Method for removing arsenic in earthworm protein based on chelate resin

Abstract

The invention discloses a method for removing metal arsenic in earthworm protein based on chelate resin. The problem that arsenic in an earthworm protein product exceeds the standard is solved. According to the method, arsenic can be specifically adsorbed through macroporous chelating resin, 100-800 g / L of pretreated macroporous chelating resin is added into earthworm protein extraction supernate, adsorption is conducted for 4-12 h under the conditions that the pH ranges from 5 to 9 and the temperature ranges from 25 DEG C to 40 DEG C, the total arsenic content of earthworm protein can be reduced to 0.3 mg / kg or below from 7 mg / kg or above, the protein recovery rate is larger than or equal to 90%, the quality standard of existing regulations is met, and the method is suitable for industrial production. The chelated and adsorbed resin can be reused after regeneration, and can be reused for more than 10 times. The chelating resin has the effects of decolorizing and chelating other heavy metals, can effectively reduce the color of a sample and reduce the content of other heavy metals, and improves the character and quality of an earthworm protein product. The process is efficient, safe, low in cost and suitable for industrial purification of the earthworm protein.

Description

Technical Field

[0001] The present invention belongs to the technical field of biological product processing, and specifically relates to a process for selectively adsorbing arsenic in the supernatant of earthworm protein extraction by using food-grade chelating resin, aiming to reduce the arsenic content in the finished earthworm protein product. Background Art

[0002] Earthworms are a traditional Chinese medicinal animal. Their main active ingredient, earthworm protein, possesses antithrombotic, antioxidant, blood pressure-lowering, and immune-boosting properties. Various earthworm protein-based products are clinically used for the prevention and treatment of cardiovascular and cerebrovascular diseases. Earthworm protein has extensive effects on the body's coagulation and fibrinolytic systems, significantly reducing platelet adhesion in rats, prolonging thrombosis and dissolving thrombi. It also increases cerebral blood flow, reduces cerebral vascular resistance, improves microcirculation, and mitigates the harmful effects of high cholesterol, high blood pressure, and high blood sugar on the human body. The Ministry of Health approved earthworm protein as a new resource food in Document No. 18 of 2009.

[0003] Due to its unique habitat, earthworms are extremely susceptible to heavy metal contamination, with excessive arsenic being the most prominent problem. Arsenic is a highly toxic heavy metal that is harmful to plants, animals, and humans. Once inside, arsenic easily binds to DNA, proteins, and enzymes in the body, disrupting metabolism and causing poisoning. Exposure to high concentrations of arsenic can cause acute poisoning, with symptoms including vomiting, abdominal pain, and coma. Long-term exposure to low concentrations can lead to chronic poisoning, affecting organs such as the intestines, respiratory system, nervous system, kidneys, and heart, causing cancers such as intestinal, lung, kidney, and bladder cancers, as well as disrupting the blood-brain barrier, heart function abnormalities, blood flow impairments, neurasthenia, and memory loss. As a high-protein animal, earthworms are highly susceptible to arsenic accumulation in soil and water. Therefore, arsenic removal is essential for their use in clinical practice, health supplements, and feed.

[0004] Currently, industrial arsenic removal technologies primarily include activated carbon adsorption and ion exchange resin adsorption. Activated carbon adsorption is associated with low adsorption capacity, poor arsenic selectivity, and complex post-processing procedures. Ion exchange resin adsorption also suffers from poor arsenic selectivity and the risk of secondary contamination from post-adsorption desorption. Due to the complex composition of earthworm extracts, including earthworm protein, various enzymes, nucleic acids, and fatty acids, few existing literature reports on how to effectively remove arsenic impurities from earthworm protein. Therefore, an efficient, safe, and scalable arsenic removal process is urgently needed to reduce the total arsenic content to below 0.3 mg / kg while maintaining the recovery rate of earthworm protein. Summary of the Invention

[0005] The purpose of the present invention is to provide a simple and efficient process for solving the problem of excessive arsenic in earthworm protein products, thereby solving the problem of difficulty in removing arsenic from earthworm protein.

[0006] In order to achieve the above-mentioned object, the present invention provides a method for removing arsenic from earthworm protein based on chelating resin, which comprises the following steps: adding pretreated macroporous chelating resin to the earthworm protein extraction supernatant for adsorption, then performing solid-liquid separation, and finally drying to obtain earthworm protein with an arsenic content of less than 0.3 mg / kg.

