Method for extracting naringin from pummelo peel

Abstract

The invention discloses a method for extracting naringin from pummelo peel, which is used for preparing high-content naringin through extraction, separation and purification. The method is relatively friendly to the environment, the production process is simple, and the 999-grade naringin can be stably and industrially produced.

Description

Technical Field

[0001] The invention relates to the technical field of extraction and purification of plant active ingredients, and in particular to a method for extracting naringin from tangerine peel. Background Art

[0002] Huajuhong (Huajuhong) is the dried, immature or nearly mature outer peel of the Huazhou pomelo (Citrus grandis 'Tomentosa') or pomelo (Citrus grandis (L.) Osbeck), both of the Rutaceae family. The Huazhou variety is particularly renowned, hence its name. Huajuhong is a food and medicine with medicinal properties, known for its benefits of regulating qi, relieving fullness, and dispelling dampness and phlegm. Modern research indicates that Huajuhong contains a significant amount of flavonoids, with naringin being the most abundant.

[0003] Naringin, a natural flavonoid with the CAS number 10236-47-2, has the effects of resolving phlegm and relieving cough, clearing away heat and detoxifying, and has been registered as a Class I new drug. It also exhibits various modern pharmacological properties, including antibacterial, anti-inflammatory, antiviral, anticancer, antioxidant, whitening, and blood pressure and blood sugar lowering properties. It can also be used in the production and processing of food and beverages as a natural pigment, flavor enhancer, and bittering agent. It also serves as a raw material for the synthesis of the novel sweeteners naringin dihydrochalcone (1,000 times sweeter than sucrose), neohesperidin (900 times sweeter than sucrose), and neohesperidin dihydrochalcone (1,500-1,800 times sweeter than sucrose), thus possessing high economic value.

[0004] The preparation of high-content naringin primarily involves extraction from the Rutaceae plant pomelo, followed by purification of the extract to obtain crude naringin crystals, followed by multiple crystallizations. The main extraction methods include organic solvent extraction, alkaline solution extraction, ultrasound-assisted extraction, supercritical fluid extraction, and enzyme-assisted extraction. Purification methods include water precipitation and crystallization, organic extraction, silica gel resin separation, activated carbon adsorption and impurity removal, and membrane filtration. The recrystallization solution is primarily an organic solution.

[0005] Naringin is a dihydroflavonoid compound whose aglycone is naringenin, and the glycosyl group is formed by the condensation of rhamnose and glucose. In an acidic environment, naringin crystallizes in several ways: First, the phenolic hydroxyl group and the glycosyl group in the naringin molecule are protonated, reducing polarity and leading to a decrease in solubility in aqueous ethanol, making it easier to reach supersaturation and crystallize. Second, some polar impurities in the crystallization solution (such as polysaccharides and acidic pigments) retain their high solubility and remain in the mother liquor. Alternatively, certain alkaloids or alkaline components form water-soluble salts under acidic conditions and remain in the mother liquor, avoiding co-crystallization with naringin. Third, pigments in the crystallization solution (such as carotenoids and flavonoid polymers) may aggregate or degrade, inhibiting the co-crystallization of the pigment and naringin. However, if the pH is too low (<2), the glycosidic bond may hydrolyze to form naringenin and glycosyl groups, thereby affecting the yield and content.

[0006] At present, the process for producing naringin in the industry is mainly a combination of the above-mentioned process technologies, but the content of naringin produced is not high enough and a large amount of highly toxic organic solvents are used.

[0007] Patent document CN109970828A discloses a method for extracting naringin from tangerine peel. The method involves heating an ethanol solution under reflux, filtering, and concentrating the filtrate to dryness to obtain a naringin extract. The naringin produced by this extraction method is not purified, and the naringin content is not high.

[0008] Patent document CN108129532A discloses a method for preparing naringin from Citrus grandis. The method involves crushing dried Citrus grandis fruit, extracting and defatting it with petroleum ether, removing the petroleum ether, and then extracting it in a hot water bath with a 95% ethanol solution. The filtrate is filtered and collected, concentrated to remove the ethanol, and then eluted with a macroporous resin and an ethanol solution. The eluate is concentrated and allowed to stand for one day to collect a precipitate. The precipitate is washed with ice water, collected by centrifugation, and dried to obtain a naringin extract. The naringin content of the extract prepared by this method is only 96.9% to 97.5%.

[0009] Patent document CN104817602A discloses a method for extracting naringin. Grapefruit peels are powdered, extracted and defatted with an organic reagent such as petroleum ether. The petroleum ether is removed, and an ethanol solution is added for reflux extraction. The filtrate is filtered and collected, and the filtrate is concentrated to remove the alcohol. The precipitate is collected by standing, dissolved in hot water for recrystallization, and the crystals are collected and dried to obtain a naringin extract. The naringin content of the extract prepared by this method is only 80.9% to 96.3%.

[0010] Patent document CN103833809A discloses a process for extracting and separating naringin. This involves extracting pomelo peel powder with methanol or ethanol reflux, concentrating it, and then precipitating it with water to remove impurities. The aqueous solution is defatted with petroleum ether, and the remaining solution is extracted with n-butanol. This solution is then stripped with n-hexane to remove impurities, followed by decolorization with activated carbon. The process is concentrated, cooled, and crystallized, and the crystals are collected and dried to obtain the naringin extract. This method utilizes large amounts of highly toxic organic reagents such as methanol, petroleum ether, n-butanol, and n-hexane, posing potential environmental risks and contradicting the nationally advocated green environmental protection philosophy.

