Method for simultaneous preparation of gallic acid and quinic acid by using tara flour enzyme method

Abstract

The application provides a method for simultaneously preparing gallic acid and quinic acid by using tara powder enzymatic method, wherein a seed liquid of Aspergillus niger is fermented, an inducing substrate tara powder or tara tannic acid is added for culture, a tara tannin enzyme crude enzyme liquid is prepared, the crude enzyme liquid catalyzes tara powder for enzymolysis reaction, the liquid after reaction is subjected to ultrafiltration, the permeate is subjected to 2-stage nanofiltration treatment, the concentrated liquid of the 2-stage nanofiltration is added with an ionic liquid for extraction, upper liquid and lower liquid are obtained, the upper liquid contains gallic acid, and the lower liquid contains quinic acid; the upper liquid and the lower liquid are respectively neutralized by alkali for recycling of the ionic liquid; the upper liquid and the lower liquid after removal of the ionic liquid are respectively subjected to cooling crystallization, alcohol is added after acidification for recrystallization, and gallic acid and quinic acid are obtained. The application does not need operations such as activated carbon decolorization and ion exchange adsorption, the total recovery rate of quinic acid reaches more than 81%, and the total recovery rate of gallic acid reaches more than 85%.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of fine chemical industry and enzyme engineering, and particularly relates to a method for simultaneously preparing gallic acid and quinic acid by using tara powder enzyme method. BACKGROUND

[0002] Tara belongs to the genus of the family of caesalpiniaceae and is mainly distributed in Peru, Ecuador, Colombia and other countries in the northwest of South America. China also has a certain scale of planting. The plant is rich in tara tannin in its fruit pod, which has similar properties to Chinese gallnut tannin, and is often used as another raw material for preparing gallic acid. However, about 15-20% of quinic acid in it is not recycled as a resource.

[0003] As for the extraction method of gallic acid, there are chemical method and enzyme method. The chemical method adopts alkali method, which is reported in the literature (Chen H, Zhang Z, Wang Y, Bi L, Wu Z, Wu D. Process research and application of tara powder direct alkaline hydrolysis for preparation of gallic acid [J]. Forest Chemistry and Industry, 1995(01): 1-8.). About 9 tons of alkali are needed for the production of 1 ton, the wastewater discharge is large, and the total yield is about 70%. The quinic acid molecules are destroyed and cannot be recycled. In 1994, Guizhou Provincial Chemical Research Institute reported the enzyme preparation process for the first time. The patent CN1083532A reports the right protection in the fermentation of enzyme and simple hydrolysis process, and does not report the related yield and separation and purification method. Yang Qiuming team of Jimei University reported the process optimization of tara tannin enzymolysis for producing gallic acid (Chen P, Liu C, Wang S, Yang Q, Zhang Y, Xiao A. Process optimization of tara tannin enzymolysis for producing gallic acid [J]. Modern Food Science and Technology, 2020, 36(12): 60-68.). The method uses Pichia pastoris to express genetically engineered tara tanninase, and then carries out enzyme hydrolysis process research to determine the optimal enzyme hydrolysis scheme as tara powder liquid ratio 1:40, reaction temperature 65℃, pH=4. Under this condition, the yield of gallic acid reaches 65.98%, the enzyme hydrolysis temperature is high, the yield is low, and it is not easy to industrialize. The high value-added quinic acid is not recycled.

[0004] Zhou Daobing et al. invented a method for recycling quinic acid by removing hydrochloric acid with vacuum evaporation method, removing gallic acid with ether extraction method, and removing pigment and sugar substances with activated carbon adsorption method and strong alkali anion exchange method. The specific operation is as follows: 2000ml tara tannin is used as raw material after acid hydrolysis for preparing gallic acid, under the action of chemical pure concentrated glacial acetic acid, the liquid phase ratio is methanol: water = 1:1, the yield or conversion rate can reach 77.95% (Zhou D, Chen H, Wang Y, et al. Process test of recycling quinic acid from tara tannin hydrolysis waste liquid [J]. Forest Chemical Industry Communication, 2001, 35(1): 17). This method requires a large amount of organic solvents, and the production safety is low, which is difficult to realize industrialization.

