CN116041385A

CN116041385A - Method for extracting phytic acid from corn steep liquor

Info

Publication number: CN116041385A
Application number: CN202211615854.1A
Authority: CN
Inventors: 陈威武; 阮班波; 龚明继
Original assignee: Hebei Yuwei Biotechnology Co ltd
Current assignee: Hebei Yuwei Biotechnology Co ltd
Priority date: 2022-12-15
Filing date: 2022-12-15
Publication date: 2023-05-02

Abstract

The invention discloses a method for extracting phytic acid from corn steep liquor, belonging to the technical field of phytic acid extraction technology. The corn soaking water selected as the production raw material in the method is a byproduct of a starch factory, and is low in cost and easy to obtain. Solves the technical problems of high acid-base consumption and large discharge of a large amount of sewage caused by adopting a multi-step ion exchange process to remove impurities in the phytic acid production by using the phytin as a raw material. The phytic acid is extracted by absorbing corn soaking liquid through one-step resin, and then the high-quality phytic acid finished product is obtained by separating and concentrating through a nanofiltration membrane, removing impurities through a chromatographic column and carrying out bipolar electrodialysis acidification, so that the product has the advantages of thorough separation of salt and organic matters, high purity, no color change during storage, long shelf life, and reduction of the sewage discharge amount of each ton of the product by more than 80 percent, thereby realizing clean civilized production and sustainable development. The phytic acid produced by the process is clear and transparent, and various indexes meet the requirements of the phytic acid standard of national standard GB 1886.237-2016 food additives.

Description

Method for extracting phytic acid from corn steep liquor

Technical Field

The invention belongs to the technical field of phytic acid extraction processes, and particularly relates to a method for extracting phytic acid from corn steep liquor.

Background

At present, two main processes are available for producing phytic acid, namely, a process of taking phenanthrene and adding diluted hydrochloric acid into phenanthrene and acidolysis to obtain mixed solution of phytic acid and calcium chloride, wherein calcium ions are removed from the mixed solution through cation exchange resin to obtain mixed solution of phytic acid and hydrochloric acid, the mixed solution is saturated and adsorbed through acrylic resin, then chlorine ions are removed through washing with a large amount of water, sodium hydroxide is used for resolving to obtain sodium phytate feed liquid, sodium phytate feed liquid is subjected to strong acid cation resin to remove sodium ions to obtain diluted phytic acid feed liquid, and the diluted phytic acid feed liquid is concentrated and decolored to obtain finished phytic acid.

A process for preparing phytic acid from rice bran includes such steps as immersing rice bran in acid, filtering to obtain an immersing liquid containing 0.8% phytic acid, neutralizing with calcium hydroxide to obtain phytic acid, and features less raw materials, high sewage discharge and difficult mass production.

Disclosure of Invention

The first objective of the present invention is to provide a method for extracting phytic acid from corn steep liquor, which is used for solving the technical problem of low extraction quality caused by the selection of phytic acid extraction raw materials.

The second object of the present invention is to provide a method for extracting phytic acid from corn steep liquor, in which only a group of anion resin columns are used for adsorption, and phytic acid in the resin columns can be washed by sleeving water and a small amount of clear water, so that the water consumption and the pollution discharge are reduced, and the technical problem that a large amount of water is required to be washed after a plurality of resin columns are used for adsorption in the prior art, and serious waste of water resources is caused is solved.

The third object of the invention is to provide a method for extracting phytic acid from corn steep liquor, in the method, the method can remarkably improve the yield of the phytic acid by utilizing the modes of nanofiltration membrane filtration concentration, chromatographic column separation and impurity removal and bipolar electrodialysis acidification treatment, and can ensure that the obtained phytic acid meets the national food additive standard.

The fourth object of the present invention is to provide a method for extracting phytic acid from corn steep liquor, wherein various residual liquids such as corn steep supernatant, eluent, water for washing resin column, filtrate, etc. which are used for treatment are circulated to corresponding steps of the whole extraction method for recycling, thereby saving resources and improving utilization rate.

