CN116354918A - Method for efficiently producing dihydroquercetin - Google Patents

Abstract

The invention provides a method for efficiently producing dihydroquercetin, and relates to the technical field of plant component extraction. The method comprises the following steps: (1) glycosylation compound enzyme enzymatic hydrolysis: crushing larch core material, adding ethanol and glycosylation compound enzyme to carry out enzymolysis reaction; (2) using negative pressure ultrasonic extraction, suction filtration, Combine the filtrates and rotate to concentrate; (3) add hydrochloric acid-petroleum ether solution and entrainer, heat and hydrolyze in-situ extraction; after the reaction, cool and stand to separate the liquid, spin the organic phase to obtain the extract; (4) macroporous resin ‑Continuous separation; (5) Recrystallization to obtain the product: dissolve the crude product in ethanol, heat to reflux with stirring, cool down, crystallize, filter at low temperature, and dry in vacuum to obtain the finished product of dihydroquercetin. The production process of the invention is simple and convenient, can be produced in a large scale, has high extraction rate and high product purity.

Description

A method for efficiently producing dihydroquercetin

technical field

The invention relates to the technical field of plant component extraction, in particular to a method for efficiently extracting and purifying dihydroquercetin from larch core material.

Background technique

Dihydroquercetin (DHO, taxifolin) is a dihydroflavonol compound, which was first isolated by the Japanese scholar Fukui from the leaves of the coniferous plant Chamaecyparis obtuse (Sieb. et Zucc.) Endl., as a glucoside aglycone. Then he studied the distribution of its 3-O-glucoside in coniferous plants and the hydrolysis of glycoside bonds in the presence of bacteria. After that, some scholars have isolated dihydroquercetin and its derivatives from various plants, which exist in two forms of aglycone or glycoside in plants, such as rose thorns and so on. In recent years, it has also been isolated from oranges, grapes and grapefruit.

The molecular formula of dihydroquercetin [2-(3,4-dihydroxyphenyl)-2,3-dihydro-3,5,7-trihydroxy-4H-benzopyran-4-one] is C ₁₅ H ₁₂ O ₇ , and the structural formula is as follows As shown, the molecular mass is 304.25. The pure product is a colorless needle-like crystal with a melting point of 240°C. It is easily soluble in ethanol, acetic acid, and boiling water, slightly soluble in cold water, and insoluble in benzene.

Dihydroquercetin has many important biological activities, and can inhibit and activate various enzymes, thereby producing different physiological effects. Because it contains more phenolic hydroxyl groups, it has anti-oxidation and anti-radiation effects. In addition, it also has antiviral and antitumor activities. The antioxidant properties and biological activity of dihydroquercetin make it a new food additive. The antioxidant properties of dihydroquercetin are comparable to synthetic or natural antioxidants, or superior to many existing antioxidants on the market, and it is non-toxic to the fetus, non-teratogenic, allergic and mutagenic. Dihydroquercetin can also be used as a stabilizer for industrial oil and generator oil, a raw material for hydrocarbons and rockets. The researchers also found that dihydroquercetin can inhibit the proliferation of common lymphocytes to varying degrees, and can inhibit the generation of antibodies against hepatitis A virus (HAV) infection caused by adding infected cells.

With the aging of society and the improvement of living standards, the incidence and mortality of cardiovascular and cerebrovascular diseases are increasing day by day. Studies in recent years have shown that dihydroquercetin can be used for oxidative stress diseases (cardiovascular disease, lung disease, etc.). In addition, dihydroquercetin can also be used as a food antioxidant, which can be added to vegetable oil, animal oil, dry milk powder, and fat-containing pastries to extend the validity period. Therefore, the extraction and purification of dihydroquercetin has attracted more and more attention.

At present, dihydroquercetin is only extracted from larch wood powder by hot water, from Rosa thorns by reflux with acetone and ethanol, and by ethanol from astragalus leaves, and there are few studies on its industrial value. In terms of purification of dihydroquercetin, methods such as traditional liquid-liquid extraction technology, open column chromatography, polyamide adsorption and refrigerator freezing and crystallization are mainly used. The above method has the disadvantages of long product production cycle, low purity, difficult utilization of waste residue and high cost.

