Curcumin extraction and purification method

Abstract

The invention discloses a curcumin extraction and purification method, which comprises the following steps: drying and crushing a fresh turmeric raw material, carrying out first solvent extraction through a feeding machine, filtering and concentrating an extracting solution to obtain a turmeric extract, adding a second solvent into the turmeric extract, heating and dissolving, and filtering to obtain the curcumin. And after dissolving, feeding into a crystallizing tank, adding a certain proportion of seed crystal into the crystallizing tank for crystallizing, and centrifugally drying to obtain the curcumin. The yield of the curcumin is 2-4%, and the purity of the curcumin is greater than 95%. The cost of solvents used in the whole process is lower than that of solvents used in other extraction and purification modes, in addition, the used solvents are all safe solvents, solvent residues are all in a safe range, in addition, the whole process is good in continuity, the problems of pipeline blockage and the like do not exist, operation is easy, and the method is suitable for large-scale 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 and purifying curcumin. Background Art

[0002] Curcumin contains three different pigments with extremely similar structures, namely curcumin, demethoxycurcumin and bisdemethoxycurcumin. As a star product in the current plant extract industry, curcumin has been in the top ten sales list for five consecutive years. Curcumin is not only a colorant, but also has liver protection, choleretic, antibacterial, antioxidant, antiviral, lipid-lowering, anti-cancer effects, as well as 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, candy boxes and canned foods. It has broad application prospects and has become a hot topic of research at home and abroad.

[0003] There are many methods for extracting curcumin, mainly organic solvent extraction, acid-base extraction, supercritical CO 2 Extraction method, enzyme method, sodium salicylate method, etc., each of these methods has its own advantages and disadvantages. There are many studies on the separation and purification of curcumin, mainly including macroporous resin adsorption method, silica gel column chromatography method, activated carbon chromatography method, activated clay chromatography method, polyphthalamide adsorption method, n-propanol recrystallization method, methanol-water recrystallization method, etc. These purification methods have the disadvantages of blockage of connecting pipelines, discontinuous production, long preparation cycle time, low yield and low purity. Summary of the invention

[0004] In view of the fact that the methods for extracting and purifying curcumin from turmeric in the prior art have the disadvantages of blockage of connecting pipelines, discontinuous production, long preparation cycle time, low yield, low purity and the like, the present invention provides a method for extracting and purifying curcumin.

[0005] To achieve the above purpose, the technical scheme adopted by the present invention is: a method for extracting and purifying curcumin, fresh turmeric raw material is dried and crushed, and a first solvent is extracted by a feeder, the first organic solvent is any one of n-hexane, n-butanol, and ethyl acetate, the extract is filtered and concentrated to obtain a turmeric extract, a second solvent is added to the turmeric extract for heating and dissolving, and after dissolving, it enters a crystallization tank, a certain proportion of crystal seeds are added to the crystallization tank for crystallization, and curcumin is obtained by centrifugal drying. The yield of curcumin of the present invention is 2-4%, and the purity is greater than 95%. The solvent used in the whole process is lower in cost than the solvent used in other extraction and purification methods. In addition, the solvents used are all safe solvents, and the solvent residues are all within the safe range. In addition, the whole process has good continuity, there is no problem of pipeline blockage, and the operation is simple and suitable for large-scale production.

[0006] More particularly, during the first organic solvent extraction, the extraction method is continuous countercurrent extraction, the solid-liquid ratio is 1:5-1:8 kg / L, and the extraction time is 1-3 hours.

[0007] More particularly, the second organic solvent is any one of acetone, ethyl acetate, n-butanol, a dichloromethane / methanol mixed solvent and a petroleum ether / ethyl acetate mixed solvent, ethanol, methanol, acetonitrile and propylene glycol.

[0008] More particularly, the second organic solvent is stirred and heated to dissolve the extract, and the solid-liquid ratio is 1:1-1:3 kg / L.

[0009] More specifically, a certain proportion of seed crystals are added to the crystallization tank for crystallization, and the seed crystals added are turmeric resin or curcumin remaining from the previous extraction and purification method, and the amount added is 1%-10% of the mass of the extract.