[0011] Patent document CN101704868A discloses a method for extracting and isolating naringin. The method involves extracting crude tangerine peel powder by warm immersion in water, filtering the filtrate, adding calcium chloride, stirring, and allowing the mixture to stand. The filtrate is filtered, the pH is adjusted to 7-8 with ammonia water, and the extract is passed through a macroporous resin. Ethanol is then eluted and the ethanol is recovered under reduced pressure. The extract is refrigerated for crystallization, the crystals are separated, recrystallized, and dried to obtain a naringin extract. The naringin content of the extract prepared by this method is 98.1%-99.2%.

[0012] In summary, the highest naringin produced by the existing production process is "99" level, and there is a technical problem of low content. Therefore, it is of great significance to find a method that is efficient, simple, safe, economical and suitable for industrial production of high-content naringin. Summary of the Invention

[0013] To overcome the above technical problems, the present invention provides a method for extracting naringin from Citrus aurantium dulcis. This method does not require the use of organic solvents that are relatively toxic to humans, does not produce difficult-to-treat resin waste, is relatively environmentally friendly, and requires relatively simple production equipment. It does not use supercritical equipment, preparative chromatography equipment, and other equipment, and can stably produce "999" grade naringin on an industrial scale.

[0014] A method for extracting naringin from tangerine peel comprises the following steps:

[0015] 1. Extraction: Take an appropriate amount of sliced ​​or crushed tangerine peel, add ethanol solvent and heat reflux extraction to obtain the extract;

[0016] 2. Concentration: The extract is concentrated under reduced pressure to obtain an extract concentrate;

[0017] 3. Alcohol precipitation: Add 95% ethanol to the concentrated extract while stirring. Let it stand at room temperature, filter, and take the filtrate to obtain the alcohol-precipitated supernatant.

[0018] 4. Concentration and drying: The alcohol precipitate is concentrated and dried under reduced pressure, and the dried product of the alcohol precipitate is collected;

[0019] 5. Water precipitation and crystallization: Take an appropriate amount of the alcohol precipitate and dry it, add purified water, heat and stir, filter it while hot, take the filtrate, let it stand at 4-20℃ for a period of time, crystallize, centrifuge, and collect the crystallized solid;

[0020] 6. Decolorization and crystallization: Take water to precipitate crystals, add 10% to 15% ethanol solution, adjust the pH to 3 to 4, add 2‰ to 5‰ activated carbon, heat and stir at 90 to 95℃ for a certain period of time, filter while hot, collect the filtrate, stir the filtrate at room temperature overnight for crystallization, centrifuge, and collect the crystalline solid;

[0021] 7. Drying and crushing: Heat and dry the crystalline solid, and crush it at a humidity of 10% to 30%.

[0022] Preferably, in step 1, 13 to 15 times (ml / g) of a 50% to 60% ethanol solution is added, and the mixture is refluxed at 65°C to 75°C for 2 hours, filtered, and the first extract is collected. 10 to 12 times (ml / g) of a 50% to 60% ethanol solution is added, and the mixture is refluxed at 65°C to 75°C for a second time, extracted for 1 hour, filtered, and the second extract is collected. 10 to 12 times (ml / g) of a 50% to 60% ethanol solution is added, and the mixture is refluxed for a third time at 65°C to 75°C for 0.5 hours, filtered, and the third extract is collected. The three extracts are combined to obtain an extract.

[0023] Preferably, in step 2, the ethanol is recovered by concentration under reduced pressure at 60-65° C. and -0.07-0.1 MPa, and the concentration is to a crude drug concentration of 0.50-0.75 g / ml.

[0024] Preferably, in step 3, 7.5 to 9 times (ml / g) of 95% ethanol is added in an amount equivalent to the amount of the medicinal material, while stirring, and the mixture is allowed to stand at room temperature for 1 to 2 hours, filtered, and the filtrate is collected to obtain an alcohol-precipitated supernatant.

[0025] Preferably, in step 4, the alcohol precipitate is collected, concentrated under reduced pressure at 60-65° C. and -0.07-0.1 MPa, and dried, and the dried product of the alcohol precipitate is collected.

[0026] Preferably, in step 5, 7.5 to 8 times (ml / g) of purified water is added, heated and stirred at 60 to 70°C for 1 hour, filtered while hot, the filtrate is taken, and allowed to stand at 4 to 20°C for 3 days, crystallized, centrifuged, and the crystallized solid is collected.

[0027] Preferably, in step 6, 10 to 15 times (ml / g) of 10% to 15% ethanol solution is added, acetic acid is added to adjust the pH to 3 to 4, 2‰ to 5‰ of activated carbon is added, and the mixture is heated and stirred at 90 to 95°C for 4 hours. The mixture is filtered while hot and the filtrate is collected. The filtrate is stirred at room temperature overnight for crystallization, centrifuged, and the crystalline solid is collected.

[0028] Preferably, in step 7, the crystalline solid is dried at 85-140° C. and crushed at 10%-30% humidity to obtain the product.

[0029] Compared with other existing technologies, the present invention has the following advantages:

[0030] 1. Relatively high safety: The present invention uses only ethanol and acetic acid as organic solvents, both of which are widely used in food. Their toxicity to the human body is lower than that of petroleum ether, methanol, n-hexane, etc., ensuring the quality of the product while reducing the pollution of organic solvents to the environment.

