JPS63145288A - Improved process for producing phytic acid - Google Patents

Abstract

PURPOSE:To obtain the titled compound having high quality and useful for corrosion protection of metals, etc., on an industrial scale at a low cost, by passing a liquid containing phytic and (salt) through an ultrafiltration membrane, adjusting the pH of the filtrate to precipitate the salt and treating the precipitate with an ion exchange membrane and a cation exchange resin. CONSTITUTION:A liquid containing phytic acid and/or a phytic acid salt is passed through an ultrafiltration membrane having a fractional molecular weight of 5,000-100,000 and separated into a filtrate passed through the membrane and a concentrated liquid. The filtrate is adjusted to 5-10pH with ammonia water or hydroxide of alkali or alkaline earth metal to precipitate the phytic acid and/or phytic acid salt in the filtrate in the form of a phytic acid salt. The precipitated phytic acid salt is treated with an ion exchange membrane and then with a cation exchange resin to obtain the objective phytic acid.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relieves metal chelation effect, provides metal corrosion protection effect,
The present invention relates to an improved method for producing phytic acid, which has interesting properties such as metal removal action, antioxidation action, and action to prevent the formation of struvite in canned foods. More specifically, the present invention relates to an improved method for producing phytic acid with high purity and efficiency by making full use of membrane separation technology.

BACKGROUND OF THE INVENTION Phytic acid is a hexaphosphoric acid ester of myo-inositol, and is an organic phosphoric acid compound widely present in the plant kingdom. In the plant kingdom, phytic acid is contained in most plants. In plants, phytic acid rarely exists in free form, but rather in mixed bound salts such as calcium, magnesium, potassium, and sodium (commonly referred to as ``phytate'' or simply ``phytin''). However, in this specification, it is hereinafter referred to as "phytin" and exists in the form of -S;a).

The conventional method for producing phytic acid begins by extracting phytic acid contained in plants such as grains and seeds. Since phytin is easily dissolved in acid at room temperature, a dilute aqueous solution of an inorganic acid or a dilute aqueous solution of an organic acid is generally used as an extraction solvent.

The extracted phytin exists as phytic acid and phytin in an acidic aqueous solution and is separated as a precipitate. The precipitation method is an organic solvent addition method.

Addition method of water-soluble heavy metals 1 (iron, manganese sulfate, etc.),
Although there are a water-soluble alkaline earth metal salt addition method and an alkali addition method, the alkali addition method is generally used from the viewpoint of ease of handling and low cost.

After dissolving most of the phytin separated by the above method in a dilute aqueous solution of inorganic acid or phytic acid,
- R-on exchange resin treatment is performed to remove cations and contaminating anions, and the product is produced as an aqueous solution of phytic acid with a concentration of about 50% by weight after passing through a thickening process, decolorization process, etc.

Problems with the conventional technology As described above, phytic acid is produced by extracting phytic acid from a plant such as a single grain seed, and performing steps such as precipitation fractionation, ion exchange resin treatment, concentration, and decolorization. In the phytin extraction process, proteins, grains, and other tissue components are dissolved in the acidic solution, so these substances may be mixed in as impurities during the separation.The separated phytin is a colloidal sediment, and the impurities that enter it are Since it is colloidal, it is very difficult to remove impurities. Further, impurities that cannot be removed not only significantly deteriorate the quality of phytic acid but also cause clogging of the resin layer during ion exchange resin treatment, shortening the life of the resin.

Furthermore, since phytin is water-insoluble, when treating it with ion exchange resin, most of it is usually dissolved in acid and passed through the solution, but phytin, which forms salts with divalent metals such as calcium and magnesium, is not dissolved. When treated with an ion exchange resin, a low concentration phytic slurry must be passed through to prevent insoluble phytic from clogging the resin layer, resulting in very low phytic acid productivity.

On the other hand, if the inorganic acids used to extract phytic acid or the inorganic acids used to dissolve most of the phytic acid before ion-exchange resin treatment remain in phytic acid, they will lead to polymerization and coloration of phytic acid, which will affect the quality of phytic acid. Significantly lower.

