A method for extracting rutin

Abstract

The present application relates to the technical field of plant extract preparation, and particularly relates to a rutin extraction method. The rutin extraction method provided by the present application extracts rutin from sophora fruitling decoction pieces, and comprises the step of mixing the sophora fruitling decoction pieces with an extraction solvent for extraction. The sophora fruitling decoction pieces are prepared by the method comprising the following steps: after maturation, the sophora fruitling is allowed to rise, and then is subjected to cracking treatment to make the sophora fruitling petal crack; the fine powder passing through a 40-mesh sieve accounts for not more than 25% in mass fraction. Compared with the traditional sophora fruitling processing technology, the sophora fruitling decoction piece preparation method can effectively reduce the loss of rutin, and can significantly improve the leaching efficiency of rutin and reduce the leaching of impurities such as polysaccharides. The rutin extraction method provided by the present application can realize efficient extraction of rutin in sophora fruitling, reduce the dissolution of impurities during extraction, and realize green and efficient industrial production of sophora fruitling-derived rutin.

Description

Technical Field

[0001] This invention relates to the field of plant extract preparation technology, and in particular to a method for extracting rutin. Background Technology

[0002] Sophora japonica buds, the dried flower buds of the Sophora japonica L. (a legume), have a long history of medicinal use. China is the origin of this traditional Chinese medicine and has abundant resources of Sophora japonica buds. The main active ingredient in Sophora japonica buds is rutin, which possesses various physiological activities, including maintaining and restoring the normal elasticity of capillaries, enhancing their resistance, and preventing blood cell aggregation. Rutin and its derivatives have shown outstanding efficacy in treating cardiovascular and cerebrovascular diseases and have been widely used in the clinical treatment of related diseases in recent years. Rutin extraction has also become the most important industrial application of Sophora japonica buds.

[0003] The common methods for industrial production and laboratory extraction of rutin are alkaline extraction and acid precipitation. Borax is typically added to stabilize the rutin in the system. This method consumes approximately 50 tons of water per ton of Sophora japonica buds. The excessive use of acids, alkalis, and borax during production causes severe environmental pollution. Currently, there are also some research reports on solvent extraction methods. CN201410071147.X discloses a green extraction process for natural active flavonoids—rutin. Sophora japonica buds are pulverized to 40-60 mesh, placed in a tank, and soaked in 5-8 times diluted ethanol for 1 hour. The mixture is then stirred and extracted for 3-5 hours, for a total of 3 extractions. After concentrating the extract to remove most of the alcohol, stirring is continued for 1-2 hours to obtain crude rutin. The crude rutin is dissolved in 0.5% alkaline water, filtered, acidified, crystallized, filtered again, and dried to obtain high-quality rutin. CN201310486906.4 discloses a process for preparing rutin, in which the raw material is pulverized to 60-120 mesh, heated and refluxed with refined methanol and acid for 1.5-3 hours, the Sophora japonica residue is added to a mixed solvent of refined methanol and acid, the pH is adjusted, calcium salt is added, and the mixture is heated and refluxed for 1-3 hours. The mixture is filtered, the filter residue is washed, the filtrate is concentrated, water is added, the pH is adjusted and crystals are precipitated, the mixture is washed with water of a certain pH, and then the mixture is added again after being fermented with methanol, pulped, centrifuged, dried and pulverized to obtain a rutin product with a content of 97-99%. CN201210237091.1 discloses a method for extracting rutin. The raw material, *Sophora japonica* buds, is pulverized to 50 mesh and extracted three times with methanol at 4, 3, and 3 times the amount used, respectively. The reflux extraction times for each extraction are 3 hours, 2 hours, and 2 hours, respectively. The extract is concentrated into a thick paste free of methanol. Lime water and borax are added, dissolved, filtered, acidified, filtered again, and dried to obtain pure rutin. The mother liquor is used to recover rutin again. The purity of the obtained rutin product is 98.69%. All of the above solvent extraction methods involve pulverizing the *Sophora japonica* buds before adding the extraction solvent for reflux extraction. Furthermore, both extraction and refining processes require alkali dissolution and acid precipitation. Moreover, obtaining high-content rutin requires further refining of the crude rutin. Summary of the Invention

[0004] This invention provides a method for extracting rutin from Sophora japonica buds.

