CN113289374A

CN113289374A - Method for extracting active ingredients from tea

Info

Publication number: CN113289374A
Application number: CN202110556557.3A
Authority: CN
Inventors: 赵军
Original assignee: Anhui Huigongfu Biotechnology Co ltd
Current assignee: Anhui Huigongfu Biotechnology Co ltd
Priority date: 2021-05-21
Filing date: 2021-05-21
Publication date: 2021-08-24

Abstract

The invention discloses a method for extracting active ingredients from tea leaves, which comprises the following steps: 1) picking fresh tea leaves, cleaning and crushing; 2) placing the pulverized tea in an extraction device, and extracting active ingredients contained in the pulverized tea with an ethanol aqueous solution; 3) after extraction, filtering and separating to obtain filtrate and tea residues; 4) distilling under reduced pressure to remove ethanol in the filtrate obtained in the step 3), concentrating under reduced pressure, and freeze-drying to obtain water-soluble, alcohol-soluble, water-soluble and alcohol-soluble components; 5) leaching the tea residue obtained in the step 3) by a salt extraction method, and filtering to obtain a leaching solution containing protein after leaching is finished; 6) and (3) precipitating the protein, collecting the precipitate after centrifugal treatment, and washing, freezing and drying to obtain the tea protein. The method for extracting the active ingredients in the tea leaves can fully extract and utilize the active ingredients, and the extracted tea protein has high purity and good biological activity and appearance quality.

Description

Method for extracting active ingredients from tea

Technical Field

The invention belongs to the technical field of tea deep processing, and particularly relates to a method for extracting active ingredients from tea.

Background

Tea leaves have a development course of thousands of years, and people all over the world are conquered with unique taste and health care efficacy. Modern researches have proved that the tea has special taste and health-care effect because of containing a large amount of various functional components such as tea polyphenol, theophylline, theanine, protein, trace elements and the like. In recent years, with the development of tea leaves in the fields of food, beverages and daily chemicals, people have begun to extract functional components from tea leaves. However, in the prior art, the extraction of the functional components of the tea leaves is mainly aimed at high-value substances such as tea polyphenol, and the research on protein accounting for 15-25% of the dry matter content of the tea leaves is less.

CN 102302083B discloses a method for extracting tea protein products, which is characterized in that a low-frequency ultrasonic-assisted alkali extraction technology is utilized to prepare the tea protein products, although the method has high protein extraction rate, the protein products obtained by the alkali extraction method have dark color, hydrogen peroxide needs to be added into an extracting solution for decolorization, and the hydrogen peroxide is a strong oxidant and can chemically react with protein to denature the protein; in addition, the alkaline liquor can change the nutritional characteristics of tea protein, so that the cysteine and the serine of the protein are combined to form toxic lysine-alanine; finally, the method is strong in pertinence and only suitable for extracting the protein in the tea, in the extraction process, part of other effective components in the tea are eluted during raw material pretreatment, and the rest of the effective components are damaged by alkali liquor during protein extraction, so that a large amount of effective components in the tea are lost, and resource waste is caused.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects in the prior art, the invention aims to extract water-soluble, alcohol-soluble, water-soluble and alcohol-soluble components in tea leaves, and extract rich water-insoluble and alcohol-insoluble tea protein from tea leaves by a salt extraction method, so that the obtained tea protein has better apparent shape and bioactivity, and the active components in the tea leaves are fully extracted and utilized. In addition, because the tea leaves are selenium-rich tea leaves, and the selenium mainly exists in the tea leaves in the forms of selenium amino acid, selenoprotein and the like, the obtained tea extract is rich in organic selenium along with the extraction of high-content tea protein, has an effective selenium supplement effect, and can realize a higher-level health care effect.

Meanwhile, when water-soluble, alcohol-soluble, water-soluble and alcohol-soluble components in the tea are extracted, a simple leaching method is adopted, and the problems of insufficient extraction of active components in the tea or low extraction efficiency exist, so that the extraction process is improved.