[0007] As an embodiment of the present invention, the earthworm extract supernatant is prepared by the following method: thawing and cleaning the earthworm, homogenizing and breaking the wall, enzymatically hydrolyzing and autolyzing, and centrifuging to collect the earthworm protein extract supernatant.

[0008] As an embodiment of the present invention, the earthworm thawing and cleaning is to place the frozen fresh earthworms at room temperature to thaw naturally, use clean water to clean the thawed fresh earthworms to wash away mud and sticky substances, and drain excess water after cleaning.

[0009] As an embodiment of the present invention, purified water is added to the cleaned earthworms in a mass volume ratio of earthworms to purified water m:v=1:1-3 to crush, homogenize and break the wall of the earthworms; the earthworms after homogenization and wall breaking are enzymatically hydrolyzed and autolyzed, and the enzymatic hydrolysis pH is controlled to 7.0-9.0, the enzymatic hydrolysis temperature is controlled to 40-50°C, and the enzymatic hydrolysis time is controlled to 4-8 hours.

[0010] As an embodiment of the present invention, after enzymatic autolysis, the sample is centrifuged and the supernatant is collected. As an embodiment of the present invention, the chelate resin pretreatment is first rinsed with purified water, then pretreated with sodium hydroxide solution and sodium chloride solution, and finally rinsed with purified water until the pH value is lower than 9.

[0011] As an embodiment of the present invention, the chelate resin pretreatment is to first rinse the resin with 2-3BV of purified water, then pretreat the resin with 2BV of 2% mass concentration sodium hydroxide and 8% mass concentration sodium chloride solution at room temperature, and finally rinse the resin with purified water until the pH value is lower than 9.

[0012] As an embodiment of the present invention, the pretreated macroporous chelating resin is added to the supernatant of earthworm protein extraction at a resin addition amount of 100-800 g / L for adsorption.

[0013] As an embodiment of the present invention, the adsorption pH is controlled to be 5-9, the adsorption temperature is controlled to be 25-40° C., and the adsorption time is controlled to be 4-12 h.

[0014] As an embodiment of the present invention, after the chelating resin adsorption is completed, suction filtration is used for solid-liquid separation, and after the separation is completed, the resin is rinsed with purified water, and the supernatant after adsorption and the resin rinsing liquid are combined.

[0015] As an embodiment of the present invention, the method further includes filtering and sterilizing the supernatant of the earthworm protein extraction after adsorption using a filter element.

[0016] As a specific embodiment of the present invention, the method further includes filtering and sterilizing the supernatant of the adsorbed earthworm protein extraction using a 0.22 μm filter element.

[0017] As an embodiment of the present invention, the drying is spray drying.

[0018] As an embodiment of the present invention, the supernatant of the earthworm protein extraction after filtration and sterilization is spray-dried, and the inlet air temperature is controlled at 180-200°C and the outlet air temperature is controlled at 80-95°C.

[0019] As an embodiment of the present invention, the method further comprises regenerating the chelate resin, first rinsing the chelate resin with sodium hydroxide solution and sodium chloride solution, and then rinsing the chelate resin with purified water until the pH value is lower than 9.

[0020] As a specific embodiment of the present invention, the resin is first rinsed with 2% mass concentration sodium hydroxide and 8% mass concentration sodium chloride solution at room temperature at 2BV, and then with purified water to a pH value below 9, so that the regenerated resin has the same arsenic chelating effect, and the resin can be used continuously for more than 10 batches.

[0021] Compared with the existing technology, the present invention has achieved the following beneficial effects: The present invention discloses an efficient and scalable method for removing arsenic from earthworm protein, which solves the problem of excessive total arsenic content in existing earthworm protein food raw materials. The present invention uses a macroporous chelating resin to specifically adsorb arsenic in the earthworm protein extract. By changing the amount of resin added, pH, temperature and adsorption time, the total arsenic residue in the earthworm protein extract is effectively controlled, and the total arsenic residue is reduced from >7 mg / kg to below 0.3 mg / kg, and the protein recovery rate is ≥90%. The chelating resin has the functions of decolorizing and chelating other heavy metals at the same time, which can effectively reduce the color of the sample and reduce the content of other heavy metals, thereby improving the properties and quality of the earthworm protein product. After adsorption, the resin can achieve solid-liquid separation by simple filtration, which is simple to operate. The adsorbed resin can be regenerated with sodium hydroxide and sodium chloride and can be reused more than 10 times, greatly reducing the production cost of earthworm protein. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is the process flow chart of this scheme; DETAILED DESCRIPTION

