阅读说明：本技术 一种富含egc的非酯型茶多酚的制备方法 (Preparation method of EGC-rich non-ester tea polyphenol ) 是由 任雪音 刘剑宏 曹后建 浦平南 于 2021-01-19 设计创作，主要内容包括：本发明涉及一种富含EGC的非酯型茶多酚的制备方法,将经粉碎破壁的茶叶利用茶叶自身含量的内源性水解酶,将酶解后的茶叶浸提,浸提液经过滤、浓缩后通过移动萃取-水洗进行精制纯化,纯化后产品经过浓缩、干燥,得到富含EGC的非酯型茶多酚产品,茶多酚含量为90-99.5%,EGC的含量大于80%,酯型儿茶素EGCG+ECG的含量在10%以下。本发明的富含EGC的非酯型茶多酚的制备方法不添加任何外源性水解酶,避免外源性水解酶对产品的污染,同时EGC含量高、生产工艺简化、产品收率高,有利于工业化生产。(The invention relates to a preparation method of non-ester tea polyphenol rich in EGC, which comprises the steps of extracting tea subjected to enzymolysis by utilizing endogenous hydrolase with the content of the tea by crushing and breaking the wall, filtering and concentrating the extract, refining and purifying the extract by mobile extraction-water washing, concentrating and drying the purified product to obtain a non-ester tea polyphenol product rich in EGC, wherein the content of the tea polyphenol is 90-99.5%, the content of the EGC is more than 80%, and the content of ester catechin EGCG and ECG is less than 10%. The preparation method of the non-ester tea polyphenol rich in EGC does not add any exogenous hydrolase, avoids the pollution of the exogenous hydrolase to the product, has high EGC content, simplified production process and high product yield, and is beneficial to industrial production.)

1. A preparation method of non-ester tea polyphenol rich in EGC is characterized by comprising the following steps: the method comprises the following steps:

(1) tea leaf pretreatment: the method comprises the following steps of (1) crushing and wall breaking the green tea leaves serving as raw materials to obtain tea leaf particles;

(2) endogenous enzyme enzymolysis: adding the pretreated tea particles into a dynamic extraction tank, adding deionized water, adding food-grade acid to adjust the pH to 2.0-6.5, and carrying out enzymolysis on ester type tea polyphenol in the tea by using hydrolase of the tea under the stirring condition;

(3) leaching: extracting the tea raw material subjected to enzymolysis twice by using deionized water, filtering after extraction is finished, and combining filtrates obtained in two times;

(4) and (3) filtering: cooling the filtrate, filtering again, and collecting the filtrate;

(5) concentration: concentrating the filtrate obtained in the step (4);

(6) moving extraction-water washing: extracting the concentrated solution in the step (5) by using ethyl acetate with the volume of 1-2 times, collecting an ethyl acetate phase, concentrating the ethyl acetate phase until the solid content is 2-10%, performing reverse phase extraction by using deionized water with the volume of 0.2-1 time, collecting a water washing phase, performing reverse phase extraction for 1-5 times by the same method, combining the water washing phases, extracting the water washing phase by using ethyl acetate with the volume of 1-2 times, and collecting the ethyl acetate phase;

(7) transferring and dissolving: concentrating the ethyl acetate phase finally collected in the step (6) to obtain an extract, and adding deionized water for dissolving to obtain a tea polyphenol water solution;

(8) concentration: vacuum concentrating the tea polyphenol water solution obtained in the step (7);

(9) and (3) drying: and (4) drying the concentrated solution obtained in the step (8) in a zero-spraying drying mode to obtain a non-ester tea polyphenol product rich in EGC.

2. The process for the preparation of EGC-enriched non-ester tea polyphenols according to claim 1, wherein: the 10-100 mesh screen residue of the pretreated tea particles in the step (1) is not more than 40%.

3. The process for the preparation of EGC-enriched non-ester tea polyphenols according to claim 1, wherein: in the step (2), the addition amount of the deionized water is 1-5 times of the volume of the pretreated tea, the food-grade acid is citric acid, the stirring speed is 50-300 r/min, the enzymolysis temperature is 30-50 ℃, and the enzymolysis time is 4-12 hours.

