Method for extracting curcumin from curcuma oil resin

Abstract

The invention relates to the technical field of extraction of effective active ingredients of plants, and provides a method for extracting curcumin from curcuma oil resin. The method comprises the following steps: removing a residual solvent in curcuma oil resin by utilizing scraper concentration, adding n-hexane for deoiling, concentrating to remove residual n-hexane, adding a dissolving solvent and inorganic salt, heating and stirring until complete dissolution, filtering to obtain a filtrate, crystallizing and centrifuging the filtrate to obtain a precipitate, and drying to obtain the curcuma oil resin. And finally, adding the precipitate into a crystallization solvent, carrying out secondary crystallization, and carrying out centrifugal drying to obtain the curcumin. According to the scheme, all the used solvents can be recycled, no by-product is generated in the whole extraction process, the purity of the curcumin subjected to secondary crystallization is larger than 95%, the recovery rate is high, column chromatography does not need to be used in the process, operation is easy, and the method is suitable for industrial production.

Description

Technical Field

[0001] The invention belongs to the technical field of extracting effective active ingredients of plants, and in particular relates to a method for extracting curcumin from turmeric oleoresin. Background Art

[0002] Curcumin has the effects of protecting liver, promoting gallbladder function, antibacterial, anti-oxidant, anti-viral, lowering blood lipids, and anti-cancer, as well as multiple pharmacological effects on the cardiovascular system, digestive system, etc. It has almost no side effects and is widely used. It is gradually applied to the production of health foods, beverages, cakes, candies, canned foods, etc. It has broad application prospects and has become a hot topic of research at home and abroad. Turmeric oleoresin is a by-product of curcumin extraction. Depending on the production process, the yield of turmeric oleoresin is between 12% and 17% (calculated based on turmeric raw materials), and turmeric oleoresin contains 15% to 20% curcumin residues.

[0003] At present, the use of curcumin oleoresin is relatively simple, mainly adding it back into turmeric residues and selling it as turmeric residues, and the price is relatively cheap. There are few research reports on the method of extracting curcumin from turmeric oleoresin. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a method for extracting curcumin from turmeric oleoresin, which aims to solve the problems mentioned in the background technology.

[0005] The invention provides a method for extracting curcumin from turmeric oleoresin. The method comprises the following steps: removing residual solvent in the turmeric oleoresin by scraper concentration, adding n-hexane for deoiling, concentrating to remove residual n-hexane, adding a dissolving solvent and an inorganic salt, heating and stirring until fully dissolved, filtering to obtain a filtrate, crystallizing the filtrate, centrifuging to obtain a precipitate, finally adding a crystallization solvent to the precipitate for secondary crystallization, and centrifugally drying to obtain curcumin.

[0006] Furthermore, the mass ratio of the turmeric oleoresin to the n-hexane is 1:1-5.

[0007] Furthermore, the dissolving solvent is any one of acetone, ethyl acetate, n-butanol and dichloromethane.

[0008] Furthermore, the mass ratio of the turmeric oleoresin to the dissolving solvent is 1:2-6.

[0009] Furthermore, the inorganic salt is any one of sodium chloride, sodium carbonate, potassium chloride and potassium carbonate.

[0010] Furthermore, the mass ratio of the dissolving solvent to the turmeric oleoresin is 1 to 5:100.

[0011] Furthermore, the heating temperature is 40-70°C.

[0012] Furthermore, the crystallization solvent is a mixed solvent with a mass ratio of methanol: petroleum ether = 1:1, ethanol: petroleum ether = 1:1, methanol: ethyl acetate = 1:1 or ethanol: ethyl acetate = 1:1.

[0013] Furthermore, the mass ratio of the crystallization solvent to the precipitate is 1 to 8:2.