[0005] Liu Fan et al. invented a method for recovering quinic acid from tara gallotannic acid waste liquid. The invention first removes macromolecular organic impurities from the gallotannic acid waste liquid by ceramic membrane filtration, then removes mechanical impurities in the waste liquid by sedimentation, reduces the salt concentration by nanofiltration membrane filtration, and adsorbs by ion resin exchange. Quinic acid is recovered by elution with water or hydrochloric acid solution. The crude product is decolorized with activated carbon, and recrystallized with methanol or ethanol aqueous solution to obtain pure quinic acid with a purity of more than 95% and a yield of more than 80% (Zhangjiajie Jiurui Biotechnology Co., Ltd., A method for recovering quinic acid from tara gallotannic acid waste liquid [P]. China CN107673511A, 2018.02.09). This method uses step-by-step recovery of gallotannic acid and quinic acid, and the loss of activated carbon decolorization for both acids is large, the product purity is not high, and a large amount of organic solvents such as methanol and ethanol aqueous solution are used for recrystallization, reducing the safety of operation.

[0006] Since the above methods are separate separation of gallotannic acid and quinic acid, high-value quinic acid and gallotannic acid cannot be obtained at the same time, and it is difficult to compete with the extraction of gallotannic acid from gallnut tannin in terms of price, and it is difficult to realize industrialization. SUMMARY

[0007] The present application provides a method for simultaneous preparation of gallotannic acid and quinic acid by enzyme method using tara powder, which can simultaneously obtain high-purity gallotannic acid and quinic acid.

[0008] The technical scheme of the present application is a method for simultaneous preparation of gallotannic acid and quinic acid by enzyme method using tara powder, comprising the following steps:

[0009] S1, activating Aspergillus niger spores to prepare Aspergillus niger spore suspension, inoculating the suspension into seed culture medium to obtain seed liquid, then adding tara powder or tara tannic acid as an inducer to culture, and obtaining tara tannin enzyme crude enzyme liquid by plate and frame filtration;

[0010] S2, the crude enzyme liquid is placed in a biological catalytic reactor, tara powder is added, and enzyme hydrolysis reaction is carried out at a temperature of 30-50℃ for 30-50h. The reacted liquid is subjected to ultrafiltration, and the concentrated liquid obtained is used for recovering the catalytic enzyme, and the permeate is reserved;

[0011] S3, the permeate is subjected to secondary nanofiltration, the permeate of the first nanofiltration is subjected to secondary nanofiltration, the concentrated liquid of the secondary nanofiltration is subjected to extraction with ionic liquid, and upper liquid and lower liquid are obtained. The upper liquid and the lower liquid are neutralized with alkali respectively, the obtained upper liquid is ionic liquid and is reused; the two kinds of lower liquid are subjected to cooling crystallization, acidification and recrystallization with alcohol to obtain gallotannic acid and quinic acid.

[0012] Further, the spore quantity in the Aspergillus niger spore suspension is 1 x 10 5 ~ 5 x 10 5 The seed culture medium contains 0.3-0.9 g / L KH2PO4, 3-7 g / L yeast extract, 0.5-1.5 g / L NH4NO3, 1-5 g / L peptone, and 10-30 g / L glucose. The inoculation amount of the suspension is 0.5-2 wt% of the total medium, the pH is 4-6, the temperature is 25-30 °C, the rotation speed is 100-300 r / min, and the culture time is 2-3 days.

[0013] Further, the amount of the inducing substrate in S1 is 0.5-1.5 wt% of the total medium, the culture time is 2-6 days, the fermentation is terminated when the enzyme activity of the tannase reaches 12-20 U / mL, and the unreacted tara powder is obtained by plate and frame filtration, and the clear liquid is the crude enzyme solution.

[0014] Further, in the enzymatic hydrolysis reaction in S2, the enzyme amount is 3-10 U / g of the tara dry powder, the stirring rotation speed during the enzymatic hydrolysis is 100-300 r / min, the mass ratio of the tara powder to the crude enzyme solution is 1:30-1:80, and preferably 1:50, and the enzyme amount is preferably 5 U / g of the tara dry powder. The enzymatic hydrolysis temperature is preferably 37 °C, the stirring rotation speed is preferably 150 r / min, the enzymatic hydrolysis time is preferably 48 h, and the enzymatic hydrolysis conversion rate (calculated based on the gallic acid) can reach 88.5%.