In addition, the existing production process mainly uses larch as a raw material and is extracted by hot water reflux, which has the following defects: long extraction time, difficult water recovery, high energy consumption, and part of the distillate will be consumed during the process of extraction and solvent recovery. Hydrogen quercetin is degraded, resulting in low product yield; some water-soluble impurities are difficult to remove, resulting in low purity of dihydroquercetin.

Such as Jin Jianzhong et al. (Research on the extraction process of dihydroquercetin in larch [J]. Forest Product Chemical Communication, 2005, 39 (4): 12-15) use larch as raw material, extract with 80 ℃ boiling water, and further After the extract is precipitated, it is extracted and recrystallized with an organic solvent, and the final extraction rate reaches 0.29%; Han Junfeng et al. : 11385-11387) improved the traditional hydrothermal extraction method, and used microwave-assisted pretreatment to extract DHQ in larch, with an average extraction rate of 0.981%.

In view of this, using modern chemical separation technology to improve the traditional dihydroquercetin extraction process to obtain high-yield and high-purity dihydroquercetin products to meet the strict requirements of modern food and pharmaceutical production has become a top priority .

Contents of the invention

Aiming at the above-mentioned problems in the prior art, the present invention provides a method for efficiently producing dihydroquercetin. The production process of the invention is simple and convenient, can be produced in a large scale, has high extraction rate and high product purity.

Technical scheme of the present invention is as follows:

A method for efficiently producing dihydroquercetin, said method comprising the following steps:

(1) Glycosylation compound enzyme enzymatic hydrolysis: the larch core material is pulverized into powder with a pulverizer, and ethanol is added, the ratio of solid to liquid is 1:10-1:20, and then 0.5-1.5wt% glycosylation compound enzyme is added , under the conditions of 30-50°C, pH=5-8, enzymolysis reaction for 3-5h;

(2) Negative pressure ultrasonic extraction: After the enzymolysis is completed, use negative pressure ultrasonic extraction, suction filtration, extract 2-4 times, combine the filtrate, and rotate to concentrate to 1/5-1/2 volume;

(3) Hydrolysis in-situ extraction: add hydrochloric acid-petroleum ether solution 2-4 times the volume of the concentrated solution, and 0.1-0.5 times the volume of entrainer, heat at 75-85°C for hydrolysis and in-situ extraction for 2-3 hours; the reaction is complete Afterwards, cooling and standing for liquid separation, spin-drying the organic phase to obtain the extract;

(4) Macroporous resin - continuous separation: Dissolve the extract with 2-4 times the volume of ethanol solution, filter and load the sample to the continuous separation equipment equipped with a macroporous resin column, and use 4-6BV/h Elute with 80% ethanol at a flow rate, collect the eluent, and spin dry the solvent to obtain the crude product;

(5) Recrystallization to obtain the product: dissolve the crude product in ethanol according to the ratio of material to liquid 1:10-1:20, heat to 85-95°C, stir and reflux for 0.5-1h, naturally cool to 20-25°C, and then put it in the cold Cool down in the well, crystallize, filter at low temperature, and dry in vacuum to obtain the finished product of dihydroquercetin.

Preferably, the mass concentration of ethanol in step (1) is 55-65%. The composition of the glycosylation compound enzyme in the step (1) is: 80-90% of cellulase and 10-20% of pectinase.

Preferably, the pressure of negative pressure ultrasonic extraction in step (2) is -0.01～-0.1Mpa, the ultrasonic frequency is 40-60kHz, the temperature is 30-60°C, and the extraction time is 15-45min.

Preferably, the concentration of the hydrochloric acid-petroleum ether solution in step (3) is 0.8-1.2mol/L. The entrainer in step (3) is methanol, ethanol or n-butanol.

Preferably, the mass concentration of the ethanol solution in step (4) is 15-25%. The macroporous resin column in step (4) is D101, AB-8 or LX158.

Preferably, the mass concentration of the ethanol solution in step (5) is 45-55%.

Preferably, in step (6), the temperature is lowered to 2-6° C., and the crystallization is performed for 7-9 hours.

