JPH09278782A - Production of phytic acid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a high-purity phytic acid (at <=0.05 weight ratio of protein/ phytic acid contents) from a phytic acid extract solution with a higher content of a protein than the content of phytic acid such as a soybean whey (at >=2 weight ratio of protein/phytic acid contents). SOLUTION: A phytic acid extract solution at >=2 weight ratio of the protein/ phytic acid contents is deproteinized to produce a phytic acid at <=0.05 weight ratio of the protein/phytic acid contents in the method for adsorbing a phytic acid extract solution on an anion exchange column, eluting the absorbed phytic acid and purifying the eluted phytic acid.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing high-purity phytic acid from a phytic acid extract having a high protein content.

[0002]

2. Description of the Related Art As a method for producing phytic acid, Japanese Patent Publication No. Sho 62-133.
In JP 58, the extracted crude phytic acid solution was directly applied to an anion exchange resin column to adsorb the phytic acid component, and then phytic acid was eluted with an alkali, and the cation was used with a cation exchange resin. A method of removing the above is disclosed.

From the third column, line 43 to the fourth column, line 10 of the same publication, corn steep liquor and defatted rice bran dilute sulfuric acid extract are described as phytin-containing acidic solutions used as raw materials.

Although the raw material extract has a relatively high phytic acid content, it has a relatively low protein content (usually protein /
Since the phytic acid content (weight ratio) is less than 2, it is possible to obtain phytic acid with a low protein content by directly adsorbing it on an anion exchange resin column and eluting it with an acid or alkali.

However, this method is unsuitable for producing high-purity phytic acid from soy whey having a high protein content (usually having a protein / phytic acid content (weight ratio) of about 7) and the like. Nowhere is disclosed the production of high purity phytic acid from soy whey. Phytic acid, which has a high protein content, has an odor and color (turbidity) derived from protein.
The effect of protein interferes with the
It is desired to reduce the protein content in phytic acid.

[0006]

DISCLOSURE OF THE INVENTION The present invention is highly applicable to a phytic acid extract solution (protein / phytic acid content (weight ratio) of 2 or more) having a high protein content relative to the phytic acid content of soybean whey. The purpose was to produce pure phytic acid (protein / phytic acid content (weight ratio) of 0.05 or less).

[0007]

[Means for Solving the Problems]
Using the method described in Japanese Patent No. 3358, soybean whey was directly applied to an anion exchange resin column to adsorb the phytic acid component, and then phytic acid was eluted using an alkali, but the protein content was low. It was not possible to obtain high-purity phytic acid.

Then, as a result of intensive research, the phytic acid extract was deproteinized to give a protein / phytic acid content (weight ratio).
The present invention has been completed by finding that the problem can be solved by setting the value to be less than 2.

That is, the present invention provides a method of adsorbing a phytic acid extract on an anion exchange column, eluting it, and purifying it, and removing a phytic acid extract having a protein / phytic acid (weight ratio) of 2 or more. This is a method for producing phytic acid having a protein / protein / phytic acid (weight ratio) of 0.05 or less. Soybean whey is suitable as the phytic acid extract. In the deproteinization mode, the phytic acid extract can be subjected to ultrafiltration, or the phytic acid extract can be adjusted to pH 7 or higher to precipitate and recover phytic acid. The eluted phytic acid eluate can be electrodialyzed to remove excess salts.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The phytic acid extract used in the present invention has a protein / phytic acid weight ratio of 2 or more, preferably 4 or less.
The above can be used. For example, soy whey having a ratio of about 7 is suitable because it is obtained in a large amount in the soy protein production process and can be stably obtained as a phytic acid extract. Corn steep liquor, rice bran sulfuric acid extract and the like having this ratio of about 1 do not need to use the method of the present invention, but if they are used, phytic acid of higher purity can be obtained.