The invention is realized by the following technical scheme:

a method of extracting phytic acid from corn steep water, the method comprising:

(1) After the corn soaking water in the starch factory is subjected to sedimentation and impurity removal treatment, the obtained corn soaking liquid primary pulp enters an anion resin column for circulating saturated adsorption, and when the phytic acid content of effluent reaches 80% of the organic phosphorus content of the primary pulp, the adsorption is finished;

(2) Ejecting corn steep liquor primary pulp in the anion resin column of the step (1) by using water, washing the anion resin column by using clear water, and eluting by using alkali liquor to obtain crude sodium phytate feed liquid with pH value not higher than 10;

(3) And (3) decoloring the crude sodium phytate feed liquid in the step (2) by using active carbon, filtering, removing impurities and concentrating by using a nanofiltration membrane, separating and removing impurities by using a chromatographic column, and acidizing by using bipolar electrodialysis to obtain the refined phytic acid.

The corn soaking water selected as the production raw material in the method is a byproduct of a starch plant, is cheap and easy to obtain, and changes waste into valuable. The method solves the technical problems of impurity removal, high acid-base consumption and large discharge of a large amount of sewage by adopting a multi-step ion exchange process for producing phytic acid by taking the phytin as a raw material. According to the method, the corn soaking water phytic acid is adsorbed by the one-step method resin, then nanofiltration membrane separation and concentration, chromatographic column impurity removal and bipolar electrodialysis acidification are adopted, so that a high-quality phytic acid finished product is obtained, the sewage discharge amount of ton products is reduced by more than 80%, and clean civilized production and sustainable development can be realized. The nanofiltration membrane is adopted for separation and concentration and the chromatographic column is adopted for impurity removal, so that the salt and organic matters are thoroughly separated, the product purity is high, the color is not changed during storage, the quality guarantee period is long, and the requirements of high-end customers can be met.

Preferably, the resin packed in the anion resin column is a free amine type acrylic acid anion exchange resin.

The resin has good selective adsorption performance on the phytate.

Preferably, the anion resin column cyclic saturation adsorption treatment includes: after the anion resin column adsorbs the extracted primary pulp, when the phytic acid content in the effluent liquid is 10wt% of the phytic acid content in the extracted primary pulp, the effluent liquid circularly enters the extracted primary pulp, and the anion resin column circularly performs saturated adsorption until the phytic acid content in the effluent liquid is not less than 80wt% of the phytic acid content in the extracted primary pulp.

Preferably, in the step (2), the alkali liquor comprises a dilute alkali solution with a mass concentration of 5wt% to 6 wt%.

Preferably, the dilute alkali solution is sodium hydroxide solution.

Preferably, in the step (2), the eluent mixture obtained after the alkali solution elution is returned to the original eluent for recycling.

Preferably, in the step (3), the use mass ratio of the crude sodium phytate feed liquid to the activated carbon is: 15wt% to 20wt%.

Preferably, in the step (3), the filtering is performed by adopting a cloth bag filtering device with the aperture of 2 μm;

the concentration adopts nanofiltration membrane filtration concentration treatment, and the molecular weight cut-off of the membrane is 150-200D.

Nanofiltration membranes have pore diameters above 1nm, typically 1-2nm. Is a functional semipermeable membrane that allows the permeation of solvent molecules or certain low molecular weight solutes or low-valent ions. It is a special and very promising separation membrane variety, it is named because of the size of the trapped substance about nanometers, it traps the molecular weight of the organic matter about 150-500, the ability to trap soluble salt is between 2-98%, desalt the monovalent anion salt solution is lower than the high-valence anion salt solution. Is used for removing organic matters and chromaticity of surface water, removing hardness of groundwater, partially removing soluble salts, concentrating fruit juice, separating useful substances in medicines, and the like. Nanofiltration membranes are mostly composite membranes, and the surface separation layer is composed of polyelectrolyte, so that the nanofiltration membranes have a certain retention rate on inorganic salts. Nanofiltration membranes commercialized abroad mostly compound an ultrathin separation layer with nanoscale pore diameter on a microporous base membrane by an interfacial polycondensation and condensation method. Nanofiltration membranes are capable of trapping nanoscale (0.001 microns) materials. The operation interval of the nanofiltration membrane is between ultrafiltration and reverse osmosis, the molecular weight of the trapped organic matters is about 200-800MW, the capacity of trapping dissolved salts is 20% -98%, the removal rate of soluble monovalent ions is lower than that of high-valence ions, the nanofiltration is generally used for removing organic matters, pigments and hardness and radium in surface water and underground water, and the dissolved salts are partially removed, so that useful substances in food and medicine production are extracted and concentrated. The operating pressure of nanofiltration membranes is generally 3.5-30bar.

