A low-loss vitamin E extraction process
Through the acid esterification-alkaline esterification-hydrolysis process, the problem of vitamin E degradation in alkaline environment was solved, the extraction rate and stability were improved, and the toxic effects of plasticizers were reduced.
Patent Information
- Application Number
- CN202510918779.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-04
- Publication Date
- 2025-09-30
- Estimated Expiration
- 2045-07-04
AI Technical Summary
During the process of concentrating natural vitamin E, plasticizers migrate into DD oil under alkaline conditions, resulting in vitamin E degradation and a decrease in extraction rate.
The process steps of acid esterification-alkaline esterification-hydrolysis are adopted. A protective agent is added in the acid esterification stage to form a stable vitamin E ester. The plasticizer is then saponified and decomposed in an alkaline environment, and the vitamin E is restored through long-term concentrated sulfuric acid catalysis.
It effectively reduces the risk of vitamin E degradation in an alkaline environment, improves the extraction rate and stability of vitamin E, and reduces the toxic effects of plasticizers.
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Abstract
Description
Technical Field
[0001] The present application relates to the field of vitamin E extraction technology, and specifically to a low-loss vitamin E extraction technology. Background Art
[0002] Deodorized distillate (DD oil) is a key raw material for concentrating natural vitamin E (VE). Its complex composition primarily includes VE, sterols, triglycerides, and free fatty acids. Acid-catalyzed esterification is currently the primary method for industrially concentrating natural VE. Through esterification, fatty acids are reacted to form fatty acid methyl esters, which are then further separated using methods such as molecular distillation and supercritical CO2 fluid extraction.
[0003] Plasticizers, also known as plasticizers or plasticizers, are additives for polymer materials. Added to polymers, they increase their plasticity. They are primarily used in the production of various plastic products, such as food packaging, toys, medical blood bags, medical hoses, and vinyl flooring. The main components of plasticizers are phthalates, such as di-n-butyl phthalate (DBP), di-(2-ethylhexyl) phthalate (DEHP), and diisononyl phthalate (DINP). In conventional transportation, distilled petroleum ether (DDE) oil is often transported in ordinary plastic barrels. Because plasticizers are fat-soluble compounds, they are easily transferred into the DDE oil during transportation. However, plasticizers are highly toxic to humans and other organisms. Therefore, during the acid-catalyzed esterification process for concentrating natural vitamin E, alkaline solution is added to hydrolyze and remove the plasticizer. However, due to its instability in alkaline environments, vitamin E is prone to degradation or isomerization reactions, which can reduce its content. Summary of the Invention
[0004] In order to solve the problem that VE is easily degraded when using alkaline solution to remove plasticizers during the process of concentrating natural VE, the present application provides a low-loss vitamin E extraction process. The extraction process is distributed through the steps of acid esterification-alkaline esterification-hydrolysis, so that vitamin E is converted into vitamin E ester before alkaline esterification, reducing the risk of vitamin E degradation in an alkaline environment. Then, after alkaline esterification, the vitamin E ester is decomposed back into vitamin E through a longer period of concentrated sulfuric acid catalysis, thereby reducing the damage to vitamin E caused by the alkaline environment while degrading the plasticizer.
[0005] The present application provides a low-loss vitamin E extraction process, which adopts the following technical solution:
[0006] A low-loss vitamin E extraction process comprises the following steps:
[0007] Acidic esterification: DD oil, concentrated sulfuric acid, methanol and a protective agent are mixed and heated to react for 0.5-1 hour to obtain an acidic esterification mixture; the protective agent comprises at least one of methoxy-polyethylene glycol-carboxyl and acetic acid;
[0008] Alkaline esterification: washing the acidic esterification mixture with water, mixing it with sodium methoxide and methanol, and then heating it to react, thereby obtaining an alkaline esterification mixture;
[0009] Hydrolysis: washing the alkaline esterification mixture with water, mixing it with concentrated sulfuric acid and methanol, and heating the mixture for 1-1.5 hours to obtain a hydrolysis mixture;
[0010] Cold precipitation: washing the hydrolysis mixture with water and then cold precipitation, removing the precipitate to obtain a cold precipitation mixture;
[0011] Molecular distillation: The mixture after cold precipitation is subjected to molecular distillation to obtain crude VE.
