RU2486258C1 - Method of obtaining collagen dissolution products - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: in order to obtain quality collagen dissolution products, rawhide is treated with a solution in form of a lactic acid composition having titratable acidity of 250-300°T, concentration of lactic acid of at least 25-30 g/dm³ and medium active response of not more than 4.0. The process is carried out at temperature of 24±2°C, float ratio=1 and alternating mechanical action. Dissolution has duration of 11-13 days. At the end of dissolution, the samples are almost transparent, loose, swollen pieces of skin which easily break up under slight mechanical action.

EFFECT: improved properties of the product.

3 tbl, 3 ex

Description

The invention relates to light industry and can be used to obtain collagen dissolution products based on waste leather production and substandard leather raw materials.

A known method of producing collagen from animal guts, which consists in the fact that the starting material is mixed with ice water at pH 5.5, the mixture is ground and then heated to 40-42 ° C and hydrolyzed at pH 10.5 using a proteolytic enzyme. At the end of hydrolysis, the pH is reduced to 5.5, the collagen is separated and collected (see patent RU No. 2094999, IPC A22C 13/00, C07K 1/36, publ. 10.11.1997).

The disadvantage of this method is that this method uses expensive proteolytic enzymes, as well as the fact that at elevated processing temperatures, thermal hydrolysis of peptide bonds occurs, which reduces the content of high molecular weight compounds.

A known method for producing collagen related to medicine and biochemistry, in particular to preparative methods for producing collagen. The method involves obtaining collagen from biological material by mechanical grinding, treatment with an alkali solution, washing with water, dissolving in acetic acid, followed by isolation of the target product and grinding of the biological material into pieces from 0.5 to 1.0 cm ² , processing 10-20 % alkali solution for 1 h, and after dissolving in acetic acid, collagen is rinsed with constant stirring in acetone (see patent RU No. 23222249, IPC A61K 35/32, A61K 35/36, A61K 38/39, published on 04/20/2008 g.).

The disadvantage of this method is the use as a solvent of aggressive and flammable chemicals.

The closest in technical essence and the achieved result to the proposed invention is a method for producing collagen sol, which consists in sequential processing of collagen-containing raw materials with an alkaline-salt mixture, salt washing with sodium sulfate, neutralization, repeated washing with running water, dissolution in organic acid, dialysis and re-dissolution ( see patent RU No. 2031597, IPC A23J 1/10, С09Н 1/00, С14С 1/08, publ. 03/27/1995).

The disadvantage of this method is the use of organic acids in high concentrations, and therefore, the relatively high cost of wastewater treatment, a significant destruction of peptide bonds, which leads to a decrease in the molecular weight of the resulting product.

The problem to be solved in the present invention is to develop a technology for producing collagen dissolution products using a fermented milk composition with the exclusion of aggressive acids, in particular acetic, sulfuric, etc. from the working bath.

The technical result of the invention is to obtain a quality collagen dissolution product.

The technical result is achieved by the fact that in the method for producing collagen dissolution products, including grinding and washing collagen-containing raw materials, its alkaline salt treatment, salt washing with sodium sulfate, neutralization, repeated washing of the product and its dissolution in an acid agent, according to the invention, when dissolved as an acid agent is a lactic acid composition having titratable acidity value of 250-300 ° T, lactic acid concentration of at least 25-30 g / dm ³ and the pH of the active reaction medium n more than 4.0, wherein the treatment is carried out at a temperature of 24 ± 2 ° C, LC = 1 and variable mechanical action, duration of dissolution within 11-13 days.

A distinctive feature of the proposed method for producing collagen dissolution products is its dissolution in a fermented milk composition having a high titratable acidity of 250-300 ° T, which allows to obtain a high-quality product with high molecular weights, having good colloid-chemical properties, due to the preservation of a significant amount of collagen in the structure polypeptide groups.