[0014] The present invention has the following technical effects:

[0015] (1) Curcumin is extracted from turmeric oleoresin by using a solvent. During the extraction process, an inorganic salt and a dissolving solvent are mixed and acted on the turmeric oleoresin, so that curcumin is fully dissolved in the solvent. The amount of solvent used is small, and the extract does not need to be concentrated. After filtering, it can be directly crystallized, which greatly shortens the production cycle. The solvent used can be recycled, and no by-products are generated during the entire extraction process. After secondary crystallization, the curcumin has a purity greater than 95%, a high recovery rate, and no column chromatography is required during the process. The operation is simple and suitable for industrial production.

[0016] (2) The content ratio of curcumin monomer, demethoxycurcumin monomer and bisdemethoxycurcumin monomer in curcumin extracted from turmeric oleoresin changes, which is different from the content ratio of each monomer of natural curcumin and curcumin extracted by other extraction methods. The content ratio of each monomer of curcumin will affect the use effect of curcumin in the fields of medicine or food. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] A more complete understanding of exemplary embodiments of the present invention may be obtained by referring to the following drawings:

[0018] Figure 1 The liquid chromatogram of curcumin in the turmeric oleoresin provided in Example 1 of the present invention.

[0019] Figure 2 This is a liquid chromatogram of the precipitate provided in Example 1 of the present invention.

[0020] Figure 3 The liquid chromatogram of curcumin provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0021] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs; the terms used herein are only for the purpose of describing specific embodiments rather than limiting the present invention.

[0023] The embodiment of the present invention provides a method for extracting curcumin from turmeric oleoresin, comprising the steps of removing residual solvent in turmeric oleoresin by scraper concentration, adding n-hexane for deoiling, concentrating to remove residual n-hexane, adding a dissolving solvent and an inorganic salt, heating and stirring until the mixture is completely dissolved, filtering to obtain a filtrate, crystallizing the filtrate, centrifuging to obtain a precipitate, adding a crystallization solvent to the precipitate for secondary crystallization, and centrifugally drying to obtain curcumin.

[0024] Specifically, the mass ratio of turmeric oleoresin to n-hexane is 1:1-5.

[0025] Specifically, the dissolving solvent is any one of acetone, ethyl acetate, n-butanol, and dichloromethane.

[0026] Specifically, the mass ratio of turmeric oleoresin to the dissolving solvent is 1:2-6.

[0027] Specifically, the inorganic salt is any one of sodium chloride, sodium carbonate, potassium chloride and potassium carbonate.

[0028] Specifically, the mass ratio of the dissolving solvent to the turmeric oleoresin is 1 to 5:100.

[0029] Specifically, the heating temperature is 40-70°C.

[0030] Specifically, the crystallization solvent is a mixed solvent with a mass ratio of methanol: petroleum ether = 1:1, ethanol: petroleum ether = 1:1, methanol: ethyl acetate = 1:1 or ethanol: ethyl acetate = 1:1.

[0031] Specifically, the mass ratio of the crystallization solvent to the precipitate is 1 to 8:2.

[0032] Embodiment 1:

[0033] The residual solvent in 100 kg of turmeric oleoresin is removed by scraper concentration, 100 kg of n-hexane is added to the removed turmeric oleoresin for deoiling, the residual n-hexane is removed after deoiling, and then 200 kg of acetone and 1 kg of sodium chloride are added thereto, heated to 40°C and stirred until fully dissolved, and then filtered to obtain a filtrate, the filtrate is transferred to a crystallization tank for crystallization, and 16.25 kg of precipitate is obtained after centrifugation, and finally the precipitate is placed in a crystallization tank, 4.06 kg of crystallization solvent is added for secondary crystallization, the crystallization solvent is a mixed solution with a mass ratio of methanol: petroleum ether = 1:1, and then centrifugal drying is performed to obtain curcumin.

[0034] The mass of the obtained curcumin was 13.26 kg, and the purity was 96.12%, wherein the contents of each monomer compound were: 20.87% bisdemethoxycurcumin, 19.83% demethoxycurcumin, and 55.42% curcumin.

