Method for removing harmful substances in fish oil

Abstract

The invention discloses a method for removing harmful substances in fish oil, and belongs to the technical field of fish oil refining processes. The method is used for solving the technical problem that in the prior art, refined fish oil subjected to degumming and deacidification treatment still contains a large amount of harmful substances such as 3-chloropropanol ester and glycidyl ester. A method for removing harmful substances in fish oil comprises the following steps: degumming and deacidifying crude fish oil to obtain primarily refined fish oil; mixing the primarily refined fish oil, polymerized cation exchange resin and solid hexa-aminobenzene ring to obtain a mixed solid liquid; standing and adsorbing the mixed solid and liquid, and then carrying out suction filtration to obtain an organic phase, namely refined fish oil. According to the invention, the adsorption capacity of 3-chloropropanol ester is improved by designing the acidic cation exchange resin with high adsorption content; by designing a polyamino hexa-amino benzene ring, the capability of removing glycidyl ester is improved, and harmful substances in the fish oil can be effectively removed through a related refining process disclosed by the invention.

Description

Technical Field

[0001] The invention relates to the technical field of fish oil refining technology, and in particular to a method for removing harmful substances from fish oil. Background Art

[0002] Freshwater fish oils such as basa catfish oil and black fish oil are rich in palmitic acid and oleic acid, which form the basic fat with high OPO content; marine fish oils such as golden pomfret have fatty acids such as palmitic acid, oleic acid and linoleic acid, which are the basis of OPO and OPL. my country's marine products are very rich, and the output of fish oil raw materials has been relatively high in recent years; however, the quality of fish oil produced along the coast of my country is uneven due to the limitations of fish species, fishing areas, storage environment, instruments and equipment, and processing procedures. Therefore, it is of great significance to accelerate the quality development of domestic fish oil.

[0003] Marine fish oil contains a large amount of characteristic fatty acids; however, the oil itself and its refining process will produce 3-MCP and glycidyl ester pollutants; glycidyl ester can be metabolized and hydrolyzed into glycidol by the human body, which can accumulate in human kidney tissue and other parts and cause tumors; after 3-MCP enters the human body, it decomposes to produce 3-MCP alcohol, which has general toxicity, genetic toxicity, reproductive toxicity and potential carcinogenicity. How to remove 3-MCP and glycidyl ester pollutants in fish oil is a technical problem that needs to be solved urgently.

[0004] In view of the technical defects in this aspect, a solution is now proposed. Summary of the invention

[0005] The object of the present invention is to provide a method for removing harmful substances from fish oil, which is used to solve the problem that the harmful substances 3-chloropropanol ester and glycidyl ester in fish oil cannot be effectively removed in the fish oil processing technology in the prior art.

[0006] The purpose of the present invention can be achieved through the following technical solutions: A method for removing harmful substances from fish oil, comprising the following steps: S1, the crude fish oil is mixed with a degumming agent, and degumming is performed for 20-30 minutes to obtain the degummed crude fish oil; the degummed crude fish oil is mixed with a 10%wt NaOH solution, and deacidification treatment is performed at 50-60°C for 30-40 minutes to obtain the once refined fish oil; S2, mixing the fish oil after the primary refinement, polymerized cation exchange resin and solid hexaaminobenzene ring to obtain a mixed solid-liquid; allowing the mixed solid-liquid to stand for adsorption, and then filtering to obtain an organic phase, which is the refined fish oil.

[0007] The invention sequentially performs degumming treatment, deacidification treatment and adsorption treatment on crude fish oil to remove harmful substances in the fish oil and obtain refined fish oil.

[0008] Furthermore, the preparation method of the polymeric cation exchange resin comprises the following steps: A1, 95-98%wt concentrated sulfuric acid and phenol are mixed and reacted at 100-110°C for 3-4h to obtain an intermediate; A2, add 10%wt NaOH solution to the intermediate, adjust the pH value of the intermediate to 8-10, then add 20-40%wt formaldehyde aqueous solution, react at 100-110°C for 3-5h to obtain a product; add the product to chlorobenzene, disperse to obtain evenly distributed spheres, and heat for 1-2h to obtain acidic cation exchange resin A; Phenol reacts with concentrated sulfuric acid in advance to obtain phenolsulfonic acid; phenolsulfonic acid and formaldehyde undergo addition polymerization to obtain a cross-linked acidic cation exchange resin A with sulfonic acid groups.

