JPH037556A - Purification of blood plasma - Google Patents

Abstract

PURPOSE:To obtain a plasma-originated protein having little odor and low content of coloring substance with simple procedure by treating plasma with an acidic or basic substance and removing the denaturated hemoglobin. CONSTITUTION:To remove a discoloration-causing substance from plasma, the plasma is treated with an acidic or basic substance and the denaturated hemoglobin is removed. Concretely, an acidic substance (preferably hydrochloric acid, phosphoric acid, acetic acid, etc.) is added to the plasma to adjust the pH to 3-6 or a basic substance (preferably sodium hydroxide or potassium hydroxide) is added to the plasma to adjust the pH to 9-13, the mixture is maintained at 0-40 deg.C to effect the denaturation of hemoglobin and the denaturated hemoglobin is removed from the system. A representative method for further improving the purification effect of plasma is the treatment of plasma with polymer electrolyte and then activated carbon and, finally, the pH-modification treatment. In addition to the above procedures, the plasma is filtered with a ceramic filter.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for purifying plasma, and more particularly to a method for deodorizing and decolorizing plasma for use in foods.

[Conventional technology]

Cow or pig blood is collected at the slaughterhouse.

Sodium citrate is immediately added to the collected blood to prevent blood from coagulating, and plasma and blood cells are separated by centrifugation. In slaughterhouses, some degree of hemolysis cannot be avoided at this stage, and therefore the plasma currently used for food contains blood cell components. Therefore, there is a problem in that if plasma collected from slaughterhouses is directly heated to gel, the gel becomes colored, which limits its range of use.

Another problem is that plasma powder obtained by drying plasma obtained at a slaughterhouse as described above has a characteristic unpleasant odor and taste.

This odor and taste are weak at the time of manufacture, but become stronger over time, so that all commercially available plasma powders have an unpleasant odor and taste. Plasma powder is used as a food quality improver, especially to improve water retention and elasticity, but if added in too much, it will harm the flavor of the food, so the amount added is often limited and sufficient effects cannot be obtained. stomach. There is a need for a plasma powder with improved odor and taste that does not impair the flavor of this snack food.

When plasma is decolorized and deodorized to prevent gel coloring and eliminate undesirable odors and tastes, the treated plasma contains adsorbents used during the treatment, insoluble proteins denatured during the treatment, Since bacteria etc. are present, it is necessary to remove them.

[Problem to be solved by the invention]

An object of the present invention is to provide a method for obtaining plasma-derived proteins with low odor and coloring substances through simple operations.Another object of the present invention is to remove impurities in plasma, particularly by decolorizing and deodorizing plasma. This method is suitable for efficiently and industrially advantageous in removing impurities that are mixed into or generated in plasma during the process (i.e., adsorbents used to remove colored substances and off-flavors, and insoluble proteins generated during the removal process). We are here to provide you with a method.

[Means to solve the problem]

In one aspect, the present invention provides a method for removing a substance that causes coloration contained in plasma, in which plasma is treated with an acidic or basic substance to denature hemoglobin that causes coloration. Provided is a method for purifying plasma with a removal rate of 1 to 5.

In another aspect, the present invention provides a plasma purification method in which the plasma is treated with activated carbon under acidic conditions in steps 5 to 5 of the method for removing substances that cause coloration contained in plasma. do.

In still another aspect, the present invention provides a method for purifying plasma in steps 1 to 5, in which a polyelectrolyte having a carboxyl group is added to plasma and then acid treatment is performed.

The present invention further provides a plasma purification method in which plasma is filtered through a ceramic filter on one side of the pond.

The plasma used in the present invention is obtained from animal blood. At this time, even if blood cell components are contained in the plasma due to hemolysis or the like, it is not a problem.

The first plasma purification method of the present invention consists of treating plasma with an acidic or basic substance to denature and remove hemoglobin that causes coloration.

