RU2115335C1 - Method for production of pectin - Google Patents

Abstract

FIELD: production of pectin from vegetable raw materials. SUBSTANCE: method includes mixing of beet pulp and apple husks in ratio of 1:(1-9); addition of cellulose phosphate in the amount of 2-4 wt.%; swelling of raw material in mixture of ultrafiltrate with water in ratio of 1:(1-2) and water duty of 1:10 for 1.0-1.5 h. Whey with acidity of 290-300 deg T is heated up to temperature of 90-95 C, held at this temperature for 15-20 min, then cooled and filtered. Prepared whey is mixed with hydrochloric and acetic acids (with ratio of hydrochloric acid: acetic acid: lactic acid = 1: (0.220-0.660): (0.374-0.943) and pH is brought to 0.6-0.8. Hydrolysis of raw materials is carried out with a mixture of acids for 1.0-1.5 h at temperature of 77-77 C and water duty of 1:10. Hydrolyzate is separated, cellulose phosphate is introduced in the amount of 2-4 wt.% and held with stirring for 20-30 min. Cellulose phosphate is separated, cooled and neutralized with sodium carbonate to pH 2.2-2.4, and with use of sodium lactate pH is brought to 2.8-3.0. Hydrolyzate is concentrated by ultrafiltration to obtain content of pectin to 3.0-4.5 wt.%. Pectin is precipitated with 96% ethyl alcohol and with volumetric ratio of ethyl alcohol to concentrate of (1-1.5):1. Then cleaning and drying are carried out. EFFECT: increased jelly-forming ability of pectin, pectin purity and yield, reduced power consumption; and utilization of secondary products. 7 tbl

Description

 The invention relates to the food industry, namely to the production of pectin from plant materials used in food production and medicine.

 A known method of producing pectin, providing for the swelling of apple pomace in a solution of acetic acid with a pH of 4.0-4.5, hydrolysis with hydrochloric acid, separation of the hydrolyzate, cooling, neutralization, precipitation of pectin, its purification, drying, grinding (Aut. St. USSR N 1399303, class C 08 B 37/06, A 23 1/04, 1986).

 A significant disadvantage of this method is that hydrolysis uses a strong acid - hydrochloric acid, which does not allow the creation of sparing conditions for the methoxylated carboxyl groups of pectin, which negatively affects its gel-forming ability. In addition, the production of pectin from apple pomace is unprofitable due to the low content of pectin substances in raw materials (5-15%) and the imperfection of the technological process. The pectin obtained by this method has a low yield and low quality indicators, which necessitates blending it with citrus pectin to obtain confectionery products that meet the requirements of the standard.

 The closest to the invention in technical essence and the achieved result is a method for producing pectin, including the preparation of a blend of beet pulp and apple squeezes, swelling the mixture in an acidic aqueous solution, washing with water, hydrolysis with a mixture containing aqueous solutions of hydrochloric and acetic acids, separation of the hydrolyzate, its cooling and neutralization, precipitation of pectin with ethyl alcohol, its purification and drying (Aut. St. USSR N 1675303, class C 08 B 37/06, publ. 1991).

 The disadvantage of this method is that for the swelling of the blend mixture of raw materials, only an aqueous solution of acetic acid with a pH of 4.0-4.5 is used, which does not allow creating gentle conditions for the pectin molecule at the initial stage. This negatively affects the quality of the obtained pectin, its student-forming ability. In addition, expensive and scarce citric acid is used in the hydrolysing mixture of acids. Despite the fact that the hydrolysis mixture of acids contains acetic and citric acids, which can eliminate the disadvantages of the analogue method and create a more effective screening of the pectin molecule at the hydrolysis stage, however, in the next stage of neutralization of the pectin hydrolyzate to a pH of 2.2-2.4, mainly sodium carbonate binding of a strong acid - hydrochloric acid, while weak acid - acetic and citric acid remain in solution. Under the influence of these carboxylic acids and low pH in the pectin hydrolyzate, after 1.5 h of storage, pectin degrades due to cleavage of the molecular chain by glycosidic bonds and saponification of ether groups. This leads to the production of low quality pectin in terms of gel-forming ability and purity, while the yield of the final product also decreases.