[0031] 2. High content: By adopting the present invention, the content of naringin can reach more than 99.9%, which is higher than the 99% level of naringin on the market, which is beneficial to subsequent applications and reduces the risks of subsequent applications.

[0032] 3. Relatively simple equipment: The present invention requires relatively simple production equipment. The main production equipment is common equipment in the extract industry, such as extraction tanks, centrifuges, concentrators, alcohol precipitation tanks, crystallization tanks, drying ovens, etc. Relatively expensive preparative chromatography, supercritical extraction equipment, and macroporous resin columns that require frequent replacement are not used. This means that the process technology is suitable for industrial production and promotion. DETAILED DESCRIPTION

[0033] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0034] The detection and data processing methods used in the following embodiments are as follows:

[0035] 1. Extraction solution for test sample: Filter through 0.25μm filter membrane and take the filtrate.

[0036] 2. Crystalline solid test sample: Accurately weigh 15 mg, dissolve in 50% methanol, dilute to 10 ml, filter through a 0.25 μm filter membrane, and obtain the filtrate.

[0037] 3. Liquid phase conditions: Follow the detection method for the content of Citrus aurantium in the 2020 edition of the Chinese Pharmacopoeia.

[0038] 4. Extraction transfer rate = Cti * Vti / (mdrug * kdrug) / 1000 * 100%, where Cti represents the concentration of naringin in the extract, in mg / L; Vti represents the volume of the extract, in L; mdrug represents the weight of the extracted medicinal material, in g; kdrug represents the naringin content in the extracted medicinal material.

[0039] Yield = mfinal / mdrug*100%, where mfinal represents the mass of the final product in g; mdrug represents the mass of the extracted medicinal material in g.

[0040] Example 1

[0041] Weigh 5 kg of Citrus aurantium dulcis (Huang Zhenghong) and add 13 times (ml / g) of 50% ethanol solution. Reflux extract at 75°C for 2 hours, filter, and collect the first extract. Add 10 times (ml / g) of 50% ethanol solution and reflux extract at 65°C for 1 hour. Filter, and collect the second extract. Add 10 times (ml / g) of 50% ethanol solution and reflux extract at 75°C for 0.5 hour. Filter, and collect the third extract. Combine the three extracts and sample for naringin concentration. The calculated naringin extraction transfer rate is 99.958%.

[0042] The extract was concentrated under reduced pressure at 60-65°C and -0.07-0.1 MPa to recover ethanol. The concentration was concentrated to a crude drug concentration of 0.75 g / ml. 7.5 times the amount of 95% ethanol (ml / g) was added while stirring. The mixture was allowed to stand at room temperature for 1 hour. Filtered and the filtrate was concentrated under reduced pressure at 60-65°C and -0.07-0.1 MPa. The precipitate was collected and dried. 7.5 times the amount of purified water (ml / g) was added. The mixture was stirred and heated at 60-70°C for 1 hour. The mixture was filtered while hot. The filtrate was collected and allowed to stand at 20°C for 3 days to crystallize. The crystallized solid was collected by centrifugation. 10 times the amount of 10% ethanol solution (ml / g) was added. Acetic acid was added to adjust the pH to 3.0. 2‰ of activated carbon was added. The mixture was heated and stirred at 90°C for 4 hours. The mixture was filtered while hot and the filtrate was collected. The filtrate was stirred at room temperature overnight to crystallize. The crystallized solid was collected by centrifugation. After drying and grinding, 150.33 g of the product was obtained, with a yield of 3.01%. The content of naringin was 99.955% after testing.

[0043] Example 2

[0044] Weigh 5 kg of Citrus aurantium dulcis (Huang Zhenghong) and add 15 times (ml / g) of 60% ethanol solution. Reflux extract at 65°C for 2 hours, filter, and collect the first extract. Add 11 times (ml / g) of 60% ethanol solution and reflux extract at 65°C for 1 hour. Filter, and collect the second extract. Add 10 times (ml / g) of 60% ethanol solution and reflux extract at 75°C for 0.5 hour. Filter, and collect the third extract. Combine the three extracts and sample for naringin concentration. The calculated naringin extraction transfer rate is 99.298%.

[0045] Recover the ethanol by vacuum concentration at 60-65°C and -0.07-0.1 MPa, concentrate to a crude drug concentration of 0.75 g / ml, add 8 times (ml / g) the amount of the medicinal material (95%) ethanol, stir while adding, let stand at room temperature for 2 hours, filter, collect the filtrate, vacuum concentrate at 60-65°C and -0.07-0.1 MPa, dry, and collect the alcohol precipitate. Add 7.6 times (ml / g) purified water, stir and heat at 60-70°C for 1 hour, filter while hot, collect the filtrate, let stand at 15°C for 3 days, crystallize, centrifuge, and collect the crystalline solid. Add 15 times (ml / g) 15% ethanol solution, add acetic acid to adjust the pH to 3.5, add 5‰ activated carbon, heat and stir at 95°C for 4 hours, filter while hot, collect the filtrate, stir the filtrate at room temperature overnight for crystallization, centrifuge, and collect the crystalline solid. After drying and grinding, 148.10 g of the product was obtained, with a yield of 2.96%. The content of naringin was 99.981%.

