Natto flavone separation method and extraction device thereof

Abstract

The invention belongs to the technical field of natto flavone extraction, and provides a natto flavone separation method and an extraction device thereof. The rotating shafts are installed in the supporting frame in a relatively rotating mode, a heating extraction tank is fixedly installed between the two rotating shafts, and a plurality of protruding points are evenly arranged on the inner surface of the heating extraction tank; the feeding assembly is arranged on the outer surface of the heating extraction tank, the feeding assembly is used for guiding natto and a glucolactone aqueous solution into the heating extraction tank, the feeding assembly comprises a feeding pipe fixedly communicated with the outer surface of the heating extraction tank, and the outer surface of the heating extraction tank is fixedly communicated with a liquid inlet pipe; the countercurrent state of natto and glucolactone aqueous solution in the heating extraction tank is realized by adopting a relatively staggered mounting mode of the feed pipe and the liquid inlet pipe. Due to the design, the contact area of the two is obviously increased, and more sufficient mixing is promoted, so that the flavone extraction efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of natto flavonoids extraction, in particular to a natto flavonoids separation method and an extraction device thereof. Background Art

[0002] Natto, a food fermented by Bacillus natto (also known as Bacillus subtilis), is rich in flavonoids with significant biological activity, such as isoflavones and anthocyanins, especially when black beans are used as raw materials. These flavonoids have shown excellent health benefits such as lowering blood sugar, anti-oxidation, anti-tumor, anti-inflammatory and antibacterial, lowering blood lipids and neuroprotection. However, although the flavonoid components in natto have many advantages, such as improving antioxidant capacity, maintaining cardiovascular health, promoting bone strength, beautifying skin and regulating immune function, their content is relatively low, which to some extent weakens its potential beneficial effects.

[0003] Secondly, in the process of extracting flavonoids from natto, traditionally, isoflavones are extracted with methanol or ethanol, followed by degreasing with petroleum ether or n-hexane, and then extracted with acetone and anhydrous ether to obtain a crude extract. Although this method is relatively simple in operation, there are many problems in the process of flavonoid separation. First, ethanol is often used to precipitate polysaccharides and proteins in order to obtain a filtrate containing flavonoids. However, in the early stage of extraction, proteins and flavonoids often coexist in the same system. If the dissolution of protein is not effectively controlled, a large amount of protein will be mixed into the extract, thereby reducing the purity of flavonoids. In the subsequent process of removing protein, some flavonoids may precipitate with protein, resulting in a waste of flavonoids, thereby reducing the efficiency of flavonoid separation and purification. In addition, proteins and flavonoids may also interact, such as through non-covalent forces (such as hydrogen bonds, van der Waals forces, etc.) or covalent bonds. This interaction may have an adverse effect on the structure and properties of flavonoids, thereby reducing their biological activity or stability.

[0004] In addition, when extracting flavonoids from natto, the natto is soaked by placing the extracting solution and the natto in a heated extraction tank. However, natto has a certain viscosity and is easy to stick together after being broken, thereby reducing the contact area between the natto and the extracting solution, and then reducing the efficiency of extracting flavonoids from natto. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a natto flavonoids separation method and an extraction device thereof to solve the problems in the background technology.

[0006] A method for separating nattoflavonoids, comprising the following steps:

[0007] S1. Processing of raw materials: firstly, black beans are selected as raw materials, and the black beans are washed and soaked for 12 hours, and then the soaked black beans are steamed for 2 hours;

[0008] S2, inoculation of Bacillus and Mucor: Then prepare Bacillus inoculation liquid and Mucor inoculation liquid, then cool the cooked black beans to 42°C, then sprinkle the Bacillus inoculation liquid and Mucor inoculation liquid on the black beans and stir evenly;

[0009] S3, fermentation of natto: Then put the inoculated black beans into the fermentation machine, then set the constant temperature to 42 degrees Celsius, and ferment for 24 hours to obtain natto:

[0010] S4, pretreatment of natto: then the natto is washed, placed in an oven and the temperature is set to 45°C to dry the natto, and then the dried natto is placed in a crusher for crushing;

[0011] S5. Preparation of gluconolactone aqueous solution: firstly weigh an appropriate amount of gluconolactone, and then dissolve the gluconolactone in deionized water to prepare a gluconolactone aqueous solution, so as to extract flavonoids in natto;