The cloth bag filter device is a novel filter system and has the advantages of high filter precision, large treatment capacity, low cost, convenience and rapidness in use and maintenance, complete specification, various materials, wide application range and the like. The method is mainly applied to: food, health, pharmaceutical, etc. The bag filters are divided into single bags and multiple bags according to the number of bags, and are divided into side-inlet type and top-inlet type according to the positions of the feed holes, and the side-inlet type is replaced by the top-inlet type. In addition, an interlayer filter which is generally of a double-layer structure can be provided according to the requirement of the filtering temperature of a user, and steam or heat conducting oil can be introduced into the interlayer to maintain or improve the temperature of fluid, prevent the fluid from solidifying, improve the filtering speed of viscous liquid or meet the requirement of the next working procedure on the temperature.

Preferably, in the step (3), after bipolar electrodialysis acidification treatment, sodium hydroxide solution is obtained;

and the sodium hydroxide solution is returned to the eluent for recycling.

Bipolar electrodialysis (shandong Tian Wei) is a novel ion exchange composite membrane, which is usually formed by compositing a cation exchange layer (N-type membrane), an interface hydrophilic layer (catalytic layer) and an anion exchange layer (P-type membrane), and is a reaction membrane in the real sense. Under the action of a direct current electric field, the bipolar membrane can dissociate water to obtain hydrogen ions and hydroxyl ions on two sides of the membrane respectively. By utilizing the characteristics, the bipolar membrane electrodialysis system formed by combining the bipolar membrane with other anion-cation exchange membranes can convert salts in aqueous solution into corresponding acids and bases without introducing new components, and the method is called a bipolar membrane electrodialysis method. The bipolar membrane electrodialysis method is not only used for preparing acid and alkali, but also can realize multiple functions and can be used in multiple fields if the bipolar membrane electrodialysis method is skillfully combined with a monopolar membrane.

The finished phytic acid is obtained by concentrating refined phytic acid obtained by the method for extracting phytic acid from corn steep liquor and decoloring 0.3wt% of activated carbon;

the phytic acid content in the finished phytic acid is 51-52 wt%.

Compared with the prior art, the invention has at least the following technical effects:

(1) The invention provides a method for extracting phytic acid from corn steep liquor, which adopts corn steep water selected as a byproduct of a starch plant as raw materials, is low in cost and easy to obtain, and changes waste into valuable.

The method solves the technical problems of impurity removal, high acid-base consumption and large discharge of a large amount of sewage by adopting a multi-step ion exchange process for producing phytic acid by taking the phytin as a raw material.

(2) According to the method, the corn soaking water phytic acid is adsorbed by the one-step method resin, then nanofiltration membrane separation and concentration, chromatographic column impurity removal and bipolar electrodialysis acidification are adopted, so that a high-quality phytic acid finished product is obtained, the sewage discharge amount of ton products is reduced by more than 80%, and clean civilized production and sustainable development can be realized.

The nanofiltration membrane is adopted for separation and concentration and the chromatographic column is adopted for impurity removal, so that the salt and organic matters are thoroughly separated, the product purity is high, the color is not changed during storage, the quality guarantee period is long, and the requirements of high-end customers can be met.

(3) The phytic acid produced by the process is clear and transparent, and various indexes meet the requirements of the phytic acid standard of national standard GB 1886.250-2016 food additives.

Drawings

FIG. 1 is a schematic flow chart of a method for extracting phytic acid in example 1.

FIG. 2 is a schematic diagram of a sample of the experimental example.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the following examples, which are to be construed as merely illustrative and not limitative of the scope of the invention, but are not intended to limit the scope of the invention to the specific conditions set forth in the examples, either as conventional or manufacturer-suggested, nor are reagents or apparatus employed to identify manufacturers as conventional products available for commercial purchase.

