阅读说明：本技术 一种从速溶茶中分离儿茶素、茶黄素、茶氨酸、茶多糖的方法 (Method for separating catechin, theaflavin, theanine and tea polysaccharide from instant tea ) 是由 张守政 于 2019-10-16 设计创作，主要内容包括：本发明公开了一种从速溶茶中分离儿茶素、茶黄素、茶氨酸、茶多糖的方法,将速溶茶吸入溶解器内,溶解速溶茶粉制备茶汤,用石油醚作为携带剂的二氧化碳超临界流体萃取分离茶汤中的咖啡碱；用乙酸乙酯作为携带剂的二氧化碳超临界流体萃取分离茶汤中的儿茶素；用乙醇作为携带剂的二氧化碳超临界流体萃取分离茶汤中茶黄素素；用氢氧化铵作为携带剂的二氧化碳超临界流体萃取分离茶汤中茶氨酸；萃余相经醇析后真空低温干燥制得茶多糖。本发明将二氧化碳超临界流体与各功能携带剂结合,调整压力和温度等物理参数,一次性从速溶茶中分离多种活性功能性成份；分离得到的儿茶素、茶黄素、茶氨酸、茶多糖色泽好,溶解性好,活性成份高。(The invention discloses a method for separating catechin, theaflavin, theanine and tea polysaccharide from instant tea, which comprises the steps of sucking instant tea into a dissolver, dissolving the instant tea powder to prepare tea soup, and extracting and separating caffeine in the tea soup by carbon dioxide supercritical fluid using petroleum ether as a carrying agent; extracting catechin in the tea soup by using carbon dioxide supercritical fluid with ethyl acetate as a carrying agent; extracting and separating theaflavin in the tea soup by carbon dioxide supercritical fluid with ethanol as carrying agent; extracting and separating theanine in the tea soup by using carbon dioxide supercritical fluid with ammonium hydroxide as a carrying agent; and carrying out alcohol precipitation on the raffinate, and then carrying out vacuum low-temperature drying to obtain the tea polysaccharide. The invention combines the carbon dioxide supercritical fluid with various functional carrying agents, adjusts physical parameters such as pressure, temperature and the like, and separates various active functional components from the instant tea at one time; the catechin, theaflavin, theanine and tea polysaccharide obtained by separation have good color, good solubility and high active ingredients.)

1. A method for separating catechin, theaflavin, theanine and tea polysaccharide from instant tea is characterized by comprising the following steps:

(1) vacuum sucking powdered instant tea into dissolver with jet flow, and dissolving with deionized water at constant temperature to obtain tea soup;

(2) injecting the tea soup into a first supercritical extraction kettle, extracting caffeine with supercritical carbon dioxide fluid using petroleum ether as a carrying agent for 15-30 minutes, keeping the temperature at 35-45 ℃ and the pressure at 35-40 MPa to obtain a first extract phase and a first raffinate phase; under the condition that the separation pressure of the first extraction phase is 6.0-6.5 MPa, continuously and quantitatively separating out caffeine and petroleum ether by using supercritical carbon dioxide fluid, washing with deionized water, purifying, recrystallizing and drying in vacuum to obtain caffeine;

(3) continuously feeding the first raffinate phase into a second supercritical extraction kettle, extracting catechin by using supercritical carbon dioxide fluid taking ethyl acetate as a carrying agent for 20-30 minutes, keeping the temperature at 55-65 ℃ and the pressure at 12-25 MPa to obtain a second extract phase and a second raffinate phase; separating catechin and ethyl acetate from the second extract phase by using supercritical carbon dioxide fluid under the condition that the separation pressure is 6.0-6.5 MPa, washing and purifying by using deionized water, recovering ethyl acetate, and then carrying out freeze drying to obtain catechin;

(4) continuously feeding the second extraction raffinate phase into a third supercritical extraction kettle, extracting theaflavin by using supercritical carbon dioxide fluid taking ethanol as a carrying agent for 20-30 minutes, keeping the temperature at 35-42 ℃ and the pressure at 15-25 MPa, and obtaining a third extraction phase and a third extraction raffinate phase; separating out theaflavin and ethanol from the third extract phase by using supercritical carbon dioxide fluid under the condition that the separation pressure is 6.0-6.5 MPa, and freeze-drying after enzymatic oxidation to obtain theaflavin;

