RU2437552C1 - Method for production of protein from flax seeds cake - Google Patents

Abstract

FIELD: food industry.

SUBSTANCE: invention relates to food industry. The raw material is milled, water-soluble non-protein mucilaginous substances are removed by way of cake treatment with acidated water solution with pH = 3.5-4.0 at a ratio of 1:15 during 0.5-1 hours. The mucilaginous solution is separated from the cake. The cake is washed with water to remove mucilaginous remains. Rinse water is separated from the cake. One extracts protein from non-mucilaginous flax seeds cake with a 0.5-0.8 M sodium chloride solution in an alkaline medium with pH = 9-10 at a temperature of 20-40°C during 1-3 hours. One separates the protein extract from the insoluble sediment. Protein is sedimented from the extract with an acid. Sedimented protein is separated, washed and dried.

EFFECT: invention allows to produce a product having enhanced food and biological value.

3 dwg, 6 tbl, 3 ex

Description

The invention relates to the food industry, and in particular to methods for producing protein from oilseeds, in particular flaxseed meal.

Traditional methods for producing protein from plant materials (Food chemistry / edited by A.P. Nechaev. - St. Petersburg: GIORD. - 2003. - P.133), in particular oilseed, are based on extraction processes in which they are used as extractant aqueous solutions of salts, most often sodium, potassium, magnesium chloride, and / or aqueous solutions of alkalis (sodium hydroxide or calcium), followed by the isolation of protein from protein extracts in any way: acid precipitation, dialysis, etc.

A known method of producing albumin-globulin protein "Linmin" from cake of flax seeds (US Pat. RF No. 2232513, CL. A23J 1/14. C11B 1/10, 2002), providing for the extraction of albumin with sodium chloride solution, separation from the protein solution of the precipitate in the form cake paste, precipitation of albumin from the protein solution with hydrochloric acid followed by separation of albumin, washing and drying it, extracting globulin from the separated cake paste with an alkaline solution, separating the alkaline protein solution, precipitating globulin from it with a solution of hydrochloric acid, washing and drying it.

The disadvantages of this method are the multi-stage extraction process, which increases the duration of the process, a large number of process water that must be treated to prevent environmental pollution, as well as the presence of carbohydrate impurities in the final product that reduce the protein content in it.

A known method of producing food protein from seeds and meal of cotton (A. C. USSR №465171, class A23J 1/14, 1970), including the extraction of protein by treating meal with a solution of sodium chloride in an alkaline medium, precipitating the protein by heating, followed by dialysis or dilution in order to remove or reduce the concentration of sodium chloride.

The disadvantages of this method are the low protein yield, its low quality due to contamination with non-proteinaceous impurities, time-consuming and lengthy stages (dialysis) and the use of heating to precipitate proteins.

A known method of obtaining flax protein product containing flax mucus from fat-free and crushed seeds of flax (US Pat. US No. 5925401, CL. A23J 1/14, A23J 1/00, 1997, prototype), involving extraction in an alkaline environment, separation of the extract from insoluble residue, treatment of the alkaline extract with acid and lower alcohol to obtain a precipitate containing proteins and mucus, separation of the lower alcohol solution from the precipitate, the use of the resulting product in its native state, or drying it.

The disadvantage of this method is the low protein content of up to 60% in the protein product due to the coprecipitation of polysaccharides of flax mucus.

The objective of the present invention is to develop a method for producing protein from oilcake of flax seeds, which allows to increase the yield of protein and the quality of the target product by increasing the protein content in it.

This object is achieved by the fact that before extraction, the crushed cake is treated with an aqueous solution of pH 3.5-4.0 in a ratio of 1:15 for 0.5-1 hours to remove water-soluble non-protein mucous substances, and the protein is extracted from the non-sludge meal of flax seeds 0.5-0.8 M solution of sodium chloride in an alkaline medium at a pH of 9-10 and a temperature of 20-40 ° C for 1-3 hours.

The choice of oilcake as a raw material obtained after degreasing flax seeds by the method of "cold" pressing is explained by the following:

- protein extraction directly from flax seeds is complicated by the presence of a significant amount of fat in them, at least 40% (Zubtsov V.A. Consumer value of flax seeds / V.A. Zubtsov, T.I. Lebedeva, L.L. Osipova, N. V. Antonova // Agrarian science. - 2002. - No. 10. - P.12);

- cake is a concentrated source of protein with a content of not less than 30% (Minkevich I.A. Len flaxseed / I.A. Minkevich. - M .: Selkhozgiz. - 1957. - P.3);

- the cost of oilcake as a waste of oil production is significantly lower than the cost of flax seeds.