The choice of parameters for the dissolution of collagen is due to experimental studies, which revealed that the optimal dissolution of collagen fibers of the dermis due to the destruction of acid-labile bonds is achieved if the fermented milk composition has a titratable acidity of 250-300 ° T and an active medium pH of not more than 4 , 0. The decrease in titratable acidity to 200 ° T or more does not give a positive result due to the insufficient content of lactic acid in the fermented milk composition. An increase in the titratable acidity of more than 300 ° T leads to an intense break in the intermolecular transverse acid-labile bonds in the structure of mature collagen due to the action of lactic acid, sour-milk microorganisms and the metabolites produced by them. The result is the production of collagen dissolution products with poorer quality and low molecular weights by reducing the number of polypeptide groups.

The sour-milk composition is a symbiosis of acid-tolerant microorganisms, as well as organic acids and enzymes produced by them. The treatment temperature should be 24 ± 2 ° C, since a decrease in it can cause inhibition of the metabolic processes of microorganisms, and an increase in temperature will lead to their death. A variable mechanical action is necessary for a more effective interaction of the fermented milk composition with dermis samples. The duration of dissolution is 11-13 days, while achieving the optimal dissolution of pieces of the dermis (from the point of view of the organoleptic criterion). An increase / decrease in the duration of dissolution will lead to a deterioration in the performance of the finished product due to insufficient / excessive disordering of collagen fibers.

The use of a fermented milk composition with a titratable acidity of 250-300 ° T and an active reaction of a pH of not more than 4.0 at the dissolution stage in the preparation of collagen products allows us to achieve good quality indicators of the finished product when using tanning waste as a raw material.

The applicant knows a method of pickling sheepskin-fur raw materials (see patent RU No. 2306345, IPC С14С 1/08, publ. September 20, 2007, bull. No. 26) in a solution, which is used as a fermented milk composition having a titratable acidity not less than 300 ° T, a lactic acid concentration of at least 25 g / dm ³ and an active reaction of the medium of not more than 3.5. The process is carried out at a temperature of 30 ± 2 ° C, with a duration of 16 hours, variable mechanical stress, LC = 7, sodium chloride consumption of 20 g / dm ³ . The technical result of the method of pickling sheepskin-fur raw materials is to increase the quality of fur sheepskins by reducing the sunset of the hairline and improving their elastic-plastic properties.

In the known method, the fermented milk composition is used using sodium chloride. The processing sequence of fur sheepskin according to patent No. 2306345 and the claimed sequence of technology for producing collagen dissolution products are completely different from each other. The action of the fermented milk composition is based on loosening the structure of collagen fibers and removing interfiber substances due to the action of lactic acid. The difference of the proposed method is the further loosening of the collagen structure until the collagen mass with high molecular weights is obtained due to the preservation of polypeptide chains. The result is a final product with optimal colloidal chemical properties. The cultivation of microbiocenosis is carried out at a temperature of 36 ± 2 ° C.

From the prior art, including a search by patent and scientific and technical sources of information, the applicant has not found sources characterized by features identical to all the essential features of the claimed method for producing collagen dissolution products set forth in the claims.

To carry out the invention, a method for producing collagen dissolution products, experimental semi-production studies were conducted, during which the cultivation conditions of the fermented milk composition, the optimal value of titratable acidity, and the amount of composition were determined.

The fermented milk composition is prepared on the basis of secondary products of the dairy industry (see patent RU No. 2306345, IPC С14С 1/08; publ. September 20, 2007), namely pasteurized curd whey and / or skim milk with a fat content of up to 0.1% and 0.05%, respectively. The cultivation according to patent No. 2306345 is carried out using pasteurized skim milk at a temperature of 22 ± 2 ° C for 5 days with periodic mechanical stress (twice a day for 15 minutes). When the value of titratable acidity of the fermented milk composition reaches 280-300 ° T, pasteurized whey and / or skim milk is added, pasteurized in a total amount of 100 cm ³ for 10-15 days, gradually increasing the volume of pasteurized curd cheese until the pasteurized skim milk is completely eliminated. At the end of the cultivation, the titratable acidity is estimated, which should be at least 300 ° T and the active pH of the medium is not more than 3.5.

The difference in the fermented milk composition according to the claimed invention is to increase the temperature of cultivation. This is due to the fact that the composition includes only thermo-tolerant microorganisms. The optimum temperature for their growth is 36 ± 2 ° C, which reduces the cultivation period to 3 days. The use of compositions with an acidity of 250-300 ° T is due to the best preparation of raw materials.