[0023] The following examples are included to illustrate preferred embodiments of the present invention. Those skilled in the art will recognize that the techniques disclosed in the following examples represent techniques discovered by the inventors to work well in the practice of the present invention. Based on this disclosure, those skilled in the art will recognize that many changes can be made to the specific embodiments disclosed without departing from the spirit and scope of the present invention, that is, any equivalent results obtained by utilizing the contents of the present specification, equivalent process changes, or direct or indirect application in other related technical fields should be included within the scope of protection of this patent.

[0024] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0025] Pretreatment of macroporous chelating resin: First, rinse the chelating resin with 2 BV of purified water, then pretreat the chelating resin with 2 BV of 2% mass concentration sodium hydroxide solution and 8% mass concentration sodium chloride solution at room temperature, and finally rinse the chelating resin with purified water until the pH value is lower than 9 to obtain the pretreated macroporous chelating resin.

[0026] Macroporous chelate resin regeneration treatment: The chelate resin used in the embodiment is first rinsed with 2% mass concentration sodium hydroxide solution and 8% mass concentration sodium chloride solution at room temperature, and then rinsed with purified water until the pH value is lower than 9 to obtain a regenerated macroporous chelate resin.

[0027] Example 1 Frozen fresh earthworms were thawed naturally at room temperature and washed with clean water to remove sludge and sticky materials. Excess water was then drained. 8 kg of washed earthworms were pulverized and homogenized with purified water at a ratio of 1:2 (m:v) for 30 minutes. The homogenate was centrifuged to collect the supernatant. The supernatant was then enzymatically autolyzed at pH 7.0 and 50°C for 6 hours with stirring. After enzymatic autolysis, the sample was centrifuged to collect 22.4 L of earthworm protein supernatant. This 22.4 L supernatant was divided equally into eight portions (2.8 L each). One portion was sterile-filtered using a 0.22 μm filter cartridge and spray-dried without chelating resin adsorption. The spray-dried supernatant was then sterilized and filtered using a 0.22 μm filter cartridge and spray-dried at an inlet temperature of 190°C and an outlet temperature of 85°C, yielding 90 g of brownish-yellow earthworm protein. Example 2

[0028] To 2.8 L of the earthworm protein extract supernatant prepared in Example 1, pretreated macroporous chelating resin (RTA-800B, Hubei Rutian Environmental Protection Technology Co., Ltd.) was added at a resin dosage of 100 g / L. Adsorption was allowed to proceed at pH 5.0 and 25°C for 12 h. After resin adsorption, solid-liquid separation was performed by suction filtration to obtain an adsorbed supernatant. The adsorbed resin was rinsed with purified water equivalent to the weight of the resin by volume. The adsorbed supernatant and the resin rinse were combined to obtain the adsorbed earthworm protein supernatant. The adsorbed earthworm protein supernatant was sterile-filtered using a 0.22 μm filter cartridge and spray-dried at an inlet temperature of 190°C and an outlet temperature of 85°C, yielding 88 g of a dark yellow earthworm protein product. Protein concentrations in both the earthworm protein supernatant and the chelating resin-adsorbed earthworm protein supernatant were determined by Kjeldahl nitrogen determination. The results showed a 98% recovery rate of earthworm protein after chelating resin treatment. Figure 1 This is a process flow chart for preparing earthworm protein finished product.

[0029] The contents of lead, total arsenic, and mercury in the finished earthworm protein product obtained in Example 1 without chelate resin treatment and the finished earthworm protein product treated with chelate resin obtained in Example 2 were respectively detected using an inductively coupled plasma mass spectrometer (ICP-MS). The results are as follows: Test items Example 1 Earth Dragon Protein Finished Product (mg / kg) Example 2 Earth Dragon Protein Finished Product (mg / kg) lead 0.269 0.00264 arsenic 7.860 0.298 mercury 0.073 Not detected Example 3