Flax seeds are also characterized by a significant amount of mucus - 10-12% that remains in the flaxseed meal (Warrand J., Michaud R., Picton L., Muller G., Courtois B., Ralainirina R., Courtois J. Structural investigation of the neutral polysaccharide of Linum usitatissimum L. seed mucilage // Intren J. Biological Macromolecules. - 2005. - V.35. - N3-4. - P.121). Slimes are highly water soluble polysaccharides that compete with proteins for release into the solution upon extraction. Preliminary removal of mucus from a meal of flax seeds helps to increase the yield of protein in the solution.

The claimed method of obtaining protein from oilcake of flax seeds is illustrated by the drawings.

Figure 1 shows a flow chart of a method for producing protein from a meal of flax seeds, figure 2 - the dependence of the output of dry mucus,%, from the hydraulic module, figure 3 - the dependence of the amount of protein in solution, g, from the hydraulic module.

In the inventive method for producing protein from a meal of flax seeds, the operation of removing non-protein mucous substances, including treating the meal with an acidified aqueous solution at pH 3.5-4.0 in a ratio of 1:15 for 0.5-1 h, is carried out with constant stirring and directed to increase the yield of protein in the solution.

Processing of oilcake with an acidified aqueous solution is carried out at a pH of 3.5-4.0, corresponding to the isoelectric point (IET) of flaxseed protein. Under the IET conditions, the solubility of proteins is minimal (Food chemistry / edited by A.P. Nechaev. - St. Petersburg: GIORD. - 2003. - P.93).

The ratio of liquid and solid phases (hydraulic module 1:15) was selected experimentally under the condition of a high yield of mucus polysaccharides in solution. A further increase in the volume of the liquid phase is inefficient, since it slightly increases the yield of polysaccharides in solution.

Continuous mixing of the components contributes to a more efficient course of the dissolution of mucus polysaccharides in the aquatic environment, and the process time for 0.5-1 hours is sufficient for mucus polysaccharides to enter the solution, as shown in Table 1.

Table 1 The effect of the duration of the process on the effectiveness of removing mucus from flaxseed meal The duration of the process, min The output of dry mucus,% by weight of raw materials Loss of protein,% by weight of protein in raw materials fifteen 8.5 5.5 thirty 9,4 6.0 45 9.9 6.0 60 10.5 6.3 75 11.5 8.5

An increase in the duration of the process leads to significant protein losses - above 8% (Table 1). This is due to the interaction of some proteins with mucus polysaccharides, accompanied by the formation of soluble complexes (Tolstoguzov VB Artificial food / VB Tolstoguzov. - M .: Nauka. - 1978. - P.42-44).

The solution of mucus is separated from the flaxseed meal by centrifugation at 3000 rpm for 10 minutes or by decantation.

The cake is washed with water in a ratio of 1:10 to remove residual mucus, the washing water is separated from the cake by centrifugation at 3000 rpm for 10 minutes or by decantation.

From a solution of mucus and wash water by vacuum distillation of water and drying, you can get an additional product - a polysaccharide complex (PS complex), the characteristics of which are presented in table 2.

table 2 Characteristics of the PS complex Name of indicator Indicator value The output of the PS complex,% by weight of raw materials 9.5-10.8 Protein,% by weight of PS complex 5.5-6.3 Fat,% by weight of PS complex 5.9-8.5 Ash content,% by weight of PS complex 10.5-12.0 Moisture,% by weight of PS complex 9.5-13.0 Carbohydrates,% by weight of PS complex 59.1-48.4

PS complex of flaxseed meal can be successfully used in the food industry. PS complexes from plant sources are widely used as thickeners and gelling agents, as well as stabilizers, emulsifiers, plasticizers in food technologies (Food chemistry / edited by A.P. Nechaev. - St. Petersburg: GIORD. - 2003. - P.374- 375).

The protein is extracted from the washed non-sludge meal with a 0.5-0.8 M sodium chloride solution in an alkaline medium at a pH of 9-10, a temperature of 20-40 ° C for 1-3 hours and a ratio of extracting solution and cake (10-15) :one.