Thus, the fermented milk composition according to the proposed method has a high titratable acidity of 250-300 ° T, an active reaction of the pH medium is not more than 4.0, which indicates a significant content of lactic acid in the composition is not less than 25-30 g / dm ³ , which should ensure optimal disordering of collagen fibers.

The resulting fermented milk composition is proposed to be stored at a temperature of 4-7 ° C, for 40-60 days. Titratable acidity during storage is 250-300 ° T. The reactivation of the fermented milk composition in the present invention should be carried out at a temperature of 36 ± 2 ° C for 8 hours and twice aeration. The dose of the added substrate (pasteurized skim milk) is 30-40% of the volume of the fermented milk composition.

The proposed method for producing collagen dissolution products is as follows. Wastes from leather production and substandard leather raw materials are subjected to the process of soaking for 14 hours in clean water, LC = 4.0. The process is carried out at a temperature of 20-22 ° C, then glaze gold-plating is carried out for a period of 2 days using an ash liquid of the composition: (NH ₄ ) ₂ SO ₄ - 0.3%; Na ₂ S (60%) - 3.2%; Ca (OH) ₂ (96%) - 4.6%, which is drained at the end, and the samples are washed for 24 hours (τ = 8 ° C). After the anesthesia process, the needles are washed with flowing water for 1 h at a flow rate of (NH ₄ ) ₂ SO ₄ - 0.3%, then chopped into pieces 2 × 2 cm in size, the resulting mass is weighed and subjected to salt treatment at a temperature of 18-20 ° С , FA = 3, the concentration of Na ₂ SO ₄ 40 g / DM ³ and the processing time of 4 hours

Next, the samples are sent to alkaline-salt treatment: NaOH 100 g / dm ³ and Na ₂ SO ₄ - 142 g / dm ³ , LC = 3, at a temperature of 18-20 ° C, for 60 hours and washing with a solution of Na ₂ SO ₄ 40 g / dm ³ with LC = 3, a temperature of 20-22 ° C for 4 hours with periodic stirring.

To remove excess alkali, a solution of (NH ₄ ) ₂ SO ₄ is neutralized with 10% by weight of the feed at LC = 5. Neutralization is carried out until there is no pink staining with phenolphthalein in the sample section. The temperature of the working solution must be maintained in the range of 18-20 ° C.

The material is thoroughly washed with running water until there are no sulfate ions in the washings (high-quality sample with BaCl ₂ ).

The dissolution of collagen in the present invention is carried out in a fermented milk composition with titratable acidity of 250-300 ° T, a concentration of lactic acid of at least 25-30 g / dm ³ and a pH of not more than 4.0 at LC = 1 (from the initial weight) at a temperature of 24 2 ° C and variable mechanical stress. The duration of dissolution is 11-13 days. Moreover, at the end of dissolution, the samples are almost transparent, loose, swollen pieces of the dermis, easily decomposed with little mechanical impact.

After swelling and dissolution, homogenization is carried out by 2-3 times grinding.

To remove the excess of acid ions in the solution of collagen dissolution products, dialysis is carried out, which ensures an active reaction of the pH medium within neutral parameters (6.0-7.0).

The resulting finished product is a viscous, gel-like substance that has a transparent, somewhat opalescent color.

Examples of the implementation of the proposed method for producing collagen dissolution products:

Example 1

Wastes from leather production and substandard leather raw materials are subjected to the process of soaking for 14 hours in clean water, LC = 4.0. The process is carried out at a temperature of 22 ° C.

Then carry out glutinous golding lasting 2 days. Use an ash liquid composition: (NH ₄ ) ₂ SO ₄ - 0.3%; Na ₂ S (60%) - 3.2%; Ca (OH) ₂ (96%) - 4.6%. At the end, the solution is drained, and the samples are washed for 24 hours (t = 8 ° C), the anesthesia of the goal at a flow rate of (NH ₄ ) ₂ SO ₄ - 0.3% for 1 hour and then alkaline-salt treatment.