In the deproteinization aspect of the present invention, removal of the protein by the isoelectric point precipitation method is not sufficient, and membrane separation such as reverse osmosis membrane method or ultrafiltration membrane method or phytic acid is subjected to alkali precipitation for recovery. The method of doing is suitable. In the method of membrane separation, filtration by ultrafiltration membrane is more effective than concentration / separation by reverse osmosis membrane
Separation is industrially suitable for a large amount of treatment, and is preferable.

As a mode of ultrafiltration, a known ultrafiltration device can be used to recover only low-molecular components including phytic acid. In this case, the molecular weight cut-off of the ultrafiltration membrane used is 5,000 to 100,000, preferably 10,000 to 50,000. Since the molecular weight of phytic acid is 1,000 or less, protein components can be efficiently removed using the ultrafiltration membrane. The concentration ratio of the protein at this time depends on the properties of the phytic acid extract and the type of the membrane, but is 2 to 20 times, preferably 5 times to
10 times is appropriate. If the concentration ratio is low, the recovery rate of phytic acid is lowered, and if the concentration ratio is high, the membrane is clogged, which is not preferable. Further, the concentration ratio can be increased by using filter treatment and centrifugation together.

The phytic acid extract obtained by deproteinization by ultrafiltration is suitable because it can be adsorbed directly to the anion exchange column without the need to redissolve phytic acid as in the alkaline precipitation method described below. is there. Further, the ultrafiltration method can be carried out before or after application to the anion exchange column in any step of column treatment or desalting treatment performed thereafter.

As the alkaline precipitation method, a method of treating the phytic acid extract with an alkaline agent and recovering phytic acid as a precipitate can be used. The alkali agent at this time is preferably a monovalent substance such as sodium hydroxide, potassium hydroxide, or ammonia water, and a substance containing a metal having a valence of 2 or more such as calcium or magnesium is deteriorated in the subsequent redissolution treatment. , Not preferable.

As a mode of treating with an alkaline agent, the pH of the solution is adjusted to 7 or more, preferably 8 or more by adding the alkaline agent to the phytic acid extract. If the pH is less than 7, phytic acid does not precipitate, which is not preferable. pH 7 ~
Phytic acid precipitates at pH 8 but the precipitate formation is not sufficient, and at pH 8 or higher, phytic acid precipitates sufficiently, which is preferable. By adjusting the pH, a precipitate containing phytic acid can be obtained within a few minutes. Also, at this time Aqualic FH
Precipitate can be recovered more effectively by using a polymer flocculant such as G (manufactured by Kurita Kogyo Co., Ltd.) or Hymoloc ZP-700 (manufactured by Hymo Co., Ltd.).

The precipitate of phytic acid thus recovered can be redissolved in an acidic solution. The presence of excess acid can also be removed by subsequent anion exchange resin column treatment. The acid used for re-dissolving the phytic acid precipitate is suitably one or more selected from organic acids such as citric acid, lactic acid and tartaric acid, and mineral acids such as hydrochloric acid, sulfuric acid and phosphoric acid.

The measurement of phytic acid was conducted according to "J. Agric Food".
Chem 1980, Vol 28, 1315 ”, and protein measurement was by the Biuret method.

Next, the deproteinized phytic acid solution is supplied to an anion exchange column, and phytic acid is adsorbed on the anion exchange resin packed in the column.

The concentration of the phytic acid extract when adsorbed on the anion exchange resin is 0.02 to 10% by weight, preferably 0.05.
-5% by weight is suitable. If the concentration is less than 0.02%, the amount of column treatment increases and the apparatus becomes large, and if the concentration is more than 10%, the viscosity is high and column treatment becomes difficult.

The anion exchange resin used for the anion exchange column is Amberlite IR-45, IR-68, IR-93, IR-41.
0, IR-411 (manufactured by Organo Corporation) and Duolite A-37
5, A-368, A-378 (manufactured by Sumitomo Chemical Co., Ltd.) or the like can be used, but regardless of this, it is appropriately selected from basic ones. Exchange groups of anion exchange resin are CO3 type, CH3COO type, Cl
Type, SO3 type, or OH type is used, but Cl type and SO3 type are particularly preferable in terms of selectivity.