Carrying out salt extraction in an alkaline medium allows, together with salt-soluble proteins, alkaline-soluble to be isolated in solution. At the same time, more protein passes into the protein extract from the mucus-free cake than from the original, as shown in the data in Table 3.

Table 3 The effect of the ionic strength of the extractant on the efficiency of protein isolation Ionic strength of saline The total amount of soluble protein in the extract, g Protein yield in
extract,% of protein in raw materials The protein content in the target product,% by weight of the product cake extraction 0.15 M 12.58 61.3 75.0 0.3 m 13.34 65.0 75.3 0.5 m 13.91 67.8 76,2 0.8 m 13.95 68.0 76.8 1M 14.10 68.6 76.8 extraction from the original cake 0.5 m 12.31 60.0 70,2

The efficiency of protein extraction is due to the selection of such optimal parameters as the ionic strength of the extracting solution, the pH of the medium, the ratio of the extracting solution to the raw material, temperature and time of the process.

The effectiveness of the process of extracting protein from oilseeds depends on the ionic strength of the saline solution. With its increase, the degree of protein extraction from oilseeds is initially increased until it reaches its maximum value. A subsequent increase in the ionic strength of the saline does not lead to a significant increase in the total amount of dissolved protein.

Salt solution of 0.5-0.8 M during extraction from flaxseed meal is optimal for dissolving significant amounts of protein and obtaining the target product of high quality with a protein content of at least 75% (Table 3).

The yield of protein in solution increases with increasing pH of the medium, however, above pH 10, the increase in yield is insignificant, while along with protein, undesirable pigments that change the color of the protein can pass into the solution (Table 4).

Table 4 The effect of pH on the efficiency of protein extraction pH of the medium The yield of protein in the extract,% of the protein content in the feed The color of the target product (after drying) 8 66.5 light cream 9 67.8 also 9.5 67.8 cream 10 68.0 also eleven 69.5 brown

The ratio of the extracting solution and flaxseed meal, as well as the duration of extraction were selected experimentally from the condition of a high yield of protein in the solution, the results are presented in table 5.

Table 5 The effect of the duration of the process on the efficiency of protein extraction The duration of the extraction, h The yield of protein in the extract,% of the protein content in the feed 0.5 63.5 one 67.3 2 68.5 3 68.8 5 67.5

An increase in the volume of extractant above 15 relative to the weight of the cake is unprofitable due to a slight increase in the yield of protein in the solution. The duration of the extraction in the range of 1-3 hours is sufficient for the transition of almost 2/3 of the protein mass from the feed to the solution.

The efficiency of the extraction process also depends on temperature, which is reflected in table.6.

Table 6 The effect of temperature on the efficiency of protein extraction Temperature ° C The yield of protein in the extract,% of the protein content in the feed twenty 66.5 40 68,2 60 66.3 70 65.7

An increase in temperature contributes to an increase in the yield of protein in the solution, but thermal denaturation of the protein proceeds above 60 ° C, which limits their solubility. The temperature should be considered optimal at 40 ° C, although the process can be conducted at room temperature to reduce the energy intensity of the technology.

A method of obtaining protein from a meal of flax seeds includes the following operations:

- grinding of raw materials;

- removal of water-soluble non-protein mucous substances by treating the cake with an acidified aqueous solution of pH 3.5-4.0 in a ratio of 1:15 for 0.5-1 h with constant stirring;

- centrifuging the mixture to separate the solution of mucus from the cake for 25 min at 3000 rpm;

- washing the non-slug cake with water in a ratio of 1:10 for 10-15 minutes with constant stirring;

- centrifuging the mixture to separate the wash water from the sludgeless cake for 25 min at 3000 rpm;

- vacuum distillation of water from a solution of mucus and wash water and drying the polysaccharide complex;

- extraction of protein from non-slug cake with 0.5-0.8 M sodium chloride solution in an alkaline medium at pH 9-10, temperature 20-40 ° C for 1-3 hours and the ratio of extracting solution and cake (10-15): one;

- centrifugation of the pulp on a cake paste and protein extract for 25 min at 3000 rpm;

- drying and grinding of cake paste;

- acid precipitation of the protein from the protein extract with a solution of hydrochloric acid at a pH of 3.5-4.0 and its aging - "maturing" for 50-60 minutes;

- centrifuging the mixture to separate the protein from whey water for 15 min at 3000 rpm;

- washing the protein with water in a ratio of 1:10 by continuous stirring for 10-15 minutes;

- centrifuging the mixture to separate the protein from the wash water for 15 min at 3000 rpm;

- spray drying of the protein.