4. The process for the preparation of EGC-enriched non-ester tea polyphenols according to claim 1, wherein: in the step (3), the leaching temperature is 60-90 ℃, the single-time deionized water addition is 6-10 times of the weight of the tea raw material, and the single-time leaching time is 20-60 min.

5. The process for the preparation of EGC-enriched non-ester tea polyphenols according to claim 1, wherein: in the step (4), the cooling temperature is 30-50 ℃, and the filtering precision is 100-300 meshes.

6. The process for the preparation of EGC-enriched non-ester tea polyphenols according to claim 1, wherein: the concentration in the step (5) is specifically as follows: and (4) concentrating the filtrate in the step (4) to Brix 0.5-2.5.

7. The process for the preparation of EGC-enriched non-ester tea polyphenols according to claim 1, wherein: in the step (6), the extraction temperature of the ethyl acetate is 30-60 ℃, and the reverse phase extraction temperature of the deionized water is 30-60 ℃.

8. The process for the preparation of EGC-enriched non-ester tea polyphenols according to claim 1, wherein: the concentration in the step (8) is specifically as follows: and (4) concentrating the tea polyphenol water solution obtained in the step (7) in vacuum at a temperature of 52-72 ℃ under a vacuum degree of-0.080 MPa to Brix 20-50.

Technical Field

The invention belongs to the technical field of natural plant extract processing, and particularly relates to a preparation method of EGC-rich non-ester tea polyphenol.

Background

Tea polyphenol is a general name of catechins, flavonoids, phenolic acids and anthocyanidins in tea, has the main effects of resisting oxidation and obviously eliminating oxygen radicals, and can inhibit bacteria and sterilize, effectively reduce the absorption of cholesterol by large intestine, prevent and treat atherosclerosis, enhance the immunity of an organism, resist tumors and radiation, delay aging and the like. Because of the unique efficacy of tea polyphenol, it has been widely used in the fields of medicine, health products and food: has been used as the prevention and treatment medicine for cardiovascular, liver, kidney and intestinal tract diseases of human body in medicine; the product has been used as the main component of products for improving human immunity, reducing blood fat, reducing blood sugar, losing weight and the like on health products, and also used as the main component of sun cream, shampoo and disinfectant; the tea polyphenol is added into the grease food, so that oyster spoilage of the food can be prevented and the food can be kept fresh.

The tea polyphenols mainly comprise catechin, which is classified into ester type catechin and non-ester type catechin, and are generally classified into ester type tea polyphenols and non-ester type tea polyphenols according to the type of catechin in the tea polyphenols. The two types of tea polyphenol have certain difference in taste, irritation to gastric sensation and stability (water solubility), the ester type tea polyphenol has stronger bitterness and astringency in the irritation aspect to taste buds and stronger irritation to gastric mucosa of a human body, and meanwhile, the product has poorer stability and safety in water solubility in dissolution; but not ester type tea polyphenol, the taste, the stimulation to the stomach sensation and the stability (water solubility) are obviously superior to ester type catechin. Therefore, due to the advantages of the non-ester tea polyphenol, the application of the non-ester tea polyphenol in food, food additives and medical industries has wider application prospect. The non-ester tea polyphenol contains a plurality of non-ester catechin monomers, wherein the biological activity of EGC is relatively high.

The prior art for preparing EGC-rich non-ester tea polyphenol generally comprises the following steps: extracting tea polyphenol from tea leaves by using an extraction solvent (at least one of water, ethanol and ethyl acetate), filtering, concentrating and the like, adding exogenous hydrolase and the like for hydrolysis, inactivating enzyme at high temperature, filtering and removing to obtain a non-ester tea polyphenol solution, purifying the product by using a chromatographic separation method, and finally drying to obtain the non-ester tea polyphenol product.