(5) continuously feeding the third extraction raffinate phase into a fourth supercritical extraction kettle, extracting theanine by using supercritical carbon dioxide fluid with ammonium hydroxide as a carrying agent for 20-30 minutes, keeping the temperature at 40-50 ℃ and the pressure at 30-38 MPa to obtain a fourth extraction phase and a fourth extraction raffinate phase; separating out theanine and ammonium hydroxide from the fourth extract phase by using supercritical carbon dioxide fluid under the condition that the separation pressure is 6.0-6.5 MPa, purifying, recrystallizing and drying in vacuum to obtain theanine;

(6) and continuously feeding the fourth extraction raffinate into an alcohol precipitation device, continuously and quantitatively precipitating tea polysaccharide by using 90% ethanol for 30-40 minutes, taking precipitated alcohol precipitation liquid, recovering and concentrating the alcohol precipitation liquid by using vacuum ethanol, and performing vacuum drying at the constant temperature of 50-60 ℃ to obtain the tea polysaccharide.

2. The process of claim 1 for the separation of catechins, theaflavins, theanine, tea polysaccharides from instant tea characterized by: in the step (1), powdery instant tea is sucked into a tangentially-rotating continuous dissolver in a jet vacuum manner, deionized water with the weight ratio of 2-6 times is used for dissolving at the constant temperature of 50-80 ℃ to prepare tea soup, the pH value of the tea soup is adjusted to 5.5-6.8 by citric acid solution, and the tea soup is filtered by a microfilter with the aperture of 0.1-5 um to obtain refined tea soup.

3. The process of claim 1 for the separation of catechins, theaflavins, theanine, tea polysaccharides from instant tea characterized by: in the step (2), continuously and quantitatively injecting the tea soup into a first supercritical extraction kettle by using a high-pressure injection pump, and using petroleum ether as a carrying agent, wherein the using amount of the carrying agent is CO₂5% of the total volume of the tea soup and CO in a volume ratio of 1:10₂Allowing the supercritical fluid to continuously and reversely flow into a first supercritical extraction kettle to extract caffeine, controlling the extraction time for 15-30 minutes, keeping the temperature at 35-45 ℃ and the pressure at 35-40 MPa, and obtaining a first extraction phase and a first raffinate phase; under the condition that the separation pressure of the first extraction phase is 6.0-6.5 MPa, continuously and quantitatively separating out caffeine and petroleum ether by using supercritical carbon dioxide fluid, washing with deionized water, purifying, recrystallizing and drying in vacuum to obtain the caffeine.

4. The process of claim 1 for the separation of catechins, theaflavins, theanine, tea polysaccharides from instant tea characterized by: in the step (3), the first raffinate phase continuously enters a second supercritical extraction kettle, ethyl acetate is used as a carrying agent, and the using amount of the carrying agent is CO₂5% by volume, using a first raffinate phase to carbon dioxide volume ratio of 1: 8.0 to 12.0 of CO₂Continuously and reversely flowing the supercritical fluid into a second supercritical extraction kettle to extract catechin, wherein the extraction time is 20-30 minutes, the temperature is kept at 55-65 ℃, and the pressure is 12-25 MPa, so that a second extraction phase and a second raffinate phase are obtained; and (3) separating catechin and ethyl acetate from the second extract phase by using supercritical carbon dioxide fluid under the separation pressure of 6.0-6.5 MPa, washing and purifying by using deionized water, recovering ethyl acetate, and freeze-drying to obtain catechin.

5. The process of claim 1 for the separation of catechins, theaflavins, theanine, tea polysaccharides from instant tea characterized by: in the step (4), the second raffinate phase continuously enters a third supercritical extraction kettle, ethanol is used as a carrying agent, and the using amount of the carrying agent is CO₂10% by volume, using a second raffinate phase to carbon dioxide volume ratio of 1: 8.0 to 12.0 of CO₂The supercritical fluid continuously flows in a countercurrent way into the firstExtracting theaflavin in a three supercritical extraction kettle for 20-30 minutes at the constant temperature of 35-42 ℃ and the pressure of 15-25 MPa to obtain a third extract phase and a third raffinate phase; and (3) separating theaflavin and ethanol from the third extract phase by using a supercritical carbon dioxide fluid under the condition that the separation pressure is 6.0-6.5 MPa, and freeze-drying after enzymatic oxidation to obtain theaflavin.