The technical scheme of a specific implementation mode of the invention is as follows:

a method for extracting phytic acid from corn steep liquor, comprising the steps of:

(1) The corn steep liquor produced and discharged from a starch mill is conveyed to a settling tank for standing and settling, and is used for separating solids such as starch, protein and the like. The corn steep supernatant obtained after precipitation was used as extraction stock. Filtering with a bedroom spiral filter, further throttling suspended impurities, allowing filtrate to enter a polypropylene resin column to adsorb phytic acid, allowing effluent to enter a settling tank for extracting original pulp when the phytic acid content in the effluent reaches 10wt% of the phytic acid content in the original pulp, settling and filtering again, and performing circulating saturated adsorption by using the polypropylene resin column, wherein the circulating saturated adsorption is finished when the phytic acid content in the effluent reaches 80wt% of the original pulp. And (5) returning all the residual extracted raw pulp after adsorption and the separated solid impurities to a starch factory for concentrating and utilizing.

(2) And (3) ejecting the extracted primary pulp in the polypropylene resin column by using water, filtering out liquid by using a nanofiltration membrane, and flushing impurities in the resin column by using a small amount of clear water until effluent liquid has no obvious suspended impurities.

(3) Preparing 5-6wt% of dilute alkali solution for eluting, collecting the sodium phytate eluent to a decoloring tank, and stopping collecting when the pH value of the eluent mixture reaches not higher than 10. And (5) collecting liquid to an alkali distribution tank for applying alkali distribution liquid eluent.

(4) And (5) after the elution is finished, obtaining crude sodium phytate feed liquid.

(5) Adding 0.2wt% of active carbon into the crude sodium phytate feed liquid for decoloring, and obtaining clear and transparent crude phytic acid feed liquid through a plate frame.

(6) The plate and frame filtrate is finely filtered by a cloth bag filter.

(7) The crude sodium phytate is filtered and concentrated by using a nanofiltration membrane, the trapped fluid is sodium phytate feed liquid, the filtered fluid contains chloride and small molecular organic matters, and the filtered fluid is used for collecting temporary fluid and flushing the resin column in the step (2) and the step (3). The filtering adopts a cloth bag filtering device with the aperture of 2 mu m to carry out fine filtering treatment; the concentration adopts nanofiltration membrane filtration concentration treatment, and the molecular weight cut-off of the membrane is 150-200D.

(8) And separating and removing impurities from the membrane concentrated and trapped about 15wt% sodium phytate feed liquid by using a chromatographic column to obtain pure sodium phytate feed liquid.

(9) And acidifying the sodium phytate feed liquid by using bipolar electrodialysis to obtain refined phytic acid and sodium hydroxide. The obtained sodium hydroxide solution is used for preparing 5-6wt% sodium hydroxide solution in the step (3).

(10) Concentrating refined phytic acid obtained by bipolar electrodialysis separation to a phytic acid content of 51-52 wt% through pp materials or other anti-corrosion materials, conveying to a decoloring kettle, decoloring by adding 0.3wt% of activated carbon, and finely filtering after plate-frame filtration of carbon cakes to obtain the finished phytic acid.

The phytic acid produced by the process is clear and transparent, and various indexes meet the requirements of the phytic acid standard of national standard GB 1886.250-2016 food additives.

Example 1: the specific flow is shown in figure 1:

(3) Preparing 5-6wt% of dilute alkali solution for eluting, collecting sodium phytate eluent to a decoloring tank, and stopping collecting when the pH value of the eluent mixture reaches 8-9 or less. And (5) collecting liquid to an alkali distribution tank for applying alkali distribution liquid eluent.

(6) The plate and frame filtrate is finely filtered by a cloth bag filter.

(8) And separating and removing impurities from the membrane concentrated and trapped about 15wt% sodium phytate feed liquid by using a chromatographic column to obtain pure sodium phytate feed liquid. This step serves as a purification.

(9) And acidifying the sodium phytate feed liquid by using bipolar electrodialysis to obtain refined phytic acid and sodium hydroxide. The obtained sodium hydroxide solution is used for preparing 5-6wt% sodium hydroxide solution in the step (3). Bipolar electrodialysis acidification in this step is a process for replacing the cationic resin treatment, reducing the water usage.

The phytic acid produced by the process is clear and transparent, and various indexes meet the requirements of the phytic acid standard of national standard GB 1886.237-2016 food additives.

