Method for extracting selenium element from Luohanshen

Abstract

The invention discloses a method for extracting selenium from Luohanshen. The method comprises the following steps: pretreating a Luohanshen raw material, and then crushing the pretreated Luohanshen raw material; carrying out deep degreasing by adopting an ultrasonic-assisted organic solvent method; the method comprises the following steps: mixing degreased powder with an extraction solvent, and carrying out multi-mode extraction by adopting one or a combined mode of hot water extraction, composite enzymolysis and ultrasonic-assisted extraction; and finally, carrying out solid-liquid separation, concentration and drying to obtain the product. According to the method, through the synergistic effect of deep degreasing and multi-mode extraction, especially efficient disintegration of composite enzymolysis on cell walls, the dissolution efficiency of selenium can be remarkably improved, and the organic selenium structure can be protected to the maximum extent. The method solves the problems of low extraction rate, low organic selenium ratio and more impurities in the traditional process, is suitable for preparing selenium-rich functional food, dietary supplements and the like, and has the advantages of high efficiency, mild conditions and excellent product quality.

Description

TECHNICAL FIELD

[0001] The present application relates to the extraction technology of selenium in radix ginseng rubra, and particularly relates to a method for extracting selenium in radix ginseng rubra. BACKGROUND

[0002] Selenium is an essential trace mineral element for human body, which has important physiological functions such as anti-oxidation, immunity enhancement, cancer prevention and anti-cancer. Selenium in human body mainly exists in the form of organic selenium (such as selenomethionine, selenocystine, etc.), and its bioavailability and safety are much higher than inorganic selenium. Therefore, the development of natural plant resources rich in organic selenium has become a research hotspot in the field of functional foods.

[0003] Radix ginseng rubra is a plant with medicinal and edible properties, and researches show that it has the ability to enrich selenium and is a potential good source of organic selenium. At present, the conventional methods for extracting selenium from plants mainly include hot water extraction, acid extraction, alkali extraction or single enzymatic hydrolysis. However, these traditional methods have obvious defects when applied to the extraction of selenium from radix ginseng rubra.

[0004] The cell wall structure of radix ginseng rubra is dense, and the selenium element is wrapped by multiple substances such as oil, protein and pectin in the cell. The traditional single extraction method is difficult to fully destroy the cell structure and release the contents, resulting in a low total extraction rate of selenium. At the same time, the severe extraction conditions (such as strong acid, strong alkali, high temperature and long time) may damage the chemical structure of organic selenium, leading to the conversion of organic selenium into inorganic selenium or loss, so that the proportion of organic selenium in the final product is difficult to improve.

[0005] The lipid components in the raw materials will be dissolved out during the extraction process, not only consuming the solvent, but also mixing with the target extract, increasing the difficulty of subsequent separation and purification, and affecting the purity and quality of the final product.

[0006] In order to achieve a high extraction rate, it is often necessary to prolong the extraction time, increase the temperature or increase the amount of solvent, which leads to high energy consumption and increased cost in the production process, and is not conducive to the preservation of active ingredients, making it difficult to carry out large-scale and economic production and application.

[0007] Therefore, there is an urgent need in the field to develop a new method for efficiently and selectively extracting organic selenium from radix ginseng rubra with mild process and suitable for industrial application. SUMMARY

[0008] The present application aims to solve the above technical problems, and provides a method for extracting selenium in radix ginseng rubra.