[0009] A3. Mix 2,4-dihydroxybenzoic acid and 10%wt NaOH solution, add sodium chloride, mix and stir until completely dissolved, and then add formaldehyde dropwise thereto to obtain a mixed solution; add acidic cation exchange resin A to the mixed solution, react at 30-40°C for 50-60min to obtain resin slurry; disperse the resin slurry into uniform particle size in leveling oil, and then heat it to 50-60°C to obtain a polymer; heat the polymer to 110-120°C for dehydration to obtain a polymerized cation exchange resin.

[0010] With sodium chloride as a porogen, 2,4-dihydroxybenzoic acid and formaldehyde can undergo addition polymerization. During the polymerization process, acidic cation exchange resin A is added therein, and the phenolic hydroxyl groups in the acidic cation exchange resin A can undergo dehydration esterification reaction with 2,4-dihydroxybenzoic acid, thereby obtaining a polymerized cation exchange resin in which two cation exchange resins are interconnected.

[0011] Acidic cation exchange resin A, 2,4-dihydroxybenzoic acid and formaldehyde react to prepare a polymeric cation exchange resin as follows: ; Among them, R is ;

[0012] Furthermore, in step A1, the ratio of concentrated sulfuric acid to phenol is 10-20 mL:100 g; in step A2, the ratio of aqueous formaldehyde solution to chlorobenzene is 100 mL:100 mL; in step A3, the ratio of 2,4-dihydroxybenzoic acid, NaOH solution, sodium chloride and formaldehyde is 10-20 g:100 mL:10 g:30 g; and the amount of acidic cation exchange resin A is 100 g.

[0013] Furthermore, the preparation method of the hexaaminobenzene ring comprises the following steps: B1, cyanuric chloride, anhydrous sodium carbonate and 1,4-dioxane are mixed evenly to obtain a reaction mixture; and then reacted at 5°C for 30-60 minutes to obtain a premix; B2. Add ethylenediamine dropwise to the premix to obtain a reaction system after the addition is completed; the reaction system is first reacted at 0-20°C for 1-3h, then at 50°C for 3h, and finally at 100°C for 3h to obtain a product; the product is filtered, washed, and dried to obtain a solid hexaaminobenzene ring.

[0014] With anhydrous sodium carbonate as a catalyst and 1,4-dioxane as an organic solvent, cyanuric chloride and ethylenediamine undergo nucleophilic substitution to prepare polyamino hexaaminobenzene rings.

[0015] The reaction equation for nucleophilic substitution between cyanuric chloride and ethylenediamine is as follows: ; Furthermore, in step B1, the usage ratio of cyanuric chloride, anhydrous sodium carbonate and 1,4-dioxane is 18-36 g:30 g:500 mL; in step B2, the usage ratio of ethylenediamine is 18-36 g.

[0016] Furthermore, in step S1, the degumming agent is citric acid, and the usage ratio of crude fish oil to the degumming agent is 200g:1-2g; the usage ratio of the degummed crude fish oil to 10%wt NaOH solution is 150g:5-10mL.

[0017] Furthermore, in step S2, the usage ratio of the once refined fish oil, the polymeric cation exchange resin and the solid hexaaminobenzene ring is 100g:5-10g:1-5g.

[0018] The present invention has the following beneficial effects: Crude fish oils such as tuna oil, sardine oil, anchovy oil, etc. have high impurity contents such as protein and mucus. The present invention uses citric acid as a degumming agent to degumming the crude fish oil, and then deacidifies the degummed crude fish oil to obtain a once refined fish oil; and then adsorbs the once refined fish oil to remove harmful substances such as 3-chloropropanol ester and glycidyl ester in the once refined fish oil.