[0046] Example 3

[0047] Weigh 10 kg of Citrus aurantium dulcis (Huang Zhenghong) and add 14 times (ml / g) of 60% ethanol solution. Reflux extract at 65°C for 2 hours, filter, and collect the first extract. Add 12 times (ml / g) of 55% ethanol solution and reflux extract at 65°C for 1 hour. Filter, and collect the second extract. Add 10 times (ml / g) of 50% ethanol solution and reflux extract at 75°C for 0.5 hour. Filter, and collect the third extract. Combine the three extracts and sample for naringin concentration. The calculated naringin extraction transfer rate is 99.908%.

[0048] Recover the ethanol by vacuum concentration at 60-65°C and -0.07-0.1MPa, concentrating under reduced pressure to a crude drug concentration of 0.50g / ml. Add 95% ethanol (9 times the amount of the medicinal material) while stirring. Let stand at room temperature for 1 hour, filter, collect the filtrate, concentrate under reduced pressure at 60-65°C and -0.07-0.1MPa, dry, and collect the alcohol precipitate. Add 8 times (ml / g) of purified water, stir and heat at 60-70°C for 1 hour, filter while hot, collect the filtrate, let stand at 20°C for 3 days, crystallize, centrifuge, and collect the crystalline solid. Add 11 times (ml / g) of 12% ethanol solution, add acetic acid to adjust the pH to 3.7, add 3‰ of activated carbon, heat and stir at 90°C for 4 hours, filter while hot, collect the filtrate, stir the filtrate at room temperature overnight for crystallization, centrifuge, and collect the crystalline solid. After drying and grinding, 299.10 g of the product was obtained, with a yield of 2.99%. The content of naringin was 99.916% after testing.

[0049] Example 4

[0050] Weigh 10 kg of Citrus aurantium dulcis (Huang Zhenghong) and add 15 times (ml / g) of 55% ethanol solution. Reflux extract at 65°C for 2 hours, filter, and collect the first extract. Add 12 times (ml / g) of 55% ethanol solution and reflux extract at 65°C for 1 hour. Filter, and collect the second extract. Add 12 times (ml / g) of 55% ethanol solution and reflux extract at 75°C for 0.5 hour. Filter, and collect the third extract. Combine the three extracts and sample for naringin concentration. The calculated naringin extraction transfer rate is 99.395%.

[0051] Recover the ethanol by vacuum concentration at 60-65°C and -0.07-0.1 MPa, concentrating to a crude drug concentration of 0.75 g / ml. Add 8 times (ml / g) the amount of 95% ethanol as the medicinal material, stirring while adding, let stand at room temperature for 1.5 hours, filter, collect the filtrate, vacuum concentrate at 60-65°C and -0.07-0.1 MPa, dry, and collect the alcohol precipitate. Add 7.8 times (ml / g) purified water, stir and heat at 60-70°C for 1 hour, filter while hot, collect the filtrate, let stand at 10°C for 3 days, crystallize, centrifuge, and collect the crystalline solid. Add 14 times (ml / g) 12% ethanol solution, add acetic acid to adjust the pH to 4.0, add 4‰ activated carbon, heat and stir at 90°C for 4 hours, filter while hot, collect the filtrate, stir the filtrate at room temperature overnight for crystallization, centrifuge, and collect the crystalline solid. After drying and grinding, 301.13 g of the product was obtained, with a yield of 3.01%. The content of naringin was 99.996% after testing.

[0052] Example 5

[0053] Weigh 20 kg of Citrus aurantium dulcis (Huang Zhenghong) and add 14 times (ml / g) of 50% ethanol solution. Reflux extract at 65°C for 2 hours, filter, and collect the first extract. Add 12 times (ml / g) of 55% ethanol solution and reflux extract at 65°C for 1 hour. Filter, and collect the second extract. Add 10 times (ml / g) of 60% ethanol solution and reflux extract at 75°C for 0.5 hour. Filter, and collect the third extract. Combine the three extracts and sample for naringin concentration. The calculated naringin extraction transfer rate is 99.405%.

[0054] Recover the ethanol by vacuum concentration at 60-65°C and -0.07-0.1 MPa, concentrating to a crude drug concentration of 0.75 g / ml. Add 8.5 times (ml / g) the amount of 95% ethanol, stirring while adding, and let stand at room temperature for 1.5 hours. Filter, collect the filtrate, vacuum concentrate at 60-65°C and -0.07-0.1 MPa, and dry. Collect the alcohol precipitate and dry the product. Add 7.9 times (ml / g) purified water, stir and heat at 60-70°C for 1 hour, filter while hot, collect the filtrate, let stand at 4°C for 3 days, crystallize, centrifuge, and collect the crystalline solid. Add 11 times (ml / g) 10% ethanol solution, add acetic acid to adjust the pH to 3.5, add 2.5‰ activated carbon, heat and stir at 95°C for 4 hours, filter while hot, collect the filtrate, stir the filtrate at room temperature overnight to crystallize, centrifuge, and collect the crystalline solid. After drying and grinding, 598.32 g of the product was obtained, with a yield of 2.99%. The content of naringin was 99.969%.

[0055] Comparative Example 1

[0056] 20g of Citrus aurantium was added to 60 times (ml / g) of 50% ethanol solution, refluxed at 55°C for 40 minutes, filtered, and the filtrate was concentrated to dryness to obtain 1.41g of Citrus aurantium extract. The naringin content was determined to be 30.557%.