In the above treatment method, first, an acidic substance or a basic substance is added to plasma and the plasma is stirred for a while. Of the proteins contained in plasma at this time,
It is important to maintain a pH range in which hemoglobin is denatured, but albumin, which has gelling properties, is not denatured. The liquid pH at this time is 3 to 6, preferably 3.5 to 5, under acidic conditions, and 9 to 13, preferably 11 to 12, under basic conditions. To adjust the pH, use hydrochloric acid, phosphoric acid, acetic acid, etc. for acidic conditions, and sodium hydroxide, potassium hydroxide, etc. for basic conditions. It is desirable to use materials that are approved for use in the manufacturing process. A solution containing an acidic or basic substance is stirred for 1 to 90 minutes at a temperature at which albumin contained in plasma is not denatured by heat, that is, 0 to 40°C, to denature and remove hemoglobin. Removal of hemoglobin can be carried out under the same acidic or basic conditions employed during such denaturation, or after the aforementioned base or acid is added dropwise to the treatment solution to adjust the pH to approximately neutrality of 7 to 8. However, it is preferable to do so after returning to neutrality. Such treatment can remove denatured hemoglobin.

The second plasma purification method of the invention consists of treating plasma with activated carbon under acidic conditions.

The amount of activated carbon added is preferably 0.5 to 10% by weight based on the weight of the solution. In this method, an acidic substance is added to make it acidic. At this time, it is important to maintain conditions so that albumin, which has gelling properties and is contained in plasma, does not denature or gel, and that hemoglobin is easily adsorbed on activated carbon. The liquid pl+ at this time is 3 to 6, preferably 3.5 to 5. To adjust the pH, consider using the obtained plasma as a food additive, use hydrochloric acid,! #
It is desirable to use acids, acetic acid, and other substances that are approved for use in food manufacturing processes.

1 at a temperature of 0 to 40 °C after adding activated carbon and acidic substances.
Stir for about 0 minutes to 24 hours. The process is terminated by removing the activated carbon. Activated carbon removal may be carried out under acidic conditions, or may be carried out after the liquid PL+ is adjusted to 7 to 8 by adding an alkaline substance. p
For H adjustment, it is desirable to use sodium hydroxide, potassium hydroxide, and other substances approved for use in food manufacturing processes.

Although there is no particular limitation on the order in which activated carbon and acidic substances are added to plasma, from the viewpoint of decolorizing and deodorizing effects, it is preferable to add activated carbon first and then add acidic substances.

Thus, according to the second method of treatment with activated carbon under acidic conditions, the first method of treatment with simply acidic or basic substances
Hemoglobin can be removed more completely compared to the method described above.

The third plasma purification method of the present invention comprises adding a polyelectrolyte having a carboxyl group to plasma, followed by acid treatment.

In addition to proteins, solutions containing plasma contain various trace components, which are thought to be the cause of the off-odor. For example, it is said that lipids react with oxygen due to ultraviolet rays and become peroxidized, causing off-flavors. At that time, metal ions are said to promote the peroxidation reaction. In addition, insolubilized proteins, which are found when frozen plasma is used as a raw material, are also thought to be the cause of the off-flavor.

According to the third purification method of the present invention using a polymer electrolyte having a carboxyl group, it is possible to almost completely remove substances that cause particularly unpleasant odors.

In this method, first, a polymer electrolyte having a carboxyl group is mixed with plasma, and the mixture is heated at about 0°C to 50'C for 1
Stir for about 0 to 60 minutes. Considering that the obtained plasma will be used as food, the polymer electrolytes with carboxyl groups used here include alginic acid, sodium alginate, polyacrylic acid, sodium polyacrylate, and carboxymethylcellulose, which are used in food manufacturing processes. It is preferable to use one that has been approved for.

As for the addition method, the polymer electrolyte may be dissolved as it is in the raw material solution containing plasma, or an aqueous solution of the polymer electrolyte may be prepared in advance and then mixed. The amount of polymer to be added is determined based on the processing solution, taking into account the operability of the equipment due to the increase in viscosity of the solution due to the addition of the polymer electrolyte, the operability when gelling and removing the polymer electrolyte, etc. (1,001 to 10% by weight, preferably about 0.01 to 5% by weight.) In order to increase the degree of purification, activated carbon can also be added to the polymer electrolyte.