[0019] In order to improve the adsorption efficiency of 3-chloropropanol ester, the present invention designs a polymeric cation exchange resin; phenol and formaldehyde are polymerized to prepare an acidic cation exchange resin A with a sulfonic acid group; 2,4-dihydroxybenzoic acid and formaldehyde are polymerized to prepare an ion exchange resin with a phenolic hydroxyl group; the sulfonic acid group and the phenolic hydroxyl group in the acidic cation exchange resin are used to undergo an esterification reaction, thereby achieving graft copolymerization of the two ion exchange resins to prepare a polymeric cation exchange resin with a high adsorption capacity for 3-chloropropanol ester. The present invention designs a hexaaminobenzene ring with a large number of amino groups for the epoxy groups contained in glycidyl ester, and the epoxy groups can react with the amino groups, thereby increasing the adsorption capacity for glycidyl ester. By adding a specific adsorbent, a refined fish oil with harmful substances 3-chloropropanol ester and glycidyl ester removed is obtained. DETAILED DESCRIPTION

[0020] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example 1

[0021] This embodiment provides a method for preparing a polymeric cation exchange resin, comprising the following steps: A1, 10 mL of 95% wt concentrated sulfuric acid and 100 g of phenol were added to a 500 mL three-necked flask. A stirring bar was set in the three-necked flask. The three-necked flask was then transferred to a water bath. The temperature of the water bath was adjusted to 100 °C and stirred at 100 r / min for 3 h to obtain an intermediate.

[0022] A2. Add 10%wt NaOH solution to the above intermediate to adjust the pH value of the intermediate to 8, then add 100mL of 20%wt formaldehyde aqueous solution, react at 100°C for 3h to obtain a product; add the product into 100mL of chlorobenzene to disperse to obtain evenly distributed spheres, and then heat for 1h to obtain spherical resin, which is acidic cation exchange resin A.

[0023] A3. Add 10 g of 2,4-dihydroxybenzoic acid to a 500 mL beaker, then add 100 mL of 10% wt NaOH solution to the beaker, then add 10 g of sodium chloride, mix and stir until completely dissolved, then add 30 g of formaldehyde dropwise to the beaker, and after the addition is complete, obtain a mixed solution; add 100 g of acidic cation exchange resin A to the beaker, react at 30°C for 50 minutes to obtain a viscous resin slurry; disperse the resin slurry into a uniform particle size in turbine oil, then heat the beaker to 50°C to obtain a polymer; heat the polymer to 105°C for dehydration to obtain a polymerized cation exchange resin. Example 2

[0024] This embodiment provides a method for preparing a polymeric cation exchange resin, comprising the following steps: A1, 15 mL of 96% wt concentrated sulfuric acid and 100 g of phenol were added to a 500 mL three-necked flask. A stirring bar was set in the three-necked flask. The three-necked flask was then transferred to a water bath. The temperature of the water bath was adjusted to 105°C and stirred at 100 r / min for 3.3 h to obtain an intermediate.

[0025] A2. Add 10%wt NaOH solution to the intermediate to adjust the pH value of the intermediate to 9, then add 100mL of 30%wt formaldehyde aqueous solution, react at 105°C for 4h to obtain a product; add the product into 100mL of chlorobenzene to disperse to obtain evenly distributed spheres, and then heat for 1.5h to obtain spherical resin, which is acidic cation exchange resin A.

[0026] A3. Add 13 g of 2,4-dihydroxybenzoic acid to a 500 mL beaker, then add 100 mL of 10% wt NaOH solution to the beaker, then add 10 g of sodium chloride, mix and stir until completely dissolved, then add 30 g of formaldehyde dropwise to the beaker, and after the addition is complete, obtain a mixed solution; add 100 g of acidic cation exchange resin A to the beaker, react at 35°C for 55 minutes to obtain a viscous resin slurry; disperse the resin slurry into a uniform particle size in turbine oil, then heat the beaker to 56°C to obtain a polymer; heat the polymer to 106°C for dehydration to obtain a polymerized cation exchange resin. Example 3

[0027] This embodiment provides a method for preparing a polymeric cation exchange resin, comprising the following steps: A1, 20 mL of 98% wt concentrated sulfuric acid and 100 g of phenol were added to a 500 mL three-necked flask. A stirring bar was set in the three-necked flask. The three-necked flask was then transferred to a water bath. The temperature of the water bath was adjusted to 110°C and stirred at 100 r / min for 4 h to obtain an intermediate.