Anion exchange resins are used to remove these inorganic acids, but it is difficult to remove contaminant anions. In order to reduce the amount of contaminant anions, a method has been considered in which most of phytin is dissolved in an aqueous phytic acid solution and the solution is passed through the solution. In addition, when passed through an anion exchange resin, phytic acid itself is also adsorbed by the resin,
The yield of phytic acid decreases.

For these reasons, when producing phytic acid, the selection of extraction solvent depends on the type of raw material.

Not only is it necessary to select the optimal extraction conditions and determine the optimal precipitation method, but also to remove impurities and inorganic acids, etc.
The manufacturing process is complicated because the removal operation must be repeated and performed repeatedly. Furthermore, these factors contribute to the cost of producing phytic acid.

Purpose of the Invention The inventors have conducted extensive studies with the aim of improving the problems of the prior art for producing phytic acid mentioned above and producing high-quality and inexpensive phytic acid. The phytin-containing liquid is passed through an ultrafiltration membrane, and the phytin precipitated from the permeate is dissolved in an aqueous solution of an inorganic acid.
The present invention was achieved by discovering that high quality phytic acid free from impurities and impurities can be obtained by treating it with an ion exchange membrane and then treating it with a cation exchange resin.

Components of the Invention The inventors prepared a solution containing phytic acid and/or phytate (phytate) with a molecular weight cut-off of 5, OO'O~t
oo, 000 ultrafiltration membrane (hereinafter referred to as ruF IIJ) to separate it into a membrane permeate and a concentrated liquid, and the permeate is treated with aqueous ammonia, alkali metal hydroxide or alkaline earth. Phytic acid and/or phytin in the permeate is precipitated by adjusting the pH to between 5 and 10 with a similar metal hydroxide (phytic acid precipitates as phytic), and the precipitated phytic is transferred to an ion exchange membrane. After processing,
Furthermore, we have discovered an improved method for producing phytic acid, which is characterized by obtaining phytic acid by treatment with a cation exchange resin.

According to this method, it is possible to remove impurities (i.e., high molecular weight proteins, tissue components, sugars, etc.) that have conventionally complicated the manufacturing process and degraded quality using an ultrafiltration membrane.
Furthermore, when treated with an ion exchange membrane, decation and deanion occur in parallel.

Decationization from phytic acid can reduce the load on the cation exchange resin and the regeneration operation in the finishing process, and can also increase the concentration of the phytic acid solution. On the other hand, since the anion derived from the inorganic acid used for preparing the phytic solution is removed in a scoop-like manner by deanion, the step of using an anion exchange resin can be omitted.

In order to further improve the purity of phytic acid, if necessary, after treatment with cation exchange resin, anion exchange resin treatment or activated carbon treatment is performed to remove impurities such as remaining anions and colored substances. You may.

The present invention will be explained in detail below.

(Starting material) A liquid containing phytic acid and/or phytin.

Liquids obtained by acid extraction from plants, such as acid extracts of rice bran, wheat bran, soybeans, etc., and soaking liquids made by soaking corn in sulfur dioxide (called corn staple liquor). Liquids containing phytic acid and/or phytin that are subject to membrane propagation technology may be of any type as long as they do not contain substances that contaminate or degrade the membranes. In particular, cornstarch liquor has a solid content of about 10% by weight, a pH of about 3.8, and a phytate content of about 8% by weight (based on pure dry matter), which is discharged from the cornstarch manufacturing process and has a molecular weight of 1 t, o.
It is a preferred raw material because it is a liquid substance that contains more than 100% protein, does not require a new acid extraction step, and also allows effective use of CO2 stay liquor, which is equivalent to waste liquid.

(Ultrafiltration) The membrane for treating phytic acid and/or phytin-containing liquid is an ultrafiltration membrane with a molecular weight cut-off of 5,000 to 100,000.The molecular weight cut-off is preferably 10.000. ~
When using an ultrafiltration membrane with a molecular weight cut-off of 100,000 or more, preferably 50,000, soluble proteins pass through the ultrafiltration membrane without being blocked and migrate into the permeate. Therefore, when recovering phytin, most of it may be mixed into phytin as impurities, which is undesirable.
Further, if an ultrafiltration membrane with a molecular weight cutoff of 5.000 or less is used, the permeation flux becomes extremely small, which is uneconomical.