[0057] Comparative Example 2

[0058] Take 20g of the medicinal material of Citrus aurantium and extract it three times with 10, 8, and 6 times (ml / g) of 95% methanol solution for 2 hours, 1.5 hours, and 1 hour, respectively. The extracts are combined and concentrated at -(0.01-0.05MPa) to a specific gravity of 1.15g / ml. To the concentrate, add purified water twice the amount of the medicinal material (ml / g), stir thoroughly, precipitate, and filter to obtain a naringin aqueous solution. Take the naringin aqueous solution and concentrate it at -(0.01-0.05MPa) to a specific gravity of 1.10g / ml. Add 3 volumes (v / v) of petroleum ether (60-90°C) and defat it three times, each time for half an hour, to obtain a naringin defatted solution. Add n-butanol at 1 volume (ml / g) of the medicinal material and extract it five times, each time for 1 hour. The n-butanol extracts are combined. Take the n-butanol extract and add an equal volume of 10% acetic acid solution for back extraction. Stir for 1 hour, let stand and separate. Collect the n-butanol solution of naringin, repeat the back extraction five times, and combine the n-butanol solutions of naringin. Add 1.5% activated carbon to the n-butanol solution of naringin and decolorize it at 85°C for half an hour. Filter to obtain a decolorized naringin solution. The decolorized naringin solution is concentrated at -(0.01-0.04MPa) to a specific gravity of 1.15g / ml, filtered, and the filtrate is stirred at room temperature for 24 hours for crystallization. Filter, collect the solid, and dry to obtain 0.38g of naringin. The content is determined to be 98.210%.

[0059] Comparative Example 3

[0060] Weigh 20g of the medicinal material "Hua Tang Hong" (Citrus aurantii) and add 13 times (ml / g) of 50% ethanol solution. Reflux extract at 75°C for 2 hours, filter, and collect the first extract. Add 10 times (ml / g) of 50% ethanol solution and reflux extract at 65°C for 1 hour. Filter, and collect the second extract. Add 10 times (ml / g) of 50% ethanol solution and reflux extract at 75°C for 0.5 hour. Filter, and collect the third extract. Combine the three extracts and sample for naringin concentration. The calculated extraction transfer rate of naringin is 99.088%.

[0061] The extract was concentrated under reduced pressure at 60-65°C and -0.07-0.1 MPa to recover ethanol. The extract was concentrated to a crude drug concentration of 0.75 g / ml. 95% ethanol (7.5 times the amount of the crude drug (ml / g)) was added with stirring. The extract was allowed to stand at room temperature for 1 hour, filtered, and the filtrate was concentrated under reduced pressure at 60-65°C and -0.07-0.1 MPa, dried, and the supernatant was collected and dried. The precipitate was pulverized to yield 1.82 g, with a yield of 9.1%. The naringin content was determined to be 36.655%.

[0062] Comparative Example 4

[0063] Weigh 20g of the medicinal material "Hua Tang Hong" (Purple Orange Red) and add 13 times (ml / g) of 50% ethanol solution. Reflux extract at 75°C for 2 hours, filter, and collect the first extract. Add 10 times (ml / g) of 50% ethanol solution and reflux extract at 65°C for 1 hour. Filter, and collect the second extract. Add 10 times (ml / g) of 50% ethanol solution and reflux extract at 75°C for 0.5 hour. Filter, and collect the third extract. Combine the three extracts and sample for naringin concentration. The calculated extraction transfer rate of naringin is 99.008%.

[0064] The ethanol was recovered by vacuum concentration at 60-65°C and -0.07-0.1 MPa, and concentrated to a crude drug concentration of 0.75 g / ml. 95% ethanol (8 times the amount of the medicinal material (ml / g)) was added while stirring. The mixture was allowed to stand at room temperature for 2 hours, filtered, and the filtrate was concentrated under reduced pressure at 60-65°C and -0.07-0.1 MPa, dried, and the alcohol precipitate was collected and dried. 7.6 times (ml / g) of purified water was added, and the mixture was heated at 60-70°C with stirring for 1 hour. The mixture was filtered while hot, and the filtrate was allowed to stand at 20°C for 3 days. Crystallization was performed, and the crystallized solid was collected by centrifugation. Drying and pulverization yielded 1.01 g, with a yield of 5.05%. The naringin content was determined to be 60.083%.

[0065] Comparative Example 5

[0066] Weigh 20g of the medicinal material "Hua Tang Hong" (Purple Orange Red) and add 14 times (ml / g) of 50% ethanol solution. Reflux extract at 65°C for 2 hours, filter, and collect the first extract. Add 12 times (ml / g) of 55% ethanol solution and reflux extract at 65°C for 1 hour. Filter, and collect the second extract. Add 10 times (ml / g) of 60% ethanol solution and reflux extract at 75°C for 0.5 hour. Filter, and collect the third extract. Combine the three extracts and sample for naringin concentration. The calculated extraction transfer rate of naringin is 99.938%.