The beneficial technical effects of the present invention are:

1. The present invention adopts glycosylation compound enzyme for enzymolysis, which has stronger enzymatic activity than ordinary enzymes, is easier to combine with reactants, effectively destroys the cell walls of plants, and makes active ingredients easy to dissolve.

2. The present invention uses vacuum negative pressure combined with ultrasound for extraction, and the cavitation effect of negative pressure combined with ultrasound makes the temperature difference and pressure difference caused in this process an effective means to strengthen the mass transfer and heat transfer process, further destroying the cells The structure accelerates the precipitation of the extracted substance.

3. The present invention utilizes hydrochloric acid-petroleum ether solution for hydrolysis in-situ extraction, since the product obtained by hydrolysis in the water phase can be directly extracted by the organic phase, so that the balance of the hydrolysis reaction continues to the right, which increases the yield and reduces the number of extractions and solvent consumption, saving reaction time. At the same time, an entrainer is added to further strengthen the mass transfer between phases and improve the overall efficiency.

4. The present invention utilizes the macroporous resin-continuous separation technology to automatically separate and purify, reduce manual operations, and improve production efficiency.

5. In terms of the synergistic effect of each technical step, the present invention uses glycosylation compound enzyme enzymolysis combined with negative pressure ultrasonic extraction, which improves the utilization rate of raw materials and improves the extraction rate; adopts glycosylation compound enzyme enzymolysis combined with negative pressure ultrasonic extraction The extraction and continuous separation technology reduces the reaction time and operation time, and improves the production efficiency; the use of entrainer for hydrolysis in-situ extraction greatly reduces the amount of extraction solvent used, saves costs, and eases the pressure on environmental protection.

6. The present invention is used to prepare dihydroquercetin, the extraction rate is 1.60%, and the purity is 98.23%. The extraction rate is significantly improved compared with the 0.29-0.981% in the existing literature, and the purity is generally recorded in the existing literature. 95% of the results have also made great progress.

Detailed ways

Below in conjunction with embodiment, the present invention is described in detail. Apparently, the described embodiments are only some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The glycosylation compound enzyme used in the following examples was purchased from Zhejiang University of Technology, and its composition is 80-90% of cellulase and 10-20% of pectinase.

The macroporous resin-continuous separation equipment used in the following examples adopts a new type of ion exchange system developed by AST Corporation of the United States: ISEP rotating disk moving bed system. It consists of two parts: a multi-slot distribution valve and a mechanical turntable. After the fluid passes through the distribution valve, it enters different resin columns to form reverse contact flow. ISEP divides the traditional fixed bed into several small exchange columns, and the rotating disc drives the resin column to rotate, thus transforming the traditional fixed bed technology into continuous operation and separation. Efficiency is greatly improved.

The advantages of the ISEP rotary moving bed system include: significantly reducing the amount of resin; reducing water and chemical consumption; reducing sewage discharge, improving product yield, purity and concentration; compact equipment, small footprint, Fully automatic operation ensures the continuous and stable operation of production and obtains products with high purity and concentration.

Example 1:

The present embodiment provides a method for efficiently producing dihydroquercetin, and the specific steps are as follows:

1, take a certain amount of larch core material and pulverize into powder with a pulverizer, add mass concentration and be 60% ethanol, the ratio of solid to liquid is 1:10, then add 1.5wt% glycosylation complex enzyme (cellulase 90 %, pectinase 10%), the enzymolysis reaction was carried out at 50°C and pH=7 for 3 hours.

2. After the enzymatic hydrolysis, extract with negative pressure (-0.1MPa) ultrasonic (60kHz) at 60°C for 30 minutes, filter with suction, extract twice in total, combine the filtrates, and spin to concentrate to 1/5 volume.

3. Add 1.0 mol/L hydrochloric acid-petroleum ether solution 4 times the volume of the concentrated solution and 0.2 times the volume of the entrainer n-butanol, heat at 85°C for 2.5 hours of in-situ hydrolysis extraction. After the reaction, cool and stand for liquid separation, and spin dry the organic phase to obtain the extract.