[0015] Further, in S2, the ultrafiltration membrane is 10-30 kD, and the flow rate of the permeate is 200-500 L / h. The concentrated solution containing the tannase is used for recycling for at least 5 times or more.

[0016] Further, in S3, in the first nanofiltration, a nanofiltration membrane with a molecular weight cut-off of 500-800 D is used, the flow rate of the permeate is controlled to be 100-300 L / h, and the flow rate of the concentrated solution is controlled to be 80-120 L / h. In the second nanofiltration, a nanofiltration membrane with a molecular weight cut-off of 100-200 D is used, the flow rate of the permeate is 100-300 L / h, and the flow rate of the concentrated solution is controlled to be 50-100 L / h. Further, in the first nanofiltration in S3, a nanofiltration membrane with a molecular weight cut-off of 500-800 D is used, the flow rate of the permeate is controlled to be 100-300 L / h, and the flow rate of the concentrated solution is controlled to be 80-120 L / h. The first nanofiltration retains the macromolecular substances, and the concentrated solution mainly contains the oligomers of the gallic acid, which can enter the enzymatic hydrolysis reactor for further recycling. In the second nanofiltration, a nanofiltration membrane with a molecular weight cut-off of 100-200 D is used to remove the salts and small molecular substances, the flow rate of the permeate is 100-300 L / h, and the flow rate of the concentrated solution is controlled to be 50-100 L / h. The concentrated solution is rich in the gallic acid and the quinic acid.

[0017] Further, in S3, the ionic liquid is an imidazole-based ionic liquid, and the volume ratio of the ionic liquid to the concentrated solution of the second nanofiltration is 1:1-1:3.

[0018] Further, the ionic liquid mixture in S3 is prepared by mixing benzyl-3-methyl imidazole chloride or 1-benzyl-3-methyl imidazole hexafluorophosphate with 1-butyl-3-methyl imidazole bromide or 1-ethyl-3-methyl imidazole acetate or 1-(2-hydroxyethyl)-3-methyl imidazole bis(trifluoromethyl sulfonate) at a mass ratio of 1:5 to 1:10. It is found through experiments that the extractant containing 1-(2-hydroxyethyl)-3-methyl imidazole bis(trifluoromethyl sulfonate) has the highest extraction rate of gallic acid, which can reach more than 98%.

[0019] Further, the upper liquid and the lower liquid in S3 are respectively added with alkali to adjust pH>9; the alkali is a 10-30wt% sodium hydroxide or calcium hydroxide solution.

[0020] Further, the cooling crystallization temperature in S3 is 0-10℃, hydrochloric acid is used to adjust pH<2, and 3-15% of alcohol substances are added to the acidified liquid; the alcohol substances are methanol or ethanol or other water-soluble alcohols; and the concentration of the hydrochloric acid is 30-36.5%.

[0021] The present application has the following beneficial effects:

[0022] The present application uses the resource-rich Tara powder as a raw material, uses a specific Tara tannin enzyme for hydrolysis, then uses high-efficiency ultrafiltration and nanofiltration to realize the separation of macromolecules and small molecules, uses ionic liquid for selective extraction, the aromatic imidazole ionic liquid has good selectivity for gallic acid, the alkane imidazole ionic liquid has good selectivity for quinic acid, the use of ion exchange or macroporous adsorption is avoided, the yield of gallic acid and quinic acid is reduced, the production efficiency is low, the enzyme after the reaction is concentrated and recycled by using the ultrafiltration technology, so as to further reduce the cost, and the present process has the technical characteristics of easy-to-obtain raw materials, low cost and high efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a molecular structure formula of Tara tannin.

[0024] Figure 2 It is a molecular structure formula of quinic acid and gallic acid.

[0025] Figure 3 It is a process flow chart of the present application.

[0026] Figure 4 It is an HPLC detection spectrum of quinic acid and gallic acid.

[0027] Figure 5 It is a spectrophotometric detection diagram of gallic acid. DETAILED DESCRIPTION

[0028] Embodiments of the application will now be described in detail by way of reference only to the examples below, which examples are not to be construed as limiting the scope of the application, as defined by the appended claims.