 Thus, the known methods do not allow the creation of sparing conditions for the pectin molecule at all stages of its preparation. To solve these problems associated with identifying the optimal conditions for the production of pectin, with the aim of improving its quality for student-forming ability, purity and yield of the final product, this invention is directed.

In the proposed method for the production of pectin, including the preparation of a blend of beet pulp and apple squeezes, swelling the mixture in an acidic aqueous solution, washing with water, hydrolysis with a mixture containing aqueous solutions of hydrochloric and acetic acids, separating the hydrolyzate, cooling and neutralizing it, precipitating with ethanol p , its cleaning and drying, the difference is that the separated hydrolyzate is mixed with cellulose phosphate taken in an amount of 2-4 wt.% from the blend mixture before cooling, kept for 20-30 minutes, le cellulose phosphate which is separated, prior to deposition in the neutralized hydrolyzate add sodium lactate to pH 2,8-3,0 and concentrated by ultrafiltration to a content of pectin in the concentrate 3.9-4.5 wt. %, and the precipitation of pectin is carried out at a ratio of ethyl alcohol and concentrate (1-1.5): 1, v / v, while ultrafiltration and mixed with water are added to the aqueous solution for swelling of the blend mixture (1-2 ): 1, part by volume, ultrafiltrate, and processed milk whey with an acidity of 290-300 ^o T is additionally added to the hydrolysis mixture, while the mass ratio of hydrochloric, acetic and lactic acids contained in milk whey is 1: (0.220 -0.660) :( 0.374-0.943).

The use of whey as a source of lactic acid for the preparation of a hydrolyzing mixture allows the rational use of material resources through the disposal of secondary products of the dairy industry. Whey is one of the cheapest and most affordable types of acid-containing raw materials. High-acid whey is obtained by fermenting lactose with lactic acid bacteria (L. bulgaricus and L. acidophilus) at a temperature of 45-50 ^o C. The high fermentation temperature of the whey complicates the development of extraneous microflora, and in a short time (1-2 days) these microorganisms transfer up to 90 % lactose in lactic acid. The lactic acid contained in serum has no color, is more active in acidic properties and does not contain anhydrides. This provides not only a reduction in material costs for the production of pectin, but also improves the quality of the final product in terms of color, purity and student-forming ability.

When using whey to prepare a hydrolyzing mixture, not only lactic acid is added along with it, but also 0.8-1.0% protein, 0.4-0.8% minerals per 100 g of product. Serum proteins, being non-sugars, react with glucose and fructose to form dark-colored compounds, which reduce the quality of the resulting pectin. In addition, protein substances form insoluble complexes with mineral salts, especially calcium, which are deposited on the surface of heating apparatus, reducing the heat transfer rate and worsening the sanitary condition of the equipment. Serum proteins also form complexes with pectins, making it difficult for them to precipitate and dry. Therefore, whey is purified from minerals and nitrogen compounds, and especially from whey proteins. Heat treatment of whey allows you to clean it from the heat-sensitive fraction of whey proteins. To remove whey proteins and partially mineral substances, whey is heated to a temperature of 90-95 ^o C, maintained at this temperature for 20-25 minutes, cooled and filtered.

When the acidity of whey is 290-300 ^o T, the isoelectric point of whey proteins is reached, and at a temperature of 90-95 ^o C they are thermocoagulated. As an increase in the acidity of milk inversion above 300 ^o T, and a decrease in its acidity less than 290 ^o T degrades the degree of purification of it from whey proteins, as well as the content of lactic acid in it. In 100 g of whey with an acidity of 290-300 ^o T contains 2.6-2.7 g of lactic acid.

 The use of lactic acid contained in whey allows more selective hydrolysis and creates sparing conditions for the methoxyl and carboxyl groups of pectin molecules. This is due to the fact that lactic acid is slightly acidic, the degree of dissociation is 3.7%, which is more than half the degree of dissociation of citric acid (8.6%). Acetic acid is also slightly acidic, the degree of dissociation is 1.34%. Therefore, a mixture of carboxylic acids - acetic and lactic compared with acetic and citric - will give a larger amount of undissociated carboxyls to the hydrolysis medium, and with their increase, the efficiency of screening of the negative charges of the pectin molecule increases. The use of lactic acid in a mixture of acids for hydrolysis can improve the quality of the obtained pectin for gelatinous ability, purity and color.