Although the adsorption of phytic acid on the anion exchange column cannot be specified unconditionally, a phytic acid extract having a pH of about 1 to 7 is usually supplied at a rate of SV of about 0.5 to 50.

Next, the phytic acid adsorbed on the anion exchange resin is eluted. The adsorbed phytic acid can be eluted using an alkali, an acid, a salt or the like. The eluted phytic acid eluate can be purified by desalting or the like. Since the aspect of purification such as desalting differs depending on the aspect of elution, it will be described below. Regarding the concentration range of each salt used below, if the concentration is higher than 5 N (M), the subsequent desalting is overloaded, and if it is lower than 0.05 N (M), phytic acid is not eluted.

In the case of alkaline elution, 0.05 to 5N of an alkaline solution such as sodium hydroxide, potassium hydroxide or aqueous ammonia is passed through an anion exchange column having phytic acid adsorbed at a rate of about SV 0.2 to 20. Can be eluted.

Pure phytic acid can be obtained by passing this phytic acid eluate through a cation exchange resin (H type) to convert cations into H +.

In the case of acid elution, an acidic solution of hydrochloric acid, sulfuric acid, phosphoric acid or the like of about 0.05 to 5N is passed through an anion exchange column having phytic acid adsorbed at a speed of about SV 0.2 to 20 to elute. Can be done.

By purifying the obtained phytic acid eluate by electrodialysis, anions other than phytic acid present therein can be eliminated and pure phytic acid can be obtained. Unlike alkaline elution and subsequent cation-exchange resin treatment, there is no need to regenerate the cation-exchange resin, so there is little drainage and industrial practicality is high.

In the case of salt elution, a neutral salt solution of about 0.05 to 5 M sodium chloride, potassium chloride, ammonium sulfate or the like is applied to the anion exchange resin column on which phytic acid is adsorbed by SV.
It is possible to elute by passing the liquid at a rate of about 0.2 to 20 bed volume / Hr (the same unit below).

To the obtained phytic acid eluate, phytic acid and an equivalent amount or more of a low-molecular-weight acid such as hydrochloric acid or sulfuric acid are added and purified by electrodialysis to remove cations and anions other than phytic acid present therein. It can be eliminated and pure phytic acid can be obtained.

The phytic acid solution purified as described above can be used as an antioxidant, a chelating agent or the like as it is or after being concentrated by vacuum concentration or the like.

[0030]

The embodiments of the present invention will be described below with reference to examples. Example 1 (alkaline precipitation method) 30 parts by weight of water was added to 2.5 parts by weight of defatted soybean to recover soluble components. This was adjusted to pH 4.5 with hydrochloric acid, and the supernatant (soybean whey) from which the protein components had been removed by precipitation was used as a phytic acid extract.

This soy whey has a dry solid content of 2.2% by weight,
Phytic acid content was 0.052% and protein content was 0.34%.
That is, the protein / phytic acid weight ratio was 6.5. However,
The measurement of phytic acid is described in "J. Agric Food Chem 1980, Vol 2
The method described in "8,1315" and the measurement of protein were based on the Biuret method.

Next, sodium hydroxide was added to the soybean whey to adjust the pH of the crude phytic acid extract to 8, and 15 ppm of a polymer flocculant (Aqualic FHG) was further added, followed by centrifugation to obtain phytic acid. A rich precipitate was collected.

Next, this phytic acid precipitate was suspended in 3 parts by weight of water, phytic acid was redissolved by adding hydrochloric acid to lower the pH to 4, and the supernatant was recovered as a phytic acid concentrate. did. This concentrated phytic acid solution had a dry solid content of 1.1% by weight, a phytic acid content of 0.40%, a protein content of 0.061%, and a protein / phytic acid weight ratio of 0.15.