(II) technical scheme

In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

a method for extracting active ingredients from tea leaves comprises the following steps:

1) picking fresh tea leaves, cleaning and crushing;

preferably, the fresh tea leaves are fresh selenium-enriched tea leaves; the selenium-rich tea is Enshi natural selenium-rich tea, and the water content of the selenium-rich tea is 70% -80%;

in the crushing process, the tea leaves are kept in a room temperature state;

the selenium-rich tea is crushed to obtain superfine slurry with fluidity;

2) placing the pulverized tea in an extraction device, and extracting active ingredients contained in the pulverized tea with an ethanol aqueous solution;

preferably, the ethanol content in the ethanol water solution is 50% -70%; the dosage of the ethanol water solution is 5-10 times of the mass of the fresh tea;

3) after extraction, filtering and separating to obtain filtrate and tea leaves;

4) distilling under reduced pressure to remove ethanol in the filtrate obtained in the step 3), concentrating under reduced pressure, and freeze-drying to obtain water-soluble, alcohol-soluble, water-soluble and alcohol-soluble components;

preferably, the reduced pressure distillation is carried out at a temperature lower than the boiling point of ethanol, and at a temperature lower than the boiling point of ethanol, when the ethanol reaches the saturated vapor pressure through reduced pressure, water does not reach the saturated vapor pressure, and the ethanol collected through the reduced pressure distillation is relatively pure and can be recycled;

preferably, said concentration under reduced pressure is carried out at a temperature of 50-70 ℃;

preferably, the water-soluble component is a component that dissolves only in water, the alcohol-soluble component is a component that dissolves only in ethanol, and the water-soluble and alcohol-soluble components are components that dissolve in both water and ethanol;

the water-soluble, alcohol-soluble, water-soluble and alcohol-soluble components are rich in theanine, chlorophyll, tea polyphenol, theophylline and other active components, and contain a small amount of water-soluble protein and alcohol-soluble protein;

5) leaching the tea residue obtained in the step 3) by a salt extraction method, and filtering to obtain a leaching liquor containing protein after leaching is finished;

preferably, the leaching liquor used in the salt extraction method is a neutral salt solution; the neutral salt solution is adopted to extract the protein in the tea residue, so that the charge on the surface of the protein molecule is increased, and the action of the protein molecule and the water molecule is enhanced, thereby increasing the solubility of the protein in the water solution;

preferably, the concentration of the neutral salt solution is 0.3-0.7 mol/L; in low concentration salt solution, the solubility of protein increases with increasing salt concentration, while high concentration salt solution inhibits the dissolution of tea protein;

preferably, the dosage of the neutral salt solution is 1-5 times of the fresh tea;

preferably, the neutral salt solution is a sodium chloride solution or a potassium chloride solution;

preferably, the leaching temperature is 30-50 ℃, and the leaching time is 1-3 hours; the solubility of the protein increases along with the increase of the temperature, so that the proper heating is favorable for the dissolution of the protein in a neutral salt solution, the extraction time is shortened, but the protein is denatured and inactivated due to the overhigh temperature;

preferably, ultrasonic wave is used for assisting in the extraction process to promote the dissolution of protein from tea cells;

6) precipitating protein from the protein-containing leaching liquor, collecting the precipitate after centrifugal treatment, and then washing, freezing and drying to obtain tea protein;

preferably, the protein is precipitated from the leaching solution containing the protein, specifically, ammonium sulfate is added into the leaching solution containing the protein until saturation, so that the protein is precipitated;

preferably, ammonium sulfate is added to be saturated, and then the mixture is kept standing for 3 to 5 hours at the temperature of between 0 and 5 ℃ to ensure that protein is fully separated out;

preferably, the washing is 3 to 5 times with pure water.

Preferably, the water-soluble, alcohol-soluble, water-soluble and alcohol-soluble components obtained after freeze-drying in step 4) are combined with the tea protein obtained after freeze-drying in step 6), and are crushed at low temperature to obtain a powdered tea extract rich in active ingredients;

selenium mainly exists in tea in the form of selenoamino acid, selenoprotein and the like, and the obtained tea extract is also rich in organic selenium along with the extraction of high-content tea protein.

Preferably, the specific operation of step 2) is as follows:

a) placing the ethanol aqueous solution in a jet flow extraction mechanism at the upper half part inside an extraction tank body of an extraction device, and spraying the ethanol aqueous solution to the center of the extraction tank body through a spraying pressurizer and a sprayer;

b) adding the crushed tea leaves into the jet flow extraction mechanism, and spraying the tea leaves downwards in an annular shape through an annular curtain spraying device to form an annular liquid curtain which collides with the ethanol water solution sprayed in the step a);

c) after the crushed tea leaves collide with the ethanol water solution, the crushed tea leaves enter an immersion liquid extraction mechanism at the lower half part of the interior of the extraction tank body to form mixed liquid;

d) starting a stirrer and an ultrasonic column in the immersion liquid extraction mechanism, leaching the mixed liquid formed in the step c), and heating the mixed liquid through a heating wire;

the ultrasonic column is internally provided with an ultrasonic generator, and the ultrasonic generator is started to carry out ultrasonic treatment on the mixed solution every 20 to 30 minutes, wherein the ultrasonic treatment time is 5 to 10 minutes each time.