[0010] Due to the adoption of the above-mentioned technical solution, the present invention has the following advantages:

[0011] The present invention adopts a direct extraction and crystallization method, avoiding the shortcomings of the traditional separation and purification preparation cycle, such as long time, low yield, low purity, etc. In addition, the first solvent used in the present invention is cheaper and has a low boiling point, and the energy consumption in the re-concentration process is reduced and the time cycle is saved; another advantage of the present invention is that the production can be continuous, and the connecting pipeline can smoothly transfer the material of the tank body of the previous process to the tank body of the next process; the extract obtained by the first solvent does not need to be defatted and dehydrated, and the addition of the second solvent and crystal seeds can directly and effectively crystallize, and the second solvent is a safe solvent. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a liquid phase chromatogram of curcumin in the turmeric raw material of the present invention.

[0013] Figure 2 The present invention is a liquid chromatogram of the turmeric extract obtained.

[0014] Figure 3 The figure is the liquid phase chromatogram of curcumin obtained by the present invention.

[0015] Figure 4 This is a liquid chromatogram of curcumin obtained by crystallization with other solvents and seed crystals in the present invention.

[0016] Figure 5 This is a liquid chromatogram of curcumin obtained by crystallization using other solvents without adding seed crystals.

[0017] Figure 6 This is a liquid phase chromatogram of curcumin obtained without adding seed crystals in the present invention. DETAILED DESCRIPTION

[0018] The present invention can be further described in detail with reference to the following examples; however, the following examples are merely illustrative, and the present invention is not limited to these examples.

[0019] A new method for extracting and purifying curcumin comprises the following steps:

[0020] Fresh turmeric raw materials are dried and crushed, and a first solvent extraction is performed through a feeder. The first organic solvent is any one of ethanol, n-butanol, methanol, acetonitrile, and ethyl acetate. When the first organic solvent is extracted, the extraction method adopts continuous countercurrent extraction, the solid-liquid ratio is 1:5-1:8 kg / L, and the extraction time is 1-3 hours; the extract is filtered and concentrated to obtain a turmeric extract, and a second solvent is added to the extract for heating and dissolution. The second organic solvent is any one of acetone, ethyl acetate, n-butanol, dichloromethane / methanol and petroleum ether / ethyl acetate, methanol, acetonitrile and propylene glycol. The second organic solvent is stirred and heated to dissolve the extract, and the solid-liquid ratio is 1:1-1:3 kg / L; after dissolution, it enters a crystallization tank, and a certain proportion of crystal seeds are added to the crystallization tank for crystallization. The added crystal seeds are turmeric resin or curcumin remaining in the previous extraction and purification method, and the amount added is 1%-10% of the mass of the extract; and curcumin is obtained through centrifugal drying. The yield of curcumin in the present invention is 2-4%, and the purity is greater than 95%.

[0021] Example 1

[0022] The fresh turmeric raw material is dried and crushed, 350 kg of raw material is added per hour, 1750 L of ethyl acetate is added per hour, the extract is filtered and concentrated to obtain 52.5 kg of turmeric extract, 52.5 L of acetone is added to the extract for heating and dissolving, after dissolving, air compression is used to enter a crystallization tank through a connecting pipeline, 0.525 kg of turmeric resin is added to the crystallization tank for crystallization, and 7.5 kg of curcumin is obtained through centrifugal drying. The yield of curcumin of the present invention is 2.14%, and the purity is 96.5%.

[0023] Example 2

[0024] Fresh turmeric raw material is dried and crushed, 350 kg of material is added per hour, 2100 L of methanol is added per hour, the extract is filtered and concentrated to obtain 56 kg of turmeric extract, 112 L of ethyl acetate is added to the extract for heating and dissolving, after dissolving, air compression is used to enter a crystallization tank through a connecting pipeline, 1.12 kg of turmeric resin is added to the crystallization tank for crystallization, and 7 kg of curcumin is obtained through centrifugal drying. The yield of curcumin of the present invention is 2%, and the purity is 97.3%.

[0025] Example 3

[0026] The fresh turmeric raw material is dried and crushed, 350 kg of raw material is added per hour, 2450 L of ethyl acetate is added per hour, the extract is filtered and concentrated to obtain 53.6 kg of turmeric extract, 107.2 L of methanol is added to the extract for heating and dissolving, after dissolving, air compression is used to enter a crystallization tank through a connecting pipeline, 1.608 kg of turmeric resin is added to the crystallization tank for crystallization, and 12.6 kg of curcumin is obtained through centrifugal drying. The yield of curcumin of the present invention is 3.6%, and the purity is 95.5%.