[0028] A2. Add 10%wt NaOH solution to the above intermediate, adjust the pH value of the intermediate to 10, then add 100mL of 40%wt formaldehyde aqueous solution, react at 110°C for 5h to obtain a product; add the product into 100mL of chlorobenzene to disperse to obtain evenly distributed spheres, and then heat for 2h to obtain spherical resin, which is acidic cation exchange resin A.

[0029] A3. Add 20 g of 2,4-dihydroxybenzoic acid to a 500 mL beaker, then add 100 mL of 10% wt NaOH solution to the beaker, then add 10 g of sodium chloride, mix and stir until completely dissolved, then add 30 g of formaldehyde dropwise to the beaker, and after the addition is complete, obtain a mixed solution; add 100 g of acidic cation exchange resin A to the beaker, react at 40°C for 60 minutes to obtain a viscous resin slurry; disperse the resin slurry into a uniform particle size in turbine oil, then heat the beaker to 60°C to obtain a polymer; heat the polymer to 110°C for dehydration to obtain a polymerized cation exchange resin. Example 4

[0030] This embodiment provides a method for preparing a hexaaminobenzene ring, comprising the following steps: B1. Add 18 g of cyanuric chloride, 30 g of anhydrous sodium carbonate and 500 mL of 1,4-dioxane into a 500 mL three-necked flask and mix well to obtain a reaction mixture; place the three-necked flask in an ice bath and stir at 100 r / min for 30 min at 5°C to obtain a premix.

[0031] B2. Add 18 g of ethylenediamine dropwise into a three-necked flask to obtain a reaction system after the addition is complete; transfer the three-necked flask to a water bath, react at 0°C for 1 hour, then at 50°C for 3 hours, and finally at 100°C for 3 hours to obtain a product. Filter the product, wash, and dry to obtain a solid hexaaminobenzene ring. Example 5

[0032] This embodiment provides a method for preparing a hexaaminobenzene ring, comprising the following steps: B1. Add 25 g of cyanuric chloride, 30 g of anhydrous sodium carbonate and 500 mL of 1,4-dioxane into a 500 mL three-necked flask and mix well to obtain a reaction mixture; place the three-necked flask in an ice bath and stir at 150 r / min for 40 min at 5°C to obtain a premix.

[0033] B2. Add 26 g of ethylenediamine dropwise into a three-necked flask to obtain a reaction system after the addition is complete; transfer the three-necked flask to a water bath, react at 10°C for 2 hours, then at 50°C for 3 hours, and finally at 100°C for 3 hours to obtain a product. Filter the product, wash, and dry to obtain a solid hexaaminobenzene ring. Example 6

[0034] This embodiment provides a method for preparing a hexaaminobenzene ring, comprising the following steps: B1. Add 36 g of cyanuric chloride, 30 g of anhydrous sodium carbonate and 500 mL of 1,4-dioxane into a 500 mL three-necked flask, mix well to obtain a reaction mixture; place the three-necked flask in an ice bath, stir at 200 r / min for 60 min at 5°C to obtain a premix.

[0035] B2. Add 36 g of ethylenediamine dropwise into a three-necked flask to obtain a reaction system after the addition is complete; transfer the three-necked flask to a water bath, react at 20°C for 13 hours, then at 50°C for 3 hours, and finally at 100°C for 3 hours to obtain a product. Filter the product, wash, and dry to obtain a solid hexaaminobenzene ring. Example 7

[0036] This embodiment provides a method for removing harmful substances from fish oil, comprising the following steps: S1. Mix 200 g of crude fish oil and 1 g of degumming agent, and degumming for 20 min at a stirring speed of 100 r / min to obtain degummed crude fish oil; add 150 g of degummed crude fish oil into a conical flask, and then add 5 mL of 10% wt NaOH solution, then transfer the conical flask to a water bath, heat the water bath to 500 ° C, and deacidify for 30 min to obtain once refined fish oil.