The temperature of the vessel (phytic acid and/or phytin-containing liquid) used for ultrafiltration membrane treatment may be at least room temperature, preferably 40°C to 60°C. , cooling energy is required, and the permeation flow rate is low at such temperatures, making it uneconomical. On the other hand, if the temperature is too high, the life of the 6 ultrafiltration membrane will be shortened and more energy will be required for heating than necessary, which is not preferable.

(Precipitation fractionation of phytin) The permeate that has passed through the ultrafiltration membrane is transparent. Aqueous ammonia, alkaline metal hydroxide or alkaline earth metal hydroxide is added to this transparent liquid, the pH is adjusted between 5 and 10, and phytin in the form of colloid 1 is precipitated. This colloidal phytin is dehydrated using a dehydrator such as a filter press to form a phytin cake. When phytin was recovered directly from the extract without ultrafiltration, the color of the phytin turned dark or yellowish, and contamination with insoluble proteins was observed. The color of the phytin recovered is white to grayish white, and it is clear that there is little insoluble protein, so there is no need to remove impurities and the next step can be carried out immediately. In this way, 1 is precipitated from the liquid that has passed through the ultrafiltration membrane.
The recovered phytic cake hardly contains any impurities, and there is no need to repeat the precipitation fractionation operation several times as in the conventional method, which simplifies the process.

(Demetallized ion of phytin) Highly pure phytin obtained by the above method is dispersed in water or acid, and is prepared using an electrodialyzer using an ion exchange membrane (in the following description, this is , D) to remove metal ions, etc.

A conventional method for obtaining phytic acid by removing metal ions from phytic acid is the ion exchange resin treatment method, but since phytic acid is water-insoluble in this method, when the phytic slurry is passed through the ion exchange resin, the phytic acid is ionized. This will block the exchange resin layer, making it impossible for liquid to pass through. Therefore, most of the phytin is generally dissolved in an aqueous phytic acid solution, and the solution is passed through a cation exchange resin. After that, it is passed through an anion exchange resin to remove contaminating anions. According to this method, a part of the produced phytic acid is used for dissolving phytic acid, which is not only uneconomical, but also causes adsorption of phytic acid to the anion exchange resin, making it difficult to remove contaminant anions. In addition to a decrease in efficiency, this results in a decrease in the yield of phytic acid, resulting in an increase in cost.

On the other hand, E and D desalinate using the ion-selective permeability of the ion-exchange membrane; in other words, cation-exchange membranes allow only cations to pass through and hardly any anions. This method utilizes the function of allowing only anions to pass through while almost no cations pass through, and uses direct current as the driving force to desalinate salts. Therefore, it has the advantage of not requiring any complicated regeneration operations unlike ion exchange resins.

As in the present invention, phytin is dissolved in an aqueous solution of an inorganic acid, and E
When treated with , D, (ion exchange membrane) and then passed through a cation exchange resin, phytin is decationized at E and D, increasing the solubility of phytin. There is no problem of blockage, and compared to treatment using only ion exchange resin, a high concentration phytic acid solution can be treated, and as a result, a high concentration phytic acid solution can be made, making it possible to improve the productivity of phytic acid. . Furthermore, in the conventional method, the use of inorganic acids such as hydrochloric acid was avoided due to the difficulty of removing anions when preparing a solution of phytic acid, and an aqueous solution of phytic acid was used instead, but according to the present invention, Since an inorganic acid such as hydrochloric acid can be used to prepare a solution of phytic acid, the problem that was conventionally considered to be uneconomical by using phytic acid can be solved. Since most of the anions derived from the inorganic acid used are removed by the E, D and (ion exchange membrane) treatments to the extent that they do not affect the product, it is possible to omit anion exchange resin treatment as required in subsequent steps.

Considering running costs and loss of phytic acid, the combination of E, D, (ion exchange membrane) and cation exchange resin as in the present invention is advantageous. By doing this, compared to conventional methods, the load on the ion exchange resin can be extremely reduced, and the number of complicated regeneration operations can also be greatly reduced.
Playback operations also become easier. Furthermore, a high concentration of phytin can be treated and anion exchange resin treatment can be omitted.

Examples Example-1 Corn soaking liquid discharged from the process of producing corn starch was passed through a 200-mesh strainer to remove foreign substances.