[0009] To solve the above technical problems, the technical scheme provided by the present application is as follows: a method for extracting selenium in radix ginseng rubra, comprising the following steps: Raw material pretreatment: washing, slicing, drying to a moisture content of ≤10%, crushing and then passing through a 40-100 mesh sieve to obtain radix ginseng rubra powder; Deep degreasing: the powder of radix ginseng is degreased by ultrasonic-assisted organic solvent method, the ratio of organic solvent to powder of radix ginseng (w / v) is 1:3-1:8, the ultrasonic frequency is 20-50 kHz, the degreasing temperature is 30-50℃, and the degreasing is performed for 1-3 times to obtain the degreased powder of radix ginseng; Multi-mode extraction: the degreased powder of radix ginseng is mixed with an extraction solvent at a ratio (w / v) of 1:8-1:30, and one or a combination of the following modes is used for extraction: a) hot water extraction: extraction at 60-90℃ for 60-150 minutes; b) complex enzymolysis: addition of complex enzymes at pH 3.0-6.0 and 40-60℃ for 60-240 minutes; the complex enzymes comprise at least two of pectinase, β-glucanase, neutral protease and cellulase; c) ultrasonic-assisted extraction: extraction at 20-40 kHz and 400-800 W power at 30-50℃ for 20-40 minutes; Post-treatment: the extraction liquid is subjected to solid-liquid separation, and the supernatant is collected; the supernatant is concentrated and dried to obtain the selenium extract of radix ginseng; In the method, the proportion of organic selenium in the finally obtained extract is ≥90%, and the selenium extraction rate is ≥85%.

[0010] Further, the extraction mode used in step 3 is a combination of a) and b), specifically: first, hot water extraction is performed, then the pH and temperature of the system are adjusted, and then complex enzymolysis is performed.

[0011] Further, in the complex enzymolysis step, the complex enzymes are compounded by pectinase, β-glucanase and neutral protease at a mass ratio of (1.0-2.0):(0.5-1.2):(0.8-1.5).

[0012] Further, the complex enzymolysis adopts a dynamic enzyme supplementing strategy, and 20-40% of the initial enzyme addition amount is supplemented every 60 minutes.

[0013] Further, the extraction mode used in step 3 is a combination of a) and c), specifically: first, hot water extraction is performed, and then ultrasonic-assisted extraction is performed after the mixed system is cooled to 30-50℃.

[0014] Further, the organic solvent in step 2 is at least one of n-hexane, petroleum ether or cyclohexane.

[0015] Further, the extraction solvent in step 3 is water, a buffer solution at pH 3.0-6.0 or an ethanol aqueous solution with a concentration of 40%-60%; the buffer solution is a citrate buffer solution or an acetate buffer solution.

[0016] Further, the solid-liquid separation in step 4 is centrifugal separation, the centrifugal speed is 3000-10000 rpm, preferably filtering by using 0.22-0.45 mu m microporous filter membrane; the drying is freeze drying or spray drying.

[0017] The application of the high-organic-selenium-content ginseng extract is used for preparing selenium-rich functional food, dietary supplement or selenium-rich microbial culture medium.

[0018] Compared with the prior art, the application has the advantages that: by deep degreasing and pretreatment, impurities are effectively removed; by multi-mode synergistic extraction strategy, especially the precise wall breaking effect of complex enzymatic hydrolysis, the dissolution efficiency of selenium is greatly improved under mild conditions, and the structural integrity of organic selenium is perfectly protected. The final product has high purity and good activity. The method successfully solves the defects of low extraction rate, low organic selenium proportion, high process energy consumption and high product impurities in the prior art, has the comprehensive advantages of high efficiency, good selectivity, mild conditions, energy saving and consumption reduction, easy industrialization and the like, and provides core technical support for developing high-quality selenium-rich functional products. DETAILED DESCRIPTION

[0019] In order to make the technical problems, technical solutions and beneficial effects of the present application clearer, the present application will be further described in detail below in combination with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0020] 9, working principle of the application: S1: raw material pretreatment unit. After washing the fresh ginseng to remove surface dirt, slice the ginseng by a slicing machine (101) to increase the specific surface area, which is beneficial for subsequent drying and crushing. Then, dry the slices to a moisture content of ≤10% by using a hot air drying oven (102) or a vacuum freeze dryer. This low moisture state is beneficial for crushing and preventing the efficiency from being reduced due to the presence of water during subsequent organic solvent degreasing. Finally, crush the ginseng by a crusher (103) and pass through a 40-100 mesh sieve to obtain ginseng powder (104) with uniform particle size, which ensures uniform mass transfer during subsequent processing.