6. The process of claim 1 for the separation of catechins, theaflavins, theanine, tea polysaccharides from instant tea characterized by: in the step (5), the third raffinate phase continuously enters a fourth supercritical extraction kettle, ammonium hydroxide is used as a carrying agent, and the using amount of the carrying agent is CO₂10% by volume, using a third raffinate phase to carbon dioxide volume ratio of 1: 10.0 to 15.0 of CO₂Allowing the supercritical fluid to continuously and reversely flow into a fourth supercritical extraction kettle to extract theanine, wherein the extraction time is 20-30 minutes, the temperature is kept at 40-50 ℃, and the pressure is 30-38 MPa, so as to obtain a fourth extraction phase and a fourth raffinate phase; and (3) separating theanine and ammonium hydroxide from the fourth extract phase by using a supercritical carbon dioxide fluid under the condition that the separation pressure is 6.0-6.5 MPa, purifying, recrystallizing and drying in vacuum to obtain the theanine.

7. The process of claim 1 for the separation of catechins, theaflavins, theanine, tea polysaccharides from instant tea characterized by: in the step (6), the volume ratio of the fourth raffinate phase to the ethanol is 1:1 to 1.5.

8. The process of claim 1 for the separation of catechins, theaflavins, theanine, tea polysaccharides from instant tea characterized by: and (4) continuously feeding the raffinate in the step (6) into a vacuum low-temperature atomization concentrator, dehydrating at the constant temperature of 50-60 ℃ to obtain thick slurry, and drying in vacuum to obtain the tea polyphenol.

9. The process of claim 1 for the separation of catechins, theaflavins, theanine, tea polysaccharides from instant tea characterized by: the purity of the caffeine is more than or equal to 99%, the purity of the catechin is more than or equal to 92%, the purity of the theaflavin is more than or equal to 80%, the purity of the theanine is more than or equal to 95%, and the purity of the tea polysaccharide is more than or equal to 62%.

10. The process for the separation of catechins, theaflavins, theanine, tea polysaccharides from instant tea as claimed in claim 8 wherein: the purity of the tea polyphenol is more than or equal to 42 percent.

Technical Field

The invention belongs to the field of tea extraction processes, relates to a method for separating and extracting functional components from tea, and particularly relates to a method for separating catechin, theaflavin, theanine and tea polysaccharide from instant tea.

Background

The tea leaf contains catechin, theanine, tea polysaccharide, cholestenone, caffeine, inositol, folic acid, pantothenic acid, etc., and can promote health. Tea beverage is known as one of three major beverages in the world.

Scientific research at home and abroad proves that the catechin in the tea has the functions of removing free radicals of human bodies, improving immunity, resisting oxidation, aging, radiation, cancer, blood fat and the like; theanine has effects in lowering blood pressure, tranquilizing mind, and improving sleep; the tea polysaccharide has the functions of reducing blood sugar, enhancing immunity and the like; theaflavin has effects of resisting blood coagulation, resisting thrombi and preventing atherosclerosis; caffeine has effects in treating asthma and relieving fatigue. Therefore, the functional components of tea have been widely applied to the fields of medicine, health care, food and the like, and have huge potential markets. The functional components of the tea are comprehensively developed and compatible with the functional components of the Chinese herbal medicines to produce functional foods and medicines for promoting the health of human beings, and the tea is an effective way for solving the problems of hypertension, hyperlipidemia and diabetes of middle-aged and elderly people in China and preventing cancers.

Disclosure of Invention

The invention aims to provide a method for separating catechin, theaflavin, theanine and tea polysaccharide from instant tea, which has low cost, low energy consumption, no pollution and good safety and can exert the health function of tea to the maximum.

In order to achieve the purpose, the technical scheme of the invention is as follows: a method for separating catechin, theaflavin, theanine and tea polysaccharide from instant tea is provided, which comprises the following steps:

(1) vacuum sucking powdered instant tea into dissolver with jet flow, and dissolving with deionized water at constant temperature to obtain tea soup;

(2) injecting the tea soup into a first supercritical extraction kettle, extracting caffeine with supercritical carbon dioxide fluid using petroleum ether as a carrying agent for 15-30 minutes, keeping the temperature at 35-45 ℃ and the pressure at 35-40 MPa to obtain a first extract phase and a first raffinate phase; under the condition that the separation pressure of the first extraction phase is 6.0-6.5 MPa, continuously and quantitatively separating out caffeine and petroleum ether by using supercritical carbon dioxide fluid, washing with deionized water, purifying, recrystallizing and drying in vacuum to obtain caffeine;