4. Dissolve the extract with 20% ethanol solution of 2 times mass concentration, filter and pass through the column with continuous separation equipment equipped with macroporous resin column LX158, and elute with 80% ethanol at a flow rate of 4BV/h for 1h. The eluate was collected, and the solvent was spin-dried to obtain the crude product.

5. Dissolve in ethanol with a mass concentration of 50% according to the ratio of material to liquid 1:10, heat to 95°C, stir and reflux for 0.5h, cool naturally to 25°C, then put it in a cold well and cool down to 4°C to crystallize for 8h, filter at low temperature , dried in vacuum to obtain the finished product.

After testing, the extraction rate of dihydroquercetin in this example is 1.60%, and the purity is 98.23%.

Comparative example 1:

The method described in Example 1 is adjusted without enzymatic hydrolysis, and the resin entrainer is replaced. The specific steps are as follows:

1. Weigh a certain amount of larch core material and pulverize it into powder with a pulverizer, add 60% ethanol, the ratio of solid to liquid is 1:10, do not carry out enzymatic hydrolysis, and extract directly at 60 negative ℃ pressure (-0.1MPa) ultrasonic (60kHz) After 30 minutes, filter with suction, extract twice in total, combine the filtrates, and spin concentrate to 1/5 volume.

2. Add 1.0 mol/L hydrochloric acid-petroleum ether solution of 4 times the volume of the concentrated solution and 0.2 times the volume of ethanol as an entrainer, and heat at 85°C for 2.5 hours of hydrolysis and in-situ extraction. After the reaction, cool and stand for liquid separation, and spin dry the organic phase to obtain the extract.

3. Dissolve the extract with 2 times 20% ethanol solution, filter and pass through the column with a continuous separation equipment equipped with a macroporous resin column LX158, the flow rate is 4BV/h, the eluent is 80% ethanol, and the elution is 1h. The eluate was collected, and the solvent was spin-dried to obtain the crude product.

4. Dissolve in 50% ethanol according to the material-to-liquid ratio of 1:10, heat to 95°C, stir and reflux for 0.5h, cool naturally to 25°C, then put it in a cold well and cool down to 4°C to crystallize for 8h, filter at low temperature, and vacuum dry. to get the finished product.

After testing, the extraction rate of dihydroquercetin in this comparative example is 0.83%, and the purity is 87.10%.

Comparative example 2:

The method described in Example 1 is adjusted, atmospheric pressure ultrasonic extraction, and the resin entrainer replaces the control group, the specific steps are as follows:

1. Take a certain amount of larch core material and pulverize it into powder with a pulverizer, add 60% ethanol, the ratio of solid to liquid is 1:10, then add 1.5wt% glycosylation compound enzyme (90% of cellulase, pectinase 10%), 50, ℃ pH=7, enzymolysis reaction 3h.

2. After the enzymatic hydrolysis, 60°C atmospheric pressure ultrasonic (60kHz) extraction for 30min, suction filtration, a total of 2 extractions, combined filtrates, rotary concentration to 1/5 volume.

3. Add 1.0 mol/L hydrochloric acid-petroleum ether solution of 4 times the volume of the concentrated solution and 0.2 times the volume of entrainer methanol, heat at 85 ° C for 2.5 hours of in-situ extraction by hydrolysis. After the reaction, cool and stand for liquid separation, and spin dry the organic phase to obtain the extract.

4. Dissolve the extract with 2 times 20% ethanol solution, filter and pass through the column with a continuous separation equipment equipped with a macroporous resin column LX158, the flow rate is 4BV/h, the eluent is 80% ethanol, and the eluent is eluted for 1h. The eluate was collected, and the solvent was spin-dried to obtain the crude product.

5. Dissolve in 50% ethanol according to the material-to-liquid ratio of 1:10, heat to 95°C, stir and reflux for 0.5h, cool naturally to 25°C, then put it in a cold well and cool down to 4°C to crystallize for 8h, filter at low temperature, and vacuum dry. to get the finished product.

After testing, the extraction rate of dihydroquercetin in this comparative example was 1.34%, and the purity was 92.11%.