Preferably, the mixed solution is heated in the step d), the heating temperature of the mixed solution is controlled to be 40-60 ℃, and the heating time is 8-12 hours.

An extraction device for an extraction method of active ingredients in tea comprises an extraction tank body and a tank cover, wherein a jet flow extraction mechanism is arranged at the upper half part inside the extraction tank body, and an immersion liquid extraction mechanism is arranged at the lower half part inside the extraction tank body;

the jet flow extraction mechanism comprises an ejector, a circular curtain sprayer and an injection pressurizer, wherein the ejector is used for ejecting the extracting solution to the center of the extraction tank body, the circular curtain sprayer is used for ejecting the raw material downwards in an annular shape, and the injection pressurizer is used for providing pressure required by the ejector for ejecting the extracting solution;

the immersion liquid extraction mechanism comprises a heating wire, a stirrer, a plurality of ultrasonic columns and a shielding cover.

(III) advantageous effects

Compared with the prior art, the invention has the following beneficial technical effects:

1. the invention picks fresh tea as raw material, firstly uses ethanol water solution to extract water-soluble, alcohol-soluble, water-soluble and alcohol-soluble active ingredients such as tea polyphenol, theophylline, chlorophyll, theanine and the like, and a small amount of water-soluble protein and alcohol-soluble protein in the tea, and then uses salt solution to assist an ultrasonic wave auxiliary extraction method to extract water-insoluble and alcohol-soluble tea protein with rich content in tea residue, the active ingredients in the tea are fully extracted and utilized, and the extracted tea protein has high purity, biological activity and good appearance.

2. The method has mild process conditions, does not use extreme conditions such as high temperature, strong alkalinity and the like to process the raw materials, effectively avoids the effective components in the tea leaves from being damaged in the extraction process, and furthest reserves the activity and the quality of the active components.

3. The invention takes the selenium-rich tea as the extraction raw material, and the selenium mainly exists in the tea in the form of selenium amino acid, selenoprotein and the like, and the organic selenium is extracted by extracting the tea eggs in the tea, thereby having effective selenium supplement effect and realizing higher health care efficacy.

4. In the invention, the filtrate from which the water-soluble, alcohol-soluble, water-soluble and alcohol-soluble components are extracted is distilled to remove ethanol, and then is concentrated and freeze-dried, so that the problem that the conversion temperature of the solution from liquid to solid is far lower than the boiling point of water due to the large amount of ethanol is avoided, and the freeze-drying operation is difficult to realize.

5. When the water-soluble, alcohol-soluble, water-soluble and alcohol-soluble components in the tea are extracted by using the ethanol aqueous solution, the tea slurry forms a downward annular liquid curtain through an annular curtain sprinkling sprayer arranged in the low-temperature extraction device, the ethanol aqueous solution is sprayed out through an inclined upward spraying head and generates impact collision with the annular liquid curtain formed by the slurry, and in the collision process, the cell walls in the tea are stressed and broken, so that the release of the active components in the tea from the interior of the cells is promoted, the subsequent extraction time is effectively shortened, and the extraction efficiency of the tea and the extraction effect of the active components in the tea are improved.

Drawings

FIG. 1 is a flow chart of the process for extracting active ingredients from tea leaves according to the present invention;

FIG. 2 is a schematic cross-sectional view of a tea leaf extracting apparatus according to the present invention;

FIG. 3 is a schematic perspective view of the tea leaf extracting apparatus according to the present invention;

FIG. 4 is a second schematic sectional view of the tea leaf extracting apparatus of the present invention;

FIG. 5 is a schematic half-sectional view of a tea leaf extraction apparatus according to the present invention;

FIG. 6 is an enlarged view of part A of FIG. 5 of the tea leaf extracting apparatus according to the present invention;

FIG. 7 is a schematic perspective view of a jet extraction mechanism of the tea leaf extraction device according to the present invention;

FIG. 8 is a schematic sectional view of a jet extraction mechanism of the tea leaf extraction device of the present invention;

fig. 9 is an enlarged schematic view of part B of fig. 8 of the tea leaf extracting apparatus according to the present invention;

fig. 10 is an enlarged view of part C of fig. 8 of the tea leaf extracting apparatus according to the present invention;

fig. 11 is an exploded view of the infusion extraction mechanism of the tea leaf extraction device of the present invention.