[0012] By adopting the above technical solution, the present application adds a protective agent during the acidic esterification step, catalyzing concentrated sulfuric acid to form an ester with vitamin E, creating a stable ester bond structure. The resulting vitamin E ester is more stable in a subsequent alkaline environment. Sodium methoxide (a strong base) then undergoes a saponification reaction with plasticizers (such as phthalates) in the acidic esterification mixture, breaking them down into low-toxic substances (such as sodium phthalate), which are then removed by washing with water.
[0013] During the hydrolysis stage, concentrated sulfuric acid reacts for a long time, lasting 1-1.5 hours. The concentrated sulfuric acid destroys the structure of the vitamin E ester, causing it to degrade and release the vitamin E, facilitating the subsequent molecular distillation to obtain more vitamin E. Because the vitamin E ester structure decomposes during prolonged exposure to concentrated sulfuric acid, the hydrolysis reaction time required is longer than the acidic esterification reaction time.
[0014] The present application distributes the steps of acidic esterification - alkaline esterification - hydrolysis, so that vitamin E is converted into vitamin E ester before alkaline esterification, reducing the risk of vitamin E degradation in an alkaline environment. Then, after alkaline esterification, the vitamin E ester is decomposed back into vitamin E through a longer period of concentrated sulfuric acid catalysis, thereby reducing the damage to vitamin E caused by the alkaline environment while degrading the plasticizer.
[0015] Preferably, the protective agent is methoxy-polyethylene glycol-carboxyl.
[0016] By adopting the above technical solution, a comparison of the two protective agents found that methoxy-polyethylene glycol-carboxyl group had the best effect. The reason is that methoxy-polyethylene glycol-carboxyl group can generate vitamin E ester with vitamin E, and at the same time, the polyethylene glycol structure of methoxy-polyethylene glycol-carboxyl group can contain the hydrophobic structure of vitamin E, thereby better improving the stability of vitamin E in an alkaline environment. However, acetic acid and vitamin E can only generate vitamin E ester and cannot contain the hydrophobic structure of vitamin E. Therefore, the structural stability of vitamin E acetate is not as good as the ester substance generated by methoxy-polyethylene glycol-carboxyl group. Therefore, in comparison, methoxy-polyethylene glycol-carboxyl group has better comprehensive performance.
[0017] Preferably, the protective agent is acetic acid, and the method further comprises, in the alkaline esterification step, washing the acidic esterification mixture with water, then adding a β-cyclodextrin solution, heating and mixing, and then filtering to obtain a containing mixture, and then adding sodium methoxide and methanol to the containing mixture, mixing, and heating to react, to obtain an alkaline esterification mixture.
[0018] By adopting the above technical solution, when acetic acid and vitamin E form vitamin E acetate, β-cyclodextrin can contain the hydrophobic structure of vitamin E acetate, effectively improving the stability of vitamin E acetate in an alkaline environment. During the hydrolysis process, concentrated sulfuric acid destroys the cyclic glycosidic bond of β-CD, causing the inclusion complex to dissociate and release VE. Compared with the ester structure formed by methoxy-polyethylene glycol-carboxyl and vitamin E, concentrated sulfuric acid can more easily decompose β-cyclodextrin, making vitamin E easier to detach. Therefore, acetic acid and β-cyclodextrin can better improve the preservation of vitamin E.
[0019] Preferably, the mass ratio of the DD oil to the β-cyclodextrin is 100:15-18.