[0030] To 2.8 L of the earthworm protein extract supernatant prepared in Example 1, pretreated macroporous chelating resin RTA-800B was added at a resin dosage of 400 g / L. Adsorption was allowed to proceed at pH 7.0 and 30°C for 6 h. After resin adsorption, solid-liquid separation was performed by suction filtration to obtain an adsorbed supernatant. The adsorbed resin was rinsed with purified water equivalent to one resin volume. The adsorbed supernatant and the resin rinse were combined to obtain an adsorbed earthworm protein supernatant. The adsorbed earthworm protein supernatant was sterile-filtered using a 0.22 μm filter cartridge and spray-dried at an inlet temperature of 190°C and an outlet temperature of 85°C, yielding 86 g of a light yellow earthworm protein product. Protein concentrations of both the earthworm protein supernatant and the chelating resin-adsorbed earthworm protein supernatant were determined by Kjeldahl nitrogen determination, demonstrating a 96% recovery rate for earthworm protein after chelating resin treatment.

[0031] The contents of lead, total arsenic, and mercury in the finished earthworm protein product treated with the chelate resin obtained in this example were detected using an inductively coupled plasma mass spectrometer (ICP-MS). The results were as follows: Test items Example 1 Earth Dragon Protein Finished Product (mg / kg) Example 3 Earth Dragon Protein Finished Product (mg / kg) lead 0.269 Not detected arsenic 7.860 0.105 mercury 0.073 Not detected Example 4

[0032] To 2.8 L of the earthworm protein extract supernatant prepared in Example 1, pretreated macroporous chelating resin RTA-800B was added at a resin dosage of 800 g / L. Adsorption was allowed to proceed at pH 9.0 and 40°C for 4 h. After resin adsorption, solid-liquid separation was performed by suction filtration to obtain an adsorbed supernatant. The adsorbed resin was rinsed with purified water equivalent to one resin volume. The adsorbed supernatant and the resin rinse were combined to obtain an adsorbed earthworm protein supernatant. The adsorbed earthworm protein supernatant was sterile-filtered using a 0.22 μm filter cartridge and spray-dried at an inlet temperature of 190°C and an outlet temperature of 85°C, yielding 84 g of a pale yellow earthworm protein product. Protein concentrations of the earthworm protein supernatant and the chelating resin-adsorbed earthworm protein supernatant were determined by Kjeldahl nitrogen determination, demonstrating a 93% recovery rate for earthworm protein after chelating resin treatment.

[0033] The contents of lead, total arsenic, and mercury in the finished earthworm protein product treated with the chelate resin obtained in this example were detected using an inductively coupled plasma mass spectrometer (ICP-MS). The results were as follows: Test items Example 1 Earth Dragon Protein Finished Product (mg / kg) Example 4 Earth Dragon Protein Finished Product (mg / kg) lead 0.269 Not detected arsenic 7.860 0.047 mercury 0.073 Not detected The data of Examples 2-4 show that when the pH of the chelating resin adsorption is controlled at 5-9, the adsorption temperature is 25-40° C., and the adsorption time is 4-12 h, a qualified earthworm protein product with an arsenic content of less than 0.3 mg / kg can be obtained.

[0034] Example 5 Pretreated macroporous chelating resin RTA-800B was added to 2.8 L of the earthworm protein extract supernatant prepared in Example 1 at a resin dosage of 50 g / L. Adsorption was allowed to proceed at pH 7.0 and 30°C for 6 h. After resin adsorption, solid-liquid separation was performed by suction filtration to obtain an adsorbed supernatant. The adsorbed resin was rinsed with purified water equivalent to one resin volume. The adsorbed supernatant and the resin rinse were combined to obtain an adsorbed earthworm protein supernatant. The adsorbed earthworm protein supernatant was sterile-filtered using a 0.22 μm filter cartridge and spray-dried at an inlet temperature of 190°C and an outlet temperature of 85°C, yielding 89 g of a dark yellow earthworm protein product. Protein concentrations of the earthworm protein supernatant and the chelating resin-adsorbed earthworm protein supernatant were determined by Kjeldahl nitrogen determination, demonstrating a 99% recovery rate for earthworm protein after chelating resin treatment.