[0027] Comparative Example 1

[0028] Fresh turmeric raw material is dried and crushed, 350 kg of material is added per hour, 2800 L of ethanol is added per hour, the extract is filtered and concentrated to obtain 62 kg of turmeric extract, 124 L of dichloromethane is added to the extract for heating and dissolution, and after dissolution, air compression is used to enter a crystallization tank through a connecting pipeline, 3.1 kg of turmeric resin is added to the crystallization tank for crystallization, and 10.5 kg of curcumin is obtained through centrifugal drying. The yield of curcumin of the present invention is 3.5%, and the purity is 78.6% ( Figure 4 ).

[0029] Comparative Example 2

[0030] Fresh turmeric raw material is dried and crushed, 350 kg of material is added per hour, 2450 L of ethyl acetate is added per hour, the extract is filtered and concentrated to obtain 53.6 kg of turmeric extract, 107.2 L of dichloromethane is added to the extract for heating and dissolution, and after dissolution, air compression is used to enter the crystallization tank through the connecting pipeline, and no crystals are added to the crystallization tank for crystallization, and 14 kg of curcumin is obtained by centrifugal drying. The yield of curcumin of the present invention is 4%, and the purity is 66.5% ( Figure 5 ).

[0031] Comparative Example 3

[0032] The fresh turmeric raw material is dried and crushed, 350 kg of raw material is added per hour, 1750 L of ethyl acetate is added per hour, the extract is filtered and concentrated to obtain 52.5 kg of turmeric extract, 52.5 L of acetone is added to the extract for heating and dissolving, and after dissolving, air compression is used to enter a crystallization tank through a connecting pipeline, and crystallization is performed without adding crystals to the crystallization tank, and 0.56 kg of curcumin is obtained through centrifugal drying. The yield of curcumin of the present invention is 0.16%, and the purity is 98.5%.

[0033] The present invention adjusts parameters on the basis of the above-mentioned embodiments to form more embodiments, as shown in the following table.

[0034]

[0035]

[0036] The solvents used for curcumin extraction are basically methanol, ethanol, acetonitrile, acetone and ethyl acetate, and the crystallization solvents are dichloromethane, ethanol, acetone, ethyl acetate and methanol. After extraction with the same solvent, you need to choose a suitable solvent for crystallization. However, some solvents cannot be directly crystallized after extraction, and need to be deoiled and decolorized before choosing a solvent for crystallization. Under the same conditions, adding seed crystals can help improve the yield and purity.

[0037] 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 and purifying curcumin, characterized in that: fresh The turmeric raw material is dried and crushed, and a first solvent extraction is performed through a feeder, the first organic solvent is any one of n-hexane, n-butanol, and ethyl acetate, the extract is filtered and concentrated to obtain turmeric extract, a second solvent is added to the turmeric extract for heating and dissolution, and after dissolution, it enters a crystallization tank, a certain proportion of seed crystals are added to the crystallization tank for crystallization, and curcumin is obtained through centrifugal drying.

2. A method for extracting and purifying curcumin according to claim 1, characterized in that: During the first organic solvent extraction, continuous countercurrent extraction is adopted, the solid-liquid ratio is 1:5-1:8 kg / L, and the extraction time is 1-3 hours.

3. A method for extracting and purifying curcumin according to claim 1, characterized in that: The second organic solvent is any one of acetone, ethyl acetate, n-butanol, a dichloromethane / methanol mixed solvent, a petroleum ether / ethyl acetate mixed solvent, ethanol, methanol, acetonitrile and propylene glycol.

4. A method for extracting and purifying curcumin according to claim 1, characterized in that: The second organic solvent is stirred and heated to dissolve the extract, and the solid-liquid ratio is 1:1-1:3kg / L.

5. A method for extracting and purifying curcumin according to claim 1, characterized in that: A certain proportion of seed crystals is added to the crystallization tank for crystallization.

6. A method for extracting and purifying curcumin according to claim 5, characterized in that: The added seed crystals are the remaining turmeric resin or curcumin from the previous extraction and purification method, and the added amount is 1%-10% of the mass of the extract.

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