hydrolysis temperature of the mixture of 75-76 ^o C for 2 hours After that, the pectin extract is filtered into an intermediate sump, where it is cooled. Hydrolyzed pulp is poured with water at a temperature of 65 - 70 ^o C and incubated for 40 minutes The resulting secondary extract is added to the main extract. Hydrolyzed pulp is desalinated with ammonia water and sent to livestock feed. Precipitation of pectin is carried out with aluminum chloride at a pH of 6 to 6.5. The neutralization of the pectin extract is carried out with a 25% solution of ammonium hydroxide. Pectin coagulum is squeezed in drainage "stands" and in hydraulic batch presses, crushed on a hammer mill and sent for cleaning.

 Pectin is purified by repeated washing with acidified ethyl alcohol, completing the washing process with pure alcohol with a strength of 70%. Then the pectin is separated from alcohol and dried in a vacuum dryer.

The prototype has the following disadvantages:
- high-temperature treatment of pulp reduces the quality of the obtained pectin;
- due to the fact that only the water-soluble part of pectin is extracted, the degree of utilization of beet pulp is not more than 15%;
- the use of toxic reagents - aluminum chloride, causes the need for multi-stage cleaning, reduces product quality and sanitary and hygienic working conditions;
- a large amount of alcohol is consumed, which causes the need for its regeneration, additional energy consumption and fire hazard.

 These shortcomings have now led to a halt in production by this method.

 The aim of the invention is to significantly increase the degree of utilization of valuable plant material (beet pulp) by in-depth comprehensive processing of it to obtain a set of valuable products, as well as improving the quality of these products and reducing their cost. In addition, the application of the method will reduce the seasonality of sugar factories.

This goal is achieved by the fact that the harvested beet pulp is washed with water, squeezed and dried at a temperature of ≤ 120 ^o C. Then the dry pulp is crushed into flour, which is prepared for further processing. The extraction of the prepared flour is carried out with a hot solution of sulphurous acid at pH ≤ 3. After that, the extract is purified, evaporated and dried in a sprayed state, to obtain pectin powder. The extracted pulp is subjected to additional extraction with a hot alkali solution at pH 8-10, and the extract is kept at pH> 12 for 1-5 hours, purified and then treated with acid and steam to pH ≤ 6.5 and a temperature of 70-100 ^° C. Precipitate separated and dried in a sprayed state, obtaining a powder of pectic acids. The plant residue is washed, squeezed, dried and ground to obtain pectin fibers.

 In addition, part of the precipitate of pectic acids is treated with a concentrated solution of ammonia, and then dried, obtaining a powder of ammonium salts of pectic acids.

 The technical result of the invention is that at moderate additional costs, using existing equipment, you can get a product - beet flour, which can then be processed almost completely during the off-season period, obtaining a set of valuable substances: pectin, pectic acids and dietary fiber.

 Figure 1 shows the technological scheme for producing pectin and pectin-containing substances from beet pulp according to the proposed method.

 The circuit includes a series-connected mixer 1, press 2, dryer 3, mill 4, extractor 5, centrifuge 6, extractor 7, centrifuge 8, filter press 9, mixer 10, separator 11, mixer 12, separator 13 and spray dryer 14.

 A section consisting of a filter press 15, a vacuum evaporation apparatus 16 and a spray dryer 17 is connected to the centrifuge 6. At the outlet of the mill 4, a store 18 for beet flour is installed.

 Example. During the sugar season, the prepared beet pulp was loaded from the diffuser into the mixer 1 and water was supplied for washing for 10 minutes. The water was separated from the pulp in a press 2, and the pulp was dried in a dryer 3 and crushed into flour in a mill 4. The flour was harvested in storage 18.

 After the end of the sugar season, beet flour from storage 18 was loaded into extractor 5, to which a solution of sulfuric acid was fed, adjusting the pH in the apparatus to a value of ≤ 3. Under these conditions, the flour was processed for one hour by hydrolysis and extraction of pectins. The resulting extract was separated from the precipitate in a centrifuge 6 and sent to a filter press 15, where it was thoroughly cleaned.

 Then the extract was sent to a vacuum evaporator 16 and evaporated to a solids concentration of 10%. After that, the pectin powder was dried in a sprayed state in the dryer 17.

 Beet cake from the centrifuge 6 was fed to the extractor 7 and treated with an alkali solution (NaOH) at pH 7.5-10.0 for 2 hours. The extract was separated from the cake in a centrifuge 8, purified in a filter press 9 and sent to a mixer 10 where alkali - sodium hydroxide was fed, the pH was adjusted to a value above 12 and kept in this state for 1 to 5 hours.

Then steam and sulfuric acid were supplied to the mixer 10, providing a pH <6.5 and a temperature of 70 - 90 ^° C. A precipitate of pectic acids precipitated, which were separated from the liquid in the separator 11, washed with water in the mixer 12 and again separated from it in separator 13, and then dried in a spray dryer 14, obtaining a powder of pectic acids having a high complexing ability.

 A part of the pectic acid powder was treated with ammonia in the presence of alcohol, dried and the resulting mass was ground. Ammonium salts of pectic acids were obtained.

 The plant residue from centrifuge 8 was returned to mixer 1, press 2, dryer 3 and mill 4 to obtain beet fiber using a technique similar to that for beet flour in the sugar season.

 The results of the experiments are shown in the table.

 From the examples it can be seen that from the beet pulp according to the proposed method, it is possible to obtain pectin powder with a high content of pectin, as well as pectic acids and beet fiber, reaching a high degree of utilization of the pulp.

Claims (2)

1. A method of producing pectin and pectin-containing substances from beet pulp, including the preparation of beet pulp, hydrolysis, extraction and isolation of pectins from extracts, characterized in that the beet pulp is washed with water, squeezed and dried at t ≤ 120 ^o C, then dried pulp is ground into flour , which is prepared for further processing, after the end of the sugar season, the prepared flour is extracted with a hot solution of sulphurous acid at pH ≤ 3, the obtained extract is purified, evaporated and dried in a sprayed state, according to irradiating pectin powder, and the extracted pulp is subjected to additional extraction with a hot alkali solution at pH 8-10 and the extract is kept at pH> 12 for 1-5 hours, purified and treated with acid and steam until pH ≤ 6.5 and a temperature of 70-100 ^o C, after which the precipitate formed is separated and dried in a sprayed state to obtain pectic acid powder, and the plant residue is washed, squeezed, dried and ground to obtain beet food substances.  2. The method according to claim 1, characterized in that the precipitate of pectic acids, all or part of it, is treated with a concentrated solution of ammonia, and then dried, obtaining a powder of ammonium salts of pectic acids.

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