[0005] To ensure higher rutin extraction efficiency, existing technologies typically involve pulverizing Sophora japonica buds into a fine powder when extracting rutin. However, using pulverized Sophora japonica buds as raw material during subsequent extraction causes polysaccharides and other components to be leached out along with the rutin, resulting in lower rutin purity. This not only increases the difficulty of rutin purification, often requiring multiple complex purification steps to obtain a high-purity rutin product, but also leads to waste and reduced content of polysaccharides and other components in the extraction residue. During the research and development of this invention, it was unexpectedly discovered that there is no need to crush the Sophora japonica buds. By pre-treating the Sophora japonica buds through maturation, fermentation, and cracking (i.e., using the above-mentioned steps to pre-treat the Sophora japonica bud raw material), the petals of the Sophora japonica buds can be cracked, thus achieving a high rutin extraction efficiency. Moreover, by controlling the amount of fine powder after the above treatment, it is possible to significantly reduce the extraction of polysaccharides and other macromolecular components while ensuring a high rutin extraction yield, thereby improving the purity of rutin, reducing the difficulty and complexity of subsequent refining, and allowing more polysaccharides and other macromolecular components to be retained in the residue after extraction for subsequent applications. In addition, compared with traditional Sophora japonica bud raw material processing methods, the above processing method significantly reduces the loss of rutin during the processing.

[0006] Specifically, the present invention provides the following technical solutions:

[0007] This invention provides a method for extracting rutin, which uses Sophora japonica flower buds as raw material to extract rutin, including the step of mixing Sophora japonica flower buds with an extraction solvent for extraction;

[0008] The Sophora japonica flower slices are prepared by a method including the following steps: the Sophora japonica flowers are cooked and then fermented, and then cracked so that the petals of the Sophora japonica flowers crack.

[0009] The proportion of fine powder passing through a 40-mesh sieve in the prepared Sophora japonica flower slices shall not exceed 25%.

[0010] Preferably, the mass percentage of fine powder passing through a 40-mesh sieve from the Sophora japonica flower buds is 5-25%. Controlling the mass percentage of fine powder from the Sophora japonica flower buds within the above range can significantly improve the rutin extraction yield while retaining more macromolecular components such as polysaccharides in the extracted residue, thereby increasing the utilization value of the residue.

[0011] In the medicinal slices prepared by the above method, most of the Sophora japonica buds still retain relatively intact flower buds, with cracks between their petals.

[0012] In the above method, the final temperature of the proofing process is 50-70℃.

[0013] In the above method, the final moisture content of the proofing process is 10-15%.

[0014] The aforementioned final temperature for proofing refers to the temperature at the end of proofing, and the final moisture content refers to the moisture content of the Sophora japonica flowers at the end of proofing.

[0015] After high-temperature cooking, the buds are directly subjected to a proofing process until the aforementioned endpoint temperature and moisture content are reached. The proofing process involves placing the cooked buds under specific temperature and humidity conditions until the endpoint temperature and moisture content are reached.

[0016] The present invention does not impose any special restrictions on the equipment used for proofing. Those skilled in the art can choose to perform proofing under cooling water and / or nitrogen flow conditions as needed, as long as the above-mentioned proofing endpoint temperature and endpoint moisture content are achieved.

[0017] This invention reveals that if the sophora japonica buds are not allowed to rest after high-temperature cooking and are directly subjected to cracking treatment, the viscosity will be too high, making it difficult to crack. Furthermore, by controlling the final resting temperature and moisture content within the aforementioned range, the cracking effect (causing the petals to split) can be guaranteed while significantly improving the integrity of the cracked sophora japonica buds. Controlling the amount of fine powder within the aforementioned required range significantly reduces the leaching of large molecular components such as polysaccharides, and also better ensures the efficiency of rutin extraction.

[0018] In the above method, the cracking is performed by compression cracking.

[0019] Extrusion cracking refers to a method of opening the material to be processed by extrusion. This invention does not impose any special restrictions on the equipment used for extrusion cracking; conventional extrusion cracking equipment can be used.

[0020] In some embodiments of the present invention, a double roller mill is used for cracking treatment.

[0021] In the above method, the aging process is high-temperature aging.

[0022] Preferably, the ripening temperature is 90-140℃.

[0023] The ripening time is 20 to 60 minutes.