[0035] The liquid chromatography of curcumin in turmeric oleoresin is shown in Figure 1 The liquid chromatogram of the precipitate is shown in Figure 2 As shown; the liquid chromatogram of curcumin is as shown Figure 3 shown.

[0036] Embodiment 2:

[0037] The residual solvent in 100 kg of turmeric oleoresin is removed by scraper concentration, 200 kg of n-hexane is added to the removed turmeric oleoresin for deoiling, the residual n-hexane is removed after deoiling, and then 300 kg of ethyl acetate and 2 kg of sodium carbonate are added thereto, heated to 50°C and stirred until fully dissolved, and then filtered to obtain a filtrate, the filtrate is transferred to a crystallization tank for crystallization, and 17.28 kg of precipitate is obtained after centrifugation, and finally the precipitate is placed in a crystallization tank, 5.76 kg of crystallization solvent is added for secondary crystallization, the crystallization solvent is a mixed solution with a mass ratio of ethanol: petroleum ether = 1:1, and then centrifugal drying is performed to obtain curcumin.

[0038] The mass of the obtained curcumin was 14.25 kg, and the purity was 95.25%, wherein the contents of each monomer compound were: 21.26% bisdemethoxycurcumin, 20.38% demethoxycurcumin, and 53.61% curcumin.

[0039] Embodiment 3:

[0040] The residual solvent in 300 kg of turmeric oleoresin is removed by scraper concentration, and 200 kg of n-hexane is added to the removed turmeric oleoresin for deoiling. After deoiling, the residual n-hexane is removed, and then 400 kg of n-butanol and 3 kg of potassium chloride are added thereto, and the mixture is heated to 70°C and stirred until fully dissolved, and then filtered to obtain a filtrate, which is transferred to a crystallization tank for crystallization. After centrifugation, 13.85 kg of precipitate is obtained, and finally the precipitate is placed in a crystallization tank, and 6.93 kg of crystallization solvent is added for secondary crystallization, wherein the crystallization solvent is a mixed solution with a mass ratio of methanol: ethyl acetate = 1:1, and then centrifuged and dried to obtain curcumin.

[0041] The mass of the obtained curcumin was 12.35 kg, and the purity was 95.68%, wherein the contents of each monomer compound were: 22.24% bisdemethoxycurcumin, 20.52% demethoxycurcumin, and 52.92% curcumin.

[0042] Embodiment 4:

[0043] The residual solvent in 100 kg of turmeric oleoresin is removed by scraper concentration, 500 kg of n-hexane is added to the removed turmeric oleoresin for deoiling, the residual n-hexane is removed after deoiling, and then 600 kg of dichloromethane and 5 kg of potassium carbonate are added thereto, heated to 60°C and stirred until fully dissolved, and then filtered to obtain a filtrate, the filtrate is transferred to a crystallization tank for crystallization, and after centrifugation, 15.86 kg of precipitate is obtained, and finally the precipitate is placed in a crystallization tank, 15.86 kg of crystallization solvent is added for secondary crystallization, the crystallization solvent is a mixed solution with a mass ratio of ethanol: ethyl acetate = 1:1, and then centrifugal drying is performed to obtain curcumin.

[0044] The mass of the obtained curcumin was 14.68 kg, and the purity was 97.23%, wherein the contents of each monomer compound were: 24.39% bisdemethoxycurcumin, 22.68% demethoxycurcumin, and 50.16% curcumin.

[0045] Comparative Example 1:

[0046] The residual solvent in 100 kg of turmeric oleoresin is removed by scraper concentration, 500 kg of n-hexane is added to the removed turmeric oleoresin for deoiling, the residual n-hexane is removed after deoiling, and then 600 kg of dichloromethane is added thereto, heated to 60°C and stirred until fully dissolved, and then filtered to obtain a filtrate, the filtrate is transferred to a crystallization tank for crystallization, and after centrifugation, 7.01 kg of precipitate is obtained, and finally the precipitate is placed in a crystallization tank, 15.86 kg of crystallization solvent is added for secondary crystallization, the crystallization solvent is a mixed solution with a mass ratio of ethanol: ethyl acetate = 1:1, and then centrifugal drying is performed to obtain curcumin.