This concentrated phytic acid solution was passed through a Duolite A-375 anion exchange resin column regenerated into Cl type with SV10 to adsorb phytic acid. Subsequently, 1 part by weight of 0.2N sodium hydroxide solution was passed through with SV10 to elute phytic acid, and the eluate was regenerated into H-type Duolite C.
-By passing SV10 through a cation exchange resin column,
0.5 parts by weight of a solution containing 0.008 parts by weight of phytic acid was obtained.

The analytical value of this phytic acid was 1.8% dry solids.
% By weight, protein content was 0.021% by weight, phytic acid content was 1.6% by weight, and protein / phytic acid (weight ratio) was 1.3%. Comparative Example 1 (without deproteinization) In the same manner as in Example 1, a crude phytic acid extract was obtained. This was passed through a Duolite A-375 anion exchange resin column that was directly regenerated to Cl type with SV50 to adsorb phytic acid. Phytic acid was eluted by passing 1 part by weight of 0.2N sodium hydroxide solution through SV10, and the eluate was added to SV10 on a Duolite C-20 cation exchange resin column regenerated to H + type.
Then, 0.5 part by weight of a solution containing 0.01 part by weight of phytic acid was obtained.

The analytical value of this phytic acid is 2.8 dry solids.
% By weight, protein content 0.40% by weight, phytic acid content 2.0% by weight, protein / phytic acid (weight ratio) was 20%.

This had a higher protein concentration than that of the phytic acid obtained in Example 1 and had a low phytic acid purity. Example 2 (Ultrafiltration method) 30 parts by weight of water was added to 2.5 parts by weight of defatted soybean, and hydrochloric acid was further added to adjust the pH to 4.5, and then a soluble component (soybean whey) was added.
Was recovered. Analysis value is 2.5% by weight of dry solids, protein content
Soybean whey, which was 0.40% by weight and phytic acid content was 0.055% by weight, was concentrated by an ultrafilter (membrane: manufactured by Daicel Chemical Industries) having a molecular weight cut off of 40,000 to obtain 24 l of a filtrate. The analytical values were 2.0% by weight of dry solids, 0.005% by weight of protein, and phytic acid content of 0.
The content was 055% by weight. Next, this filtrate was passed through a Duolite A-375 anion exchange resin column regenerated into Cl type at SV50 to adsorb phytic acid. Phytic acid was eluted by passing 1 part by weight of 1N sodium chloride solution through SV10, and 15 ml of concentrated hydrochloric acid was added to the eluate, followed by electrolysis for 2 hours at 9V using an electrodialyzer (Membrane Process). By performing dialysis and removing coexisting salts out of the system, phytic acid 0.00
0.5 parts by weight of a solution containing 8 parts by weight was obtained. Deposition value is 1.8% by weight of dry solid, 0.02% by weight of protein, phytic acid content
1.6% by weight, protein / phytic acid (weight ratio) 1.3%
Met.

[0038]

Industrial Applicability According to the present invention, it becomes possible to obtain highly pure phytic acid having a low protein content even from a phytic acid extract having a high protein content.

Claims (5)

[Claims] 1. A method of adsorbing a phytic acid extract onto an anion exchange column, eluting and purifying the phytic acid, wherein the phytic acid extract having a protein / phytic acid (weight ratio) of 2 or more is deproteinized to obtain a protein. / A method for producing phytic acid having a phytic acid (weight ratio) of 0.05 or less. 2. The method according to claim 1, wherein the phytic acid extract is soy whey. 3. The method according to claim 1 or 2, wherein the deproteinization mode is ultrafiltration of the phytic acid extract. 4. The mode of deproteinization is that the phytic acid extract is adjusted to pH 7
The production method according to claim 1 or 2, wherein the phytic acid is recovered by precipitation. 5. The method according to any one of claims 1 to 4, wherein the eluted phytic acid eluate is electrodialyzed to remove excess salts.