[0024] Controlling the ripening temperature and time within the above-mentioned range helps to reduce the loss of active ingredients such as rutin during the processing. Moreover, it can better ensure the integrity of the Sophora japonica buds after cracking treatment and control the amount of fine powder within the above-mentioned requirements.

[0025] The present invention does not impose any special restrictions on the raw material of Sophora japonica for preparing Sophora japonica slices. Freshly picked Sophora japonica without processing or Sophora japonica that has been properly stored can be used.

[0026] Based on the above-mentioned pretreatment method for Sophora japonica buds, and taking advantage of the characteristics of Sophora japonica bud slices prepared by the pretreatment method, this invention further optimizes the rutin extraction step.

[0027] Preferably, in the above-mentioned rutin extraction method, the extraction solvent is an 85%-95% aqueous methanol solution and / or a 70%-80% aqueous ethanol solution.

[0028] Preferably, in the extraction, the mass-to-volume ratio of Sophora japonica flower slices to extraction solvent is 1 kg: (5-12) L.

[0029] Preferably, the extraction temperature is 55-70℃.

[0030] Preferably, the extraction method is continuous countercurrent.

[0031] Preferably, the extraction time is 1-10 hours.

[0032] The extraction of rutin can be carried out using conventional extraction equipment. There is no special limit to the number of extractions. Depending on industrial needs, the number of extractions can be increased or a cyclic extraction method can be used.

[0033] In industrial applications, extraction can be carried out using methods such as tank groups, baskets, and horizontal rotation, and the extracted liquid can be concentrated and crystallized.

[0034] The rutin extraction method described above also includes: concentrating the extracted liquid to 1 / 4.5-1 / 7.5 of its original volume and then crystallizing it.

[0035] Preferably, the crystallization is carried out by cooling and stirring, the crystallization time is 5-10 hours, and the final crystallization temperature is 10-50℃.

[0036] Preferably, after crystallization, wet crystals are obtained by solid-liquid separation, and the wet crystals are washed with the extraction solvent.

[0037] In the above-mentioned wet crystal washing process, the volume of the extraction solvent used is 1-2 times the mass of the Sophora japonica flower slices.

[0038] The beneficial effects of this invention are as follows: This invention uses Sophora japonica flower buds as raw material for rutin extraction. Compared with the traditional Sophora japonica flower bud processing technology, the Sophora japonica flower buds preparation method adopted in this invention can effectively reduce the loss of rutin and achieve a greater retention of rutin in Sophora japonica flower buds. Moreover, the Sophora japonica flower buds prepared by this method can significantly improve the rutin leaching efficiency, while reducing the leaching of impurities such as polysaccharides, and retaining large molecular components such as polysaccharides in the Sophora japonica flower bud residue to a greater extent, thereby maximizing the application value of the residue and improving the comprehensive output and added value of Sophora japonica flower bud resources.

[0039] The rutin extraction method provided by this invention can achieve efficient extraction of rutin from Sophora japonica buds, with a high rutin extraction yield. At the same time, it reduces the dissolution of impurities during the extraction process, improves the purification efficiency of rutin, and realizes the production of high-purity rutin products with only simple purification (one-step concentration and crystallization). It completely avoids the use of acids and alkalis in the rutin extraction process and the resulting environmental pollution problems. Moreover, the process is simple and easy to implement, and can realize the green and efficient industrial production of rutin from Sophora japonica buds. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0041] The maturation device used in the preparation method of this invention can be a disc dryer, evaporator, oven, distillation pot, wok, or other device capable of uniform heating. The proofing device can also be a disc dryer, evaporator, oven, distillation pot, wok, or other device capable of uniform temperature control. The configuration can be tailored to the workshop equipment. If the equipment permits, in-situ proofing with a maturation device can be considered. To eliminate the influence of different equipment on the amount of fine powder from the medicinal slices, all the following examples and comparative examples use the same maturation and proofing equipment.

[0042] Example 1

[0043] This embodiment provides a method for preparing Sophora japonica flower bud slices, the steps of which are as follows:

[0044] Five tons of Sophora japonica buds with a rutin content of 19.98% and a moisture content of 13.0% were transferred to the raw material silo via a feeding auger. They were then conveyed by a scraper to a primary steam desalination machine for maturation at 140℃ for 20 minutes. After maturation, they were transferred to a secondary steam desalination machine in a sealed state via a feeding scraper for proofing. The proofing endpoint temperature was 59-61℃, and the moisture content was 13.0-13.5%. After proofing, the Sophora japonica buds were cracked by a roller mill to break the bud petals, resulting in Sophora japonica bud slices. The fine powder content of the Sophora japonica bud slices passing through a 40-mesh sieve was 10%.