[0037] S2. Add 100 g of the fish oil after the primary refinement, 5 g of the polymeric cation exchange resin prepared in Example 1 and 1 g of the solid hexaaminobenzene ring prepared in Example 4 into a beaker to obtain a mixed solid-liquid; transfer the mixed solid-liquid to a water bath for static adsorption at a temperature of 70° C. for 30 min, and then filter with suction to obtain the organic phase, which is the refined fish oil. Example 8

[0038] This embodiment provides a method for removing harmful substances from fish oil, comprising the following steps: S1. Mix 200 g of crude fish oil and 2 g of degumming agent, degumming for 25 min at a stirring speed of 150 r / min to obtain degummed crude fish oil; add 150 g of degummed crude fish oil into a conical flask, add 6 mL of 10% wt NaOH solution, transfer the conical flask to a water bath, heat the water bath to 55 ° C, deacidify for 35 min, and obtain fish oil after primary refining.

[0039] S2. Add 100 g of the once refined fish oil, 6 g of the polymeric cation exchange resin prepared in Example 2 and 3 g of the solid hexaaminobenzene ring prepared in Example 5 into a beaker to obtain a mixed solid-liquid; transfer the mixed solid-liquid to a water bath for static adsorption at a temperature of 75 ° C and a duration of static adsorption of 40 min, and then filter with suction to obtain the refined fish oil. Example 9

[0040] S1. Mix 200 g of crude fish oil and 2 g of degumming agent, degumming for 30 min at a stirring speed of 200 r / min to obtain degummed crude fish oil; add 150 g of degummed crude fish oil into a conical flask, add 10 mL of 10% wt NaOH solution, transfer the conical flask to a water bath, heat the water bath to 60 ° C, deacidify for 40 min, and obtain once refined fish oil.

[0041] S2. Add 100 g of the once refined fish oil, 10 g of the polymeric cation exchange resin prepared in Example 3 and 5 g of the solid hexaaminobenzene ring prepared in Example 6 into a beaker to obtain a mixed solid-liquid; transfer the mixed solid-liquid to a water bath for static adsorption at a temperature of 80° C. for 60 min, and then filter with suction to obtain the refined fish oil.

[0042] Comparative Example 1 Compared with Example 9, in step 2, the polymeric cation exchange resin is replaced by an acidic cation exchange resin A of equal mass.

[0043] Comparative Example 2 Compared with Example 9, in step 2, no polymeric cation exchange resin was added in this comparative example.

[0044] Comparative Example 3 Compared with Example 9, in step 2, no hexaaminobenzene ring was added in this comparative example.

[0045] Performance Test: The contents of 3-chloropropanol ester and glycidyl ester in the fish oil after the first refining in Examples 7-9 were detected, and then the contents of 3-chloropropanol ester and glycidyl ester in the refined fish oil were detected, and then the adsorption amounts of 3-chloropropanol ester and glycidyl ester in the adsorption process in Examples 7-9 were calculated.

[0046] Table 1 ; Data Analysis: Analyzing the data in Table 1, the polymeric cation exchange resins used in Examples 7-9 of the present invention have a high adsorption rate for 3-chloropropanol esters, which is manifested in that in the adsorption process of the corresponding fish oil after primary refining, the adsorption amount of 3-chloropropanol esters and glycidyl esters is high. However, in Comparative Example 1, the polymeric cation exchange resin is replaced by the acidic cation exchange resin A, which reduces the adsorption capacity of the ion exchange resin; in Comparative Example 2, the polymeric cation exchange resin is not added, so that the adsorption amount of 3-chloropropanol ester is significantly reduced.

[0047] The hexaaminobenzene ring used in Examples 7-9 of the present invention has a high adsorption rate for glycidyl ester, which is manifested in that the adsorption amount of glycidyl ester is high in the adsorption process of the corresponding fish oil after primary refining. However, in Comparative Example 3, the hexaaminobenzene ring was not added, resulting in a decrease in the adsorption capacity for glycidyl ester, thereby significantly decreasing the adsorption amount of glycidyl ester.