[0021] S2: Deep defatting unit. This is the key pre-step of the invention. Deep defatting is carried out by ultrasonic-assisted organic solvent method. The radix salviae miltiorrhizae powder (104) is placed in an ultrasonic extraction tank (201) with organic solvent (such as n-hexane) at a specific liquid-solid ratio. The ultrasonic generator (202) generates high-frequency ultrasonic waves of 20-50 kHz, which produces "cavitation effect" in the liquid, generating strong impact force and micro-jet flow, which can instantly destroy plant cell walls, fully expose the internal lipids, and contact with organic solvents. Compared with traditional Soxhlet extraction, this method can achieve efficient and rapid defatting at a mild temperature (30-50°C), and can be repeated 1-3 times to ensure that most of the oil is removed. The defatted radix salviae miltiorrhizae powder (203) avoids the interference of oil in subsequent water-phase extraction, reduces the subsequent purification burden, and clears the obstacles for the subsequent extraction solvent to fully contact the target components.

[0022] S3: Multi-mode extraction unit. This is the core of efficient dissolution of selenium elements. According to the characteristics of the defatted material, three extraction modes that can work independently or cooperatively are designed, and their common principle is to accurately and gently break down different components of the cell wall and the existing forms of selenium.

[0023] a) Hot water leaching module (301): In hot water at 60-90°C, water-soluble components (including part of water-soluble organic selenium compounds) in plant cells are first leached out. The heat reduces the viscosity of the solvent, increases the molecular motion rate, and promotes diffusion. This step preliminarily softens the material structure.

[0024] b) Complex enzymatic hydrolysis module (302): This is the core means to improve the extraction rate and proportion of organic selenium. In the enzyme reaction kettle (302), under specific pH and temperature, complex enzymes (303) compounded by pectinase, β-glucanase, neutral protease, etc. are added. These enzymes can synergistically and accurately degrade pectin, cellulose, glucan, and proteins that wrap selenium elements, which constitute the intercellular matrix and cell wall, thereby completely releasing the combined organic selenium without destroying the organic structure of selenium like strong acid and strong base. The specificity and gentleness of enzymatic hydrolysis ensure the efficient dissolution of selenium in organic form. Further, the dynamic enzyme supplementing strategy (304) maintains the efficiency of the enzyme reaction system by adding enzyme solution at regular intervals, overcoming the problem of enzyme deactivation during the reaction, ensuring the sufficiency and stability of extraction.

[0025] c) Ultrasonic-assisted extraction module (305): Using the cavitation effect, mechanical action, and thermal effect of ultrasonic waves, the material is subjected to intense impact at low temperature (30-50°C), causing cell wall cracks, increasing solvent penetration channels, and accelerating the dissolution and mass transfer of target components. This method can be used alone or in combination with other modes as an intensification means to greatly shorten the extraction time.

[0026] The combination of the above modes (such as hot water extraction followed by enzymatic hydrolysis, or hot water extraction followed by ultrasonic) realizes the synergistic effect of physical (thermal energy, mechanical force), chemical (enzyme catalysis) methods, realizes the multi-level and all-round cracking of radix salviae miltiorrhizae matrix, and thus realizes the efficient and complete extraction of selenium elements, especially organic selenium.

[0027] S4: post-treatment unit. After extraction is completed, the mixed solution is subjected to solid-liquid separation at 3000-10000 rpm by a centrifuge (401) to remove residues. The collected supernatant is subjected to fine filtration by a microporous filter membrane (402) (0.22-0.45 μm) to obtain a clear selenium-containing extraction solution. The extraction solution is finally introduced into a concentration and drying device (403) (such as a vacuum concentration tank, a spray drying tower or a freeze dryer), and after the solvent is removed, a radix salviae miltiorrhizae extract powder (404) with high organic selenium content is obtained. The whole post-treatment process is efficient and closed, avoiding the pollution and loss of the product.

[0028] 10. Embodiment: Example 1: Combination mode of hot water extraction and composite enzymatic hydrolysis 1. Raw material pretreatment (S1): Take 5 kg of fresh radix salviae miltiorrhizae tuber and wash it with clean water. Slice it into slices with a thickness of about 3 mm using a slicing machine (101) and dry it in a hot air drying oven (102) at 65°C until the water content is 8%. Crush it using a crusher (103) and pass it through a 60-mesh sieve to obtain radix salviae miltiorrhizae powder (104).