[0029] The present application provides a method for simultaneously preparing gallic acid and quinic acid by using tara powder, a tara tannin enzyme capable of hydrolyzing tara powder is prepared by fermentation, and then enzyme hydrolysis, plate and frame separation, ultrafiltration, nanofiltration, cooling crystallization and recrystallization are performed to simultaneously obtain high-purity gallic acid and quinic acid. The molecular structures of tara tannin, quinic acid and gallic acid in tara powder are as follows Figure 1 and Figure 2 . The process flow chart is shown in Figure 3 .

[0030] In the present application, the detection methods of quinic acid and gallic acid are involved, and the HPLC detection conditions of gallic acid and quinic acid are established through literature review and condition optimization, which are as follows: column type: HPX-87H, 300mm x 7.8mm; mobile phase: A 5mmol / L H2SO4; injection volume: 20μL; wavelength: 210nm; column temperature: 45℃; flow rate: 0.6mL / min; peak time: quinic acid 9.61min (the separation degree of pure sample can reach 2.02), gallic acid 13.6min (see Appendix Figure 4 ).

[0031] The rapid spectrophotometric detection method of gallic acid is as follows: a small amount of reaction solution is diluted in a beaker. 0.5mL of the diluted solution is taken into three centrifuge tubes, 0.3mL of methanol is added, and the mixture is shaken and mixed, and then placed in a 30℃ water bath for 5min, and then 0.2mL of KOH solution is added, and the mixture is shaken and mixed, and then placed in a 30℃ water bath for 5min, and then 4mL of distilled water is added, and the mixture is shaken and mixed, and then placed in a 30℃ water bath for 5min, and then the absorbance value at 520nm is detected by a spectrophotometer. Three groups of parallel experiments are determined, and the arithmetic mean value is taken, and the standard error is calculated, and the result is expressed as arithmetic mean value ± standard error.

[0032] Gallic acid yield (%) = M1 / M2 x 100%

[0033] In the formula, M1 = the amount of gallic acid generated in the enzyme hydrolysate; M2 = the mass of gallic acid contained in the tara powder.

[0034] The present application also establishes a method for determining the enzyme activity of tannase, specifically adopting the pyrogallol method, taking propyl gallate (PG) as the reaction substrate, and the gallate acid produced by the decomposition of tannase can form a red complex with pyrogallol under alkaline conditions, which has a maximum absorption at 520 nm. Accordingly, the amount of generated gallate acid can be calculated by measuring the change in A520 (the standard curve of gallate acid is shown in Figure 5 ), so as to calculate the enzyme activity. (Definition of enzyme activity unit: the amount of enzyme required to degrade 1 μmol of propyl gallate (P) solution to release gallate acid per minute under the conditions of 30°C and pH 5.0 is defined as one enzyme activity unit (U)).

[0035] Aspergillus niger can be directly purchased on the market, such as CGMCC3.1454, CGMCC3.13901 or CGMCC3.15297, or naturally enriched Aspergillus niger. In the following examples, CGMCC3.1454 is selected. First, the spores of Aspergillus niger are activated to prepare an Aspergillus niger spore suspension, and the suspension is inoculated into a seed culture medium to obtain a seed liquid. The seed culture medium is configured according to 0.5 g / L of KH2PO4, 6 g / L of Angel yeast powder, 1 g / L of NH4NO3, 3 g / L of proteose peptone, and 20 g / L of glucose; the inoculation amount of the spore suspension is 1.5 wt% of the total medium, the pH is 4-6, the temperature is 28°C, the rotation speed is 200 r / min, and the culture time is 3 days.

[0036] Example 1

[0037] In a 50L fermenter, 1% (mass ratio) of Aspergillus niger seed liquid is inoculated, the pH is controlled at 5, the temperature is 28°C, the stirring speed is 200 r / min, after 2 days of culture, the bacterial amount reaches 10 g / L, 1 g / L of tara powder is added as an induction substrate, and then the culture is stirred for another 3.5 days. The enzyme activity of tannase can reach a maximum of 15 U / mL, the fermentation is terminated, centrifuged for 10 min, the unreacted tara powder is recovered, the clear liquid is collected by plate and frame filtration, and finally the enzyme activity reaches 18 U / mL; 1 kg of tara powder (water content <0.2%) is added and stirred uniformly, then 600 mL of tannase is added, the enzymatic reaction temperature is controlled at 37°C, the stirring speed is 150 r / min, and the enzymatic reaction time is 40 h. The enzymatic conversion rate (calculated based on the amount of gallic acid) can reach 88.4%.