Next, the pH of the solution is adjusted to a range where the added polymer electrolyte gels and proteins are difficult to denature. At this time, if the liquid is made too acidic, dissolved proteins will be damaged, so the pH is adjusted to about 1 to 5, preferably about 3 to 4.

Thereafter, insoluble substances and precipitates formed are filtered off, and a basic substance is added to the resulting supernatant to neutralize the PTT. Considering that the obtained protein will be used as food, the above pH adjustment is carried out using acidic substances such as hydrochloric acid, acetic acid, phosphoric acid, etc., and basic substances such as sodium hydroxide, potassium hydroxide, etc. in the food manufacturing process. It is desirable to use materials that are approved for use above. Thereafter, by appropriately performing operations such as concentration on the obtained solution and drying it according to a conventional method, plasma proteins with less foreign odor can be obtained.

The fourth plasma purification method of the present invention comprises subjecting plasma to ceramic filter treatment.

Plasma contains impurities such as denatured proteins, and in particular, plasma obtained by decolorizing and deodorizing treatment does not contain activated carbon used as an adsorbent, denatured insoluble proteins that may be generated during the treatment, and viable bacteria. I'm here. These impurities can be removed very efficiently by ceramic filter treatment.

In this treatment method, the treatment is completed by directly filtering the plasma through a ceramic filter.

The filter used at this time may be a commercially available one, and the pore diameter cannot be absolutely limited because it is determined by the size of the impurities contained, but
It is preferable to use one with a pore size of 5 μm or less.
More preferably, it is less than or equal to μ.

The filtrate obtained by ceramic filter treatment contains almost no impurities in plasma, especially decolorizing and deodorizing agents such as activated carbon used for decolorizing and deodorizing treatment, viable bacteria, and denatured and insolubilized proteins, and contains almost no protein, salts, etc. Contains only those dissolved in water. Therefore, it goes without saying that the commercial value of plasma proteins obtained by ceramic filter treatment is increased, and when a MiM condensation step is performed next, the concentration rate becomes faster, which has the effect of preventing membrane deterioration.

The first to fourth plasma purification methods described above can be carried out in appropriate combinations, thereby achieving a high degree of purification. An example of a typical plasma purification method is a method in which a polymer electrolyte having a carboxyl group and activated carbon are added to plasma and the plasma is treated with an acid. That is, activated carbon and a polymer electrolyte having a carboxyl group are added to plasma, and the mixture is stirred at about 10° C. to 50° C. for about 10 minutes to about 4 hours. The type and amount of polymer electrolyte used at this time,
The addition method etc. are as described above. In addition, the amount of activated carbon added is usually determined based on the amount of protein contained in the liquid.
Approximately 25% by weight is appropriate. Thereafter, the acid treatment described above is performed to obtain a deodorized and decolorized protein.

This combination of treatments results in plasma with less color and odor. At this time, the processing sequence is that plasma is treated with polyelectrolyte, then treated with activated carbon, and finally p
l+ modification treatment is preferred. This is because plasma with particularly little coloration can be obtained.

Furthermore, in addition to such treatments, by finally performing ceramic filter treatment, it is possible to obtain excellent blood/plasma that is more suitable as food or food additives.

〔Example〕

The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited to these Examples.

In each example, the protein content was determined using Biuret's reagent, and the hemoglobin content was determined by measuring the absorbance of hemin at 410 nm.

In addition, the hemoglobin concentration in protein is determined by the hemin absorbance (
A) and protein concentration (+ng/ml, (B)) ratio (A
)/(B).

Example 1 Pig blood was centrifuged to obtain plasma, and blood cells were added to the plasma to prepare the following samples.

