Method for extracting high-purity and high-quality sodium phytate from defatted rice bran

Abstract

The invention discloses a method for extracting high-purity and high-quality sodium phytate from defatted rice bran, and belongs to the technical field of organic extraction.The method comprises the steps that the defatted rice bran and water are mixed, hydrochloric acid is added to adjust the pH value of mixed liquid for extraction, then a settling agent is added to remove impurities, the impurities are further removed through filtering of a filtering membrane, and a sodium phytate solution is obtained; and after ion exchange, the resin is desorbed by using a sodium hydroxide solution, and high-purity and high-quality sodium phytate is obtained after filtration by using a special membrane and purification. According to the method disclosed by the invention, the pure water cleaning amount can be reduced, the utilization rate of the acid-containing wastewater is increased to nearly 90% from the original 60% through membrane treatment recycling and cyclic extraction, a large amount of water and acid are saved, meanwhile, the wastewater treatment cost and the wastewater discharge amount are reduced, and the green and environment-friendly characteristics of the method disclosed by the invention are highlighted.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of organic extraction, in particular to a method for extracting high-purity and high-quality sodium phytate from defatted rice bran. BACKGROUND

[0002] Sodium phytate is mainly in the form of calcium, magnesium and potassium complex salt of its anion (phytic acid) and widely exists in plant seeds and germ. Sodium phytate is an important natural antioxidant of organic phosphorus, has unique physiological, pharmacological functions and chemical properties, and is widely used in food, medicine, daily chemical, environmental protection, metallurgy, chemical reagent and other fields.

[0003] There are two existing extraction processes for sodium phytate. The first process is to recover crude calcium phytate from the soaking solution of corn soaked with sulfurous acid in a corn starch factory. After adding acid to dissolve and filtering, ion exchange treatment is performed. A large amount of tap water and deionized water are used to clean the organic and inorganic substances on the surface of the resin. Sodium hydroxide is used for elution, concentration, crystallization and drying to obtain sodium phytate. The disadvantage is that the finished product contains many impurities such as organic matter. The second process is to use membrane concentration and chromatography column separation to remove impurities after ion exchange and sodium hydroxide elution of the corn soaking solution. Sodium phytate solution (pH 8-9) is obtained, and then the pH is adjusted to ≥12 with alkali. Finally, sodium phytate is obtained by concentration, crystallization and drying. The advantage is that the purity is higher than the first process. The disadvantage is that the process is complicated and difficult to control (such as the need for segmented collection of elution solution and secondary pH adjustment), and may affect the quality of sodium phytate. For example, in the comparative examples 1 and 2 of Chinese patent (202211615869.8), 5%-6% sodium hydroxide solution is used for elution, and the elution solution is collected in segments at pH 8-9. After membrane concentration and chromatography, the pH is adjusted to 12-12.5. This two-step alkali adjustment increases the complexity of the process. In summary, the existing processes are contradictory in terms of purity and operational convenience, and need to be optimized.

[0004] The quality of phytic acid and sodium phytate is determined by the content of IP6. Since the content of IP6 in corn is 74%, and the content of IP6 in defatted rice bran is 93%, it is difficult to produce high-quality sodium phytate products by extracting sodium phytate from corn soaking solution regardless of the purification method. However, corn soaking solution is the first choice for production enterprises in terms of cost and ease of extraction, and the products can only be used in general food additives and daily chemical additives, but cannot be used in high-quality fields such as medical health products and medical reagents.