In the figure: 1. an extraction tank body; 2. a can lid; 21. an air duct; 3. a jet extraction mechanism; 31. an ejector; 311. a spray ring; 312. an injector head; 32. a circular curtain shower; 321. a liquid inlet pipe; 322. a liquid separating pipe; 323. an annular tube; 324. spraying the nozzle; 33. a jet pressurizer; 331. a containing cylinder; 332. a pressure pump; 333. a connecting pipe; 334. a shunt port; 4. an immersion liquid extraction mechanism; 41. heating wires; 42. a stirrer; 43. an ultrasonic column; 44. a shield can.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The embodiment of the invention discloses a method for extracting active ingredients from tea leaves, which comprises the following steps:

1) picking fresh Enshi natural selenium-rich tea, cleaning, and pulverizing into flowable superfine slurry;

a) placing the ethanol water solution in a jet flow extraction mechanism 3 at the upper half part inside an extraction tank body 1 of an extraction device, and spraying the ethanol water solution to the center of the extraction tank body 1 through a spraying pressurizer 33 and a sprayer 31;

b) adding the crushed tea leaves into the jet flow extraction mechanism 3, and downwards spraying the tea leaves in an annular shape through an annular curtain spraying device 32 to form an annular liquid curtain which collides with the ethanol water solution sprayed in the step a);

c) after being collided with the ethanol water solution, the crushed tea leaves enter an immersion liquid extraction mechanism 4 at the lower half part of the interior of the extraction tank body 1 to form a mixed liquid;

d) the stirrer 42 and the ultrasonic column 43 in the immersion extraction mechanism 4 are turned on to extract the mixed liquid formed in step c), and the mixed liquid is heated by the heating wire 41.

3) After extraction, filtering and separating to obtain filtrate and tea residues;

4) distilling under reduced pressure to remove ethanol in the filtrate obtained in the step 3), concentrating under reduced pressure at 50-70 deg.C, and freeze drying to obtain water-soluble, alcohol-soluble, water-soluble and alcohol-soluble components;

6) precipitating protein from the protein-containing leaching liquor, centrifuging, collecting precipitate, washing, and freeze-drying to obtain tea protein.

The following description of the extraction process and its effects will be made by specific examples.

Comparative example 1

Based on embodiment 1, the difference from embodiment 1 is that: common fresh tea leaves without selenium are used as extraction raw materials, and other process conditions are unchanged.

Comparative example 2

Based on embodiment 1, the difference from embodiment 1 is that: after the crushed superfine slurry of the tea with fluidity enters the immersion liquid extraction mechanism through the annular curtain sprinkling sprayer in the jet flow extraction mechanism of the extraction device, the ethanol water solution also enters the immersion liquid extraction mechanism from the annular curtain sprinkling sprayer in the jet flow extraction mechanism to form a mixed solution with the slurry of the tea, the mixed solution does not enter through the injection pressurizer and the injector, and the mixed solution does not enter into the immersion liquid extraction mechanism after colliding with the crushed tea slurry, and other process conditions are not changed.

Comparative example 3

Based on embodiment 1, the difference from embodiment 1 is that: after the smashed tea slurry collides with the ethanol water solution, the smashed tea slurry enters an immersion liquid extraction mechanism of the extraction device, after a mixed liquid is formed, a stirrer in the immersion liquid extraction mechanism is started, the mixed liquid of the extraction raw material and the extraction liquid is heated through a heating wire, an ultrasonic device is not started, and other technological conditions are not changed.

Example 4

The technical scheme solves the problems that in the prior art, the protein in the tea leaves is extracted by using alkali liquor, the extracted protein has low water solubility and deep color, toxic substances are possibly generated in an alkaline environment, and the tea leaves cannot be extracted and utilized only by researching the protein in the tea leaves and not extracting other effective components in the tea leaves. However, when water-soluble, alcohol-soluble, water-soluble and alcohol-soluble components in tea leaves are extracted, a simple extraction method is adopted, so that the problems that high-temperature extraction easily causes failure of active components and the extraction efficiency of conventional low-temperature extraction is low exist, and the extraction efficiency needs to be high while the active components in the tea leaves are not damaged.