[0012] S6, extraction of natto flavonoids: then mixing the natto with the gluconolactone aqueous solution, stirring the natto and the gluconolactone aqueous solution so that the gluconolactone aqueous solution can completely cover the natto, and then soaking the mixture of the natto and the gluconolactone aqueous solution in an environment of 50°C to 60°C for 3 hours;

[0013] S7, filtration: then pour the soaked natto and the gluconolactone aqueous solution mixture into a filtering device, and collect the filtrate in a container;

[0014] S8, treatment of the filtrate: then pouring 60% ethanol by volume into the filtrate while stirring, so that impurities such as polysaccharides and proteins are precipitated, and then standing for 1 hour to obtain a precipitate and a supernatant, and then filtering to obtain a flavonoid separation liquid;

[0015] S9, flavonoid adsorption: firstly, the macroporous adsorption resin is washed and pre-equilibrated, then the pre-treated macroporous adsorption resin is loaded into the chromatography column, and then a peristaltic pump is used to load the sample and pump the flavonoid separation liquid into the chromatography column;

[0016] S10, elution of flavonoids: eluting the flavonoids adsorbed on the macroporous adsorption resin multiple times using ethanol-water solutions of various concentrations;

[0017] S11. Concentration and drying of flavonoids: The eluent is then concentrated using a rotary evaporator at a concentration temperature of 60°C to 75°C, and the concentrated solution is then placed in a drying oven for drying at a drying temperature of 45°C to obtain a flavonoid compound extract.

[0018] Preferably, the inoculation amount of Bacillus in S2 is 3% of the amount of black beans, and the inoculation amount of Mucor is 3% of the amount of black beans.

[0019] Preferably, the culturing of the Bacillus inoculum solution in S2 comprises the following steps: firstly activating and expanding the Bacillus, then drying the Bacillus, and then adding the dried Bacillus powder into deionized water to prepare the Bacillus inoculum solution.

[0020] Preferably, the cultivation of the Mucor inoculum in S2 comprises the following steps: firstly activating and expanding the Mucor, then drying the Mucor, and then adding the dried Mucor powder into deionized water to prepare the Mucor inoculum.

[0021] Preferably, the concentration of the gluconolactone aqueous solution in S5 is 1.5%.

[0022] Preferably, the pretreatment of the macroporous adsorption resin in S8 comprises the following steps: first, pre-washing the resin with deionized water, then rinsing the resin with a large amount of deionized water until the conductivity or other indicators of the washing liquid are stable, then removing the deionized water in the resin by a low-temperature vacuum drying method, and then mixing the resin with an organic solvent mixed with water, and balancing at room temperature for 12 hours.

[0023] A nattoflavonoids separation and extraction device, comprising:

[0024] Support frame;

[0025] A rotating shaft is installed inside the support frame for relative rotation, a heating extraction tank is fixedly installed between the two rotating shafts, and a plurality of convex points are evenly arranged on the inner surface of the heating extraction tank;

[0026] A feeding component is arranged on the outer surface of the heating and extraction tank, and is used to introduce natto and gluconolactone aqueous solution into the heating and extraction tank. The feeding component includes a feeding pipe fixedly connected to the outer surface of the heating and extraction tank, and the outer surface of the heating and extraction tank is fixedly connected with a liquid inlet pipe, and a limiting disk is fixedly installed on the outer surface of the liquid inlet pipe. The feeding pipe and the liquid inlet pipe are relatively staggered. A connecting disk is fixedly installed on the outer surface of the liquid inlet pipe. The feeding component also includes a flexible tube, and a mounting disk is fixedly installed on the output end of the flexible tube. The connecting disk and the mounting disk are connected by a plurality of mounting bolts, and the input end of the flexible tube is fixedly connected with a conveying member.

[0027] The sealing assembly is installed inside the feed pipe and the liquid inlet pipe, and the sealing assembly is used to seal the feed pipe and the liquid inlet pipe.

[0028] Preferably, the outer surface of the heating extraction tank is provided with a heat-insulating layer.

[0029] Preferably, a control component is fixedly mounted on one side of the support frame, and an output end of the control component is fixedly connected to one end of the rotating shaft.