 The ratio of hydrochloric, acetic and lactic acids in the hydrolysis mixture should be 1: (0.220-0.660) :( 0.374-0.943).

 If there is less than 0.220 part of acetic acid and more than 0.943 part of lactic acid in the ternary mixture of acids per part of hydrochloric acid, the quality of the obtained pectin in terms of gelding ability and purity decreases.

 If there is more than 0.660 parts of acetic acid and less than 0.374 parts of lactic acid in a ternary mixture of acids, one part of hydrochloric acid also reduces the quality of pectin by its gel-forming ability, while the yield of pectin decreases, which affects its cost.

 The introduction of cellulose phosphate into the pectin hydrolyzate in an amount of 2-4 wt.% And exposure for 20-30 minutes can improve the quality of the obtained pectin for gelatinous ability, color, purity and yield of the final product. This is due to the fact that cellulose phosphate is a multifunctional cation exchange resin and contains strongly and weakly acid groups. As a polymeric acid, cellulose phosphate ion-exchanges inorganic and organic cations in a pectin hydrolyzate to form the corresponding salts. During sorption of cations in cellulose phosphate, predominantly strongly acidic groups are involved in the reaction, since phosphoric acid released during the exchange inhibits the dissociation of the second, weakly acidic group. At the same time, the dissociation of lactic and acetic acids in the hydrolyzate is also suppressed. In addition, during the sorption of the pectin hydrolyzate, the methoxy groups of pectin are screened with cellulose phosphate together with undissociated carboxylic acids. This ensures the production of pectin with a high content of esterified groups and, as a result, high student-forming ability.

 The amount of cellulose phosphate introduced into the pectin hydrolyzate was determined experimentally. The quality of the obtained pectin after purification with cellulose phosphate was evaluated by gelation ability, pectin yield and purity. The experimental data are presented in table. one.

 As can be seen from the data table. 1, the introduction of cellulose phosphate into the hydrolyzate in an amount of less than 2 wt.% To the mass of raw materials does not provide an improvement in the quality of the obtained pectin. In all respects, it corresponds to pectin obtained by the prototype method (control). The optimal dosage of cellulose phosphate to the hydrolyzate in an amount of 2-4 wt.% To the mass of raw materials, while the resulting pectin has a gel-forming ability of 88-89 kPa, the yield is 86.8-89.0% and the purity is 85-86%. The introduction of cellulose phosphate into the hydrolyzate in an amount of more than 4 wt.% By weight of the raw material does not provide an improvement in the quality of the obtained pectin in terms of gel-forming ability, yield and purity; they remain at the level achieved at the optimal dosage.

 The process of sorption of cations in the pectin hydrolyzate occurs over time. Moreover, the degree of purification of the pectin solution depends not only on the amount of introduced cellulose phosphate, but also on the duration of its exposure to the hydrolyzate. The duration of sorption of the pectin hydrolyzate was determined by the quality of the obtained pectin, its purity. The experimental data are presented in table 2.

 As can be seen from the table. 2, the duration of sorption of pectin hydrolyzate by cellulose phosphate should be not less than 15 minutes, but not more than 25 minutes. When the cellulose phosphate is kept in the pectin hydrolyzate for less than 15 minutes, an insufficient degree of purification of the obtained pectin is observed, while the purity is 85-86%. It is impractical to increase the exposure time of the pectin hydrolyzate with cellulose phosphate for more than 25 minutes, since the pectin purity index remains at the level achieved with the optimal sorption duration. In addition, there is a decrease in the gelling ability of pectin.

 In the hydrolyzate, pectin is in a dissolved state. According to the modern classification, pectin solutions belong to homogeneous solutions having a number of colloid properties (pectin solutions diffuse slowly, do not penetrate through dialysis membranes, their particle sizes correspond to colloids), as well as specific properties, i.e. unlike colloids, they do not have an interface in solutions. Pectin solutions are most stable in the gel state, which proceeds at a pH of 2.8-3.2.