[0020] By adopting the above technical solution, when the content of β-cyclodextrin is too low, β-cyclodextrin is insufficient in containing vitamin E acetate, resulting in limited improvement in its stability in an alkaline environment; when the content of β-cyclodextrin is too high, β-cyclodextrin is already able to fully contain vitamin E acetate, and the stability of vitamin E acetate is difficult to further improve; for this reason, the applicant finally determined after a lot of research and experimental verification that the mass ratio of the DD oil and the β-cyclodextrin in this application is preferably the above.
[0021] Preferably, in the acidic esterification step, the weight proportions of the components are 100 parts of DD oil, 3-4 parts of concentrated sulfuric acid, 20 parts of methanol and 7-10 parts of protective agent.
[0022] Preferably, in the hydrolysis step, the weight portion of concentrated sulfuric acid is 4-8 parts, and the weight portion of methanol is 30 parts.
[0023] Preferably, in the alkaline esterification step, the weight portion of sodium methoxide is 4-5 parts, and the weight portion of methanol is 20 parts.
[0024] Preferably, in the hydrolysis step, the weight portion of concentrated sulfuric acid is 6-8 parts.
[0025] By adopting the above technical solution, since in the hydrolysis step, concentrated sulfuric acid not only continues to complete the esterification reaction, but also decomposes the ester substances generated by the protective agent and vitamin E, the concentrated sulfuric acid content in the hydrolysis step needs to be higher than the concentrated sulfuric acid content in the acidic esterification step.
[0026] In summary, this application has the following beneficial effects:
[0027] 1. Since the present application is distributed through the steps of acidic esterification-alkaline esterification-hydrolysis, vitamin E is converted into vitamin E ester before alkaline esterification, reducing the risk of vitamin E degradation in an alkaline environment. Then, after alkaline esterification, the vitamin E ester is decomposed back into vitamin E through a longer period of concentrated sulfuric acid catalysis, thereby reducing the damage to vitamin E caused by the alkaline environment while degrading the plasticizer;
[0028] 2. The present application adopts a combination of acetic acid and β-cyclodextrin, wherein acetic acid and vitamin E are combined to form vitamin E acetate, and β-cyclodextrin contains vitamin E acetate, which further improves the stability of vitamin E ester in an alkaline environment; and compared with methoxy-polyethylene glycol-carboxyl, β-cyclodextrin is more easily destroyed by concentrated sulfuric acid, thereby further improving the extraction rate of vitamin E. DETAILED DESCRIPTION
[0029] The raw materials in this application include the following parts:
[0030] Methoxy-polyethylene glycol-carboxyl: a commercially available product with CAS number 67665-18-3 and a molecular weight of 400 was used;
[0031] β-cyclodextrin: a commercially available product with CAS number 68168-23-0 was used.
[0032] The present application is further described in detail below with reference to examples and comparative examples.
[0033] Example 1
[0034] A low-loss vitamin E extraction process comprises the following steps:
[0035] Acidic esterification: 1000 g DD oil, 40 g concentrated sulfuric acid, 200 g methanol and 100 g methoxy-polyethylene glycol-carboxyl were mixed and heated to 80°C for 0.8 h to obtain an acidic esterification mixture;
[0036] Alkaline esterification: The acidic esterification mixture was washed with water, allowed to stand for stratification to remove the acidic wastewater, mixed with 50g of sodium methoxide and 200g of methanol, and heated to react for 2h at a heating temperature of 80°C to obtain an alkaline esterification mixture;
[0037] Hydrolysis: After washing the alkaline esterified product with water, standing for stratification to remove the alkaline wastewater, mixing it with 80g of concentrated sulfuric acid and 300g of methanol, and heating it for 1.2h to obtain a hydrolysis mixture;
[0038] Cold precipitation: The hydrolysis mixture was washed with water and then cold precipitation was performed at a temperature of 4°C for 4 hours. After removing the precipitate, a cold precipitation mixture was obtained;
[0039] Molecular distillation: The mixture after cold precipitation was molecularly distilled. The conditions of molecular distillation were as follows: vacuum degree of 0.5 Pa, temperature of 220° C., scraper speed of 120 r / min, time of 3 h, and crude VE was obtained.