Comparative example 3:

The method described in Example 1 is adjusted, and the control group is not ultrasonicated, and the specific steps are as follows:

1. Take a certain amount of larch core material and pulverize it into powder with a pulverizer, add 60% ethanol, the ratio of solid to liquid is 1:10, then add 1.5% glycosylation compound enzyme (90% cellulase, 10% pectinase %), 50, ℃pH=7, enzymolysis reaction 3h.

2. After the enzymatic hydrolysis, extract with negative pressure (-0.1MPa) ultrasonic (60kHz) at 60°C for 30 minutes, filter with suction, extract twice in total, combine the filtrates, and spin to concentrate to 1/5 volume.

3. Add 1.0 mol/L hydrochloric acid-petroleum ether solution 4 times the volume of the concentrated solution and 0.2 times the volume of the entrainer n-butanol, heat at 85°C for 2.5 hours of in-situ hydrolysis extraction. After the reaction, cool and stand for liquid separation, and spin dry the organic phase to obtain the extract.

4. Dissolve the extract with 2 times 20% ethanol solution, filter and pass through the column with a continuous separation equipment equipped with a macroporous resin column LX158, the flow rate is 4BV/h, the eluent is 80% ethanol, and the elution is 1h. The eluate was collected, and the solvent was spin-dried to obtain the crude product.

5. Dissolve in 50% ethanol according to the material-to-liquid ratio of 1:10, heat to 95°C, stir and reflux for 0.5h, cool naturally to 25°C, then put it in a cold well and cool down to 4°C to crystallize for 8h, filter at low temperature, and vacuum dry. to get the finished product.

After testing, the extraction rate of dihydroquercetin in this comparative example was 0.91%, and the purity was 89.21%.

Comparative example 5:

Adjust the method described in Example 1, different enzyme control groups, the specific steps are as follows:

1. Take a certain amount of larch core material and pulverize it into powder with a pulverizer, add 60% ethanol, the ratio of solid to liquid is 1:10, then add 1.5% glycosylation compound enzyme (cellulase 70%, hemicellulase 30%), 50, ℃ pH=7, enzymolysis reaction 3h.

2. After the enzymatic hydrolysis, extract with negative pressure (-0.01MPa) ultrasonic (30kHz) at 60°C for 30 minutes, filter with suction, extract twice in total, combine the filtrates, and spin to concentrate to 1/5 volume.

3. Add 1.0 mol/L hydrochloric acid-petroleum ether solution 4 times the volume of the concentrated solution and 0.5 times the volume of the entrainer n-butanol, heat at 85°C for 2.5 hours of in-situ hydrolysis extraction. After the reaction, cool and stand for liquid separation, and spin dry the organic phase to obtain the extract.

4. Dissolve the extract with 2 times 20% ethanol solution, filter and pass through the column with a continuous separation equipment equipped with a macroporous resin column LX158, the flow rate is 4BV/h, the eluent is 80% ethanol, and the elution is 1h. The eluate was collected, and the solvent was spin-dried to obtain the crude product.

5. Dissolve in 50% ethanol according to the material-to-liquid ratio of 1:10, heat to 95°C, stir and reflux for 0.5h, cool naturally to 25°C, then put it in a cold well and cool down to 4°C to crystallize for 8h, filter at low temperature, and vacuum dry. to get the finished product.

After testing, the extraction rate of dihydroquercetin in this comparative example was 1.32%, and the purity was 95.43%.

Comparative example 6:

Adjust the method described in Example 1, extract the control group after hydrolysis, and the specific steps are as follows:

1. Take a certain amount of larch core material and pulverize it into powder with a pulverizer, add 60% ethanol, the ratio of solid to liquid is 1:10, then add 1.5% glycosylation compound enzyme (90% cellulase, 10% pectinase %), 50, ℃pH=7, enzymolysis reaction 3h.

2. After enzymatic hydrolysis, extract with negative pressure (-0.01MPa) ultrasound (60kHz) at 60°C for 30 minutes, filter with suction, extract twice in total, combine the filtrates, and concentrate by rotation to 1/5 volume.