[0045] Example 2

[0046] This embodiment provides a method for preparing Sophora japonica flower bud slices, the steps of which are as follows:

[0047] Five tons of Sophora japonica buds with a rutin content of 18.46% and a moisture content of 12.5% ​​were transferred to the raw material silo via a feeding auger. They were then conveyed by a scraper to a primary steam desalination machine for maturation at 90℃ for 60 minutes. After maturation, they were transferred to a secondary steam desalination machine in a sealed state via a feeding scraper for proofing at a final temperature of 50-52℃ and a final moisture content of 14.5-15.0%. After proofing, the Sophora japonica buds were cracked by a roller mill to break the bud petals, resulting in Sophora japonica bud slices. The fine powder content of the Sophora japonica bud slices passing through a 40-mesh sieve was 8%.

[0048] Example 3

[0049] This embodiment provides a method for preparing Sophora japonica flower bud slices, the steps of which are as follows:

[0050] Five tons of Sophora japonica buds with a rutin content of 17.47% and a moisture content of 12.5% ​​were transferred to the raw material silo via a feeding auger. They were then conveyed by a scraper to a primary steam desalination machine for maturation at 130℃ for 30 minutes. After maturation, they were transferred to a secondary steam desalination machine in a sealed state via a feeding scraper for proofing at a final temperature of 50-52℃ and a final moisture content of 10.0-10.5%. After proofing, the Sophora japonica buds were cracked by a roller mill to break the bud petals, resulting in Sophora japonica bud slices. The fine powder content of the Sophora japonica bud slices passing through a 40-mesh sieve was 25%.

[0051] Example 4

[0052] This embodiment provides a method for preparing Sophora japonica flower bud slices, the steps of which are as follows:

[0053] Five tons of Sophora japonica buds with a rutin content of 19.32% and a moisture content of 13.0% were transferred to the raw material silo via a feeding auger. They were then conveyed by a scraper to a primary steam desalination machine for maturation at 110℃ for 40 minutes. After maturation, they were transferred to a secondary steam desalination machine in a sealed state via a feeding scraper for proofing at a final temperature of 68-70℃ and a final moisture content of 10.0-10.5%. After proofing, the Sophora japonica buds were cracked by a roller mill to break the bud petals, resulting in Sophora japonica bud slices. The fine powder content of the Sophora japonica bud slices passing through a 40-mesh sieve was 18%.

[0054] Example 5

[0055] This embodiment provides a method for preparing Sophora japonica flower bud slices, the steps of which are as follows:

[0056] Five tons of Sophora japonica buds with a rutin content of 20.41% and a moisture content of 13.0% were transferred to the raw material silo via a feeding auger. They were then conveyed to the maturation device via a scraper conveyor. The maturation temperature was 105℃ and the maturation time was 50 minutes. After that, they were transferred to the proofing device in a sealed state. The proofing endpoint temperature was 68-70℃ and the moisture content was 14.5-15.0%. After proofing, the Sophora japonica buds were cracked by a roller mill to make the petals of the Sophora japonica buds split, thus obtaining Sophora japonica bud slices. The fine powder mass percentage of the Sophora japonica bud slices that passed through a 40-mesh sieve was 5%.

[0057] Example 6

[0058] This embodiment provides a method for extracting rutin, the steps of which are as follows:

[0059] Rutin was extracted from the Sophora japonica flower buds prepared by the method in Example 1. 500 kg of the Sophora japonica flower buds were conveyed to a 10m high-temperature conveyor belt via a scraper. 3 After the extraction tank is filled, a 5.0m³ pump is used to pump the material into it through the material pipeline. 3 Extract with 70% ethanol at 65-70℃, stirring at 20Hz for 1 hour, filter, and repeat the extraction five times under the same conditions to obtain 24.5 ml of extract. 3 Each extraction solution is stirred evenly, the volume is measured, a sample is taken, and the solutions are mixed in proportion to obtain a mixed extract.