[0038] The reaction solution after enzymatic hydrolysis is centrifuged to separate the unreacted Tara powder, which can be reused for enzymatic hydrolysis again. Then, 25 kD membrane material is selected for ultrafiltration, and the flow rate of the permeate is controlled at 280 L / h. The concentrated solution containing Tara tanninase is obtained and used for recycling. The permeate is subjected to primary nanofiltration using a 650 D nanofiltration membrane to retain substances with a molecular weight greater than 650, which are mostly oligomers containing gallic acid, and the flow rate of the permeate is controlled at 250 L / h. The permeate is subjected to secondary nanofiltration using a 110 D nanofiltration membrane to remove salts and small molecules with a molecular weight less than 110, and the flow rate of the permeate is 180 L / h, and the flow rate of the concentrated solution is controlled at 70 L / h. 8 L of concentrated solution rich in gallic acid and quinic acid is obtained.

[0039] In the concentrated solution, 10 L of mixed imidazole ionic liquid (wherein the mixed imidazole ionic liquid is benzyl-3-methylimidazole chloride and 1-(2-hydroxyethyl)-3-methylimidazole bis(trifluoromethylsulfonyl) mixed at a volume ratio of 1:8) is added in 5 times for extraction, and the total extraction rate is greater than 95%. The upper liquid and the lower liquid are collected respectively. 20 L of 15% sodium hydroxide is added for neutralization and layering, and the upper liquid and the lower liquid are collected to recover 9.8 L of ionic liquid. The raffinate rich in quinic acid and gallic acid obtained is cooled and crystallized at 5°C, and then acidified with 13 L of 36% hydrochloric acid, pH less than 2, slowly added with 1 L of anhydrous ethanol, and recrystallized at room temperature under stirring to obtain gallic acid with a purity greater than 99% and quinic acid with a purity greater than 99%, and the total yield of gallic acid reaches 85.4%, and the total yield of quinic acid reaches 81.7%.

[0040] Example 2

[0041] In a 400 L fermenter, 1.5% (mass ratio) of Aspergillus niger spore suspension is inoculated. The pH is controlled at 4.8, 26°C, 250 r / min, and the culture is incubated for 2 days. When the bacterial amount reaches 15 g / L, the inducing substrate Tara tannin 1.5 g / L is added, and the culture is incubated for another 4 days. The enzyme activity of Tara tanninase reaches the maximum, which can reach 18 U / mL. The fermentation is terminated, and the unreacted Tara powder is recovered by centrifugation for 10 min. The clear liquid is collected by plate and frame filtration, and the enzyme activity finally reaches 20 U / mL. Then, 12 kg of Tara powder (with water content <0.2%) is added and stirred uniformly. 7.5 L of Tara tanninase is added, and the enzymatic hydrolysis reaction temperature is controlled at 35°C. The stirring speed is 200 r / min, and the enzymatic hydrolysis time is 48 h. The enzymatic hydrolysis conversion rate (calculated based on gallic acid) can reach 88%.

[0042] The reaction solution is centrifuged to separate the unreacted tara powder, which can be reused for enzyme hydrolysis again, and then ultrafiltration is performed using a 30 kD membrane to control the flow rate of the permeate at 300 L / h to obtain a concentrated solution for recycling the tara tannin enzyme. The permeate enters the next section.

[0043] Primary nanofiltration is performed using a 600D nanofiltration membrane to retain substances with a molecular weight greater than 600, and the concentrated solution mainly contains oligomers containing gallic acid, which can enter the enzyme reactor for further recycling. The flow rate of the permeate is controlled at 240 L / h, and secondary nanofiltration is performed using a 100D nanofiltration membrane to remove salts and small molecules with a molecular weight less than 100. The flow rate of the permeate is 180 L / h, and the flow rate of the concentrated solution is controlled at 75 L / h to obtain 18 L of concentrated solution rich in gallic acid and quinic acid.