Wastes from leather production and substandard leather raw materials are washed with running water for 1 hour after the anesthesia process. Then they are chopped into pieces 2 × 2 cm in size and subjected to salt treatment at a temperature of 18 ° С, ZhK = 3, concentration of Na ₂ SO ₄ - 40 g / dm ³ , the processing time is 4 hours. After that, the samples are sent to alkaline-salt treatment (t = 20 ° C), which is carried out in a solution containing NaOH - 100 g / dm ³ and Na ₂ SO ₄ - 142 g / dm ³ , LC = 3 for 60 hours. At the end of the treatment, the samples are washed in a solution of Na ₂ SO ₄ - 40 g / dm ³ , LC = 3, t = 20 ° C in for 4 hours

To remove excess alkali, they are neutralized with a solution of (NH ₄ ) ₂ SO ₄ - 10% by weight of the raw material, LC = 3, t = 18 ° C for 15 hours until the pink staining with phenolphthalein is completely absent on the section. Then the material is thoroughly washed in running water (t = 8 ° C) until there are no sulfate ions in the wash water (high-quality sample with BaCl ₂ ).

The acid dissolution of collagen is carried out in a fermented milk composition with a titratable acidity of 252 ° T, a concentration of lactic acid of 25.8 g / dm ³ and a pH of 3.7 at LC = 1 (of the initial weight) at t = 24 ° C. Duration of dissolution is 13 days.

After swelling and dissolution, homogenization is carried out by 3-fold grinding.

Dialysis is carried out to remove excess acid in the solution of collagen dissolution products.

The characteristics of the obtained product are presented in table 1.

Table 1 Name of parameters (a.s.v.) Quantitative expression Dry residue,% 3,208 Mass fraction of minerals,% 0.123 Mass fraction of fatty substances,% 4,514 The concentration of protein, g / DM ³ 4,58 pH 6.43 Density, g / cm ³ 1,197

Example 2

Wastes from leather production and substandard leather raw materials are subjected to the process of soaking for 14 hours in clean water, LC = 4.0. The process is carried out at a temperature of 20 ° C.

Then carry out gluttonous golding lasting 2 days. Use an ash liquid composition: (NH ₄ ) ₂ SO ₄ - 0.3%; Na ₂ S (60%) - 3.2%; Ca (OH) ₂ (96%) - 4.6%. At the end, the solution is drained, and the samples are washed for 24 hours (t = 8 ° C), the anesthesia of the goal at a flow rate of (NH ₄ ) ₂ SO ₄ - 0.3% for 1 hour and then alkaline-salt treatment.

Wastes from leather production and substandard leather raw materials are washed with running water for 1 hour after the anesthesia process. Then they are chopped into pieces 2 × 2 cm in size and subjected to salt treatment at a temperature of 18 ° С, ZhK = 3, concentration of Na ₂ SO ₄ - 40 g / dm ³ , the processing time is 4 hours. After that, the samples are sent to alkaline-salt treatment (t = 20 ° C), which is carried out in a solution containing NaOH - 100 g / dm ³ and Na ₂ SO ₄ - 142 g / dm ³ , LC = 3 for 60 hours. At the end of the treatment, the samples are washed in a solution of Na ₂ SO ₄ - 40 g / dm ³ , LC = 3, t = 21 ° С for 4 hours

To remove excess alkali, they are neutralized with a solution of (NH ₄ ) ₂ SO ₄ - 10% by weight of the raw material, LC = 3, t = 19 ° C for 14 hours until the pink staining with phenolphthalein is completely absent on the section. Then the material is thoroughly washed in running water (t = 8 ° C) until there are no sulfate ions in the wash water (high-quality sample with BaCl ₂ ).

The acid dissolution of collagen is carried out in a fermented milk composition with a titratable acidity of 278 ° T, a concentration of lactic acid of 26.3 g / dm ³ and a pH of 3.4 at LC = 1 (from the initial weight) at t = 25 ° C. The duration of dissolution is 12 days.

After swelling and dissolution, homogenization is carried out by 3-fold grinding.

Dialysis is carried out to remove excess acid in the solution of collagen dissolution products.