Pig plasma 50g (sample 1, control) Pig plasma 50g+
Pig blood cells 1. ．． og (sample floor 2) pig plasma 50g + pig blood cells 2.0g (sample floor 3) pig plasma 508 + pig blood cells 5.
0g (Sample No. 4) The protein amount and hemoglobin content in each sample were measured.

The sample prepared as described above was subjected to the following treatments at room temperature.

1) Adjust the pH of the liquid to 4.0 by adding hydrochloric acid,
Stir for 30 minutes.

2) Add sodium hydroxide to neutralize the liquid p++ and stir for 30 minutes.

3) Denatured and precipitated hemoglobin? be considerate.

The protein content and hemoglobin content of the supernatant of each sample thus obtained was measured. The hemoglobin concentration was determined from these values, and the results are summarized in Table 1.

Table 1 From Table 1, it can be seen that the amount of hemoglobin decreases with respect to the amount of protein π. It is also found that the greater the amount of hemoglobin contained in the plasma, the better the removal rate.

Furthermore, as a result of spray drying the obtained solution, the odor decreased as the amount of hemoglobin contained in the protein decreased.

Example 2 After adding 10% by weight of blood cells to pig plasma, the following treatment was performed at room temperature.

1) Add hydrochloric acid to adjust the pH of the liquid. 3.0 (sample floor 5), 4, O (sample floor 6), or 5.0 (sample l!117) and stir for 30 minutes.

2) Add sodium hydroxide to neutralize the liquid PL+ and stir for 30 minutes.

3) Filter off the denatured and precipitated hemoglobin.

Furthermore, after adding 10% by weight of blood cells to pig plasma, the following treatment was performed at room temperature.

1) Add sodium hydroxide to bring the liquid pl+ to 12.0
(Sample size 8) 13.0 (Sample size 9) and stir for 30 minutes.

2) Add hydrochloric acid to neutralize the liquid pFl and stir for 30 minutes.

3) Remove the denatured and precipitated hemoglobin.

The amount of protein and amount of hemoglobin in the supernatant of each sample thus obtained before and after treatment were measured. The results are summarized in Table 2.

Table 2 Example 3 Pig plasma containing blood cells (sample Nctl) at room temperature
The pH was adjusted to 4 by adding hydrochloric acid (O1 control) and stirred for 20 minutes. After removing the precipitate, activated charcoal was added to the obtained supernatant (sample N [Lll, control) at 5% by weight of the protein amount (sample 1IkL12), 10% by weight (sample It13), and 15% by weight (sample 14). ,2
0% by weight (sample 1Ih15), 25% by weight (sample 16), and 30% by weight (sample 17) were added. After stirring as it was for 3 hours, the added activated carbon was filtered off, and the pH was adjusted to 7 by adding sodium hydroxide. Protein concentration and hemoglobin content in each sample was determined. From these values, the hemoglobin concentration in the protein was determined, and the results are summarized in Table 3.

Table 3 (Sample! 1h24), 24 hours (Sample 1kL
25) After stirring, the added activated carbon was filtered off, and the pH was adjusted to 7 by adding sodium hydroxide. Protein concentration and hemoglobin content in each sample was determined. From these values, the hemoglobin concentration in the protein was determined, and the results are summarized in Table 4.

Table 4 Example 4 Pig plasma containing blood cells (sample magnet 18,
control) by adding hydrochloric acid to adjust pl+ to 4,
Stirred for 20 minutes. After removing the precipitate, activated charcoal was added to the obtained supernatant (sample 19, control) in an amount of 15% by weight based on the protein amount. Leave it as it is for 10 minutes (sample floor 2)
0), 30 minutes (sample block 21), 60 minutes (sample block 22), 120 minutes (sample block 23), 180 minutes Example 5 2% sl-lium alginate aqueous solution 20 minutes in 1 kg of pig plasma
0ml was added and stirred at 30°C for 1 hour. After adjusting pFl to 3.8 by adding hydrochloric acid to this solution, the precipitate was removed by filtration. After concentrating the obtained solution, it was dried with a spray dryer to obtain plasma powder. The odor of the obtained plasma powder was considerably reduced compared to that of untreated plasma powder.