[0030] Preferably, the sealing assembly includes a sealing plug inserted into the inside of the feed pipe, a sealing disk is fixedly mounted on the upper end of the sealing plug, and the sealing disk and the limit disk are assembled through a plurality of limit bolts.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1. The present invention adds gluconolactone as a flocculant. During the extraction of natto flavonoids, GDL reduces the electrostatic repulsion between protein molecules by reducing the pH value of the system, thereby promoting protein aggregation and precipitation, reducing the amount of protein dissolved in the separation liquid, thereby reducing protein impurities in the separation liquid, and further improving the purity of flavonoid compounds. Secondly, by reducing the content of protein dissolved in the separation liquid, the precipitation of protein precipitation in the ethanol precipitation method step can be further reduced, thereby reducing the amount of flavonoids contained in the precipitated protein, and further improving the extraction rate of flavonoids. Finally, by controlling the dissolution of protein, the interaction between protein and flavonoids can be reduced, thereby protecting the structure and properties of flavonoid compounds and ensuring their biological activity and stability.

[0033] 2. The present invention uses black beans as raw materials to make natto, and inoculates Mucor at the same time as Bacillus. Mucor can utilize nutrients in plant raw materials during the fermentation process, and synthesize or transform flavonoids through related genes in its metabolic pathway, thereby increasing the content of flavonoids in natto. Therefore, when eaten, it can not only enhance its antioxidant capacity, prevent cardiovascular diseases, promote bone health, beautify and nourish the skin, regulate immune function, but also help improve menopausal symptoms. At the same time, when using the natto to extract flavonoid substances, the flavonoid extraction amount can be increased and the flavonoid extraction efficiency can be improved.

[0034] 3. The present invention realizes the countercurrent state of natto and gluconolactone aqueous solution in the heating extraction tank by adopting the relative dislocation installation mode of the feed pipe and the liquid inlet pipe. This design significantly increases the contact area between the two, promotes more complete mixing, and thus improves the efficiency of flavonoid extraction. Secondly, the gluconolactone aqueous solution can effectively impact and disperse the natto during the conveying process of the conveyor, further improving the dispersion degree of the natto. This not only helps to release the flavonoid substance, but also makes the extraction process more uniform and efficient. Finally, the full contact and mixing of natto and gluconolactone aqueous solution, as well as the effective dispersion of natto, can significantly improve the extraction efficiency of flavonoids, thereby saving time and energy costs.

[0035] 4. The present invention starts the control member through the PLC controller to drive the rotation of the rotating shaft and the heating extraction tank. This design significantly improves the mixing disorder of natto and the gluconolactone aqueous solution. This highly mixed state helps the flavonoids to be released more effectively from the natto, thereby improving the extraction efficiency. Secondly, the convex points arranged inside the heating extraction tank collide with the natto during the rotation process. This physical action further breaks the natto, increases its surface area, and makes the flavonoids more easily extracted by solvents. The broken natto particles are easier to fully contact with the gluconolactone aqueous solution, thereby improving the extraction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the structure of the extraction device of the present invention from a first viewing angle;

[0037] Figure 2 This is a schematic diagram of the internal structure of the heating extraction tank of the extraction device of the present invention;

[0038] Figure 3 It is a schematic diagram of the structure of the extraction device of the present invention from a second viewing angle;

[0039] Figure 4 It is a schematic structural diagram of the extraction device of the present invention from a third viewing angle;

[0040] Figure 5 It is a schematic diagram of the structure of the extraction device of the present invention from a fourth viewing angle;

[0041] Figure 6 The figure is a flow chart of the separation method of the present invention.

[0042] In the figure:

[0043] 1. Support frame; 2. Rotating shaft; 3. Heating and extraction tank; 4. Insulation layer; 5. Bump; 6. Feed assembly; 61. Feed pipe; 62. Limit plate; 63. Liquid inlet pipe; 64. Connecting plate; 65. Mounting plate; 66. Mounting bolt; 67. Flexible tube; 68. Conveying part; 7. Sealing assembly; 71. Sealing plate; 72. Limit bolt; 73. Sealing plug; 8. Control part. DETAILED DESCRIPTION

[0044] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0045] As attached Figure 1 To Attachment Figure 6 As shown:

[0046] Embodiment 1: The present invention provides a method for separating nattoflavonoids, which specifically comprises the following steps:

[0047] S1. Processing of raw materials: firstly, black beans are selected as raw materials, and the black beans are washed and soaked for 12 hours, and then the soaked black beans are steamed for 2 hours;

[0048] S2, inoculation of Bacillus and Mucor: Then prepare Bacillus inoculation liquid and Mucor inoculation liquid, then cool the cooked black beans to 42°C, then sprinkle the Bacillus inoculation liquid and Mucor inoculation liquid on the black beans and stir evenly;

[0049] S3, fermentation of natto: Then put the inoculated black beans into the fermentation machine, then set the constant temperature to 42 degrees Celsius, and ferment for 24 hours to obtain natto:

[0050] S4, pretreatment of natto: then the natto is washed, placed in an oven and the temperature is set to 45°C to dry the natto, and then the dried natto is placed in a crusher for crushing;

[0051] S5. Preparation of gluconolactone aqueous solution: firstly weigh an appropriate amount of gluconolactone, and then dissolve the gluconolactone in deionized water to prepare a gluconolactone aqueous solution, so as to extract flavonoids in natto;

[0052] S6, extraction of natto flavonoids: then mixing the natto with the gluconolactone aqueous solution, stirring the natto and the gluconolactone aqueous solution so that the gluconolactone aqueous solution can completely cover the natto, and then soaking the mixture of the natto and the gluconolactone aqueous solution in an environment of 50°C to 60°C for 3 hours;

[0053] S7, filtration: then pour the soaked natto and the gluconolactone aqueous solution mixture into a filtering device, and collect the filtrate in a container;

[0054] S8, treatment of the filtrate: then pouring 60% ethanol by volume into the filtrate while stirring, so that impurities such as polysaccharides and proteins are precipitated, and then standing for 1 hour to obtain a precipitate and a supernatant, and then filtering to obtain a flavonoid separation liquid;

[0055] S9, flavonoid adsorption: firstly, the macroporous adsorption resin is washed and pre-equilibrated, then the pre-treated macroporous adsorption resin is loaded into the chromatography column, and then a peristaltic pump is used to load the sample and pump the flavonoid separation liquid into the chromatography column;

[0056] S10, elution of flavonoids: eluting the flavonoids adsorbed on the macroporous adsorption resin multiple times using ethanol-water solutions of various concentrations;

[0057] S11. Concentration and drying of flavonoids: The eluent is then concentrated using a rotary evaporator at a concentration temperature of 60°C to 75°C, and the concentrated solution is then placed in a drying oven for drying at a drying temperature of 45°C to obtain a flavonoid compound extract.

[0058] The inoculation amount of Bacillus in S2 is 3% of the amount of black beans, and the inoculation amount of Mucor is 3% of the amount of black beans.

[0059] The culturing of the bacillus inoculum in S2 comprises the following steps: firstly activating and expanding the bacillus, then drying the bacillus, and then adding the dried bacillus powder into deionized water to prepare the bacillus inoculum.

[0060] The cultivation of the Mucor inoculum in S2 comprises the following steps: firstly activating and expanding the Mucor, then drying the Mucor, and then adding the dried Mucor powder into deionized water to prepare the Mucor inoculum.

[0061] The concentration of the gluconolactone aqueous solution in S5 is 1.5%.

[0062] The pretreatment of the macroporous adsorption resin in S8 includes the following steps: first, pre-washing the resin with deionized water, then rinsing the resin with a large amount of deionized water until the conductivity or other indicators of the washing liquid are stable, then using a low-temperature vacuum drying method to remove the deionized water in the resin, and then mixing the resin with an organic solvent mixed with water, and balancing at room temperature for 12 hours.

[0063] As can be seen from the above, when making natto, black beans are used as raw materials to make natto, and Mucor is inoculated at the same time as Bacillus. Mucor can utilize nutrients in plant raw materials during the fermentation process, and synthesize or transform flavonoids through related genes in its metabolic pathway, thereby increasing the content of flavonoids in natto. Therefore, when eaten, it can not only enhance its antioxidant capacity, prevent cardiovascular diseases, promote bone health, beautify and nourish the skin, regulate immune function, but also help improve menopausal symptoms. At the same time, when using the natto to extract flavonoid substances, the flavonoid extraction amount can be increased and the flavonoid extraction efficiency can be improved.