As shown in fig. 2, the phytic acid sample pictures were prepared in 4 batches by the extraction method of the above example 1. Wherein the samples are respectively batch 1 sample, batch 2 sample, batch 3 sample, and batch 4 sample.

Conclusion: each of the above samples was a phytic acid obtained by the extraction method of example 1, and the samples obtained for different batches were tested, showing that the phytic acid obtained by the extraction method of example 1 meets the national standard.

Comparative example 1: the nanofiltration membrane filtration, impurity removal and concentration treatment in step (7) in the method of example 1 was deleted, and the other steps were the same as in example 1.

Comparative example 1 and example 1 obtained sample results: comparative example 1 produced a sample that was not acceptable in chloride and the product was yellow brown in color.

Comparative example 2: the step (8) column separation and impurity removal treatment in the method of example 1 was omitted, and the other steps were the same as in example 1.

Comparative example 2 and example 1 obtained sample results: the inorganic phosphorus, chloride, sulfate and calcium salt indexes of the produced samples of comparative example 2 are unstable, and part of batches are unqualified.

Comparative example 3: step (7) and step (8) in the method of example 1 were deleted, and the other steps were the same as in example 1.

Comparative example 3 and example 1 obtained sample results: the indexes of inorganic phosphorus, chloride, sulfate and calcium salt of the sample produced in the comparative example 3 are unstable, part of batches are unqualified, and the color of the product is yellow brown, so that the use of customers is influenced.

Comparative example 4: the bipolar electrodialysis acidification treatment of step (9) of the method of example 1 was omitted, and the other steps were identical to those of example 1.

Comparative example 4 and example 1 obtained sample results: the sample produced in comparative example 4 was not stripped of sodium ions, and the sample produced was 7 sodium phytate solution, and a phytic acid product could not be obtained.

Finally, it should be noted that: the foregoing description is only of the preferred embodiments of the invention and is not intended to limit the scope of the invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for extracting phytic acid from corn steep water, the method comprising:

2. The method of extracting phytic acid from corn steep liquor according to claim 1, wherein the resin packed in the anion resin column is a free amine type acrylic acid anion exchange resin.

3. The method for extracting phytic acid from corn steep liquor according to claim 1, wherein said anion resin column cyclic saturation adsorption treatment comprises: after the anion resin column adsorbs the extracted primary pulp, when the phytic acid content in the effluent liquid is 10wt% of the phytic acid content in the extracted primary pulp, the effluent liquid circularly enters the extracted primary pulp, and the anion resin column circularly performs saturated adsorption until the phytic acid content in the effluent liquid is not less than 80wt% of the phytic acid content in the extracted primary pulp.

4. The method for extracting phytic acid from corn steep liquor according to claim 1, wherein in the step (2), the alkaline solution comprises a diluted alkaline solution with a mass concentration of 5wt% to 6 wt%.

5. The method of extracting phytic acid from corn steep liquor of claim 4, wherein the dilute alkaline solution is sodium hydroxide solution.

6. The method for extracting phytic acid from corn steep liquor according to claim 1, wherein in the step (2), the eluent mixture obtained after alkali liquor elution is decolorized by activated carbon in a mass ratio of 1:0.15wt% to 0.20 wt%.

7. The method for extracting phytic acid from corn steep liquor according to claim 1, wherein in the step (3), the use mass ratio of the crude sodium phytate feed liquid to the activated carbon is 1:15wt% to 20wt%.

8. The method for extracting phytic acid from corn steep liquor according to claim 7, wherein in the step (3), the fine filtration treatment is carried out by adopting a cloth bag filter with a pore diameter of 2 μm;

9. The method for extracting phytic acid from corn steep liquor according to claim 1, wherein in said step (3), after bipolar electrodialysis acidification treatment, sodium hydroxide solution is obtained;

and the sodium hydroxide solution is returned to the eluent for recycling.

10. A finished phytic acid characterized in that the refined phytic acid obtained by the method for extracting phytic acid from corn steep liquor according to any one of claims 1-9 is obtained after concentrating and decolorizing with 0.3wt% of activated carbon;

the phytic acid content in the finished phytic acid is 51-52 wt%.