[0060] Example 7

[0061] This embodiment provides a method for extracting rutin, the steps of which are as follows:

[0062] Rutin was extracted from the Sophora japonica flower slices prepared by the method in Example 2. 500 kg of the Sophora japonica flower slices were conveyed to a 10m high-speed conveyor via a scraper. 3 After the extraction tank is filled, a 5.0m³ pump is used to pump the material into it through the material pipeline. 3 Extract with 70% ethanol at 65-70℃, stirring at 20Hz for 1 hour, filter, and repeat the extraction five times under the same conditions to obtain 24.5 ml of extract. 3 Each extraction solution is stirred evenly, the volume is measured, a sample is taken, and the solutions are mixed in proportion to obtain a mixed extract.

[0063] Example 8

[0064] This embodiment provides a method for extracting rutin, the steps of which are as follows:

[0065] Rutin was extracted from the Sophora japonica flower slices prepared by the method in Example 3. 500 kg of the Sophora japonica flower slices were conveyed to a 10m high-temperature conveyor belt via a scraper. 3 After the extraction tank is filled, a 5.0m³ pump is used to pump the material into it through the material pipeline. 3Extract with 70% ethanol at 65-70℃, stirring at 20Hz for 1 hour, filter, and repeat the extraction five times under the same conditions to obtain 24.5 ml of extract. 3 Each extraction solution is stirred evenly, the volume is measured, a sample is taken, and the solutions are mixed in proportion to obtain a mixed extract.

[0066] Example 9

[0067] This embodiment provides a method for extracting rutin, the steps of which are as follows:

[0068] Rutin was extracted from the Sophora japonica flower slices prepared by the method in Example 4. 500 kg of the Sophora japonica flower slices were conveyed to a 10m high-speed conveyor via a scraper. 3 After the extraction tank is filled, a 5.0m³ pump is used to pump the material into it through the material pipeline. 3 Extract with 70% ethanol at 65-70℃, stirring at 20Hz for 1 hour, filter, and repeat the extraction five times under the same conditions to obtain 24.5 ml of extract. 3 Each extraction solution is stirred evenly, the volume is measured, a sample is taken, and the solutions are mixed in proportion to obtain a mixed extract.

[0069] Example 10

[0070] This embodiment provides a method for extracting rutin, the steps of which are as follows:

[0071] Rutin was extracted from the Sophora japonica flower slices prepared by the method in Example 5. 500 kg of the Sophora japonica flower slices were conveyed to a 10m high-temperature conveyor belt via a scraper. 3 After the extraction tank is filled, a 5.0m³ pump is used to pump the material into it through the material pipeline. 3 Extract with 70% ethanol at 65-70℃, stirring at 20Hz for 1 hour, filter, and repeat the extraction five times under the same conditions to obtain 24.5 ml of extract. 3 Each extraction solution is stirred evenly, the volume is measured, a sample is taken, and the solutions are mixed in proportion to obtain a mixed extract.

[0072] Comparative Example 1

[0073] This comparative example provides a method for preparing Sophora japonica flower bud slices, the steps of which are as follows:

[0074] Five tons of Sophora japonica buds with a rutin content of 20.00% and a moisture content of 13.0% were transferred to the raw material silo via a feeding auger. The Sophora japonica buds were then directly fed into a roller mill for cracking, which caused the petals of the Sophora japonica buds to split, resulting in Sophora japonica bud slices. The fine powder content of the Sophora japonica bud slices that passed through a 40-mesh sieve accounted for 65% of the total mass.

[0075] Comparative Example 2

[0076] This comparative example provides a method for preparing Sophora japonica flower bud slices, the steps of which are as follows:

[0077] Five tons of Sophora japonica buds with a rutin content of 20.00% and a moisture content of 13.0% were transferred to the raw material silo via a feeding auger. They were then conveyed to a steam decanter for maturation at a temperature of 100℃ for 50 minutes. After maturation, the buds were transferred to a roller mill in a sealed state for cracking. The equipment made abnormal noises and was forced to stop. A large amount of Sophora japonica buds stuck to the rollers.