In the process, exogenous hydrolase is added, so that the product is easily polluted, allergen is generated due to poor treatment, the product is prepared by a chromatography method, the process is relatively complex and is not beneficial to industrial production, the product loss is relatively high in the processing process, and the yield is relatively low.

Disclosure of Invention

The invention aims to provide a preparation method of non-ester tea polyphenol rich in EGC, which does not add any exogenous hydrolase, avoids the pollution of the exogenous hydrolase to products, has high EGC content, simplified production process and high product yield and is beneficial to industrial production.

The technical scheme adopted by the invention for solving the problems is as follows: a method for preparing non-ester tea polyphenol rich in EGC comprises the following steps:

(1) tea leaf pretreatment: the tea granules are prepared by adopting green tea leaves as raw materials and crushing and breaking the walls of the tea leaves.

(2) Endogenous enzyme enzymolysis: adding the pretreated tea particles into a dynamic extraction tank, adding deionized water, adding food-grade acid to adjust the pH to 2.0-6.5, and carrying out enzymolysis on ester type tea polyphenol in the tea by using hydrolase of the tea under the stirring condition.

(3) Leaching: and (3) extracting the tea raw material subjected to enzymolysis twice by using deionized water, filtering after extraction is finished, and combining the two filtrates.

(4) And (3) filtering: cooling the filtrate, filtering again, and collecting the filtrate.

(5) Concentration: and (4) concentrating the filtrate in the step (4).

(6) Moving extraction-water washing: extracting the concentrated solution in the step (5) by using ethyl acetate with the volume of 1-2 times, collecting an ethyl acetate phase, concentrating the ethyl acetate phase until the solid content is 2-10%, performing reverse phase extraction by using deionized water with the volume of 0.2-1 time, collecting a water washing phase, performing reverse phase extraction for 1-5 times by the same method, combining the water washing phases, extracting the water washing phase by using ethyl acetate with the volume of 1-2 times, and collecting the ethyl acetate phase.

(7) Transferring and dissolving: and (4) concentrating the ethyl acetate phase finally collected in the step (6) to obtain an extract, and adding deionized water for dissolving to obtain a tea polyphenol water solution.

(8) Concentration: and (4) concentrating the tea polyphenol water solution in the step (7) in vacuum.

(9) And (3) drying: and (4) drying the concentrated solution obtained in the step (8) in a zero-spraying drying mode to obtain a non-ester tea polyphenol product rich in EGC.

Preferably, the 10-100 mesh residue of the pretreated tea particles in the step (1) is not more than 40%, namely the pretreated tea particles are more than 60% in the range of 10-100 mesh.

Preferably, the adding amount of the deionized water in the step (2) is 1-5 times of the volume of the pretreated tea, the food-grade acid is citric acid, the stirring speed is 50-300 r/min, the enzymolysis temperature is 30-50 ℃, and the enzymolysis time is 4-12 hours.

Preferably, in the step (3), the leaching temperature is 60-90 ℃, the addition amount of single deionized water is 6-10 times of the mass of the tea raw material, and the single leaching time is 20-60 min.

Preferably, the cooling temperature in the step (4) is 30-50 ℃, and the filtration precision is 100-300 meshes.

Preferably, the concentration in the step (5) is specifically: concentrating the filtrate obtained in step (4) to 0.5-2.5 Brix.

Preferably, the extraction temperature of the ethyl acetate in the step (6) is 30-60 ℃, and the reverse phase extraction temperature of the deionized water is 30-60 ℃.

Preferably, the concentration in the step (8) is specifically: and (4) concentrating the tea polyphenol water solution obtained in the step (7) to 20-50Brix under the conditions that the vacuum degree is more than-0.080 MPa and the temperature is 52-72 ℃.

The invention uses the endogenous hydrolase of the tea content to carry out enzymolysis before leaching, and the ester catechin in the tea is enzymolyzed into non-ester theacrine substances (especially EGCG is converted into EGC), and then the product is leached; refining and purifying the collected leaching solution by a mobile extraction-water washing method, concentrating and drying the purified product to obtain a non-ester type tea polyphenol product rich in EGC, wherein the content of the tea polyphenol is 90-99.5%, the content of the EGC is more than 80%, and the content of ester type catechin EGCG + ECG is within a controllable range (below 10%).