[0035] The contents of lead, total arsenic, and mercury in the finished earthworm protein product treated with the chelate resin obtained in this example were detected using an inductively coupled plasma mass spectrometer (ICP-MS). The results were as follows: Test items Example 1 Earth Dragon Protein Finished Product (mg / kg) Example 5 Earth Dragon Protein Finished Product (mg / kg) lead 0.269 0.00385 arsenic 7.860 0.456 mercury 0.073 0.011 Example 6

[0036] To 2.8 L of the earthworm protein extract supernatant prepared in Example 1, pretreated macroporous chelating resin RTA-800B was added at a resin dosage of 1000 g / L. Adsorption was allowed to proceed at pH 7.0 and 30°C for 6 h. After resin adsorption, solid-liquid separation was performed by suction filtration to obtain an adsorbed supernatant. The adsorbed resin was rinsed with purified water equivalent to one resin volume. The adsorbed supernatant and the resin rinse were combined to obtain an adsorbed earthworm protein supernatant. The adsorbed earthworm protein supernatant was sterile-filtered using a 0.22 μm filter cartridge and spray-dried at an inlet temperature of 190°C and an outlet temperature of 85°C, yielding 82 g of a pale yellow earthworm protein product. Protein concentrations of the earthworm protein supernatant and the chelating resin-adsorbed earthworm protein supernatant were determined by Kjeldahl nitrogen determination, demonstrating a 91% recovery rate of earthworm protein after chelating resin treatment.

[0037] The contents of lead, total arsenic, and mercury in the finished earthworm protein product treated with the chelate resin obtained in this example were detected using an inductively coupled plasma mass spectrometer (ICP-MS). The results were as follows: Test items Example 1 Earth Dragon Protein Finished Product (mg / kg) Example 6 Earth Dragon Protein Finished Product (mg / kg) lead 0.269 Not detected arsenic 7.860 0.041 mercury 0.073 Not detected Example 7

[0038] According to the resin addition amount of 400 g / L, the regenerated macroporous chelating resin RTA-800B was added to 2.8 L of the earth dragon protein extraction supernatant prepared in Example 1 (the earth dragon protein extraction supernatant was adsorbed and regenerated after 10 batches). The adsorption was carried out at pH 7.0 and temperature 30°C for 6 h. After the resin adsorption was completed, solid-liquid separation was performed by filtration to obtain the adsorbed supernatant. After the separation was completed, the adsorbed resin was rinsed with purified water with a weight of 1 volume of resin, and the adsorbed supernatant and the resin rinsing liquid were combined to obtain the adsorbed earth dragon protein extraction supernatant; the adsorbed earth dragon protein extraction supernatant was sterile filtered and spray-dried using a 0.22 μm filter element. The inlet air temperature of the spray drying was 190°C and the outlet air temperature was 85°C to obtain 86 g of a light yellow earth dragon protein product. The protein concentration of the supernatant of earthworm protein extraction and the supernatant of earthworm protein extraction after chelating resin adsorption were detected by Kjeldahl method. The results showed that the recovery rate of earthworm protein after chelating resin treatment was 96%.

[0039] The contents of lead, total arsenic, and mercury in the finished earthworm protein product treated with the regenerated chelating resin obtained in this example were detected using an inductively coupled plasma mass spectrometer (ICP-MS). The results were as follows: Test items Example 1 Earth Dragon Protein Finished Product (mg / kg) Example 7 Earth Dragon Protein Finished Product (mg / kg) lead 0.269 Not detected arsenic 7.860 0.115 mercury 0.073 Not detected The results of Examples 2-4 show that when a pretreated macroporous chelate resin is added to the earth dragon protein extraction supernatant according to a chelate resin addition amount of 100-800 g / L for adsorption, the lead, arsenic, and mercury contents in the final earth dragon protein product all meet the quality requirements, and the arsenic content is less than 0.3 mg / kg. And as the amount of chelate resin addition increases, the arsenic content in the earth dragon protein product decreases significantly. Combined with the results of Examples 5-6, it is shown that when the amount of chelate resin addition is reduced to 50 g / L, due to the weakening of adsorption capacity, the arsenic content exceeds 0.3 mg / kg, which does not meet the quality requirements; when the amount of resin addition is increased to 1000 g / L, although the arsenic content meets the quality requirements, the trend of arsenic content reduction slows down, and too much chelate resin will non-specifically adsorb earth dragon protein, resulting in excessive loss of earth dragon protein and increasing the material cost of the chelate resin. Therefore, selecting an appropriate amount of chelate resin addition is crucial for balancing the arsenic removal effect and the earth dragon protein recovery rate.

[0040] The chelating resin of the present invention has the functions of decolorizing and chelating other heavy metals, can effectively reduce the color of the sample and reduce the content of other heavy metals, and improve the properties and quality of the earthworm protein product.