Example 6 200 ml of 0.5% sodium polyacrylate aqueous solution was added to 1 kg of pig plasma and stirred at 30°C for 1 hour. After adjusting the pH to 1.8 by adding hydrochloric acid to this solution, the precipitate was removed by filtration. After concentrating the obtained solution, it was dried with a spray dryer to obtain plasma powder. The odor of the obtained plasma powder was considerably reduced compared to that of untreated plasma powder.

Example 7 After adding 1 g of activated carbon to 1 kg of pig plasma, hydrochloric acid was added to adjust the pH to 4, and the mixture was stirred at room temperature for 3 hours. In this solution,
0.1% by weight sodium alginate aqueous solution 10100
O was added to remove insoluble materials. The resulting solution was subjected to ultrafiltration (
After desalting and concentrating using a UF) membrane, plasma powder was obtained by drying with a spray dryer. The resulting plasma powder had considerably less coloring and off-odor than untreated plasma powder.

Example 8 1 kg of pig plasma with 1 g of activated carbon and 1 g of sodium alginate
After that, the pH was adjusted to 4 by adding hydrochloric acid, and the mixture was stirred at room temperature for 3 hours. Thereafter, the precipitate was separated by filtration, the resulting solution was desalted and concentrated using a UF membrane, and then dried with a spray dryer to obtain plasma powder. The resulting plasma powder had considerably less coloring and off-odor than untreated plasma powder.

Example 9.10 Plasma 2001 after decolorization and deodorization treatment was filtered using a ceramic filter (manufactured by NGK Insulators, Inc.) with a pore size of 1.0 μm in Example 9 and 0.2 μm in Example 10, each with a filtration area of 0.48 m2. Cross-flow filtration was performed using At this time, the number of particles, number of viable bacteria, protein concentration, and permeation rate in the pre-treatment solution, concentrated solution, and permeated solution were compared. The number of particles can be determined by using the laser beam machine mentioned above, and
The number of viable bacteria was measured using a standard agar medium. The protein concentration was also measured and the results are shown in Tables 5 and 6. Furthermore, the obtained permeate and pre-treatment liquid were concentrated using Concentration M (manufactured by Tosoh Corporation, TS-30), and the plasma concentration rates at that time were compared. The permeate was 1.5 times faster in initial velocity than the pre-treatment solution.

Plasma powder was obtained by spray drying the membrane concentrate of the permeate. When a 10% aqueous solution of the obtained plasma powder was prepared and gelatinized, a whiter gel was obtained compared to that without the treatment, and the commercial value increased.

Example 11 After adding 2 kg of activated carbon and 101 ml of 0.1% sodium alginate solution to 100 kg of pig plasma, the pH of the solution was adjusted to 4 by adding hydrochloric acid. The mixture was stirred at 25°C for 3 hours. Filter the formed precipitate and added activated carbon through a cloth filter.
After filtering through (pore size 15-30 μm), the pH was adjusted to 7 by adding sodium hydroxide. The resulting solution was desalted and concentrated using a UF membrane, and then dried with a spray dryer to obtain plasma powder. The resulting plasma powder had considerably less coloring and off-odor than untreated plasma powder.

Example 12 After adding 4 kg of activated carbon and 101 ml of 0.1% sodium alginate solution to 100 kg of pig plasma, the PTT of the solution was adjusted to 4 by adding hydrochloric acid. The mixture was stirred at 25°C for 3 hours. Example 11 The resulting precipitate and added activated carbon etc.
After filtering through the same cloth filter as above, the pH was adjusted to 7 by adding sodium hydroxide. The obtained solution was filtered using a ceramic filter (pore size: 1.0 μm). The resulting solution was desalted and concentrated using a UF membrane, and then dried with a spray dryer to obtain plasma powder. The obtained plasma powder was compared to the untreated one.
Coloration and off-odor were significantly reduced.