Compared with the prior art, the invention has the advantages that:

(1) the ester-type tea polyphenol in the tea is hydrolyzed by adopting an endogenous hydrolase combined hydrolysis system contained in the tea without adding any exogenous hydrolase, so that the ester-type tea polyphenol is converted into non-ester-type tea polyphenol to the maximum extent, the content of a non-ester-type tea polyphenol product is increased, and the pollution of the exogenous hydrolase to the product is avoided.

(2) The product purification is carried out by using a moving extraction-water washing method, so that the EGC content is greatly improved, the production process is simplified, the product loss is greatly reduced, the product yield is greatly improved, and the industrial production is facilitated.

(3) The non-ester tea polyphenol product rich in EGC obtained by the preparation method has the tea polyphenol content of 90-99.5%, the EGC content of more than 80%, and the content of ester catechin EGCG plus ECG in a controllable range (below 10%).

Detailed Description

The present invention will be described in further detail with reference to examples.

Example 1

A method for preparing non-ester tea polyphenol rich in EGC comprises the following steps:

(1) pulverizing green tea, breaking cell wall, and making the particle size of the treated tea be above 60% in the range of 10-100 meshes, i.e. the residue of 10-100 meshes of the pretreated tea is not more than 40%.

(2) Adding 5.0Kg of pretreated tea leaves into a dynamic extraction tank (with stirring), adding 4 times of deionized water, adjusting pH to 5.0 with citric acid, and performing enzymolysis at 40 deg.C at 100r/min for 6 hr.

(3) Then stopping stirring, adding deionized water, performing primary extraction at 80 ℃, controlling the mass ratio of the tea leaves to the deionized water in the extraction tank to be 1:8, and performing extraction for 30 min; after the primary leaching is finished, filtering out filtrate, adding deionized water in the same proportion, leaching once in the same method, filtering after the leaching is finished, and combining the two filtrates.

(4) The collected filtrate was cooled to 40 ℃, further filtered with a filter of 200 mesh precision, and the filtrate was collected.

(5) Concentrating the tea water to 1.0Brix by a concentrating device.

(6) Extracting the concentrated tea water with 1.2 times volume of ethyl acetate at 40 deg.C, and collecting ethyl acetate phase; concentrating the ethyl acetate phase until the solid content is 8%, performing reverse phase extraction (water washing) with 0.5 times volume of deionized water at 40 deg.C, separating and collecting the water washing phase, washing with water for 3 times, and collecting and combining all the water washing phases; then extracting with 1.5 times volume of ethyl acetate at 40 deg.C, and collecting ethyl acetate phase.

(7) Concentrating the collected ethyl acetate solution to obtain extract, and adding 3L of deionized water for dissolving to obtain tea polyphenol water solution.

(8) Vacuum concentrating tea polyphenol water solution at vacuum degree of above-0.080 MPa and temperature of 52-72 deg.C, and concentrating the water solution to 35 Brix.

(9) And (4) drying the concentrated solution in a zero-spraying drying mode, and collecting 305g of powder product.

The product adopts an ultraviolet spectrophotometer commonly used in the industry to detect that the content of the tea polyphenol reaches 98.6 percent; HPLC detection shows that the EGC content is 81.3%, and the ester catechin EGCG + ECG content is 7.3%.

Example 2

(1) Pulverizing green tea, breaking cell wall, and making the particle size of the processed tea be above 60% within 10-100 meshes.

(2) Adding 5.0Kg of pretreated tea leaves into a dynamic extraction tank (with stirring), adding 4 times of deionized water, adjusting pH to 6.0 with citric acid, and performing enzymolysis at 45 deg.C at 150r/min for 10 hr.