[0029] 2. Deep degreasing (S2): Take 1000 g of radix salviae miltiorrhizae powder (104) and place it in an ultrasonic extraction tank (201), and add petroleum ether according to a solid-liquid ratio of 1:5 (w / v). Set the ultrasonic frequency to 40 kHz and the temperature to 40°C, and ultrasonically treat it for 45 minutes. After treatment, filter and collect the residue, and repeat the above degreasing process once to obtain degreased radix salviae miltiorrhizae powder (203), which is dried in a fume hood for standby use.

[0030] 3. Multi-mode extraction (S3): Hot water extraction: Take 100 g of degreased radix salviae miltiorrhizae powder (203) and add purified water according to a solid-liquid ratio of 1:20 (w / v), and extract it in a stirring hot water extraction tank (301) at 80°C for 120 minutes.

[0031] Composite enzymatic hydrolysis: naturally cool the above extraction system to 50°C, adjust the pH to 4.5 with citric acid, and add composite enzymes (303) (composed of pectinase, β-glucanase, and neutral protease according to a mass ratio of 1.5:1.0:1.2, and the total amount of added enzyme is 2% of the substrate mass). Place it in an enzyme reaction kettle (302) and hydrolyze it at 50°C under constant stirring for 180 minutes. During this period, every 60 minutes, 30% of the initial enzyme amount is added through a supplementary enzyme system (304).

[0032] 4. Post-treatment (S4): After the end of enzymolysis, the extract was centrifuged at 8000 rpm for 15 minutes by a centrifuge (401), and the supernatant was collected. The supernatant was filtered by a 0.45 μm microporous filter membrane (402). The filtrate was transferred into a vacuum concentration tank and concentrated to 1 / 5 of the original volume at 60°C. The concentrated solution was subjected to spray drying (403) (inlet air temperature 180°C, outlet air temperature 80°C) to obtain a yellowish Arisaema amurense Maxim. selenium extract powder (404) of about 15.2 g.

[0033] Example 2: Combination mode of hot water extraction and ultrasonic-assisted extraction 1. Raw material pretreatment and deep degreasing: same as steps S1 and S2 of Example 1, to obtain the degreased Arisaema amurense Maxim. powder (203).

[0034] 2. Multi-mode extraction (S3): Hot water extraction: 100 g of the degreased Arisaema amurense Maxim. powder (203) was added with a pH 5.0 acetate buffer solution at a solid-liquid ratio of 1:15 (w / v), and extracted at 80°C for 100 minutes.

[0035] Ultrasonic-assisted extraction: the above system was cooled to 40°C and transferred to an ultrasonic-assisted extraction device (305). The ultrasonic power was set to 600 W and the frequency was set to 30 kHz, and the ultrasonic extraction was continued at 40°C for 30 minutes.

[0036] 3. Post-treatment (S4): the subsequent centrifugation, filtration, concentration and spray drying steps of the extract were the same as those of Example 1. About 14.8 g of Arisaema amurense Maxim. selenium extract powder (404) was obtained.

[0037] Example 3: Single complex enzymolysis mode 1. Raw material pretreatment and deep degreasing: same as steps S1 and S2 of Example 1, to obtain the degreased Arisaema amurense Maxim. powder (203).

[0038] 2. Multi-mode extraction (S3): 100 g of the degreased Arisaema amurense Maxim. powder (203) was added with a pH 4.0 citrate buffer solution at a solid-liquid ratio of 1:25 (w / v) and placed in an enzyme reaction kettle (302). The complex enzyme (303) (the enzyme ratio was the same as that of Example 1, and the total amount of added enzyme was 2.5% of the mass of the substrate) was directly added, and the enzymolysis was carried out at 55°C for 240 minutes. No dynamic enzyme supplement was needed.

[0039] 3. Post-treatment (S4): the subsequent steps were the same as those of Example 1. About 16.0 g of Arisaema amurense Maxim. selenium extract powder (404) was obtained.