 The introduction of sodium lactate into the neutralized hydrolyzate and increasing its pH from 2.2-2.4 to 2.8-3.0 allows the pectin molecules to be in a buffer solution with a pH equal to their thermodynamic stability in a gel state. The formation of a stable environment for the pectin molecule is due to the fact that the introduced sodium lactate (sodium salt of lactic acid) is a weak base, which not only increases the pH of the medium, but also causes a buffering effect with the lactic acid contained in the solution. The resulting buffer mixture provides the pectin hydrolyzate with the ability to maintain a constant pH value and be slightly sensitive to dilution. The pH of the medium when adjusting the pectin hydrolyzate with sodium lactate was determined by the quality of the obtained pectin, its gelatinous ability and the yield of the final product. The experimental data are presented in table. 3.

 As can be seen from the table. 3, the optimum values for adjusting the pectin hydrolyzate with sodium lactate should be pH 2.8-3.0, while pectin with a gel-forming ability of 92-94 kPa and a yield of 89-90% is observed.

 Lowering the pH of the medium when bringing the pectin hydrolyzate with sodium lactate to a value of less than 2.8 does not allow to obtain pectin with a high gel-forming ability and yield, they remain at the level achieved by the prototype method (gel-forming ability of 75.0 kPa, pectin yield - 74%) . An increase in the pH of the medium when bringing the pectin hydrolyzate with sodium lactate to a value of more than 3.0 is also impractical, since there is a decrease in the quality of the obtained pectin by gelatin-forming ability (90 kPa) and yield (87%). A longer stay of pectin in such an environment leads to the saponification of methoxy groups, and then to the destruction of bonds in the macromolecule chain and its degradation.

 The presence of sodium lactate in the pectin hydrolyzate provides a decrease in the thickness of the diffusion layer and the potential value on the surface of the pectin molecule. This leads to a decrease in electrostatic repulsion forces and a decrease in the energy barrier for the association of pectin molecules. In the ultrafiltration process, the molecular sieve of the solvent from the pectin hydrolyzate occurs due to the pressure created on the solution, while the solvent passes through the membrane, and the pectin substances are retained. The advantage of ultrafiltration over other methods of concentration is the ability to conduct the process at low temperatures, which does not adversely affect the structure of pectin. Ultrafiltration of pectin hydrolyzate promotes the formation of ordered structures in pectin with the formation of intermolecular bonds, which increase the gelatin-forming ability of pectin.

 The optimal degree of pectin concentration by ultrafiltration was determined experimentally by the quality of the obtained pectin, its gel-forming ability. The experimental data are presented in table. 4.

 As can be seen from the table. 4, the best indicators of the gel-forming ability of pectin are observed during ultrafiltration of the pectin hydrolyzate to a content of 3.0-4.5 wt. % pectin in concentrate. When the pectin content in the concentrate is less than 3.0 wt.%, The high gel-forming ability in the obtained pectin is not provided. The increase in pectin in the concentrate is more than 4.5 wt. % is inexpedient, since the quality of the obtained pectin by its student-forming ability remains at the level achieved with the optimal degree of concentration. In addition, there is a sharp increase in the viscosity of pectin concentrate, which leads to significant energy costs for creating pressure on the solution.

 The final operation for fixing the native structure of pectin from the concentrate is precipitation with ethyl alcohol. The presence of a buffer mixture in the concentrate enhances the precipitating effect of alcohol on pectin. The alcohol added for precipitation interacts with water and removes solvate shells from pectin, while the proppant pressure decreases, which does not prevent the pectin particles from joining and coarsening. This provides an increase in the student-forming ability of pectin and the yield of the final product.

 The quality of the obtained pectin depends on the volume ratio of the concentrate and ethyl alcohol during precipitation.

 The optimal ratio of the volumes of alcohol and concentrate was determined experimentally by the quality of the obtained pectin, its gel-forming ability and yield. The experimental data are presented in table. 5.