[0044] Imidazole-based ionic liquids are added to the concentrated solution, and the mixed imidazole-based ionic liquids are benzyl-3-methylimidazole chloride and 1-(2-hydroxyethyl)-3-methylimidazole bis(trifluoromethylsulfonyl) mixed at a volume ratio of 1:6. The amount of this composite extractant is 24 L, and the extraction rate is greater than 96%. The upper and lower liquids are collected separately. 20 L of 25% calcium hydroxide is added to neutralize the lower and upper liquids, and the upper liquid is collected after standing and separating. The ionic liquid is recovered, and the two groups of raffinate obtained are rich in gallic acid and quinic acid, respectively. Cooling crystallization is performed at 3°C, and then 30 L of 30% hydrochloric acid is added to acidify the solution to a pH less than 2. 3.6 L of methanol is added for recrystallization to obtain gallic acid and quinic acid with a purity greater than 99%. The total yield of gallic acid is greater than 88.2%, and the total yield of quinic acid is 82.1%.

[0045] Example 3

[0046] In a 5000 L fermenter, 1.8% (mass ratio) of Aspergillus niger seed slurry is inoculated, the pH is controlled at 5.5, the temperature is controlled at 26°C, and the stirring speed is controlled at 250 r / min. After 2.5 days of cultivation, the bacterial amount reaches 13 g / L, and 1 g / L of tara powder is added as an inducer. After stirring for another 4 days, the enzyme activity of tara tannin enzyme reaches a maximum of 17 U / mL, and the fermentation is terminated. After centrifugation for 10 min, the unreacted tara powder is recovered, and the clear liquid is collected by plate and frame filtration. The enzyme activity reaches 18 U / mL. After stirring 50 kg of tara powder evenly, 20 L of tara tannin enzyme solution is added. The enzyme hydrolysis temperature is controlled at 35°C, the stirring speed is 250 r / min, and the enzyme hydrolysis time is 40 h. The enzyme hydrolysis conversion rate (based on gallic acid) can reach 88.1%.

[0047] The reaction solution is centrifuged to separate the unreacted Tara powder, which can be reused for enzymatic hydrolysis again, and then ultrafiltration is performed using a 25kD membrane to obtain a concentrated solution containing tanninase for recycling. The flow rate of the permeate is controlled at 350L / h, and the permeate is subjected to primary nanofiltration using a 700D nanofiltration membrane to retain substances with a molecular weight greater than 700. The concentrated solution mainly contains oligomers of gallic acid, which can enter the enzymatic reactor for further recovery and utilization, and the flow rate of the permeate is controlled at 250L / h. The permeate is subjected to secondary nanofiltration using a 100D nanofiltration membrane to remove salts and small molecules with a molecular weight less than 100, and the flow rate of the permeate is 280L / h, and the flow rate of the concentrated solution is controlled at 90L / h. A 100L concentrated solution rich in gallic acid and quinic acid is obtained.

[0048] Imidazole ionic liquids are added to the concentrated solution, and the mixed imidazole ionic liquids are benzyl-3-methylimidazole chloride and 1-(2-hydroxyethyl)-3-methylimidazole bis(trifluoromethylsulfonyl) mixed at a volume ratio of 1:8. Extraction is performed with an extractant dosage of 250L, and the extraction rate reaches 97%. 110L of 15% sodium hydroxide is added to neutralize the lower liquid and the upper liquid, respectively. After standing and separating, the upper liquid is collected, and the ionic liquid is recovered. The lower liquid is cooled and crystallized at 8°C, and then acidified with 120L of 20% hydrochloric acid to a pH of less than 2. 10L of anhydrous ethanol is added for recrystallization to obtain gallic acid and quinic acid with a purity of greater than 99%. The total yield of gallic acid reaches more than 87.3%, and the total yield of quinic acid reaches 82.5%.