[0040] Example 2-3
[0041] In Example 2-3, based on the preparation method of Example 1, the reaction time in the acidic esterification step (hereinafter referred to as "acid reaction time") and the reaction time in the hydrolysis step (hereinafter referred to as "hydrolysis reaction time") were adjusted. The specific adjustments are shown in Table 1.
[0042] Comparative Examples 1-3
[0043] Comparative Example 1 is based on the preparation method of Example 1, except that 100 g of methoxy-polyethylene glycol-carboxyl is not added in the acidic esterification step.
[0044] Comparative Example 2 is based on the preparation method of Example 1, except that 100 g of methoxy-polyethylene glycol-carboxyl is not added in any step, the reaction time in the acidic esterification step is adjusted to 2 h, the hydrolysis step is not performed, and the alkaline esterification mixture is directly washed with water and then cold-precipitated.
[0045] Comparative Example 3 Based on the preparation method of Example 1, the reaction time in the acidic esterification step and the reaction time in the hydrolysis step were adjusted. The specific adjustments are shown in Table 1.
[0046] The crude VE products of Examples 1-3 and Comparative Examples 1-3 were subjected to the following performance test.
[0047] Performance testing
[0048] 1. Plasticizer content
[0049] Determine the plasticizer content according to GB / T 21911-2008 “Determination of phthalates in foods”.
[0050] 2. Extraction rate
[0051] The extraction rate of vitamin E = (B / A) * 100%, where A represents the mass of vitamin E in DD oil (g) and B represents the mass of vitamin E in crude VE (g).
[0052] Table 1 Reaction time in the initial acidic esterification step and reaction time in the secondary acidic esterification step of Examples 1-3 and Comparative Examples 1-3
[0053]
[0054] Referring to Table 1, it can be seen from the comparison of Examples 1-3 and Comparative Examples 1-3 that Comparative Examples 1-2 show that, without the addition of methoxy-polyethylene glycol-carboxyl groups, whether the acidic esterification step reaction time is set to 2 hours and the hydrolysis step is not performed; or the acidic esterification step reaction time is set to 0.8 hours and the subsequent hydrolysis step reaction time is set to 1.2 hours, the removal of the plasticizer is not affected. Example 1 and Comparative Example 1 show that methoxy-polyethylene glycol-carboxyl groups can effectively improve the stability of vitamin E during the extraction process. This may be due to the addition of methoxy-polyethylene glycol-carboxyl groups in the acidic esterification step, which can generate ester substances with vitamin E and is more stable in a subsequent alkaline environment. In the hydrolysis stage, under the reaction of concentrated sulfuric acid for 1-1.5 hours, the structure of the vitamin E ester is destroyed, degraded, and the vitamin E is released, making it convenient to obtain more vitamin E during subsequent molecular distillation.
[0055] Compared with Examples 1-3 and Comparative Example 3, it can be found that the vitamin E extraction rate of Example 1 is the highest. This may be because in the acidic esterification step, the reaction time is too short, the catalytic effect of concentrated sulfuric acid is incomplete, the ester substances generated by vitamin E and methoxy-polyethylene glycol-carboxyl groups are not enough, and vitamin E is easily decomposed in the subsequent alkaline esterification. If the reaction time is too long, the concentrated sulfuric acid will destroy the ester substances that have been formed, thereby destroying the protective effect of the methoxy-polyethylene glycol-carboxyl group. In the hydrolysis step, the reaction time is too short, the ester substances are not decomposed, and the extraction amount of vitamin E during the subsequent molecular distillation is affected. The reaction time is too long, the ester substances have been fully decomposed, and there is no need to continue to extend the time. Therefore, Example 1 is preferred.