(3) continuously feeding the first raffinate phase into a second supercritical extraction kettle, extracting catechin by using supercritical carbon dioxide fluid taking ethyl acetate as a carrying agent for 20-30 minutes, keeping the temperature at 55-65 ℃ and the pressure at 12-25 MPa to obtain a second extract phase and a second raffinate phase; separating catechin and ethyl acetate from the second extract phase by using supercritical carbon dioxide fluid under the condition that the separation pressure is 6.0-6.5 MPa, washing and purifying by using deionized water, recovering ethyl acetate, and then carrying out freeze drying to obtain catechin;

(4) continuously feeding the second extraction raffinate phase into a third supercritical extraction kettle, extracting theaflavin by using supercritical carbon dioxide fluid taking ethanol as a carrying agent for 20-30 minutes, keeping the temperature at 35-42 ℃ and the pressure at 15-25 MPa, and obtaining a third extraction phase and a third extraction raffinate phase; separating out theaflavin and ethanol from the third extract phase by using supercritical carbon dioxide fluid under the condition that the separation pressure is 6.0-6.5 MPa, and freeze-drying after enzymatic oxidation to obtain theaflavin;

(5) continuously feeding the third extraction raffinate phase into a fourth supercritical extraction kettle, extracting theanine by using supercritical carbon dioxide fluid with ammonium hydroxide as a carrying agent for 20-30 minutes, keeping the temperature at 40-50 ℃ and the pressure at 30-38 MPa to obtain a fourth extraction phase and a fourth extraction raffinate phase; separating out theanine and ammonium hydroxide from the fourth extract phase by using supercritical carbon dioxide fluid under the condition that the separation pressure is 6.0-6.5 MPa, purifying, recrystallizing and drying in vacuum to obtain theanine;

(6) and continuously feeding the fourth extraction raffinate into an alcohol precipitation device, continuously and quantitatively precipitating tea polysaccharide by using 90% ethanol for 30-40 minutes, taking precipitated alcohol precipitation liquid, recovering and concentrating the alcohol precipitation liquid by using vacuum ethanol, and performing vacuum drying at the constant temperature of 50-60 ℃ to obtain the tea polysaccharide.

Preferably, in the step (1), the powdery instant tea is sucked into a continuous dissolver in a tangential rotation mode in a jet vacuum mode, deionized water with the weight ratio of 2-6 times is used for dissolving at the constant temperature of 50-80 ℃ to prepare tea soup, the pH value of the tea soup is adjusted to 5.5-6.8 by using citric acid solution to prevent the active phenolic hydroxyl of catechin from being oxidized and dehydrogenated into quinones, and the refined tea soup is obtained after filtering by a microfilter with the aperture of 0.1-5 mu m.

Preferably, in the step (2), the tea soup is continuously and quantitatively injected into the first supercritical extraction kettle by using a high-pressure injection pump, petroleum ether is used as a carrying agent, and the using amount of the carrying agent is CO₂5% of the total volume of the tea soup and CO in a volume ratio of 1:10₂Allowing the supercritical fluid to continuously and reversely flow into a first supercritical extraction kettle to extract caffeine, controlling the extraction time for 15-30 minutes, keeping the temperature at 35-45 ℃ and the pressure at 35-40 MPa, and obtaining a first extraction phase and a first raffinate phase; under the condition that the separation pressure of the first extraction phase is 6.0-6.5 MPa, continuously and quantitatively separating out caffeine and petroleum ether by using supercritical carbon dioxide fluid, washing with deionized water, purifying, recrystallizing and drying in vacuum to obtain the caffeine.

Preferably, in the step (3), the first raffinate phase continuously enters the second supercritical extraction kettle, ethyl acetate is used as a carrying agent, and the using amount of the carrying agent is CO₂5% by volume, using a first raffinate phase to carbon dioxide volume ratio of 1: 8.0 to 12.0 of CO₂Continuously and reversely flowing the supercritical fluid into a second supercritical extraction kettle to extract catechin, wherein the extraction time is 20-30 minutes, the temperature is kept at 55-65 ℃, and the pressure is 12-25 MPa, so that a second extraction phase and a second raffinate phase are obtained; and (3) separating catechin and ethyl acetate from the second extract phase by using supercritical carbon dioxide fluid under the separation pressure of 6.0-6.5 MPa, washing and purifying by using deionized water, recovering ethyl acetate, and freeze-drying to obtain catechin.