[0078] Comparative Example 3

[0079] This comparative example provides a method for preparing Sophora japonica flower bud slices, the steps of which are as follows:

[0080] Five tons of Sophora japonica buds with a rutin content of 20.00% and a moisture content of 13.0% were transferred to the raw material silo via a feeding auger. They were then conveyed by a scraper to a primary steam desalination machine for maturation at 100℃ for 50 minutes. After maturation, they were transferred to a secondary steam desalination machine in a sealed state via a feeding scraper for proofing at a final proofing temperature of 40-42℃ and a final moisture content of 13.0-13.5%. After proofing, the Sophora japonica buds were cracked by a roller mill to break the bud petals, resulting in Sophora japonica bud slices. The fine powder content of the Sophora japonica bud slices passing through a 40-mesh sieve was 45%.

[0081] This comparative example also provides a method for extracting rutin, the steps of which are as follows:

[0082] The Sophora japonica flower slices prepared using the method described in this comparative example were used as raw materials for rutin extraction. 500 kg of Sophora japonica flower slices were conveyed to a 10m high-temperature conveyor via a scraper. 3 After the extraction tank is filled, a 5.0m³ pump is used to pump the material into it through the material pipeline. 3 Extract with 70% ethanol at 65-70℃, stirring at 20Hz for 1 hour, filter, and repeat the extraction five times under the same conditions to obtain 24.5 ml of extract. 3 Each extraction solution is stirred evenly, the volume is measured, a sample is taken, and the solutions are mixed in proportion to obtain a mixed extract.

[0083] Comparative Example 4

[0084] This comparative example provides a method for preparing Sophora japonica flower bud slices, the steps of which are as follows:

[0085] Five tons of Sophora japonica buds with a rutin content of 20.00% and a moisture content of 13.0% were transferred to the raw material silo via a feeding auger. They were then conveyed by a scraper to a primary steam desalination machine for maturation at 100℃ for 50 minutes. After maturation, they were transferred to a secondary steam desalination machine in a sealed state via a feeding scraper for proofing at a final proofing temperature of 59-61℃ and a final moisture content of 5.0-5.5%. After proofing, the Sophora japonica buds were cracked by a roller mill to break the bud petals, resulting in Sophora japonica bud slices. The fine powder content of the Sophora japonica bud slices passing through a 40-mesh sieve was 65%.

[0086] Experiment Example 1: Detection of Rutin and Moisture Content in Sophora japonica Flower Slices

[0087] The Sophora japonica flower slices prepared in Examples 1-5 and Comparative Examples 3 and 4 were sampled from different parts and mixed together. The rutin content and moisture content were then tested. The test results are shown in Table 1. The results show that the rutin content of the Sophora japonica flower slices in Examples 1-5 remained at a level comparable to that of the raw Sophora japonica flower before processing, and the dry basis content of the processed Sophora japonica flower was also at the same level as that before processing.

[0088] Table 1

[0089] project Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 3 Comparative Example 4 Rutin content 19.98％ 17.99％ 17.93％ 19.95％ 20.01％ 19.95％ 21.77％ Moisture content 13.1％ 14.8％ 10.3％ 10.3％ 14.7％ 13.20％ 5.20％

[0090] Experiment Example 2: Rutin Extraction Efficiency Detection

[0091] The rutin extraction efficiency and the retention of polysaccharides and other macromolecular components in the residue were tested using the rutin extraction methods of Examples 6-10 and Comparative Example 3. The specific methods are as follows:

[0092] The remaining residue after extraction was evaporated to dryness in the original extraction tank. The volumetric solids content (dry matter / volume*100%), dry matter leaching rate (leaked dry matter / raw material dry matter*100%), and rutin volume content of the extract were determined. The extract was vacuum dried at below 70℃ to obtain crude rutin extract with volatile matter ≤7%, and the rutin content on a dry basis was determined by HPLC. The residue was vacuum dried at below 70℃ to obtain volatile matter ≤7%, and the rutin, polysaccharide, and protein content of the residue (converted to 10% moisture content) was determined. The residue was dried using a disc dryer, and the mass of the residue with 10.0% volatile matter was determined.

[0093] Using the commonly used method of extracting rutin from crushed Sophora japonica buds as a control, the only difference between this method and the rutin extraction method in Examples 6-10 is that the Sophora japonica bud slices are replaced with Sophora japonica bud powder with a 100% pass rate of 80 mesh and a rutin content of 19.98%, and the moisture content of the Sophora japonica bud powder is 13.10%.