〔Effect of the invention〕

Plasma treated by the method of the present invention has less color and odor than untreated plasma, and is useful as a food additive. In addition, if a method of treating with a polymer electrolyte is used, fine powder adsorbents and proteins insolubilized by denaturation are removed, so no special operation is required to remove them.
When concentrating the solution obtained after treatment through a membrane, the membrane is not damaged.

Furthermore, by using plasma with a low hemoglobin content that has been previously subjected to pH denaturation treatment, substances that cause coloring can be removed more efficiently.

In addition, it is thought that the hematin (iron ions) contained in hemoglobin that is removed by this treatment peroxidizes the lipids contained in plasma, so plasma that has undergone this treatment may be used for food or other purposes. It is considered more suitable as a food additive.

The plasma obtained after ceramic filter treatment has its commercial value because impurities, especially decolorizing agents such as activated carbon, deodorizing agents, viable bacteria, and denatured and insolubilized proteins contained in plasma after decolorizing and deodorizing treatment have been removed. goes up. In addition, the filter used is made of ceramic, so even if it becomes clogged, it can be regenerated by reheating, making it highly durable. Furthermore, even if a subsequent membrane concentration step is added, insoluble matter is removed, so the membrane efficiency is high and there is little deterioration of the membrane. As described above, the method of the present invention has excellent durability and operability.

Claims (1)

[Claims] 1. A method for removing substances that cause coloration contained in plasma, which comprises treating plasma with an acidic or basic substance to denature and remove hemoglobin. Purification method. 2. Add an acidic substance to the plasma to adjust the pH value to 3 to 6, or add a basic substance to adjust the pH value to 9 to 13, and hold at 0 to 40°C to denature hemoglobin; The purification method according to claim 1, wherein hemoglobin is then removed. 3. The purification method according to claim 1 or 2, wherein after denaturing hemoglobin, a basic substance or an acidic substance is added to adjust the pH value to 7 to 8, and then hemoglobin is removed. 4. A method for purifying plasma, which involves treating plasma with activated carbon under acidic conditions in the method for removing substances that cause coloration contained in plasma. 5. Add activated charcoal to plasma in an amount of 0.5 to 10% by weight based on the solution weight, and add an acidic substance to adjust the pH value to 3 to 6.
The purification method according to claim 4, wherein the temperature is maintained at ~40°C, and then the activated carbon is removed. 6. The purification method according to claim 5, wherein when removing the activated carbon, the pH value is adjusted to 7 to 8 by adding an alkaline substance to the mixed liquid, and then the activated carbon is removed. 7. A method for purifying plasma, which comprises adding a polymer electrolyte having a carboxyl group to plasma, and then treating the plasma with an acid. 8. Claim 7, wherein the polymer electrolyte having a carboxyl group is at least one selected from the group consisting of alginic acid, sodium alginate, polyacrylic acid, sodium polyacrylate, and carboxymethyl cellulose.
Purification method described in section. 9. The purification method according to claim 7 or 8, wherein the amount of the polymer electrolyte having a carboxyl group added is 0.001 to 10% by weight based on the weight of the treatment liquid. 10. The method according to claim 7, 8 or 9, wherein activated carbon is added together with the polymer electrolyte having a carboxyl group. 11. Adding a polymer electrolyte having a carboxyl group to 0
11. A purification method according to any one of claims 7 to 10, wherein the temperature is maintained at ~50[deg.] C. and then an acid is added to bring the pH value to 1 to 5. 12. A method for purifying plasma, which comprises filtering plasma using a ceramic filter. 13. The purification method according to claim 12, wherein a ceramic filter with a pore size of 25 μm or less is used. 14. A method for purifying plasma, which comprises adding activated carbon and a polymer electrolyte having a carboxyl group to plasma, and then treating the plasma with an acid. 15. The purification method according to claim 14, which further comprises filtration using a ceramic filter after the acid treatment.