 As can be seen from the table. 5, the ratio of the volumes of alcohol and concentrate for the precipitation of pectin should be equal to (1-1.5): 1, v / v, while there is an increase in the quality of pectin: gel-forming ability - 95-97 kPa and yield - 89-90%. It is undesirable to introduce less than one part of alcohol per one part of the concentrate to precipitate pectin, since there is a decrease in the yield of the final product (70%) and a deterioration in the gel-forming ability (82 kPa). To introduce one part of the concentrate more than one and a half parts of alcohol is impractical, since the obtained pectin has quality indicators - gel-forming ability and output at the level achieved at the optimum ratio.

 The resulting ultrafiltrate after concentration of pectin contains 3.5-4.0 wt. % solids, including sodium chloride, sodium lactate, lactic acid, acetic acid and other organic acids. The presence in the ultrafiltrate of a mixture of weak carboxylic acids, as well as their sodium salts, causes the formation of buffer media. Therefore, the use of ultrafiltrate for swelling a blend of raw materials allows the pectin molecules to be effectively screened from the very initial stages of pectin production and then to create mild, sparing conditions for the methoxyl and carboxyl groups of pectin at the hydrolysis stage. For swelling of the blend mixture of raw materials using a mixture of ultrafiltrate with water.

 The optimal ratio of ultrafiltrate with water for swelling of the blend mixture of raw materials was determined experimentally. The quality of the obtained pectin was evaluated by the student's forming ability and yield. The experimental data are presented in table. 6.

 As can be seen from the table. 6, for the swelling of the blend mixture of raw materials, it is necessary to mix ultrafiltrate with water in a ratio of 1: (1-2), while there is a high quality of the obtained pectin with a gel-forming ability of 98-100 kPa and a yield of 92-93%. When using a mixture for swelling of raw materials, in which 1 part of ultrafiltrate accounts for less than 1 part of water, a decrease in the quality of the obtained pectin is observed both in the gel-forming ability and in the yield of the final product. When using a mixture for swelling of raw materials, in which 1 part of ultrafiltrate accounts for more than 2 parts of water, a decrease in the quality of the obtained pectin by the gel-forming ability and the yield of the final product is also observed.

 The method is as follows. A blend mixture is prepared from beet pulp and apple pomace in the ratio (1-3) :( 9-7) and poured with an aqueous solution consisting of ultrafiltrate and water in the ratio 1: (1-2), part by volume, with a water module 1:10. The resulting mixture was stirred and kept to swell the raw material at room temperature for 1.0-1.5 hours. Then the mixture was filtered, the swollen raw material was washed twice with water and loaded into the hydrolyzer.

In parallel, whey proteins are purified from whey. Why milk whey with an acidity of 290-300 ^o T is heated to a temperature of 90-95 ^o C and incubated for 15-25 minutes for coagulation of whey proteins. After heat treatment, whey is cooled and filtered to separate whey proteins. Then an aqueous solution of a mixture of acids with a pH of 0.6-0.8 is prepared, for which purpose purified milk whey, aqueous solutions of 3% hydrochloric acid and 2% acetic acid are poured into the container, while the mass ratio of hydrochloric, acetic and lactic the acid contained in whey ranges from 1: (0.220-0.660) :( 0.374-0.943). The resulting aqueous solution of a mixture of acids is poured into the hydrolyzer.

The hydrolysis of the feed is carried out for 1.0-1.5 hours at a temperature of 75-77 ^o C and a hydraulic module of 1: 10. After separation, cellulose phosphate in an amount of 2-4 wt. % of the blending mixture and kept under stirring for 20-30 minutes, after which the cellulose phosphate is removed, and the hydrolyzate after cooling is neutralized with sodium carbonate to a pH of 2.2-2.4 and sodium lactate is added to a pH of 2.8-3.0 . Then the hydrolyzate is concentrated by ultrafiltration to a pectin content in the concentrate of 3.0-4.5 wt.%. Pectin is precipitated from the concentrate with ethanol of 96% concentration at a ratio of ethyl alcohol and concentrate (1.0-1.5): 1, vol. After twofold purification, the pectin coagulate is dried at a temperature of 60 ^o C to a moisture content of 8%, then crushed.