[0047] The mass of the obtained curcumin was 3.21 kg, and the purity was 87.56%, wherein the contents of each monomer compound were: 25.62% bisdemethoxycurcumin, 18.69% demethoxycurcumin, and 43.25% curcumin.

[0048] It can be understood that the present invention extracts curcumin from turmeric oleoresin by using a solvent, and an inorganic salt and a dissolving solvent are mixed and acted on the turmeric oleoresin during the extraction process, so that curcumin is fully dissolved in the solvent, the amount of solvent used is small, and the extract does not need to be concentrated, and then it can be directly crystallized after filtering, which greatly shortens the production cycle. The solvent used can be recycled, and no by-products are generated in the whole process. The curcumin after secondary crystallization has a purity greater than 95%, a high recovery rate, does not need to use column chromatography, and is simple to operate and suitable for industrial production.

[0049] In addition, the content ratio of curcumin monomer, demethoxycurcumin monomer and bisdemethoxycurcumin monomer in curcumin extracted from turmeric oleoresin changes, which is different from the content ratio of each monomer of natural curcumin and curcumin extracted by other extraction methods. The content ratio of each monomer of curcumin will affect the use effect of curcumin in medicine or food and other fields. For example, in the field of medicine, a high curcumin content ratio is beneficial for anti-inflammatory, antioxidant and enhanced neuroprotection; a high demethoxycurcumin content ratio is beneficial for protecting the liver and assisting in the treatment of tumors; a high bisdemethoxycurcumin content ratio is beneficial for anti-angiogenesis and targeted treatment of skin diseases.

[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for extracting curcumin from turmeric oleoresin, characterized in that: The residual solvent in the turmeric oleoresin is removed by scraper concentration, and then n-hexane is added for de-oiling, and the residual n-hexane is removed by concentration, and then a dissolving solvent and an inorganic salt are added, and the mixture is heated and stirred until fully dissolved, and then filtered to obtain a filtrate, and the filtrate is crystallized and centrifuged to obtain a precipitate, and finally the precipitate is added to a crystallization solvent for secondary crystallization, and then centrifuged and dried to obtain curcumin.

2. A method for extracting curcumin from turmeric oleoresin as claimed in claim 1, characterized in that: The mass ratio of the turmeric oleoresin to the n-hexane is 1:1-5.

3. A method for extracting curcumin from turmeric oleoresin as claimed in claim 2, characterized in that: The dissolving solvent is any one of acetone, ethyl acetate, n-butanol and dichloromethane.

4. A method for extracting curcumin from turmeric oleoresin as claimed in claim 3, characterized in that: The mass ratio of the turmeric oleoresin to the dissolving solvent is 1:2-6.

5. A method for extracting curcumin from turmeric oleoresin as claimed in claim 4, characterized in that: The inorganic salt is any one of sodium chloride, sodium carbonate, potassium chloride and potassium carbonate.

6. A method for extracting curcumin from turmeric oleoresin as claimed in claim 5, characterized in that: The mass ratio of the dissolving solvent to the turmeric oleoresin is 1 to 5:

100.

7. A method for extracting curcumin from turmeric oleoresin as claimed in claim 6, characterized in that: The heating temperature is: 40~70℃.

8. A method for extracting curcumin from turmeric oleoresin as claimed in claim 7, characterized in that: The crystallization solvent is a mixed solvent with a mass ratio of methanol: petroleum ether = 1:1, ethanol: petroleum ether = 1:1, methanol: ethyl acetate = 1:1 or ethanol: ethyl acetate = 1:

1.

9. A method for extracting curcumin from turmeric oleoresin as claimed in claim 8, characterized in that: The mass ratio of the crystallization solvent to the precipitate is 1 to 8:2.

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