[0041] By comparing the results of Example 4 and Example 7, it was found that the regenerated macroporous chelating resin had a considerable arsenic chelating effect / arsenic removal effect, and the chelating resin could be used continuously for 10 batches or more, thereby greatly reducing material costs. Example 8

[0042] The effect of the added ratio of purified water on the results during the preparation of earthworm protein extraction supernatant was studied.

[0043] Frozen fresh earthworms were thawed naturally at room temperature, and the thawed fresh earthworms were washed with clean water to remove sludge and sticky matter, and the excess water was drained after washing. 5 kg of washed earthworms were taken and purified water was added to the washed earthworms at the ratio of m:v = 1:0.5, 1:1, 1:2, 1:3 and 1:5 (mass volume ratio of washed earthworms to purified water), and the washed earthworms were crushed and homogenized for 30 min. The homogenate was centrifuged to collect the homogenate supernatant. The homogenate supernatant was stirred and enzymatically hydrolyzed and autolyzed at pH 7.0 and 50°C for 6 h. After enzymatic hydrolysis and autolysis, the samples were centrifuged and the earthworm protein extraction supernatants were collected.

[0044] Pretreated macroporous chelating resin RTA-800B was added to the supernatants of earthworm protein extraction with different extraction ratios at a resin addition rate of 400 g / L. The resin was adsorbed at pH 7.0 and 30°C for 6 h. After the resin adsorption, solid-liquid separation was performed by filtration to obtain the adsorbed supernatant. After the separation, the adsorbed resin was rinsed with purified water with a weight of 1 resin volume. The adsorbed supernatant and the resin rinse were combined to obtain 5 portions of adsorbed earthworm protein supernatant. The adsorbed earthworm protein supernatant was sterile filtered and spray-dried using a 0.22 μm filter cartridge. The spray drying air inlet temperature was 190°C and the air outlet temperature was 85°C to obtain the finished earthworm protein product.

[0045] The Kjeldahl method was used to determine the concentration of earthworm protein in the supernatant of earthworm protein extraction at different extraction ratios and to calculate the earthworm protein recovery rate. The results are as follows: m:v Extraction volume (L) Protein concentration in the extraction supernatant (g / L) Total protein (g) Recovery rate of earthworm protein (%) 1：0.5 1.3 38.7 50.3 99 1：1 1.8 33.2 59.8 98 1:2 (Example 1) 2.8 22.5 63.0 96 1：3 3.8 17.2 65.4 92 1：5 4.8 14.3 68.6 85 Results showed that while the recovery rate of earthworm protein was highest when the m:v ratio was 1:0.5, the smaller volume of the extract hindered its extraction and release, resulting in the lowest total protein content of all extraction ratios. Furthermore, the resin dosage was also low, hindering the removal of arsenic and other heavy metal ions. Conversely, when the m:v ratio was 1:5, the total amount of earthworm protein was highest, but the recovery rate was lowest due to the increased resin dosage. Furthermore, the increased extract volume increased the volume of the post-processing process, which in turn increased energy consumption and costs. Therefore, selecting the appropriate ratio of earthworm to purified water is crucial for ensuring the efficiency and quality of earthworm protein extraction. The optimal mass-to-volume ratio of cleaned earthworm to purified water in the present invention is m:v = 1:1-3.

[0046] Example 9 By replacing other types of adsorbents and keeping the other conditions as those in Example 3, the effects of different adsorbent selections on the results were studied.