[0067] Recover the ethanol by vacuum concentration at 60-65°C and -0.07-0.1 MPa, concentrating to a crude drug concentration of 0.65 g / ml. Add 8 times the amount of 95% ethanol (ml / g) while stirring. Let stand at room temperature for 1.5 hours, filter, and collect the filtrate. Concentrate under reduced pressure at 60-65°C and -0.07-0.1 MPa, dry, and collect the supernatant. Add 7.8 times (ml / g) of purified water, stir and heat at 60-70°C for 1 hour, filter while hot, collect the filtrate, let stand at 10°C for 3 days, crystallize, centrifuge, and collect the crystalline solid. Add 14 times (ml / g) of 12% ethanol solution, add 4‰ of activated carbon, heat and stir at 90°C for 4 hours, filter while hot, collect the filtrate, stir the filtrate at room temperature overnight for crystallization, centrifuge, and collect the crystalline solid. Dry and pulverize to obtain 0.65 g, with a yield of 3.25%. After testing, the content of naringin was 95.006%.

[0068] Comparative Example 6

[0069] Weigh 20g of the medicinal material "Hua Tang Hong" (Citrus aurantii) and add 15 times (ml / g) of 60% ethanol solution. Reflux extract at 65°C for 2 hours, filter, and collect the first extract. Add 11 times (ml / g) of 55% ethanol solution and reflux extract at 65°C for 1 hour. Filter, and collect the second extract. Add 10 times (ml / g) of 50% ethanol solution and reflux extract at 75°C for 0.5 hour. Filter, and collect the third extract. Combine the three extracts and sample for naringin concentration. The extraction transfer rate of naringin was calculated to be 99.868%.

[0070] Recover the ethanol by vacuum concentration at 60-65°C and -0.07-0.1MPa, concentrating under reduced pressure to a crude drug concentration of 0.50g / ml. Add 95% ethanol (9 times the amount of the medicinal material) while stirring. Let stand at room temperature for 1 hour, filter, collect the filtrate, concentrate under reduced pressure at 60-65°C and -0.07-0.1MPa, dry, and collect the alcohol precipitate. Add 8 times (ml / g) of purified water, stir and heat at 60-70°C for 1 hour, filter while hot, collect the filtrate, let stand at 10°C for 3 days, crystallize, centrifuge, and collect the crystalline solid. Add 11 times (ml / g) of 12% ethanol solution, add acetic acid to adjust the pH to 2.0, add 3‰ of activated carbon, heat and stir at 90°C for 4 hours, filter while hot, collect the filtrate, stir the filtrate at room temperature overnight for crystallization, centrifuge, and collect the crystalline solid. After drying and grinding, 0.51 g of the product was obtained, with a yield of 2.55%. The content of naringin was 98.946%.

[0071] Comparative Example 7

[0072] Weigh 20g of the medicinal material "Hua Tang Hong" (Citrus aurantium) and add 13 times (ml / g) of 60% ethanol solution. Reflux extract at 65°C for 2 hours, filter, and collect the first extract. Add 11 times (ml / g) of 55% ethanol solution and reflux extract at 65°C for 1 hour. Filter, and collect the second extract. Add 10 times (ml / g) of 50% ethanol solution and reflux extract at 75°C for 0.5 hour. Filter, and collect the third extract. Combine the three extracts and sample for naringin concentration. The calculated naringin extraction transfer rate is 99.260%.

[0073] Recover the ethanol by vacuum concentration at 60-65°C and -0.07-0.1MPa, concentrating under reduced pressure to a crude drug concentration of 0.55g / ml. Add 95% ethanol (9 times the amount of the medicinal material) while stirring. Let stand at room temperature for 1 hour, filter, collect the filtrate, vacuum concentrate at 60-65°C and -0.07-0.1MPa, dry, and collect the alcohol precipitate. Add 8 times (ml / g) of purified water, stir and heat at 60-70°C for 1 hour, filter while hot, collect the filtrate, let stand at 20°C for 3 days, crystallize, centrifuge, and collect the crystalline solid. Add 10 times (ml / g) of 12% ethanol solution, add acetic acid to adjust the pH to 5.0, add 4‰ of activated carbon, heat and stir at 90°C for 4 hours, filter while hot, collect the filtrate, stir the filtrate at room temperature overnight for crystallization, centrifuge, and collect the crystalline solid. After drying and grinding, 0.61 g of the product was obtained, with a yield of 3.05%. The content of naringin was 98.559%.

[0074] Comparative Example 8

[0075] Weigh 20g of the medicinal material "Hua Tang Hong" (Purple Orange Red) and add 14 times (ml / g) of 60% ethanol solution. Reflux extract at 65°C for 2 hours, filter, and collect the first extract. Add 12 times (ml / g) of 55% ethanol solution and reflux extract at 65°C for 1 hour. Filter, and collect the second extract. Add 10 times (ml / g) of 50% ethanol solution and reflux extract at 75°C for 0.5 hour. Filter, and collect the third extract. Combine the three extracts and sample for naringin concentration. The calculated extraction transfer rate of naringin is 99.234%.

[0076] Recover the ethanol by vacuum concentration at 60-65°C and -0.07-0.1 MPa, concentrating to a crude drug concentration of 0.65 g / ml. Add 95% ethanol (9 times the amount of the medicinal material, ml / g) while stirring. Let stand at room temperature for 1 hour, filter, collect the filtrate, vacuum concentrate at 60-65°C and -0.07-0.1 MPa, and dry. Collect the alcohol precipitate and dry the product. Add 8 times (ml / g) purified water, stir and heat at 60-70°C for 1 hour, filter while hot, collect the filtrate, let stand at 15°C for 3 days, crystallize, centrifuge, and collect the crystalline solid. Add 11 times (ml / g) 12% ethanol solution, add acetic acid to adjust the pH to 3.4, heat and stir at 90°C for 4 hours, filter while hot, collect the filtrate, stir the filtrate at room temperature overnight to crystallize, centrifuge, and collect the crystalline solid. Dry and pulverize to obtain 0.60 g, with a yield of 3.00%. After testing, the content of naringin was 97.398%.