 The yield of pectin is 93% of the content of protopectin in beet pulp and apple pomace, purity 90%, gel-forming ability - 98 kPa.

 Example 1. Prepare a blend of 10 kg of beet pulp and 90 kg of apple pomace (in a ratio of 1: 9) and fill it with 1000 kg of an aqueous solution consisting of 500 kg of ultrafiltrate and 500 kg of water (in a ratio of 1: 1, vol.h .), with a hydraulic module 1:10. The resulting mixture was stirred and allowed to swell the raw material at room temperature for 1.0 hour. Then the mixture was filtered, the swollen raw material was washed twice with water and loaded into a hydrolyzer.

In parallel, whey proteins are purified from whey. Why milk whey with an acidity of 290 ^o T is heated to a temperature of 95 ^o C and incubated for 15 minutes to coagulate whey proteins. After heat treatment, whey is cooled and filtered to separate whey proteins. Then, an aqueous solution of a mixture of acids with a pH of 0.6 is prepared, for which purified milk whey, aqueous solutions of 3% hydrochloric acid and 2% acetic acid are poured into the container, while the mass ratio of hydrochloric, acetic and lactic acids contained in whey ranges from 1: 0.660: 0.374. The resulting aqueous solution of a mixture of acids is poured into the hydrolyzer.

The hydrolysis of the feed is carried out for 1.0 h at a temperature of 75 ^o C and a water module of 1.10. After separation, 4 kg of cellulose phosphate is introduced into the hydrolyzate (4% by weight of the blend) and is kept under stirring for 30 minutes, after which the cellulose phosphate is removed and the hydrolyzate is neutralized after cooling with sodium carbonate to pH 2.2 and lactate is added. sodium to a pH of 2.8. Then the hydrolyzate is concentrated by ultrafiltration to a pectin content in a concentrate of 3.0 wt. % Pectin is precipitated from the concentrate with ethanol of 96% concentration at a ratio of ethyl alcohol and concentrate of 1: 1, vol. h. After twofold purification, the pectin coagulate is dried at a temperature of 60 ^o C to a moisture content of 8%, then crushed.

 The yield of pectin is 93% of the content of protopectin in beet pulp and apple pomace, purity 90%, gel-forming ability - 98 kPa.

 Example 2. Prepare a blend of 15 kg of beet pulp and 85 kg of apple pomace (in the ratio of 1.5: 8.5) and fill it with 1000 kg of an aqueous solution consisting of 400 kg of ultrafiltrate and 600 kg of water (in the ratio of 1: 1 , 5, vol.h), with a hydraulic module 1:10. The resulting mixture was stirred and allowed to swell the raw material at room temperature for 1.25 hours. Then the mixture was filtered, the swollen raw material was washed twice with water and loaded into a hydrolyzer.

In parallel, whey proteins are purified from whey. Why milk whey with an acidity of 295 ^o T is heated to a temperature of 93 ^o C and incubated for 20 minutes to coagulate whey proteins. After heat treatment, whey is cooled and filtered to separate whey proteins. Then an aqueous solution of a mixture of acids with a pH of 0.7 is prepared, for which purified milk whey, aqueous solutions of 3% hydrochloric acid and 2% acetic acid are poured into the container, while the mass ratio of hydrochloric, acetic and lactic acids contained in whey ranges from 1: 0.440: 0.658. The resulting aqueous solution of a mixture of acids is poured into the hydrolyzer.

The hydrolysis of the feed is carried out for 1.25 hours at a temperature of 76 ^o C and a hydraulic module of 1: 10. After separation, cellulose phosphate in the amount of 3 kg (3 wt.% From the blend mixture) is introduced into the hydrolyzate and kept under stirring for 25 minutes, after whereupon the cellulose phosphate is removed and the hydrolyzate after cooling is neutralized with sodium carbonate to a pH of 2.3 and sodium lactate is added to a pH of 2.9. The hydrolyzate is then concentrated by ultrafiltration to a pectin content of 3.75 wt.% In a concentrate. Pectin is precipitated from the concentrate with ethanol of 95% concentration at a ratio of ethyl alcohol and concentrate of 1.25: 1, vol. After twofold purification, the pectin coagulate is dried at a temperature of 60 ^o C to a moisture content of 8%, then crushed.