(3) Then stopping stirring, adding deionized water, performing primary extraction at 80 ℃, controlling the mass ratio of the tea leaves to the deionized water in the extraction tank to be 1:10, and performing extraction for 30 min; after the primary leaching is finished, filtering out filtrate, adding deionized water in the same proportion, leaching once in the same method, filtering after the leaching is finished, and combining the two filtrates.

(4) The collected filtrate was cooled to 40 ℃, further filtered with a filter of 200 mesh precision, and the filtrate was collected.

(5) Concentrating the tea water to 1.0Brix by a concentrating device.

(6) Extracting the concentrated tea water with 1.2 times volume of ethyl acetate at 40 deg.C, and collecting ethyl acetate phase; concentrating the ethyl acetate phase until the solid content is 8%, performing reverse phase extraction (water washing) with 0.5 times volume of deionized water at 40 deg.C, separating and collecting the water washing phase, washing with water for 3 times, and collecting and combining all the water washing phases; then extracting with 1.5 times volume of ethyl acetate at 40 deg.C, and collecting ethyl acetate phase.

(7) Concentrating the collected ethyl acetate phase to obtain extract, and dissolving with 3L deionized water to obtain tea polyphenol water solution.

(8) Vacuum concentrating tea polyphenol water solution at vacuum degree of above-0.080 MPa and temperature of 52-72 deg.C, and concentrating the water solution to 35 Brix.

(9) Drying the concentrated solution by a spray drying method, and collecting 312g of powder product.

The product adopts an ultraviolet spectrophotometer commonly used in the industry to detect that the content of the tea polyphenol reaches 99.2 percent; HPLC detection shows that the EGC content is 83.0%, and the ester catechin EGCG + ECG content is 6.6%.

Example 3

(1) Pulverizing green tea, breaking cell wall, and making the particle size of the processed tea be above 60% within 10-100 meshes.

(2) Adding 5.0Kg of pretreated tea leaves into a dynamic extraction tank (with stirring), adding 4 times of deionized water, adjusting pH to 6.0 with citric acid, and performing enzymolysis at 40 deg.C at 100r/min for 8 hr.

(3) Then stopping stirring, adding deionized water, performing primary extraction at 80 ℃, controlling the mass ratio of the tea leaves to the deionized water in the extraction tank to be 1:8, and performing extraction for 30 min; after the primary leaching is finished, filtering out filtrate, adding deionized water in the same proportion, leaching once in the same method, filtering after the leaching is finished, and combining the two filtrates.

(4) The collected filtrate was cooled to 40 ℃, further filtered with a filter of 200 mesh precision, and the filtrate was collected.

(5) The filtrate was concentrated to 1.5Brix by a concentration apparatus.

(6) Extracting the concentrated solution with 1.5 times volume of ethyl acetate at 50 deg.C, and collecting ethyl acetate phase; concentrating the ethyl acetate phase until the solid content is 10%, performing reverse phase extraction (water washing) with 0.8 times volume of deionized water at 50 deg.C, separating and collecting the water washing phase, washing with water for 2 times, and collecting and combining all the water washing phases; then extracting with 1.5 times volume of ethyl acetate, controlling the extraction temperature at 50 ℃, and collecting the ethyl acetate phase.

(7) Concentrating the collected ethyl acetate phase to obtain extract, and dissolving with 3L deionized water to obtain tea polyphenol water solution.

(8) Vacuum concentrating tea polyphenol water solution at vacuum degree of above-0.080 MPa and temperature of 52-72 deg.C, and concentrating the water solution to 40 Brix.

(9) And drying the concentrated solution in a zero-spraying drying mode, and collecting 303g of powder product.

The product adopts an ultraviolet spectrophotometer commonly used in the industry to detect that the content of the tea polyphenol reaches 98.3 percent; HPLC detection shows that the EGC content is 80.8%, and the ester catechin EGCG + ECG content is 7.5%.

In addition to the above embodiments, the present invention also includes other embodiments, and any technical solutions formed by equivalent transformation or equivalent replacement should fall within the scope of the claims of the present invention.