[0094] The test results are shown in Table 2. As shown in Table 2, using the Sophora japonica flower slices from Examples 1-5 as raw materials for rutin extraction resulted in high rutin extraction efficiency (high rutin extraction yield and high rutin dry-basis HPLC content, and low rutin content in the residue). Furthermore, the residue showed minimal loss of polysaccharides, fiber, and protein, significantly increasing the content of these components (low dry matter leaching rate, and high crude fiber, crude protein, and volatile matter content of the residue at 10.0%). In contrast, the control group, which replaced the Sophora japonica flower slices with 80-mesh 100% pass-through Sophora japonica flower powder, experienced a decrease in rutin extraction efficiency, a significant reduction in the content of polysaccharides, fiber, and protein in the residue, and a substantial decrease in residue quality. In Comparative Example 3, 45% of the Sophora japonica flower slices passed through a 40-mesh sieve. Using Comparative Example 3 as the extraction raw material resulted in a decrease in rutin extraction efficiency, a significant reduction in the content of polysaccharides, fiber, and protein in the residue, and a significant decrease in residue quality.

[0095] Table 2

[0096]

[0097] The following embodiments provide a method for extracting rutin from Sophora japonica flower buds in industrial production equipment, and verify the performance and application potential of the rutin extraction method in industrial production practice.

[0098] Example 11

[0099] This embodiment provides a method for extracting rutin, the steps of which are as follows:

[0100] Rutin was extracted using the Sophora japonica flower slices prepared by the method in Example 5. The Sophora japonica flower slices were fed into the extractor through a scraper, with the feeding rate controlled at 20±0.2 kg per hour. A 94.5-95.0% methanol aqueous solution was used as the extraction solvent, with a solvent replenishment rate of 160±1.6 L / h and a solvent temperature of 55.0-55.5℃. The extraction time was controlled to be 3.0-3.5 h by adjusting the operating frequency of the extractor. After extraction, the rutin extraction yield was calculated based on the amount of raw material added per hour, the amount of extract collected, and the amount of rutin remaining in the residue.

[0101] The extract was concentrated using a thin-film evaporator, with the material temperature controlled at 55-70℃ and the vacuum degree at -0.050 to -0.095 MPa. After being concentrated to 1 / 4.5 of the original volume, it was transferred to a crystallizer for uniform cooling and stirring crystallization. The total crystallization time was 5 hours, and the final crystallization temperature was 50℃. The product was then filtered, and the filter cake was washed with the extraction solvent. The washing liquid was returned to the second-to-last extraction stage of the extractor. After vacuum drying of the filter cake, the rutin product was obtained.

[0102] The extraction yield of rutin is calculated as follows: (daily rutin weight × HPLC content) / daily input of Sophora japonica flower slices × HPLC content). After the production system stabilizes, the rutin extraction yield is calculated to be 92.3%, and the dry basis content of the rutin product is 98.5% (HPLC).

[0103] Example 12

[0104] This embodiment provides a method for extracting rutin, the steps of which are as follows:

[0105] Rutin was extracted from the Sophora japonica flower buds prepared by the method in Example 5. The Sophora japonica flower buds were conveyed to the extraction tank using a scraper. 3 In each horizontal extraction tank, 1 ton of Sophora japonica flower slices is added, and 7000L of 90.0-90.5% methanol aqueous solution (volume fraction) is pumped in as the extraction solvent. The extraction solvent is heated to 60-60.5℃ through a heat exchanger, and the temperature inside the tank is maintained at 59-61℃. The first batch is extracted 5 times with the extraction solvent, each extraction lasting 0.75-1.0h. From the second batch onwards, the extraction solvent is only added in the last extraction. The extracts from the 2nd, 3rd, 4th, and 5th extractions of the previous batch are used for the 1st, 2nd, 3rd, and 4th extractions of the current batch, respectively. Only the extract from the first extraction of the raw material is collected and enters the concentration process. Starting from the fifth batch, the extract is concentrated using a thin-film evaporator, with the material temperature controlled at 55-70℃ and the vacuum degree at -0.050 to -0.095 MPa. After being concentrated to 1 / 6 of the original volume, it is transferred to a crystallization tank for uniform cooling and stirring crystallization. The total crystallization time is 7.5 hours, and the final crystallization temperature is 30℃. After filtration, the filter cake is washed with 3.0 times the volume (m / v) of the wet filter cake using the extraction solvent. The washing liquid is returned to the fourth-stage extraction tank for extraction. After vacuum drying of the filter cake, the rutin product is obtained.