[0047] Adsorbent type factory Mechanism of action Adsorbent addition amount Arsenic content (mg / kg) RTA-800B resin (Example 3) Hubei Rutian Environmental Protection Technology Co., Ltd. Macroporous chelation 400 g / L 0.105 D401 resin Beijing Kehaisi Technology Co., Ltd. Macroporous chelation 400 g / L 4.638 LKA20 resin Amicogen (China) Biopharmaceutical Co., Ltd. Ion exchange 400 g / L 3.075 NH01 metal adsorbent Golden Key High-Tech Materials Co., Ltd. Coordination complex 100 g / L 0.783 NH01 metal adsorbent Golden Key High-Tech Materials Co., Ltd. Coordination complex 400 g / L 0.286 NH03 metal adsorbent Golden Key High-Tech Materials Co., Ltd. Coordination complex 100 g / L 3.780 NH05 metal adsorbent Golden Key High-Tech Materials Co., Ltd. Coordination complex 100 g / L 7.070 Absorbent cotton strips N / A Coordination, complexation and electrostatic adsorption 400 g / L 6.040 activated carbon Shanghai Activated Carbon Factory Co., Ltd. Physical or chemical adsorption 2% 7.150 No adsorption operation was performed - - - 7.860 The results of Example 3 and Example 9 show that the present invention has screened a kind of macroporous chelating resin that is particularly sensitive to arsenic, such as RTA-800B or NHO1 metal adsorbent. Relative to other resins of ion exchange mechanism, other two NH series metal adsorbents of coordination complex, adsorption cotton strips or activated carbon, have higher selectivity to arsenic. Wherein NHO1 metal adsorbent is expensive (NHO1 metal adsorbent price is about 3500 yuan / Kg, and chelating resin price is about 80-100 yuan / Kg, and the former is about 35-45 times of the latter price), is unfavorable for production amplification use, and RTA-800B resin price is cheap and easy to get, is more suitable for industrial amplification use. The special group carried in the macroporous chelating resin can selectively form stable small molecule complex with the arsenate ion in water, fixes and chelates arsenic impurities in a large range, and is not easy to resolve and returns to solution to form secondary pollution.

[0048] The above descriptions are merely embodiments of the present invention and are not intended to limit the scope of the present invention. Any equivalent results or equivalent process transformations made using the contents of the present invention specification, or any direct or indirect application in other related technical fields, should be included in the scope of protection of this patent.

Claims

1. A method for removing arsenic from earthworm protein based on chelating resin, characterized in that: The method comprises the following steps: adding pretreated macroporous chelating resin to the supernatant of earthworm protein extraction for adsorption, performing solid-liquid separation, and finally drying to obtain earthworm protein with an arsenic content of less than 0.3 mg / kg.

2. A method for removing arsenic from earthworm protein based on chelating resin according to claim 1, characterized in that: The earthworm extract supernatant is prepared by the following method: thawing and cleaning the earthworm, homogenizing and breaking the wall, enzymatically hydrolyzing and autolyzing, and centrifuging to collect the earthworm protein extract supernatant.

3. A method for removing arsenic from earthworm protein based on chelating resin according to claim 2, characterized in that: Purified water is added to the cleaned earthworms in a mass-volume ratio of earthworms to purified water (m:v=1:1-3) to crush, homogenize and break the wall of the earthworms; the earthworms after homogenization and wall breaking are enzymatically hydrolyzed and autolyzed, and the enzymatic hydrolysis pH is controlled at 7.0-9.0, the enzymatic hydrolysis temperature is controlled at 40-50°C, and the enzymatic hydrolysis time is controlled at 4-8 hours.

4. The method for removing arsenic from earthworm protein based on chelating resin according to claim 1, wherein: The chelate resin pretreatment is to first rinse the chelate resin with purified water, then pretreat the chelate resin with sodium hydroxide solution and sodium chloride solution, and finally rinse the chelate resin with purified water until the pH value is lower than 9.

5. The method for removing arsenic from earthworm protein based on chelating resin according to claim 1, wherein: The pretreated macroporous chelating resin is added to the supernatant of the earthworm protein extraction according to the addition amount of chelating resin of 100-800 g / L for adsorption.

6. The method for removing arsenic from earthworm protein based on chelating resin according to claim 5, characterized in that: The adsorption pH is controlled at 5-9, the adsorption temperature is 25-40°C, and the adsorption time is 4-12 h.

7. The method for removing arsenic from earthworm protein based on chelating resin according to claim 1, wherein: After the chelating resin adsorption is completed, use suction filtration to separate the solid and liquid. After the separation is completed, use purified water to rinse the resin, and combine the supernatant after adsorption and the resin rinsing liquid.

8. The method for removing arsenic from earthworm protein based on chelating resin according to claim 1, wherein: The method further comprises using a filter element to filter and sterilize the supernatant of the earthworm protein extraction after adsorption.

9. The method for removing arsenic from earthworm protein based on chelating resin according to claim 1, wherein: The drying is spray drying, and the air inlet temperature is controlled at 180-200°C and the air outlet temperature is controlled at 80-95°C.

10. The method for removing arsenic from earthworm protein based on chelating resin according to claim 1, characterized in that: The method further comprises a regeneration step of the chelate resin, wherein the chelate resin is firstly rinsed with a sodium hydroxide solution and a sodium chloride solution, and then rinsed with purified water until the pH value of the chelate resin is lower than 9.

Images