[0064] During the extraction, gluconolactone is added as a flocculant. During the extraction of natto flavonoids, GDL reduces the pH value of the system, thereby reducing the electrostatic repulsion between protein molecules, thereby promoting protein aggregation and precipitation, and can reduce the amount of protein dissolved in the separation liquid, thereby reducing protein impurities in the separation liquid and further improving the purity of flavonoid compounds. Secondly, by reducing the content of protein dissolved in the separation liquid, the precipitation of protein precipitation can be further reduced in the ethanol precipitation step, thereby reducing the amount of flavonoids contained in the precipitated protein and further improving the extraction rate of flavonoids. Finally, by controlling the dissolution of protein, the interaction between protein and flavonoids can be reduced, thereby protecting the structure and properties of flavonoid compounds and ensuring their biological activity and stability.

[0065] Embodiment 2: The present invention provides an extraction device for separating natto flavonoids, comprising:

[0066] Support frame 1;

[0067] The rotating shaft 2 is relatively rotatably mounted inside the support frame 1, a heating and extracting tank 3 is fixedly mounted between the two rotating shafts 2, and a plurality of convex points 5 are evenly arranged on the inner surface of the heating and extracting tank 3;

[0068] A feed assembly 6 is arranged on the outer surface of the heating and extraction tank 3. The feed assembly 6 is used to introduce natto and gluconolactone aqueous solution into the heating and extraction tank 3. The feed assembly 6 includes a feed pipe 61 fixedly connected to the outer surface of the heating and extraction tank 3. The outer surface of the heating and extraction tank 3 is fixedly connected with a liquid inlet pipe 63. A limit plate 62 is fixedly installed on the outer surface of the liquid inlet pipe 63. The feed pipe 61 and the liquid inlet pipe 63 are relatively staggered. A connecting plate 64 is fixedly installed on the outer surface of the liquid inlet pipe 63. The feed assembly 6 also includes a flexible tube 67. A mounting plate 65 is fixedly installed at the output end of the flexible tube 67. The connecting plate 64 is connected to the mounting plate 65 through a plurality of mounting bolts 66. The input end of the flexible tube 67 is fixedly connected with a conveying member 68;

[0069] A sealing assembly 7, which is installed inside the feed pipe 61 and the liquid inlet pipe 63, and is used to seal the feed pipe 61 and the liquid inlet pipe 63;

[0070] The outer surface of the heating extraction tank 3 is provided with a heat-insulating layer 4;

[0071] A control component 8 is fixedly mounted on one side of the support frame 1 , and an output end of the control component 8 is fixedly connected to one end of the rotating shaft 2 .

[0072] The sealing assembly 7 includes a sealing plug 73 inserted into the inside of the feed pipe 61 , a sealing disk 71 is fixedly mounted on the upper end of the sealing plug 73 , and the sealing disk 71 and the limiting disk 62 are assembled via a plurality of limiting bolts 72 .

[0073] As can be seen from the above, when extracting flavonoids from natto, first, the pre-treated natto is poured into the feed pipe 61 of the heating extraction tank 3. In this process, the input end of the conveying member 68 is connected to the gluconolactone aqueous solution. Subsequently, the conveying member 68 is started by the PLC controller to pump the gluconolactone aqueous solution into the interior of the heating extraction tank 3. Since the feed pipe 61 and the liquid inlet pipe 63 are installed in a relatively dislocated manner, the natto and the gluconolactone aqueous solution form a countercurrent state in the tank. This design not only increases the contact area between the natto and the gluconolactone aqueous solution, but also enables the gluconolactone aqueous solution to effectively impact and disperse the natto, further improving the dispersion of the natto. As a result, the contact area between the natto and the gluconolactone aqueous solution is significantly improved, thereby promoting the efficiency of flavonoid extraction, wherein the conveying member 68 includes but is not limited to a pump, and the countercurrent state between the natto and the gluconolactone aqueous solution in the heating extraction tank 3 is achieved by adopting the relatively dislocated installation mode of the feed pipe 61 and the liquid inlet pipe 63. This design significantly increases the contact area between the two, promotes more complete mixing, and thus improves the efficiency of flavonoid extraction. Secondly, the gluconolactone aqueous solution can effectively impact and disperse the natto during the conveying process of the conveying member 68, further improving the dispersion of the natto. This not only helps to release the flavonoids, but also makes the extraction process more uniform and efficient. Finally, the full contact and mixing of the natto and the gluconolactone aqueous solution, as well as the effective dispersion of the natto, can significantly improve the extraction efficiency of flavonoids, thereby saving time and energy costs.