[0049] The above examples only express the preferred embodiments of the present application, which are described in more detail and in detail, but cannot be construed as limiting the scope of the present application. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, several modifications, improvements and substitutions can be made, which are within the scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A method for the simultaneous production of gallic acid and quinic acid by enzymatic process using tara powder, characterized by, The method comprises the following steps: S1, activating the spores of Aspergillus niger to prepare a spore suspension, inoculating the suspension into a seed culture medium to obtain a seed liquid, and then adding an induction substrate of tara powder or tara tannin acid for culture, and obtaining a crude enzyme liquid of tara tannin enzyme through plate and frame filtration; the amount of the induction substrate is 0.5-1.5 wt% of the total culture medium, the culture is performed for 2-6 days, the fermentation is terminated when the enzyme activity of the tara tannin enzyme reaches 12-20 U / mL, and the plate and frame filtration is performed to obtain unreacted tara powder, and the clear liquid is the crude enzyme liquid; S2, the crude enzyme liquid is placed in a biological catalytic reactor, tara powder is added, and enzymatic reaction is performed, the reaction temperature is 30-50 DEG C, the enzymatic reaction time is 30-50 h, the liquid after the reaction is subjected to ultrafiltration, and the concentrated liquid obtained is used for recycling the catalytic enzyme, and the permeate liquid is reserved; S3, the permeate liquid is subjected to secondary nanofiltration, the permeate liquid of the primary nanofiltration is subjected to secondary nanofiltration, the concentrated liquid of the secondary nanofiltration is added with an ionic liquid for extraction, upper liquid and lower liquid are obtained, the upper liquid and the lower liquid are neutralized with alkali respectively, the upper liquid obtained is an ionic liquid and is recycled; the two kinds of lower liquid are subjected to cooling crystallization, acidification, and recrystallization with an alcohol substance to obtain gallic acid and quinic acid; The ionic liquid is an imidazole ionic liquid, the volume ratio of the ionic liquid to the concentrated liquid of the secondary nanofiltration is 1:1-1:3; the ionic liquid is a mixture, and the benzyl-3-methyl imidazole chloride salt or 1-benzyl-3-methyl imidazole hexafluorophosphate is mixed with 1-butyl-3-methyl imidazole bromide or 1-ethyl-3-methyl imidazole acetate or 1-(2-hydroxyethyl)-3-methyl imidazole bis(trifluoromethylsulfonyl) according to a mass ratio of 1:5-1:10 to prepare the ionic liquid.

2. The method of claim 1, wherein: The spore quantity in the spore suspension of Aspergillus niger is 1 x 10 5 5 x 10 5 The seed culture medium contains 0.3-0.9 g / L KH2PO4, 3-7 g / L yeast extract powder, 0.5-1.5 g / L NH4NO3, 1-5 g / L peptone and 10-30 g / L glucose; the inoculation quantity of the suspension is 0.5-2 wt% of the total culture medium, the pH is 4-6, the temperature is 25-30℃, the rotating speed is 100-300 r / min, and the culture time is 2-3 days.

3. The method of claim 1, wherein: In the enzymatic reaction of S2, the enzyme amount is 3-10 U / g of tara dry powder, and the stirring speed during the enzymatic reaction is 100-300 r / min.

4. The method of claim 3, wherein: In S2, the ultrafiltration membrane is 10-30 kD, the flow rate of the permeate liquid is 200-500 L / h, and the concentrated liquid contains tara tannin enzyme and is used for recycling for at least 5 times.

5. The method of claim 1, wherein: In S3, the nanofiltration membrane used in the primary nanofiltration is 500-800 D, the flow rate of the permeate liquid is controlled to be 100-300 L / h, and the flow rate of the concentrated liquid is controlled to be 80-120 L / h; the nanofiltration membrane used in the secondary nanofiltration is 100-200 D, the flow rate of the permeate liquid is 100-300 L / h, and the flow rate of the concentrated liquid is controlled to be 50-100 L / h.

6. The method of claim 1, wherein: In S3, the upper liquid and the lower liquid are respectively added with alkali to adjust the pH to be greater than 9; the alkali is a 10-30 wt% sodium hydroxide or calcium hydroxide solution.

7. The method of claim 1, wherein: In S3, the cooling crystallization temperature is 0-10 DEG C, the pH is adjusted to be less than 2 by using hydrochloric acid, and an alcohol substance is added in an amount of 3-15% of the acidified liquid; the alcohol substance is methanol or ethanol or other water-soluble alcohol.

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