Liquid L251 from which foreign substances were removed has a solid content of 94-09g/fL, a total nitrogen content of 7.30g/fL, and a total phosphorus content of 3.4g/fL.
It contained 0g/liter and inorganic phosphorus 0.80g/liter. This liquid was filtered through a tubular type ultrafiltration membrane (40,000 fractions)
UF membrane) DUY-L (manufactured by Daicel Chemical Industries, Ltd.) was treated batchwise to obtain a permeate. The processing conditions are: average circulation linear velocity of 2 m/sec, input pressure of 8.8 kg/c.
rrf, outlet pressure of 4.8 Kg/cm'', and liquid temperature of 45° C. At this time, the capacity reduction rate t was 5.

(Wood Capacity reduction rate = Supply liquid volume / (Supply liquid volume - Permeate volume) This permeate contains 5.89 g/liter of total nitrogen, 2.58 g/l of total phosphorus, and 0.6 og/i of inorganic phosphorus. , solid content was 80.50 gel.

Next, add hydric soda to the permeated liquid to adjust the pH to 8,
5 to obtain a precipitate.

This precipitate was collected using a Buchner funnel and No.
After passing through a suction port and performing solid-liquid separation using a 131, the mixture was thoroughly washed with water to obtain 4,200 g of cake.

This cake contained 17.1% by weight of solids, with a total nitrogen content of 1.0% by weight and a total phosphorus content of 17.1% by weight.
1% by weight, and 0.2% by weight of inorganic phosphorus.

Dissolve this in a 1.5% aqueous hydrochloric acid solution to give a solution with a pH of 3.5 and a solid content of 10% (W/V).

This solution was first applied to an electrodialyzer (Asahi Glass Co., Ltd. 011- Ob type), energizing time 3 hours, voltage 10V, 1% as polar liquid and concentrated liquid.
Treated using saline.

Next, this treatment solution was applied to an acrylic resin column with a diameter of 6 cm and a height of 90 cm, and a strongly acidic cation exchange resin (Diaion 5KIB manufactured by Mitsubishi Chemical Industries, Ltd.)
1, and the liquid was passed through at a rate of 5V (liquid flow rate/hour/ion exchange resin capacity/hour) and processed until the solid content was 78.
A phytic acid solution with a total nitrogen content of 0.003 g/min, a total phosphorus content of 22.0 g/min, an inorganic phosphorus content of 0.2 g/min, and a chlorine concentration of 0.04 g/min was obtained.

The liquid thus obtained was concentrated using an evaporator to obtain a phytic acid solution having a degree of a of 50% by weight.

This phytic acid solution was subjected to high performance liquid chromatography (column: strongly acidic cation exchange resin CK08H type, detector R).
1. When analyzed at a flow rate of 1 ml/ml (n), the result was 98.5
% purity of phytic acid solution was obtained.

Example-2 Similar to Example-1, the 200-mesh strainer-treated corn soaking liquid 125λ had a solid content of 98.0 g/l.
, total nitrogen 7.80g/M, total phosphorus 3.50
g/liter and contained 0.6 g/liter of inorganic phosphorus. This liquid was transferred to a capillary type UF membrane MU-63 with 13,000 fractions.
02H (manufactured by Kuraray Co., Ltd.) in a batchwise manner. Processing conditions are: average circulation linear velocity 2m/sec, inlet pressure 2.2kg
/ crn', outlet pressure 0.4 kg/cm', and liquid temperature 45°C. The capacity reduction rate at this time was 5.

This permeate had a solid content of 82.1 g/liter and a total nitrogen content of 6
．． It contained 14 g/liter, total phosphorus 2.45 g/liter, and inorganic phosphorus 0.6 g/Q. Solid content is 82.1g/
It was a sentence.

This permeate too! 1 was treated in the same manner as in Example-1 to obtain 4350 g of cake. This cake contained a solid content of 171 weight % taro, total nitrogen in the solid content was 1.1 weight % taro, total phosphorus was 16.7% by weight, and inorganic phosphorus was 0.
It was 2% by weight.

After this cake was treated in the same manner as in Example 1, E, D
After treatment with strong acidic cation/ion exchange resin, solid content 78.9g/unit, total nitrogen 0.003g/unit, total phosphorus 22.2g/unit, inorganic phosphorus 0.2g/unit, chlorine concentration 0,04g/unit. A fresh phytic acid solution was obtained.