[0074] After the natto and the gluconolactone aqueous solution are all put into the heating extraction tank 3, first use a sealing component 7 to seal the feed pipe 61 at the top, insert the sealing plug 73 into the feed pipe 61, the sealing disk 71 is tightly attached to the limit disk 62, and then use the limit bolt 72 to assemble, and then start the rotating shaft 2 through the PLC controller to drive the heating extraction tank 3 to rotate 180°, so that the liquid feed pipe 63 is at the top, and then take out a sealing component 7 to seal the liquid feed pipe 63, first remove the mounting bolt 66, and then remove the mounting disk 65 and the flexible tube 67, Then, the sealing plug 73 is inserted into the liquid inlet pipe 63 and assembled with a plurality of limit bolts 72. After the feed pipe 61 and the liquid inlet pipe 63 are sealed with two sealing components 7, the control component 8 is started through the PLC controller, wherein the control component 8 includes but is not limited to a motor, which drives the rotating shaft 2 to rotate, thereby rotating the heating extraction tank 3, which can further increase the degree of confusion between the natto and the gluconolactone aqueous solution, and the heating extraction tank 3 is provided with convex points 5. During the rotation of the natto, the natto collides with the convex points 5, further increasing the degree of crushing of the natto, thereby improving the flavonoid extraction efficiency.

[0075] The PLC controller starts the control member 8 to drive the rotation of the rotating shaft 2 and the heating extraction tank 3. This design significantly improves the mixing disorder of natto and the gluconolactone aqueous solution. This highly mixed state helps the flavonoids to be released more effectively from the natto, thereby improving the extraction efficiency. Secondly, the convex points 5 provided inside the heating extraction tank 3 collide with the natto during the rotation process. This physical action further breaks the natto, increases its surface area, and makes the flavonoids more easily extracted by solvents. The broken natto particles are easier to fully contact with the gluconolactone aqueous solution, thereby improving the extraction efficiency.

[0076] The embodiments of the present invention are provided for the purpose of illustration and description. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A method for separating nattoflavonoids, characterized in that: The specific steps include: S1. Processing of raw materials: firstly, black beans are selected as raw materials, and the black beans are washed and soaked for 12 hours, and then the soaked black beans are steamed for 2 hours; S2, inoculation of Bacillus and Mucor: Then prepare Bacillus inoculation liquid and Mucor inoculation liquid, then cool the cooked black beans to 42°C, then sprinkle the Bacillus inoculation liquid and Mucor inoculation liquid on the black beans and stir evenly; S3, fermentation of natto: Then put the inoculated black beans into the fermentation machine, then set the constant temperature to 42 degrees Celsius, and ferment for 24 hours to obtain natto: S4, pretreatment of natto: then the natto is washed, placed in an oven and the temperature is set to 45°C to dry the natto, and then the dried natto is placed in a crusher for crushing; S5. Preparation of gluconolactone aqueous solution: firstly weigh an appropriate amount of gluconolactone, and then dissolve the gluconolactone in deionized water to prepare a gluconolactone aqueous solution, so as to extract flavonoids in natto; S6, extraction of natto flavonoids: then mixing the natto with the gluconolactone aqueous solution, stirring the natto and the gluconolactone aqueous solution so that the gluconolactone aqueous solution can completely cover the natto, and then soaking the mixture of the natto and the gluconolactone aqueous solution in an environment of 50°C to 60°C for 3 hours; S7, filtration: then pour the soaked natto and the gluconolactone aqueous solution mixture into a filtering device, and collect the filtrate in a container; S8, treatment of the filtrate: then pouring 60% ethanol by volume into the filtrate while stirring, so that impurities such as polysaccharides and proteins are precipitated, and then standing for 1 hour to obtain a precipitate and a supernatant, and then filtering to obtain a flavonoid separation liquid; S9, flavonoid adsorption: firstly, the macroporous adsorption resin is washed and pre-equilibrated, then the pre-treated macroporous adsorption resin is loaded into the chromatography column, and then a peristaltic pump is used to load the sample and pump the flavonoid separation liquid into the chromatography column; S10, elution of flavonoids: eluting the flavonoids adsorbed on the macroporous adsorption resin multiple times using ethanol-water solutions of various concentrations; S11. Concentration and drying of flavonoids: The eluent is then concentrated using a rotary evaporator at a concentration temperature of 60°C to 75°C, and the concentrated solution is then placed in a drying oven for drying at a drying temperature of 45°C to obtain a flavonoid compound extract.