[0106] After the production system stabilized, the rutin extraction yield was calculated using the following formula: Rutin extraction yield = (weight of rutin produced per batch × rutin HPLC content of the product) / (weight of Sophora japonica flower slices added in the corresponding batch × rutin HPLC content of the product). The calculated rutin extraction yield was 96.5%, and the dry basis content of the rutin product was 95.6% (HPLC).

[0107] Example 13

[0108] This embodiment provides a method for extracting rutin, the steps of which are as follows:

[0109] Rutin was extracted using the Sophora japonica flower slices prepared by the method in Example 5. The Sophora japonica flower slices were fed through the scraper of a rotary extractor, with the feeding rate controlled at 1000±20 kg per hour. An 85.0-85.5% methanol aqueous solution was used as the extraction solvent, with a solvent replenishment rate of 10000±100 L / h and a solvent temperature of 63.5-64.0℃. The operating frequency of the extractor was adjusted and the total extraction time was controlled at 6-7 hours. After 7 hours of operation, the rutin extraction yield was calculated based on the amount of raw material added per hour, the amount of extract collected, and the amount of rutin remaining in the residue.

[0110] The extract was concentrated using a thin-film evaporator, with the material temperature controlled at 55-70℃ and the vacuum degree at -0.050 to -0.095 MPa. After being concentrated to 1 / 7.5 of the original volume, it was transferred to a crystallizer for uniform cooling and stirring crystallization. The total crystallization time was 10 hours, and the final crystallization temperature was 10℃. The product was then filtered, and the filter cake was washed with 4.5 times the volume (m / v) of the extraction solvent. The washing liquid was returned to the second-to-last extraction stage of the extractor. After vacuum drying of the filter cake, the rutin product was obtained.

[0111] After the production system stabilizes, the rutin extraction yield is calculated using the formula: rutin extraction yield = (daily rutin weight × HPLC content) / daily weight of Sophora japonica buds × content). The calculated rutin extraction yield is 97.8%, and the dry basis content of the rutin product is 93.2% (HPLC).

[0112] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for extracting rutin, characterized in that, The method uses Sophora japonica flower buds as raw material to extract rutin, including the step of mixing Sophora japonica flower buds with an extraction solvent for extraction; The Sophora japonica flower slices are prepared by a method including the following steps: the Sophora japonica flowers are cooked and then fermented, and then cracked so that the petals of the Sophora japonica flowers crack. The curing temperature is 90-140℃, and the time is 20-60 minutes; The final temperature of the proofing process is 50-70℃, and the final moisture content of the proofing process is 10-15%. The cracking is performed by compression cracking; The proportion of fine powder passing through a 40-mesh sieve in the prepared Sophora japonica flower slices shall not exceed 25% by mass. The extraction solvent is an 85%-95% methanol aqueous solution and / or a 70%-80% ethanol aqueous solution.

2. The method for extracting rutin according to claim 1, characterized in that, The fine powder content of the Sophora japonica flower slices that passes through a 40-mesh sieve is 5-25%.

3. The method for extracting rutin according to claim 1 or 2, characterized in that, In the extraction process, the mass-to-volume ratio of Sophora japonica flower slices to extraction solvent is 1 kg: (5-12) L.

4. The method for extracting rutin according to claim 3, characterized in that, The extraction temperature is 55-70℃.

5. The method for extracting rutin according to any one of claims 1, 2, and 4, characterized in that, The method further includes: concentrating the extracted solution to 1 / 4.5-1 / 7.5 of its original volume and then crystallizing it.

6. The method for extracting rutin according to claim 3, characterized in that, The method further includes: concentrating the extracted solution to 1 / 4.5-1 / 7.5 of its original volume and then crystallizing it.

7. The method for extracting rutin according to claim 5, characterized in that, The crystallization is carried out by cooling and stirring, with a crystallization time of 5-10 hours and a final crystallization temperature of 10-50℃.

8. The method for extracting rutin according to claim 6, characterized in that, The crystallization is carried out by cooling and stirring, with a crystallization time of 5-10 hours and a final crystallization temperature of 10-50℃.

9. The method for extracting rutin according to claim 7 or 8, characterized in that, After crystallization, wet crystals are obtained by solid-liquid separation, and the wet crystals are washed with the extraction solvent.

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