[0040] Comparative Example: Traditional hot water extraction method Take 100g of ordinary powder of radix ginseng without defatting (pass through 60 mesh sieve), add purified water according to the ratio of 1:20, reflux extraction at 90℃ for 3 hours. After centrifugation, filtration, concentration and drying, the extract is obtained. The selenium extraction rate is only 52.3%, and the proportion of organic selenium is less than 70%

[0041] The above describes the present application and its embodiments, which is not limited, in general, if the ordinary skilled in the art is inspired, without departing from the purpose of the present application, without creative design of similar structure and embodiments of the technical solution, which should belong to the protection scope of the present application.

Claims

1. A method for extracting selenium element from radix ginseng, characterized by: The method comprises the following steps: (1) raw material pretreatment: clean and slice the radix ginseng, dry to moisture content≤10%, crush and sieve through 40-100 mesh to obtain radix ginseng powder; (2) deep degreasing: degrease the radix ginseng powder by ultrasonic-assisted organic solvent method, the ratio of organic solvent to radix ginseng powder (w / v) is 1:3-1:8, the ultrasonic frequency is 20-50 kHz, the degreasing temperature is 30-50℃, and the degreasing is performed for 1-3 times to obtain degreased radix ginseng powder; (3) multi-mode extraction: mix the degreased radix ginseng powder with extraction solvent according to the ratio (w / v) 1:8-1:30, and extract by one or a combination of the following modes: a) hot water extraction: extract at 60-90℃ for 60-150 minutes; b) complex enzymolysis: add complex enzymes under the conditions of pH 3.0-6.0 and 40-60℃ for 60-240 minutes; the complex enzymes comprise at least two of pectinase, β-glucanase, neutral protease and cellulase; c) ultrasonic-assisted extraction: extract at 30-50℃ for 20-40 minutes under the conditions of 20-40 kHz and 400-800 W power; (4) post-treatment: perform solid-liquid separation on the extraction liquid, collect the supernatant, concentrate and dry the supernatant to obtain the radix ginseng selenium extract; wherein the extract prepared by the method has an organic selenium proportion≥90% and a selenium extraction rate≥85%.

2. The method of claim 1, wherein the selenium is extracted from the plant of the genus Panax. In step (3), the extraction mode is a combination of a) and b), specifically, hot water extraction is performed first, then the pH and temperature of the system are adjusted, and then complex enzymolysis is performed.

3. The method of claim 2, wherein the selenium is extracted from the plant. In the complex enzymolysis step, the complex enzymes are compounded by pectinase, β-glucanase and neutral protease according to the mass ratio (1.0-2.0):(0.5-1.2):(0.8-1.5).

4. The method of claim 3, wherein the selenium is extracted from the plant. The complex enzymolysis adopts a dynamic enzyme supplementing strategy, and 20-40% of the initial enzyme addition amount is supplemented every 60 minutes.

5. The method of claim 1, wherein the selenium is extracted from the ginseng. In step (3), the extraction mode is a combination of a) and c), specifically, hot water extraction is performed first, and then ultrasonic-assisted extraction is performed after the mixed system is cooled to 30-50℃.

6. The method of claim 1, wherein the selenium is extracted from the ginseng. In step (2), the organic solvent is at least one of n-hexane, petroleum ether or cyclohexane.

7. The method of claim 1, wherein the selenium is extracted from the ginseng plant. In step (3), the extraction solvent is water, a buffer solution with pH 3.0-6.0 or an ethanol aqueous solution with a concentration of 40%-60%; the buffer solution is a citrate buffer or an acetate buffer.

8. The method of claim 1, wherein the selenium is extracted from the ginseng plant. In step (4), the solid-liquid separation is centrifugal separation, the centrifugal speed is 3000-10000 rpm, and the filtration is preferably performed by using a 0.22-0.45 μm microporous filter membrane; the drying is freeze-drying or spray-drying.

9. A high-organoselenium-content ginseng extract, characterized in that, Prepared by the method of any one of claims 1-8.

10. Use of the high-organic selenium content ginseng extract according to claim 9, characterized in that, Used for preparing selenium-rich functional food, dietary supplement or selenium-rich microbial culture medium.