The characteristics of the obtained product are presented in table 2.

table 2 Name of parameters (% a.s.v.) Quantitative expression Dry residue,% 3,581 Mass fraction of minerals,% 0,099 Mass fraction of fatty substances,% 3,843 The concentration of protein, g / DM ³ 4.81 pH 6.04 Density, g / cm ³ 1,246

Example 3

Wastes from leather production and substandard leather raw materials are subjected to the process of soaking for 14 hours in clean water, LC = 4.0. The process is carried out at a temperature of 20 ° C.

Then carry out glutinous golding lasting 2 days. Use an ash liquid composition: (NH ₄ ) ₂ SO ₄ - 0.3%; Na ₂ S (60%) - 3.2%; Ca (OH) ₂ (96%) - 4.6%. At the end, the solution is drained, and the samples are washed for 24 hours (t = 8 ° C), the anesthesia of the goal at a flow rate of (NH ₄ ) ₂ SO ₄ - 0.3% for 1 hour and then alkaline-salt treatment.

Wastes from leather production and substandard leather raw materials are washed with running water for 1 hour after the anesthesia process. Then they are chopped into pieces 2 × 2 cm in size and subjected to salt treatment at a temperature of 18 ° С, ZhK = 3, concentration of Na ₂ SO ₄ - 40 g / dm ³ , the processing time is 4 hours. After that, the samples are sent to alkaline-salt treatment (t = 20 ° C), which is carried out in a solution containing NaOH - 100 g / dm ³ and Na ₂ SO ₄ - 142 g / dm ³ , LC = 3 for 60 hours. After processing, the samples are washed in a solution of Na ₂ SO ₄ - 40 g / dm ³ , LCD = 3, t = 22 ° C for 4 hours

To remove excess alkali, they are neutralized with a solution of (NH ₄ ) ₂ SO ₄ - 10% by weight of the raw material, LC = 3, t = 20 ° C for 14 hours until the pink staining with phenolphthalein is completely absent on the section. Then the material is thoroughly washed in running water (t = 8 ° C) until there are no sulfate ions in the wash water (high-quality sample with BaCl ₂ ).

The acid dissolution of collagen is carried out in a fermented milk composition with a titratable acidity of 299 ° T, a concentration of lactic acid of 28.1 g / dm ³ and a pH of 3.2 at LC = 1 (from the initial weight) at t = 26 ° C. The duration of dissolution is 11 days.

After swelling and dissolution, homogenization is carried out by 3-fold grinding.

Dialysis is carried out to remove excess acid in the solution of collagen dissolution products.

The characteristics of the obtained product are presented in table 3.

Table 3 Name of parameters (% a.s.v.) Quantitative expression Dry residue,% 3,594 Mass fraction of minerals,% 0,101 Mass fraction of fatty substances,% 3,987 The concentration of protein, g / DM ³ 5.21 pH 6.39 Density, g / cm 1,124

The proposed method compared with the prototype (see patent RU No. 2031597, IPC A23J 1/10, C09H 1/00, C14C 1/08, publ. 03/27/1995) allows you to achieve the following advantages:

- improving the quality of collagen dissolution products with high molecular weights having good colloid-chemical properties, due to the preservation of a significant amount of polypeptide groups in the collagen structure;

- reducing the cost of the finished product through the use of waste from the dairy industry (whey curd pasteurized and / or skimmed pasteurized milk) instead of organic acids;

- use for processing waste leather production and substandard leather raw materials;

- environmental protection due to the exclusion of aggressive acids, acetic acid from the solution, in particular, and the rational use of leather and milk production wastes.

Claims (1)

A method of obtaining collagen dissolution products, including grinding and washing collagen-containing raw materials, its alkaline salt treatment, salt washing with sodium sulfate, neutralization, repeated washing of the product and its dissolution in an acid agent, characterized in that when dissolved as an acid agent, the sour-milk composition is used, having a titratable acidity value of 250-300 ° T, a lactic acid concentration of at least 25-30 g / dm ³ and an active reaction of the medium, a pH of not more than 4.0, while the treatment is carried out while temperature (24 ± 2) ° C, LC = 1 and variable mechanical stress, the duration of dissolution for 11-13 days.