 The yield of pectin is 92% of the content of protopectin in beet pulp and apple pomace, purity 90.5%, gel-forming ability - 99 kPa.

 Example 3. Prepare a blend of 30 kg of beet pulp and 70 kg of apple pomace (in a ratio of 3: 7) and fill it with 1000 kg of an aqueous solution consisting of 333 kg of ultrafiltrate and 667 kg of water in a ratio of 1: 2, vol.h. , with a hydraulic module 1:10. The resulting mixture was stirred and allowed to swell the raw material at room temperature for 1.5 hours. Then the mixture was filtered, the swollen raw material was washed twice with water and loaded into the hydrolyzer.

In parallel, whey proteins are purified from whey. Why milk whey with an acidity of 300 ^o T is heated to a temperature of 90 ^o C and incubated for 25 minutes to coagulate whey proteins. After heat treatment, whey is cooled and filtered to separate whey proteins. Then an aqueous solution of a mixture of acids with a pH of 0.8 is prepared, for which purpose purified milk whey, aqueous solutions of 3% hydrochloric acid and 2% acetic acid are poured into the container, while the mass ratio of hydrochloric, acetic and lactic acids contained in whey ranges from 1: 0.220: 0.943. The resulting aqueous solution of a mixture of acids is poured into the hydrolyzer.

The hydrolysis of the feed is carried out for 1.0 h at a temperature of 77 ^o C and a water module of 1: 10. After separation, cellulose phosphate is introduced into the hydrolyzate in an amount of 2 kg (2 wt.% Of the blend mixture) and is kept under stirring for 20 minutes, after whereupon the cellulose phosphate is removed and the hydrolyzate after cooling is neutralized with sodium carbonate to a pH of 2.4 and sodium lactate is added to a pH of 3.0. Then the hydrolyzate is concentrated by ultrafiltration to a pectin content in the concentrate of 4.5 wt.%. Pectin is precipitated from the concentrate with ethanol of 95% concentration at a ratio of ethyl alcohol and concentrate of 1.5: 1, vol. h. After twofold purification, the pectin coagulate is dried at a temperature of 60 ^o C to a moisture content of 8%, then crushed.

 The yield of pectin is 92.5% of the content of protopectin in beet pulp and apple pomace, purity 90.5%, gel-forming ability - 100 kPa.

 From the data table. 7 shows that a distinctive feature of the pectin obtained by the proposed method are higher quality indicators for student-forming ability, purity and yield of the final product. The resulting pectin contains a smaller amount of free carboxyl groups and acetyl groups with a higher degree of esterification and is purified from organic and inorganic impurities. This allows us to recommend the obtained pectin as an effective enterosorbent for use in therapeutic nutrition.

Claims (1)

A method of producing pectin, including the preparation of a blend of beet pulp and apple pomace, swelling of the mixture in an acidic aqueous solution, washing with water, hydrolysis with a mixture containing aqueous solutions of hydrochloric and acetic acids, separation of the hydrolyzate, its cooling and neutralization, precipitation of pectin with ethanol, it cleaning and drying, characterized in that the separated hydrolyzate is mixed with cellulose phosphate taken in an amount of 2 to 4 wt.% of the blend mixture before cooling, incubated for 20 to 30 minutes, after which methylcelluloses separated before precipitation neutralized hydrolyzate add sodium lactate to pH 2.8 - 3.0 and concentrated by ultrafiltration to its content of pectin in concentrate 3.0 - 4.5 wt. %, and the precipitation of pectin is carried out at a ratio of ethyl alcohol and concentrate (1 - 1.5): 1 part by volume, while ultrafiltration and mixed with water in the ratio (1 - 2) are added to the aqueous solution for swelling of the blend mixture : 1 vol. ultrafiltrate, and processed milk whey with an acidity of 290 - 300 ^o T is additionally added to the hydrolysis mixture, while the ratio of hydrochloric, acetic acids and lactic acid contained in milk whey is in the mixture 1: (0.220 - 0.660): (0.374 - 0.943) parts by weight

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