[0077] Comparative Example 9

[0078] Weigh 20g of the medicinal material "Hua Tang Hong" (Purple Orange Red) and add 14 times (ml / g) of 60% ethanol solution. Reflux extract at 65°C for 2 hours, filter, and collect the first extract. Add 12 times (ml / g) of 55% ethanol solution and reflux extract at 65°C for 1 hour. Filter, and collect the second extract. Add 11 times (ml / g) of 50% ethanol solution and reflux extract at 75°C for 0.5 hour. Filter, and collect the third extract. Combine the three extracts and sample for naringin concentration. The extraction transfer rate of naringin was calculated to be 99.216%.

[0079] Recover the ethanol by vacuum concentration at 60-65°C and -0.07-0.1 MPa, concentrating to a crude drug concentration of 0.65 g / ml. Add 95% ethanol (9 times the amount of the medicinal material) while stirring. Let stand at room temperature for 1 hour, filter, collect the filtrate, vacuum concentrate at 60-65°C and -0.07-0.1 MPa, dry, and collect the alcohol precipitate. Add 8 times (ml / g) of purified water, stir and heat at 60-70°C for 1 hour, filter while hot, collect the filtrate, let stand at 10°C for 3 days, crystallize, centrifuge, and collect the crystalline solid. Add 11 times (ml / g) of 12% ethanol solution, add acetic acid to adjust the pH to 3.5, add 4‰ of activated carbon, heat and stir at 80°C for 4 hours, filter while hot, collect the filtrate, stir the filtrate at room temperature overnight for crystallization, centrifuge, and collect the crystalline solid. After drying and grinding, 0.59 g of the product was obtained, with a yield of 2.95%. The content of naringin was 98.304%.

[0080] Comparative Example 10

[0081] Weigh 20g of the medicinal material "Hua Tang Hong" (Purple Orange Red) and add 14 times (ml / g) of 60% ethanol solution. Reflux extract at 65°C for 2 hours, filter, and collect the first extract. Add 12 times (ml / g) of 55% ethanol solution and reflux extract at 65°C for 1 hour. Filter, and collect the second extract. Add 11 times (ml / g) of 50% ethanol solution and reflux extract at 75°C for 0.5 hour. Filter, and collect the third extract. Combine the three extracts and sample for naringin concentration. The extraction transfer rate of naringin was calculated to be 99.066%.

[0082] Recover the ethanol by vacuum concentration at 60-65°C and -0.07-0.1 MPa, concentrating to a crude drug concentration of 0.65 g / ml. Add 95% ethanol (9 times the amount of the medicinal material) while stirring. Let stand at room temperature for 1 hour, filter, collect the filtrate, vacuum concentrate at 60-65°C and -0.07-0.1 MPa, dry, and collect the alcohol precipitate. Add 7.5 times (ml / g) of purified water, stir and heat at 60-70°C for 1 hour, filter while hot, collect the filtrate, let stand at 4°C for 3 days, crystallize, centrifuge, and collect the crystalline solid. Add 11 times (ml / g) of 12% ethanol solution, add acetic acid to adjust the pH to 3.5, add 4‰ of activated carbon, heat and stir at 100°C for 4 hours, filter while hot, collect the filtrate, stir the filtrate at room temperature overnight for crystallization, centrifuge, and collect the crystalline solid. After drying and grinding, 0.45 g of the product was obtained, with a yield of 2.25%. The content of naringin was 97.994%.

[0083] Comparative Example 11

[0084] Weigh 20g of the medicinal material "Hua Tang Hong" (Purple Orange Red) and add 13 times (ml / g) of 60% ethanol solution. Reflux extract at 65°C for 2 hours, filter, and collect the first extract. Add 12 times (ml / g) of 55% ethanol solution and reflux extract at 65°C for 1 hour. Filter, and collect the second extract. Add 11 times (ml / g) of 50% ethanol solution and reflux extract at 75°C for 0.5 hour. Filter, and collect the third extract. Combine the three extracts and sample for naringin concentration. The calculated naringin extraction transfer rate is 99.005%.

[0085] The ethanol was recovered by vacuum concentration at 60-65°C and -0.07-0.1 MPa, followed by drying and collecting the dried product. Add 8 times (ml / g) of purified water, stir and heat at 60-70°C for 1 hour, filter while hot, collect the filtrate, let it stand at 4°C for 3 days, crystallize, centrifuge, and collect the crystalline solid. Add 15 times (ml / g) of 10% ethanol solution, add acetic acid to adjust the pH to 3.8, add 3‰ of activated carbon, heat and stir at 90°C for 4 hours, filter while hot, collect the filtrate, stir the filtrate at room temperature overnight to crystallize, centrifuge, and collect the crystalline solid. Dry and pulverize to obtain 0.50g, with a yield of 2.5%. After testing, the naringin content was 98.115%.