This solution was concentrated in the same manner as in Example-1 to obtain a phytic acid solution with a solid content of 50% by weight. When this was analyzed by high performance ring chromatography, it was found to be a phytic acid solution with a purity of 98.9%.

Example-3 Using 10 kg of raw rice bran, stir in 120 g of 1.5% hydrochloric acid aqueous solution at room temperature for 2 hours to remove phytin and remove rice bran.
Thereafter, 100 g of this extract was treated in the same manner as in Example 1, and 4,840 g of phytic cake was obtained from 80 g of the permeate.

This cake contained 18.5% solids, 0.1% total nitrogen in the solids, and 19% r-talurine.
2% by weight, and inorganic phosphorus was 0.1% by weight. As in Example 1, this phytic cake was dissolved in an aqueous hydrochloric acid solution and then subjected to E, D, (ion exchange membrane) treatment, and ion exchange resin treatment. .

A phytic acid solution was obtained. The phytic acid solution at this time had a solid content of 79.8 g/liter and a total nitrogen content of 0°002 g/liter.
l, total phosphorus 22.5g/liter, inorganic phosphorus 0.18
/ sentence, chlorine concentration 0, 035 g/cross.

After concentrating this phytic acid solution to 50% by weight, it was analyzed by high performance ring chromatography and was found to be a phytic acid solution with a purity of 99.6%.

Control example-1 Solid content 10% from the phytic cake produced in Example-1
(W/V) slurry and a slurry with a solid content of 1% (W/V) were prepared, and these were immediately treated with a strongly acidic cation exchange resin without dissolving in an aqueous hydrochloric acid solution, E, D, or treatment. . The toL3b slurry clogged the resin layer while flowing through the column, making it impossible to operate. A phytic acid solution having a solid content of 7.7 g/Q, a total phosphorus of 1.95 g/u, and an inorganic phosphorus of 0.03 g/i was obtained from the 1% slurry.

The purity of this phytic acid was found to be 88.5% by high performance liquid chromatography analysis.

In the case of cation exchange resin column treatment - Highly concentrated slurry clogs the resin layer, making it impossible to use.

- Low concentration slurry can be passed through, but it becomes a low concentration phytic acid solution. - If phytic slurry is dissolved in hydrochloric acid and passed through, clogging will be eliminated, but it will be difficult to remove chlorine.

Control example-2 Phytic cake produced in Example-2 with a solid content of 10%
(W/V) slurry was prepared and treated in the same manner as Control Example 1. As in Control Example 1, the resin layer was clogged during passage through the column, making it impossible to operate.

Control example-3 (conventional method that does not use ultrafiltration membrane) Solid content 8
A corn steeping solution containing 9.0 g/Ai, total nitrogen 7° x 1 liter, total phosphorus 3.1 g/liter, and inorganic phosphorus 0.7 g/l was treated in the same way as was applied to the permeate of Example 1. 7.080 g of cake was obtained.

This cake contained 17.6% solids by weight.

The total nitrogen in the solid content was 3.35% by weight, the total phosphorus was 12.0% by weight, and the inorganic phosphorus was 0.2% by weight.

A slurry with a solid content of 10% (W/V) was prepared from this cake and treated in the same manner as in Control Example 1. As in Control Example 1, clogging occurred during liquid passage through the column, making it impossible to operate.

In this control example, ultrafiltration membrane treatment was not performed, so
When alkali was added to the corn soaking solution to form a phytin precipitate, protein aggregates were formed and mixed into the phytin cake.

Control Example-4 Raw rice bran oil extract treated in the same manner as in Example-3 was not subjected to ultrafiltration treatment, but was treated in the same manner as the permeate in Example-3, and 5.830 g of cake was obtained. Obtained. This goo contained a solid content of 19.3% by weight, and the total nitrogen in the solid content was 1.6% by weight, the total phosphorus was 13.6% by weight, and the inorganic phosphorus was 0.1% by weight.

A phytic slurry is prepared from this cake, and further,
This slurry was dissolved in an aqueous hydrochloric acid solution, and the solid content was 10% (W
/V)-, a slurry with a pH of 3.5.

This slurry was treated in the same manner as Example 1.

As in Control Example 1, a blockage occurred during the passage of liquid through the cation exchange resin column, making it impossible to operate.