[0056] Examples 4-5
[0057] Example 4 Based on the preparation method of Example 1, 100g of methoxy-polyethylene glycol-carboxyl is replaced by 100g of acetic acid.
[0058] Example 5 Based on the preparation method of Example 1, 100g of methoxy-polyethylene glycol-carboxyl was replaced with 100g of acetic acid;
[0059] The steps of alkaline esterification are adjusted as follows:
[0060] The acidic esterification mixture was washed with water, and after standing and stratification, the acidic waste water was removed, and then a saturated aqueous solution of β-cyclodextrin was added, wherein the saturated aqueous solution of β-cyclodextrin had a β-cyclodextrin content of 180 g. The mixture was heated and mixed, and then filtered. The heating temperature was 60° C. and the heating time was 3 h to obtain a mixture;
[0061] The mixture was mixed with 50 g of sodium methoxide and 200 g of methanol and heated for reaction for 2 h at a heating temperature of 80° C. to obtain an alkaline esterification mixture.
[0062] The crude VE of Example 4-5 was subjected to the above performance test, and the test results are shown in Table 2.
[0063] Table 2 Types of protective agents and addition of β-cyclodextrin and performance test data for Example 1 and Examples 4-5
[0064]
[0065] Referring to Table 2, it can be seen from the comparative example 1 and the examples 4-5 that both methoxy-polyethylene glycol-carboxyl and acetic acid as protective agents can be used in the present application, wherein the comprehensive performance of methoxy-polyethylene glycol-carboxyl is better. The reason is that methoxy-polyethylene glycol-carboxyl can generate vitamin E ester with vitamin E, and at the same time, the polyethylene glycol structure of methoxy-polyethylene glycol-carboxyl can contain the hydrophobic structure of vitamin E, thereby better improving the stability of vitamin E in an alkaline environment. However, acetic acid and vitamin E can only generate vitamin E ester and cannot contain the hydrophobic structure of vitamin E. Therefore, the structural stability of vitamin E acetate is not as good as the ester substances generated by methoxy-polyethylene glycol-carboxyl.
[0066] However, the acidic esterification mixture is first heated and mixed with β-cyclodextrin. β-cyclodextrin can contain the hydrophobic structure of vitamin E acetate, effectively improving the stability of vitamin E acetate in an alkaline environment. During the hydrolysis process, concentrated sulfuric acid destroys the cyclic glycosidic bond of β-cyclodextrin, causing the inclusion complex to dissociate and release VE. Moreover, compared to the ester structure formed by methoxy-polyethylene glycol-carboxyl and vitamin E, concentrated sulfuric acid can more easily decompose β-cyclodextrin, making vitamin E easier to separate. Therefore, the effect of acetic acid and β-cyclodextrin is better than that of methoxy-polyethylene glycol-carboxyl.
[0067] Examples 6-9
[0068] In Examples 6-9, based on the preparation method of Example 5, the β-cyclodextrin content in the β-cyclodextrin solution was adjusted. The specific adjustments are shown in Table 3.
[0069] The crude VE products of Examples 6-9 were subjected to the above performance tests, and the test results are shown in Table 3.
[0070] Table 3 β-cyclodextrin content and performance test data of Examples 4-9
[0071]
[0072] Referring to Table 3, it can be seen from Comparative Examples 4-9 that as the amount of β-cyclodextrin added continues to increase, the extraction rate of vitamin E continues to increase until it tends to be stable. This may be because β-cyclodextrin continues to include vitamin E acetate, and the stability of vitamin E acetate continues to increase until it tends to be stable, thereby continuously improving the extraction rate of vitamin E.
[0073] Examples 10-13
[0074] Examples 10-13 are based on the preparation method of Example 1, except that the contents of concentrated sulfuric acid and methoxy-polyethylene glycol-carboxyl in the acidic esterification step, and the content of sodium methoxide in the alkaline esterification step are adjusted. The specific adjustments are shown in Table 4.