[0086] Comparative Example 12

[0087] Weigh 20g of the medicinal material "Hua Tang Hong" (Purple Orange Red) and add 15 times (ml / g) of 60% ethanol solution. Reflux extract at 65°C for 2 hours, filter, and collect the first extract. Add 12 times (ml / g) of 55% ethanol solution and reflux extract at 65°C for 1 hour. Filter, and collect the second extract. Add 12 times (ml / g) of 50% ethanol solution and reflux extract at 75°C for 0.5 hour. Filter, and collect the third extract. Combine the three extracts and sample for naringin concentration. The calculated naringin extraction transfer rate is 99.786%.

[0088] The ethanol was recovered by vacuum concentration at 60-65°C and -0.07-0.1 MPa, and concentrated to a crude drug concentration of 0.60 g / ml. 95% ethanol (9 times the amount of the medicinal material, ml / g) was added while stirring. The mixture was allowed to stand at room temperature for 1 hour, filtered, and the filtrate was collected. It was then vacuum concentrated at 60-65°C and -0.07-0.1 MPa, dried, and the alcohol precipitate was collected. 14 times (ml / g) of 12% ethanol solution was added, acetic acid was added to adjust the pH to 3.5, 4‰ of activated carbon was added, and the mixture was heated and stirred at 90°C for 4 hours. The mixture was filtered while hot and the filtrate was collected. The filtrate was stirred at room temperature overnight for crystallization. The crystalline solid was collected by centrifugation and dried. 0.46 g of naringin was obtained, with a yield of 2.30%. The content of naringin was determined to be 97.482%.

[0089] The above embodiments are merely examples of preferred embodiments of the present invention and are not intended to be exhaustive. Persons skilled in the art may make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope defined in the claims.

Claims

1. A method for extracting naringin from Citrus aurantium, characterized in that: The steps include:

1. Extraction: Take an appropriate amount of sliced ​​or crushed tangerine peel, add ethanol solvent and heat reflux extraction to obtain the extract; 2. Concentration: The extract is concentrated under reduced pressure to obtain an extract concentrate; 3. Alcohol precipitation: add 95% ethanol to the concentrated extract, stirring while adding, let it stand at room temperature, filter, and take the filtrate to obtain the alcohol precipitation supernatant; 4. Concentration and drying: concentrate and dry the alcohol precipitate under reduced pressure, and collect the dried product of the alcohol precipitate; 5. Water precipitation and crystallization: Take an appropriate amount of alcohol precipitate and dry it, add purified water, heat and stir, filter it while hot, take the filtrate, let it stand at 4-20℃ for a period of time, crystallize, centrifuge and collect the crystallized solid; 6. Decolorization and crystallization: Take water to precipitate crystals, add 10% to 15% ethanol solution, adjust the pH to 3 to 4, add 2‰ to 5‰ activated carbon, heat and stir at 90 to 95℃ for a certain period of time, filter while hot, collect the filtrate, stir the filtrate at room temperature overnight for crystallization, centrifuge and collect the crystalline solid; 7. Drying and crushing: Heat and dry the crystalline solid, and crush it at a humidity of 10% to 30%.

2. The method according to claim 1, characterized in that In step 1, add 13 to 15 times (ml / g) of 50% to 60% ethanol solution, reflux extract at 65°C to 75°C for 2 hours, filter, and collect the first extract. Add 10 to 12 times (ml / g) of 50% to 60% ethanol solution, reflux extract at 65°C to 75°C for a second time, extract for 1 hour, filter, and collect the second extract. Add 10 to 12 times (ml / g) of 50% to 60% ethanol solution, reflux extract at 65°C to 75°C for a third time, extract for 0.5 hour, filter, and collect the third extract. Combine the three extracts to obtain the extract.

3. The method according to claim 1, characterized in that In step 2, the ethanol is recovered by concentration under reduced pressure at 60-65° C. and -0.07-0.1 MPa, and the concentration is adjusted to a crude drug concentration of 0.50-0.75 g / ml.

4. The method according to claim 1, wherein In step 3, add 7.5 to 9 times (ml / g) of 95% ethanol in an amount equivalent to the amount of the medicinal material, stirring while adding, let stand at room temperature for 1 to 2 hours, filter, and collect the filtrate to obtain the alcohol-precipitated supernatant.

5. The method according to claim 1, wherein In step 4, the alcohol precipitate is collected, concentrated under reduced pressure at 60 to 65° C. and -0.07 to -0.1 MPa, and dried, and the dried product of the alcohol precipitate is collected.

6. The method according to claim 1, wherein In step 5, add 7.5 to 8 times (ml / g) purified water, heat and stir at 60 to 70°C for 1 hour, filter while hot, take the filtrate, stand at 4 to 20°C for 3 days, crystallize, centrifuge, and collect the crystallized solid.

7. The method according to claim 1, characterized in that In step 6, 10 to 15 times (ml / g) of 10% to 15% ethanol solution is added, acetic acid is added to adjust the pH to 3 to 4, 2‰ to 5‰ of activated carbon is added, and the mixture is heated and stirred at 90 to 95°C for 4 hours. The mixture is filtered while hot and the filtrate is collected. The filtrate is stirred at room temperature overnight for crystallization, centrifuged, and the crystalline solid is collected.

8. The method according to claim 1, characterized in that In step 7, the crystalline solid is dried at 85-140° C. and crushed at 10%-30% humidity to obtain the product.