In this control example, hydrochloric acid was used to increase the column concentration.
Although the solubility of phytin was increased by lowering H, this shows that there is a limit to the amount of water that can be passed through the solution once.

Control Example-5 (When using an electrodialyzer) The cake prepared in Control Example 3 was dissolved in hydrochloric acid, pH 3.5, solid content 1.
After setting it to 6 (W/V).

E, D, (ion exchange membrane) treatment was performed, but protein aggregates that do not dissolve in hydrochloric acid clog during ED film formation.
It became inoperable.

Control Example-5 When using ED after physical pretreatment (removal of protein aggregates) After passing the neutralization solution (PH8, 5) of Control Example 3 through a 150-mesh sieve to remove as much protein aggregates as possible,
The same treatment as in Example 1 was carried out to obtain 7.000 g of cake.

This cake contains 17.5% solids by weight, with a total nitrogen content of 2.35% by weight and a total phosphorus content of 13% by weight.
．． 9% by weight, and inorganic phosphorus was 0.2% by weight.

This was dissolved in hydrochloric acid, pH 3.5, solid content 109g (W
/v) and then passed through filter paper No. L manufactured by Toyo Roshi Co., Ltd. to remove insoluble fine protein aggregates.

This was subjected to the same E, D and (ion exchange membrane) treatments as in Example 1, resulting in a solid content of 82.0 g/i.

Total nitrogen 0.9g/text, total phosphorus 14°3g/
A phytic acid solution containing 0.2 g of inorganic phosphorus and 0.041 g of chlorine was obtained.

This liquid was condensed using an evaporator, and the solid content was 50% by weight.
A phytic acid solution was obtained. The purity of this phytic acid is 61
%Met.

Control Example-7 The phytic cake produced in Example-2 was dissolved in an aqueous hydrochloric acid solution to adjust the pH to 3.5 and solid content to 3.5% (W/V), and then treated with a strongly acidic cation exchange resin and further It was treated with a weakly basic anion exchange resin (Diaion WA30 manufactured by Mitsubishi Chemical Industries, Ltd.). As a result, the solid content was 8.3g/l,
Total phosphorus 2.1g/kg, inorganic phosphorus 0.03g/kg,
A phytic acid solution with a chlorine concentration of 0.2 g/l was obtained. The purity of this phytic acid was 89.8%. This phytic acid solution had a high chlorine concentration, coloration was rapid, and the yield of phytic acid was poor.

(Summary of analysis results) Comparative data on the phytic acid cake and phytic acid solution obtained in the above examples and control examples are shown in Sections 1 to 3 below.
They are summarized in the table.

C, R = cation exchange resin, A, R - anion exchange resin.

Table 2 shows a comparison of phytic acid solutions. By carrying out treatment B, followed by treatment E, treatment D, and cation exchange resin treatment, a phytic acid solution with high purity and high strength can be obtained.

Table 3 Measured at 435 mm and shows absorbance.

Table 3 shows the change over time in the coloring of the phytic acid solutions obtained in Example-1 and Control Example-7.

Coloration is greatly influenced by storage temperature, but also depends on the amount of anions remaining in phytic acid.

Effects of the Invention According to the present invention, by introducing a membrane separation technology that combines an ultrafiltration membrane and an ion exchange membrane, strict process control in the phytic acid extraction process can be eliminated, and the impurity removal process in the phytic acid production process can be greatly improved. It becomes possible to reduce the width and easily obtain highly pure phytic acid.

Applicant: Food Industry Membrane Utilization Technology Research Association Agent: Patent attorney: Saneo Isaka (1 person) Procedural amendment January 30, 1982

Claims (1)

[Claims] A solution containing phytic acid and/or phytate is passed through an ultrafiltration membrane with a molecular weight cutoff of 5,000 to 100,000, separated into a membrane permeate and a concentrated solution, and the permeate is treated with ammonia. By adjusting the pH to between 5 and 10 with water, an alkali metal hydroxide or an alkaline earth metal hydroxide,
Phytic acid and/or phytate in the permeate is precipitated as phytate, and the precipitated phytate is treated with an ion exchange membrane and then further treated with a cation exchange resin to obtain phytic acid. An improved method for producing phytic acid.