[0005] Therefore, it is a problem that needs to be solved by those skilled in the art to provide a method for directly extracting high-purity and high-quality sodium phytate from defatted rice bran. SUMMARY

[0006] Therefore, the present application provides a method for extracting high-purity and high-quality sodium phytate from defatted rice bran to solve the problems in the background art.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A method for extracting high-purity and high-quality sodium phytate from defatted rice bran comprises the following steps:

[0009] (1) Mix defatted rice bran and water and stir to obtain a mixed solution;

[0010] (2) adding hydrochloric acid to the mixed solution to adjust the pH value of the mixed solution, and then stirring and extracting for 5 to 7 hours to obtain an extract;

[0011] (3) adding a sedimentation agent to the extract, and then filtering and settling to remove impurities to obtain a primary filtrate;

[0012] (4) filtering the primary filtrate through a filter membrane to further remove impurities to obtain a secondary filtrate;

[0013] (5) exchanging the secondary filtrate with an ion exchange resin until saturated, and then washing the resin surface with water;

[0014] (6) decomposing the resin with a sodium hydroxide solution to obtain a decomposition solution containing phytic acid and sodium;

[0015] (7) filtering the analytical solution through a special membrane to obtain a high-purity sodium phytate solution;

[0016] (8) The high-purity sodium phytate solution is sequentially subjected to low-temperature vacuum concentration, cooling crystallization, centrifuge dehydration, and low-temperature drying to obtain high-purity and high-quality sodium phytate.

[0017] Furthermore, the mass ratio of the defatted rice bran to water in step (1) is 1:10-20.

[0018] Furthermore, hydrochloric acid is added in step (2) to adjust the pH value of the mixed solution to 1.8-2.4; and the pH value of the mixed solution is maintained at 1.8-2.4 during the stirring extraction process, and the stirring extraction time is 5-7 hours.

[0019] Furthermore, in step (3), the sedimentation agent is polyacrylamide (zwitterion), and the amount of the sedimentation agent is 0.3% to 0.6% of the mass of the defatted rice bran.

[0020] Furthermore, the filter membrane in step (4) is a ceramic membrane or an organic membrane, and its pore size is less than 0.01 micron.

[0021] Furthermore, the ion exchange resin in step (5) is weakly alkaline D201 or D301 resin.

[0022] Furthermore, the mass concentration of the sodium hydroxide solution in step (6) is 5%.

[0023] Further, the special membrane polysulfone ultrafiltration membrane in step (7) has a filtration pressure greater than 0.6 MPa and a pH value of 12-13.

[0024] Further, the low-temperature vacuum concentration in step (8) is performed at 50±5℃ and -0.08 to -0.09 MPa for 3 hours, the centrifugal dehydration is performed at a centrifugal speed of 1400 r / min, and the low-temperature drying is performed at a temperature of 50±5℃ for 1 hour.

[0025] The impurity content of the sodium phytate produced by the prior art process is compared with that of the sodium phytate produced by the process of the present application as follows:

[0026] project Existing technology (national standard) Invention Standard content ≥75 ≥75 Inorganic phosphorus (P) W / % ≤0.02 ≤0.01 <![CDATA[氯化物(Cl - )W / %]]> ≤0.01 ≤0.001 <![CDATA[硫酸盐(SO4 2+ )W / %]]> ≤0.01 ≤0.001 <![CDATA[钙盐(Ca 2+ )W / %]]> ≤0.01 ≤0.001 Lead (Pb) mg / kg ≤1.0 ≤0.01 Arsenic (As) mg / kg ≤1.0 ≤0.01

[0027] The present application has the following advantages:

[0028] 1. The present application uses high-purity hydrochloric acid to extract defatted rice bran, avoiding the introduction of impurities by impure hydrochloric acid.

[0029] 2. An organic sedimentation agent is added to the extraction solution to remove a large amount of organic impurities introduced by the rice bran.

[0030] 3. The present application uses ceramic membranes or organic membranes to further remove organic impurities and then saturates by ion exchange.

[0031] 4. The present application uses high-purity sodium hydroxide solution to elute the resin, avoiding the introduction of impurities by impure sodium hydroxide, and obtaining a high-purity sodium phytate solution.

[0032] 5. The present application uses special membrane filtration to obtain a high-purity sodium phytate solution, which is then concentrated, cooled and crystallized, and dried at low temperature to prepare a high-purity and high-quality sodium phytate product. The sodium phytate prepared by this technology has very low impurity content, high purity and high quality.