A method of obtaining protein from a meal of flax seeds is as follows.

Example 1

To obtain protein used industrial cake with the following indicators:

protein content - 34.2%

fat content - 12.0%

crude fiber content - 8.9%

moisture content - 7.8%.

Flax cake, crushed in a laboratory mill, in an amount of 60 g is mixed with 900 ml of an acidified aqueous solution of pH 3.5. The mixture was stirred for 1 hour. The mixture was centrifuged for 25 minutes at 3000 rpm to separate the mucus solution from the meal.

600 ml of water are added to the wet cake for washing and stirred for 15 minutes. Wash water is separated from the sludgeless cake by centrifugation for 25 min at 3000 rpm.

Water is removed from a solution of mucus and wash water under vacuum to a solids content of not more than 60%. The thickened polysaccharide mass is spread in a thin layer on a baking sheet and dried at 60 ° C until the moisture content is not more than 15%. The resulting polysaccharide complex has the indicators presented in table.2.

600 ml of 0.8 M sodium chloride solution was added to the non-sludge cake, the pH was adjusted to 10 by adding 30% NaOH solution, and the protein was extracted for 2 hours at 40 ° C with constant stirring.

The protein extract is separated from the cake by centrifugation for 25 minutes at 3000 rpm. In this case, 68.0% of the protein from its content in the raw material passes into the protein extract.

3H is added to the protein extract to precipitate the protein. hydrochloric acid solution until a pH of 3.5 is reached. The protein is kept for "maturing" (coagulation into large formations) for 50 minutes.

The protein is separated from serum water by centrifugation for 15 minutes at 3000 rpm.

The separated protein is washed with water at a ratio of 1:10 for 10 minutes with constant stirring, and the washing water is separated by centrifugation for 15 minutes at 3000 rpm.

The wet protein is spray dried.

The resulting product is a light cream powder with a protein content of 76.8%.

Example 2

The method was carried out analogously to example 1 with the only difference that the removal of mucus was carried out at pH 4.0 for 0.5 h, and the extraction of the protein with 0.5 M sodium chloride solution for 3 hours. The protein yield in the extract was 67.8 % The final powder had a light cream color and a protein content of 76.2%.

Example 3

The method was carried out analogously to example 1 with the only difference that the extraction of the protein was carried out at pH 9 for 1 h, and the precipitation of the protein was carried out at pH 4.0. The protein yield in the extract was 67.8%. The final powder had a light cream color and a protein content of 76.5%

The claimed method for producing protein from a meal of flax seeds allows you to get a product containing at least 75% flaxseed protein, characterized by a complete set of amino acids essential for the human body (Vinogradov V.F. Technological and biomedical aspects of using flax as a complex nutraceutical / V.F. Vinogradov, L.E.Smirnova, E.M.Sulman, A.I. Sidorov, V.P. Kozlov, I.V. Ushchapovsky // Materials of the scientific and practical conference "Flax complex of Russia. Problems and prospects." - Vologda. - 2001. - P.86; Food chemistry / edited by A.P. Nech Aeva .-- SPb .: GIORD. - 2003. - P.41). Flax protein product as a concentrated protein component will increase the nutritional and biological value of food products, in particular bakery products, as well as develop a range of functional foods with guaranteed protein content.

Claims (1)

A method of obtaining protein from a meal of flax seeds, including grinding raw materials, removing water-soluble non-protein mucous substances by treating the meal with an acidified aqueous solution of pH 3.5-4.0 in a ratio of 1:15 for 0.5-1 h, separating the solution of mucus from the meal washing the meal with water from the residues of mucus, separating the washing water from the meal, extracting the protein from the non-sludge meal of flax seeds with a 0.5-0.8 M solution of sodium chloride in an alkaline medium at a pH of 9-10 and a temperature of 20-40 ° C for 1 -3 h, separation of the protein extract from the insoluble precipitate, precipitation f protein from the extract with acid, separation of the precipitated protein, washing and drying thereof.

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