3. Add 1.0 mol/L hydrochloric acid solution of 4 times the volume of the concentrated solution, heat and hydrolyze at 85°C for 2.5 hours. After the reaction was cooled, it was extracted three times with 4 times the volume of the concentrated solution of petroleum ether and 0.2 times the volume of the entrainer n-butanol, the combined organic layers were spin-dried to obtain the extract.

4. Dissolve the extract with 2 times 20% ethanol solution, filter and pass through the column with a continuous separation equipment equipped with a macroporous resin column LX158, the flow rate is 4BV/h, the eluent is 80% ethanol, and the eluent is eluted for 1h. The eluate was collected, and the solvent was spin-dried to obtain the crude product.

5. Dissolve in 50% ethanol according to the material-to-liquid ratio of 1:10, heat to 95°C, stir and reflux for 0.5h, cool naturally to 25°C, then put it in a cold well and cool down to 4°C to crystallize for 8h, filter at low temperature, and vacuum dry. to get the finished product.

After testing, the extraction rate of dihydroquercetin in this comparative example was 1.27%, and the purity was 93.86%.

Example 2:

The present embodiment provides a method for efficiently producing dihydroquercetin, and the specific steps are as follows:

1, take a certain amount of larch core material and pulverize it into powder with a pulverizer, add mass concentration and be 60% ethanol, the ratio of solid to liquid is 1:15, then add 0.5wt% glycosylation complex enzyme (cellulase 80 %, pectinase 20%), the enzymolysis reaction was carried out at 30°C and pH=8 for 5 hours.

2. After the enzymatic hydrolysis, extract with negative pressure (-0.1MPa) ultrasonic (40kHz) at 50°C for 15 minutes, filter with suction, extract twice in total, combine the filtrates, and concentrate by rotation to 1/5 volume.

3. Add 1.0 mol/L hydrochloric acid-petroleum ether solution 4 times the volume of the concentrated solution and 0.2 times the volume of the entrainer n-butanol, heat at 85°C for 2.5 hours of in-situ hydrolysis extraction. After the reaction, cool and stand for liquid separation, and spin dry the organic phase to obtain the extract.

4. Dissolve the extract with 2 times the mass concentration of 20% ethanol solution, filter and pass through the column with continuous separation equipment equipped with macroporous resin column AB-8, the flow rate is 5BV/h, and the eluent is 80% ethanol , eluted for 1h. The eluate was collected, and the solvent was spin-dried to obtain the crude product.

5. Dissolve in ethanol with a mass concentration of 50% according to the ratio of material to liquid 1:15, heat to 95°C, stir and reflux for 0.5h, cool naturally to 25°C, then put it into a cold well and cool down to 5°C to crystallize for 9h, filter at low temperature , dried in vacuum to obtain the finished product.

After testing, the extraction rate of dihydroquercetin in this example is 1.52%, and the purity is 97.41%.

Example 3:

The present embodiment provides a method for efficiently producing dihydroquercetin, and the specific steps are as follows:

1. Take a certain amount of larch core material and pulverize it into powder with a pulverizer, add ethanol with a mass concentration of 60%, the ratio of solid to liquid is 1:20, and then add 1.0wt% glycosylation compound enzyme (cellulase 85 %, pectinase 15%), the enzymolysis reaction was carried out at 40°C and pH=6 for 4 hours.

2. After enzymatic hydrolysis, extract with negative pressure (-0.1MPa) ultrasound (50kHz) at 30°C for 45 minutes, filter with suction, extract twice in total, combine the filtrates, and spin to concentrate to 1/5 volume.

3. Add 1.0 mol/L hydrochloric acid-petroleum ether solution of 4 times the volume of the concentrated solution and 0.2 times the volume of the entrainer n-butanol, heat at 80°C for hydrolysis and in-situ extraction for 2 hours. After the reaction, cool and stand for liquid separation, and spin dry the organic phase to obtain the extract.

4. Dissolve the extract with 20% ethanol solution with 2 times the mass concentration, and pass through the column with a continuous separation equipment equipped with a macroporous resin column D101 after filtration. The flow rate is 6BV/h, and the eluent is 80% ethanol. Take off for 1h. The eluate was collected, and the solvent was spin-dried to obtain the crude product.