[0033] 6. The present application adds an organic impurity sedimentation agent to the defatted rice bran extraction solution to settle, removes most of the organic impurities through plate and frame filtration, further removes residual organic impurities through ceramic membrane or organic membrane filtration, and obtains a clear and transparent extraction solution, which is then subjected to ion exchange. Not only does this increase the exchange capacity, but it also greatly reduces the amount of pure water required for cleaning. In particular, the extraction solution is removed from a large amount of organic impurities through a series of measures, which greatly reduces the amount of waste water treatment and waste water discharge after the exchange of a large amount of acid-containing waste water through membrane treatment and recycling extraction utilization rate from the original 60% to nearly 90%, saving a large amount of water and acid, while greatly reducing the cost of waste water treatment and waste water discharge, highlighting the green and environmentally friendly process. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the protection scope of the present application.

[0035] Embodiment 1

[0036] (1) Defatted rice bran is added into an extraction tank with water in a mass ratio of 1:10 and stirred uniformly;

[0037] (2) High-purity hydrochloric acid is added to keep the pH value at 1.8 and stirred for 5 hours;

[0038] (3) Polyacrylamide precipitant (0.3%) for removing organic matters such as starch, protein, ash and polysaccharide is added to precipitate impurities, and most of the organic matters are removed through plate and frame filtration;

[0039] (4) The filtrate is further filtered through a polyvinylidene fluoride organic membrane to remove residual organic matters and other impurities;

[0040] (5) Ion exchange is performed with D201 ion exchange resin until saturation, then the surface of the resin is washed with water, and the resin is eluted with high-purity sodium hydroxide solution (5%);

[0041] (6) The elution liquid is filtered through a special membrane to obtain high-purity sodium phytate solution, and then vacuum concentration is performed at 50°C and -0.09 MPa for 3 hours, cooling crystallization is performed, dehydration is performed by a centrifuge at 1400 r / min, and low-temperature drying is performed at 50°C for 1 hour to obtain high-purity high-quality sodium phytate.

[0042] Embodiment 2

[0043] (1) Defatted rice bran is added into an extraction tank with water in a mass ratio of 1:15 and stirred uniformly;

[0044] (2) High-purity hydrochloric acid is added to keep the pH value at 2.0 and stirred for 6 hours;

[0045] (3) Polyacrylamide precipitant (0.6%) for removing organic matters such as starch, protein, ash and polysaccharide is added to precipitate impurities, and most of the organic matters are removed through plate and frame filtration;

[0046] (4) The filtrate is further filtered through a polyvinylidene fluoride organic membrane to remove residual organic matters and other impurities;

[0047] (5) Ion exchange is performed with D201 ion exchange resin until saturation, then the surface of the resin is washed with water, and the resin is eluted with high-purity sodium hydroxide solution (5%);

[0048] (6) The analytical solution is then filtered through a special membrane to obtain a high-purity sodium phytate solution, which is then vacuum concentrated at 50°C and -0.09 MPa for 3 hours, cooled for crystallization, dehydrated by a centrifuge at 1400 r / min, and low-temperature dried at 50°C for 1 hour to obtain high-purity and high-quality sodium phytate.

[0049] Example 3

[0050] (1) Add defatted rice bran and water in a mass ratio of 1:20 into an extraction tank and stir evenly;

[0051] (2) adding high-purity hydrochloric acid to maintain the pH at 2.4 and stirring and extracting for 7 hours;

[0052] (3) Add polyacrylamide sedimentation agent (0.5%) to remove organic matter such as starch, protein, ash, and polysaccharides to precipitate impurities, and filter through plate and frame to remove most of the organic matter;

[0053] (4) The filtrate is filtered through an acid and alkali resistant zirconia ceramic membrane to further remove residual organic matter and other impurities;

[0054] (5) Perform ion exchange with D201 ion exchange resin until saturated, then wash the resin surface with water and resolve with high-purity sodium hydroxide solution (5%);

[0055] (6) The analytical solution is then filtered through a special membrane to obtain a high-purity sodium phytate solution, which is then vacuum concentrated at 50°C and -0.09 MPa for 3 hours, cooled for crystallization, dehydrated by a centrifuge at 1400 r / min, and low-temperature dried at 50°C for 1 hour to obtain high-purity and high-quality sodium phytate.