[0075] The crude VE products of Examples 10-13 were subjected to the above performance tests, and the test results are shown in Table 4.
[0076] Table 4 Component contents and performance test data of Example 1 and Examples 10-13
[0077]
[0078] Referring to Table 4, it can be seen from the comparison between Example 1 and Examples 10-13 that the acidic esterification adopts the above ratio and can be used in this application.
[0079] Examples 14-17
[0080] In Examples 14-17, based on the preparation method of Example 1, the concentrated sulfuric acid in the hydrolysis step was adjusted. The specific adjustments are shown in Table 5.
[0081] The crude VE products of Examples 14-17 were subjected to the above performance tests, and the test results are shown in Table 5.
[0082] Table 5 Concentrated sulfuric acid and performance test data in the hydrolysis step of Example 1 and Examples 14-17
[0083]
[0084] As shown in Table 5, by comparing Example 1 with Examples 14-17, it can be seen that in the hydrolysis step, the concentrated sulfuric acid not only continues to complete the esterification reaction but also decomposes the ester substances generated by the protective agent and vitamin E. Since the acidic esterification has a relatively high content of methoxy-polyethylene glycol-carboxyl groups, the content of concentrated sulfuric acid in the hydrolysis step is higher than that in the acidic esterification step, which is beneficial for improving the extraction rate of vitamin E.
[0085] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.
Claims
1. A low-loss vitamin E extraction process, characterized in that: The following steps are involved: Acidic esterification: DD oil, concentrated sulfuric acid, methanol and a protective agent are mixed and heated to react for 0.5-1 hour to obtain an acidic esterification mixture; the protective agent comprises at least one of methoxy-polyethylene glycol-carboxyl and acetic acid; Alkaline esterification: washing the acidic esterification mixture with water, mixing it with sodium methoxide and methanol, and then heating it to react, thereby obtaining an alkaline esterification mixture; Hydrolysis: washing the alkaline esterification mixture with water, mixing it with concentrated sulfuric acid and methanol, and heating the mixture for 1-1.5 hours to obtain a hydrolysis mixture; Cold precipitation: washing the hydrolysis mixture with water and then cold precipitation, removing the precipitate to obtain a cold precipitation mixture; Molecular distillation: The mixture after cold precipitation is subjected to molecular distillation to obtain crude VE.
2. The low-loss vitamin E extraction process according to claim 1, wherein: The protective agent is methoxy-polyethylene glycol-carboxyl.
3. The low-loss vitamin E extraction process according to claim 1, wherein: The protective agent is acetic acid, and the method further includes washing the acidic esterification mixture with water in the alkaline esterification step, then adding a β-cyclodextrin solution, heating and mixing, and then filtering to obtain a containing mixture, and then adding sodium methoxide and methanol to the containing mixture, mixing, and heating to react to obtain an alkaline esterification mixture.
4. The low-loss vitamin E extraction process according to claim 3, wherein: The mass ratio of the DD oil to the β-cyclodextrin is 100:15-18.
5. The low-loss vitamin E extraction process according to claim 1, wherein: In the acidic esterification step, the weight proportions of the components are 100 parts of DD oil, 3-4 parts of concentrated sulfuric acid, 20 parts of methanol and 7-10 parts of protective agent.
6. The low-loss vitamin E extraction process according to claim 5, characterized in that: In the alkaline esterification step, the weight portion of sodium methoxide is 4-5 parts, and the weight portion of methanol is 20 parts.
7. The low-loss vitamin E extraction process according to claim 6, wherein: In the hydrolysis step, the weight portion of concentrated sulfuric acid is 4-8 parts, and the weight portion of methanol is 30 parts.
8. The low-loss vitamin E extraction process according to claim 6, wherein: In the hydrolysis step, the weight portion of concentrated sulfuric acid is 6-8 parts.