[0048] The above contents are merely examples and explanations of the structure of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

[0049] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0050] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for removing harmful substances from fish oil, characterized in that: The following steps are involved: S1, the crude fish oil is mixed with a degumming agent, and degummed for 20-30 minutes to obtain the degummed crude fish oil; the degummed crude fish oil is mixed with a 10%wt NaOH solution, and deacidified at 50-60°C for 30-40 minutes to obtain the once refined fish oil; S2, mixing the fish oil after the primary refinement, polymerized cation exchange resin and solid hexaaminobenzene ring to obtain a mixed solid-liquid; allowing the mixed solid-liquid to stand for adsorption, and then filtering to obtain an organic phase, which is the refined fish oil.

2. A method for removing harmful substances from fish oil according to claim 1, characterized in that: The preparation method of the polymeric cation exchange resin comprises the following steps: A1, 95-98%wt concentrated sulfuric acid and phenol are mixed and reacted at 100-110°C for 3-4h to obtain an intermediate; A2, add 10%wt NaOH solution to the intermediate, adjust the pH value of the intermediate to 8-10, then add 20-40%wt formaldehyde aqueous solution, react at 100-110°C for 3-5h to obtain a product; add the product to chlorobenzene, disperse to obtain evenly distributed spheres, and heat for 1-2h to obtain acidic cation exchange resin A; A3. Mix 2,4-dihydroxybenzoic acid and 10%wt NaOH solution, add sodium chloride, mix and stir until completely dissolved, and then add formaldehyde dropwise thereto to obtain a mixed solution; add acidic cation exchange resin A to the mixed solution, react at 30-40°C for 50-60min to obtain resin slurry; disperse the resin slurry into uniform particle size in leveling oil, and then heat it to 50-60°C to obtain a polymer; heat the polymer to 110-120°C for dehydration to obtain a polymerized cation exchange resin.

3. A method for removing harmful substances from fish oil according to claim 2, characterized in that: In step A1, the usage ratio of concentrated sulfuric acid and phenol is 10-20mL:100g; in step A2, the usage ratio of formaldehyde aqueous solution and chlorobenzene is 100mL:100mL; in step A3, the usage ratio of 2,4-dihydroxybenzoic acid, NaOH solution, sodium chloride and formaldehyde is 10-20g:100mL:10g:30g; and the usage ratio of acidic cation exchange resin A is 100g.

4. A method for removing harmful substances from fish oil according to claim 1, characterized in that: The preparation method of the hexaaminobenzene ring comprises the following steps: B1, cyanuric chloride, anhydrous sodium carbonate and 1,4-dioxane are mixed evenly to obtain a reaction mixture; and then reacted at 5°C for 30-60 minutes to obtain a premix; B2. Add ethylenediamine dropwise to the premix to obtain a reaction system after the addition is completed; the reaction system is first reacted at 0-20°C for 1-3h, then at 50°C for 3h, and finally at 100°C for 3h to obtain a product; the product is filtered, washed, and dried to obtain a solid hexaaminobenzene ring.

5. A method for removing harmful substances from fish oil according to claim 4, characterized in that: In step B1, the usage ratio of cyanuric chloride, anhydrous sodium carbonate and 1,4-dioxane is 18-36 g:30 g:500 mL; in step B2, the usage of ethylenediamine is 18-36 g.

6. A method for removing harmful substances from fish oil according to claim 1, characterized in that: In step S1, the degumming agent is citric acid, and the usage ratio of crude fish oil to the degumming agent is 200g:1-2g; the usage ratio of the degummed crude fish oil to 10%wt NaOH solution is 150g:5-10mL.

7. A method for removing harmful substances from fish oil according to claim 1, characterized in that: In step S2, the usage ratio of the once refined fish oil, the polymeric cation exchange resin and the solid hexaaminobenzene ring is 100g:5-10g:1-5g.