[0056] Using the extraction methods of the above three embodiments, sodium phytate samples were prepared through the three embodiments. The comparison of the samples of Example 1, Example 2, and Example 3 of the present invention with the sodium phytate prepared by the prior art process is shown in Table 1:

[0057] Table 1

[0058]

[0059] In summary, the sodium phytate obtained by the extraction method in each embodiment meets and exceeds the national standards in various indicators.

[0060] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A method for extracting high-purity and high-quality sodium phytate from defatted rice bran, characterized in that: The following steps are involved: (1) Mix defatted rice bran and water and stir to obtain a mixed solution; (2) adding hydrochloric acid to the mixed solution to adjust the pH value of the mixed solution, and then stirring and extracting to obtain an extract; (3) adding a sedimentation agent to the extract, and then filtering and settling to remove impurities to obtain a primary filtrate; (4) filtering the primary filtrate through a filter membrane to further remove impurities to obtain a secondary filtrate; (5) exchanging the secondary filtrate with an ion exchange resin until saturated, and then washing the resin surface with water; (6) decomposing the resin with a sodium hydroxide solution to obtain a decomposition solution containing phytic acid and sodium; (7) filtering the analytical solution through a special membrane to obtain a high-purity sodium phytate solution; (8) The high-purity sodium phytate solution is sequentially subjected to low-temperature vacuum concentration, cooling crystallization, centrifuge dehydration, and low-temperature drying to obtain high-purity and high-quality sodium phytate.

2. A method for extracting high-purity, high-quality sodium phytate from defatted rice bran according to claim 1, characterized in that, The mass ratio of the defatted rice bran to water in step (1) is 1:10-20.

3. A method for extracting high-purity, high-quality sodium phytate from defatted rice bran according to claim 1, characterized in that, In step (2), hydrochloric acid is added to adjust the pH value of the mixed solution to 1.8-2.4; and the pH value of the mixed solution is maintained at 1.8-2.4 during the stirring extraction process, and the stirring extraction time is 5-7 hours.

4. A method for extracting high-purity, high-quality sodium phytate from defatted rice bran according to claim 1, characterized in that, In step (3), the sedimentation agent is polyacrylamide, and the consumption of the sedimentation agent is 0.3% to 0.6% of the mass of the defatted rice bran.

5. A method for extracting high-purity, high-quality sodium phytate from defatted rice bran according to claim 1, characterized in that, The filter membrane in step (4) is a ceramic membrane or an organic membrane.

6. A method for extracting high-purity, high-quality sodium phytate from defatted rice bran according to claim 1, characterized in that, The ion exchange resin in step (5) is weakly alkaline D201 or D301 resin.

7. A method for extracting high-purity, high-quality sodium phytate from defatted rice bran according to claim 1, characterized in that, The mass concentration of the sodium hydroxide solution in step (6) is 5%.

8. A method for extracting high-purity, high-quality sodium phytate from defatted rice bran according to claim 1, characterized in that: The special membrane described in step (7) is a polysulfone ultrafiltration membrane.

9. A method for extracting high-purity, high-quality sodium phytate from defatted rice bran according to claim 1, characterized in that: The low-temperature vacuum concentration in step (8) is vacuum concentration at 50±5°C and -0.08 to -0.09 MPa for 3 hours, the centrifugal dehydration speed is 1400 r / min, and the low-temperature drying is drying at 50±5°C for 1 hour.

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