5. Dissolve in ethanol with a mass concentration of 50% according to the ratio of material to liquid 1:20, heat to 95°C, stir and reflux for 0.5h, cool naturally to 25°C, then put it in a cold well and cool down to 3°C to crystallize for 7h, filter at low temperature , dried in vacuum to obtain the finished product.

After testing, the extraction rate of dihydroquercetin in this example is 1.55%, and the purity is 97.75%.

Although the embodiment of the present invention has been disclosed as above, it is not limited to the use listed in the specification and implementation, it can be applied to various fields suitable for the present invention, for those familiar with the art, for this For those of ordinary skill in the art, without departing from the principle and spirit of the present invention, various changes, modifications, substitutions and variations can be made to these embodiments, so without departing from the general concept defined by the claims and the equivalent scope Below, the invention is not limited to the specific details.

Claims (10)

1. A method for efficiently producing dihydroquercetin, comprising the steps of:

(1) Enzymolysis of glycosylation complex enzyme: pulverizing larch core material into powder by a pulverizer, adding ethanol with a feed-liquid ratio of 1:10-1:20, adding 0.5-1.5wt% of glycosylation complex enzyme, and performing enzymolysis reaction for 3-5h under the conditions of 30-50 ℃ and pH=5-8;

(2) Negative pressure ultrasonic extraction: after enzymolysis, extracting by negative pressure ultrasonic extraction and suction filtration for 2-4 times, mixing filtrates, and concentrating to 1/5-1/2 volume;

(3) Hydrolysis in-situ extraction: adding 2-4 times of hydrochloric acid-petroleum ether solution and 0.1-0.5 times of entrainer into the concentrated solution, heating and hydrolyzing at 75-85 ℃ for in-situ extraction for 2-3h; after the reaction is finished, cooling, standing, separating liquid, and spin-drying an organic phase to obtain an extract;

(4) Macroporous resin-continuous ion exchange: dissolving the extract with 2-4 times of ethanol solution, filtering, loading to continuous ion exchange equipment equipped with macroporous resin column, passing through column, eluting with 80% ethanol with flow rate of 4-6BV/h, collecting eluate, and spin drying solvent to obtain crude product;

(5) Recrystallizing to obtain the product: dissolving the crude product in ethanol according to a feed liquid ratio of 1:10-1:20, heating to 85-95 ℃, stirring and refluxing for 0.5-1h, naturally cooling to 20-25 ℃, then placing into a cold well for cooling, crystallizing, filtering at low temperature, and vacuum drying to obtain the finished product of the dihydroquercetin.

2. The method for efficiently producing dihydroquercetin according to claim 1, wherein the mass concentration of the ethanol in the step (1) is 55-65%.

3. The method for efficiently producing dihydroquercetin according to claim 1, wherein the composition of the glycosylation complex enzyme in step (1) is as follows: 80-90% of cellulase and 10-20% of pectase.

4. The method for efficiently producing dihydroquercetin according to claim 1, wherein the pressure of the negative pressure ultrasonic extraction in the step (2) is-0.01 to-0.1 Mpa, the ultrasonic frequency is 40-60kHz, the temperature is 30-60, and the extraction time is 15-45min.

5. The method for producing dihydroquercetin efficiently according to claim 1, wherein the concentration of the hydrochloric acid-petroleum ether solution in the step (3) is 0.8-1.2mol/L.

6. The method for producing dihydroquercetin efficiently according to claim 1, wherein the entrainer in step (3) is methanol, ethanol or n-butanol.

7. The method for efficiently producing dihydroquercetin according to claim 1, wherein the mass concentration of the ethanol solution in the step (4) is 15-25%.

8. The method for efficiently producing dihydroquercetin according to claim 1, wherein the macroporous resin column in the step (4) is D101, AB-8 or LX158.

9. The method for efficiently producing dihydroquercetin according to claim 1, wherein the mass concentration of the ethanol solution in the step (5) is 45-55%.

10. The method for efficiently producing dihydroquercetin according to claim 1, wherein the temperature reduction range in the step (6) is 2-6 ℃ and the crystallization time is 7-9h.