Preferably, in the step (4), the second raffinate phase continuously enters a third supercritical extraction kettle, and ethanol is used as the ethanolIs a carrier agent, and the dosage of the carrier agent is CO₂10% by volume, using a second raffinate phase to carbon dioxide volume ratio of 1: 8.0 to 12.0 of CO₂Continuously and reversely flowing the supercritical fluid into a third supercritical extraction kettle to extract theaflavin, wherein the extraction time is 20-30 minutes, the temperature is kept at 35-42 ℃, and the pressure is 15-25 MPa, so as to obtain a third extraction phase and a third raffinate phase; and (3) separating theaflavin and ethanol from the third extract phase by using a supercritical carbon dioxide fluid under the condition that the separation pressure is 6.0-6.5 MPa, and freeze-drying after enzymatic oxidation to obtain theaflavin.

Preferably, in the step (5), the third raffinate phase continuously enters a fourth supercritical extraction kettle, ammonium hydroxide is used as a carrying agent, and the using amount of the carrying agent is CO₂10% by volume, using a third raffinate phase to carbon dioxide volume ratio of 1: 10.0 to 15.0 of CO₂Allowing the supercritical fluid to continuously and reversely flow into a fourth supercritical extraction kettle to extract theanine, wherein the extraction time is 20-30 minutes, the temperature is kept at 40-50 ℃, and the pressure is 30-38 MPa, so as to obtain a fourth extraction phase and a fourth raffinate phase; and (3) separating theanine and ammonium hydroxide from the fourth extract phase by using a supercritical carbon dioxide fluid under the condition that the separation pressure is 6.0-6.5 MPa, purifying, recrystallizing and drying in vacuum to obtain the theanine.

Preferably, in step (6), the volume ratio of the fourth raffinate phase to ethanol is 1:1 to 1.5.

Preferably, the raffinate in the step (6) is continuously fed into a vacuum low-temperature atomization concentrator, dehydrated at the constant temperature of 50-60 ℃ to obtain thick slurry, and dried in vacuum to obtain the tea polyphenol.

Preferably, the purity of the caffeine is more than or equal to 99%, the purity of the catechin is more than or equal to 92%, the purity of the theaflavin is more than or equal to 80%, the purity of the theanine is more than or equal to 95%, and the purity of the tea polysaccharide is more than or equal to 62%.

Preferably, the purity of the tea polyphenol is more than or equal to 42 percent.

The method for separating catechin, theaflavin, theanine and tea polysaccharide from instant tea has the following beneficial effects:

1. the separation technology of catechin, theaflavin, theanine and tea polysaccharide is to separate substances by using non-Newtonian physical carbon dioxide supercritical fluid under different temperature and different pressure states under low temperature and oxygen deficiency, oxidation, hydrolysis and other reactions are not generated in the process of substance separation, and the maximum amount of active ingredients of tea leaves is reserved and separated, so that the product yield is high.

2. The separation technology of catechin, theaflavin, theanine and tea polysaccharide is to separate, purify and dry the components under the condition of low temperature and oxygen deficiency, does not generate chemical reaction in the separation process, has high activity and good quality of products, and does not have pesticide, solvent and heavy metal residue. The purity of catechin is more than or equal to 92 percent, the EGCG is more than or equal to 70 percent, and the content of caffeine is less than or equal to 0.1 percent; the purity of the caffeine is more than or equal to 99.0 percent; the purity of the tea polysaccharide is more than or equal to 62 percent; the purity of theaflavin is more than or equal to 80 percent; the purity of theanine is more than or equal to 95 percent.

3. The separation technology of the invention is a pure physical method, and uses solvent or does not use solvent in the minimum amount, and adopts a carbon dioxide supercritical device, and can separate each functional component in the instant tea only by using a minimum amount of carrying agent and changing temperature and pressure.

4. The method combines the carbon dioxide supercritical fluid with various functional carrying agents, adjusts physical parameters such as pressure, temperature and the like, and separates various active functional components from the instant tea at one time; the catechin, theaflavin, theanine and tea polysaccharide obtained by separation have good color, good solubility and high active ingredients.

Drawings

FIG. 1 is a schematic process flow diagram of the method for separating catechin, theaflavin, theanine and tea polysaccharide from instant tea according to the invention.

Detailed Description