2. A method for separating nattoflavonoids according to claim 1, characterized in that: The inoculation amount of Bacillus in S2 is 3% of the amount of black beans, and the inoculation amount of Mucor is 3% of the amount of black beans.

3. A method for separating nattoflavonoids according to claim 1, characterized in that: The culturing of the bacillus inoculum in S2 comprises the following steps: firstly activating and expanding the bacillus, then drying the bacillus, and then adding the dried bacillus powder into deionized water to prepare the bacillus inoculum.

4. A method for separating nattoflavonoids as claimed in claim 1, characterized in that: The cultivation of the Mucor inoculum in S2 comprises the following steps: firstly activating and expanding the Mucor, then drying the Mucor, and then adding the dried Mucor powder into deionized water to prepare the Mucor inoculum.

5. A method for separating nattoflavonoids as claimed in claim 1, characterized in that: The concentration of the gluconolactone aqueous solution in S5 is 1.5%.

6. A method for separating nattoflavonoids as claimed in claim 1, characterized in that: The pretreatment of the macroporous adsorption resin in S8 includes the following steps: first, pre-washing the resin with deionized water, then rinsing the resin with a large amount of deionized water until the conductivity or other indicators of the washing liquid are stable, then using a low-temperature vacuum drying method to remove the deionized water in the resin, and then mixing the resin with an organic solvent mixed with water, and balancing at room temperature for 12 hours.

7. A method for separating nattoflavonoids according to any one of claims 1 to 6, further comprising an extraction device for separating nattoflavonoids, characterized in that: include: Support frame (1); A rotating shaft (2), the supporting frame (1) is internally provided with the rotating shaft (2) for relative rotation, a heating extraction tank (3) is fixedly installed between the two rotating shafts (2), and the inner surface of the heating extraction tank (3) is evenly provided with a plurality of convex points (5); A feed assembly (6) is arranged on the outer surface of the heating and extraction tank (3), and is used to introduce natto and gluconolactone aqueous solution into the heating and extraction tank (3). The feed assembly (6) comprises a feed pipe (61) fixedly connected to the outer surface of the heating and extraction tank (3), and a liquid inlet pipe (63) is fixedly connected to the outer surface of the heating and extraction tank (3). A limit plate (62) is fixedly installed on the outer surface of the liquid inlet pipe (63). The feed pipe (61) and the liquid inlet pipe (63) are installed in a relatively staggered manner. A connecting plate (64) is fixedly installed on the outer surface of the liquid inlet pipe (63). The feed assembly (6) also comprises a flexible tube (67). A mounting plate (65) is fixedly installed at the output end of the flexible tube (67). The connecting plate (64) and the mounting plate (65) are connected via a plurality of mounting bolts (66). A conveying member (68) is fixedly connected to the input end of the flexible tube (67); A sealing assembly (7) is installed inside the feed pipe (61) and the liquid feed pipe (63), and the sealing assembly (7) is used to seal the feed pipe (61) and the liquid feed pipe (63).

8. The extraction device for separating nattoflavonoids according to claim 7, characterized in that: The outer surface of the heating extraction tank (3) is provided with a heat-insulating layer (4).

9. The extraction device for separating nattoflavonoids according to claim 7, characterized in that: A control component (8) is fixedly mounted on one side of the support frame (1), and an output end of the control component (8) is fixedly connected to one end of the rotating shaft (2).

10. The extraction device for separating nattoflavonoids according to claim 7, characterized in that: The sealing assembly (7) comprises a sealing plug (73) inserted into the inside of the feed pipe (61), a sealing disk (71) is fixedly mounted on the upper end of the sealing plug (73), and the sealing disk (71) and the limiting disk (62) are assembled via a plurality of limiting bolts (72).

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