In order to solve the technical problems that the high-temperature leaching is easy to cause the failure of active ingredients and the extraction efficiency of the conventional low-temperature leaching is low, the invention provides the following technical scheme:

referring to fig. 2-11, the perspective structure of the tea leaf extraction device provided by the invention is schematically shown.

The extraction device comprises an extraction tank body 1 and a tank cover 2, wherein the upper half part inside the extraction tank body 1 is provided with a jet flow extraction mechanism 3, and the lower half part inside the extraction tank body 1 is provided with an immersion liquid extraction mechanism 4;

the jet flow extraction mechanism 3 comprises an ejector 31, a circular curtain sprayer 32 and a jet pressurizer 33, wherein the ejector 31 is used for spraying the extracting solution to the center of the extraction tank body 1, the circular curtain sprayer 32 is used for downwards spraying the raw material in a circular shape, and the jet pressurizer 33 is used for providing the pressure required by the ejector 31 for spraying the extracting solution;

the immersion liquid extraction mechanism 4 includes a heating wire 41, a stirrer 42, a plurality of ultrasonic columns 43, and a shield 44.

Further, the injector 31 is composed of a plurality of injection rings 311, the inner wall of the injection ring 311 in the extraction tank 1 is provided with a plurality of injection heads 312, the plurality of injection heads 312 are all arranged obliquely upwards, the injection heads 312 all point to the center of the extraction tank 1, the liquid sprayed by the spraying heads 312 is uniformly directed to the upper position of the same height center of the extraction tank 1 by the inclination of the spraying heads 312 upwards and pointing to the center of the extraction tank 1, so that the ejected extracting solution is ejected upwards in an inclined way and forms an opposite impact with the downward annular liquid curtain, thereby improving the collision force between the extracting solution and the pulp, leading the extracting solution to impact the pulp in the collision process between the extracting solution and the pulp, the cell wall of the tea is stressed and broken, active ingredients of the tea are released from the inside of the cell, the extraction efficiency in jet extraction is improved, and the extraction effect of the active ingredients in the tea is improved.

Further, the annular curtain sprayer 32 is composed of a liquid inlet pipe 321, a liquid dividing pipe 322 and an annular pipe 323, the liquid dividing pipe 322 is communicated with the liquid inlet pipe 321 and the annular pipe 323, a plurality of spraying nozzles 324 are arranged on the bottom surface of the annular pipe 323, the plurality of spraying nozzles 324 cooperate with each other to form an annular liquid curtain, so that the slurry fed through the liquid inlet pipe 321 is evenly guided into the annular pipe 323 through the liquid dividing pipe 322, is transported to the spraying nozzles 324 to flow out in the annular pipe 323, so that the liquid flows out from the spraying nozzles 324, and because the plurality of spraying nozzles 324 are evenly distributed at the bottom end of the annular pipe 323, the liquid is not cut off by the plurality of spraying nozzles 324, the annular liquid curtain is formed at the upper half part of the extraction tank body 1, so that the slurry is evenly fed into the extraction tank body 1, and the extracting solution sprayed out by the plurality of spraying nozzles 312 is evenly mixed with the slurry at the center position of the extraction tank body 1, the extraction effect is generated in the mixing process.

Further, the injection pressurizer 33 includes a containing cylinder 331, a pressure pump 332 and a connecting pipe 333, the containing cylinder 331 is used for temporarily storing the extracting solution, the pressure pump 332 is used for pumping the extracting solution in the containing cylinder 331 and pressurizing the extracting solution and then delivering the extracting solution to the connecting pipe 333, in a specific application, the containing cylinder 331 is provided with an observation window and scales, and the adding amount of the extracting solution can be conveniently seen through the observation window and the scales.

Further, one end of the connection pipe 333 is communicated with the pressure pump 332, one end of the connection pipe 333 away from the pressure pump 332 is provided with a plurality of branch ports 334, the connection pipe 333 is respectively communicated with the plurality of injection rings 311 through the plurality of branch ports 334, and the connection pipe 333 respectively provides the extraction liquid to the injection rings 311 through the plurality of branch ports 334.

Before the extraction device is used, the selected extraction liquid is added into the containing cylinder 331, the pressure pump 332 pumps the extraction liquid in the containing cylinder 331 and then conveys the extraction liquid to the connecting pipe 333, and the extraction liquid is equally injected into the inner parts of the plurality of injection rings 311 by the plurality of branch ports 334 of the connection pipe 333, so that the extraction liquid is transported in the spray rings 311 and sprayed out through the respective spray heads 312, so that the extraction liquid can be uniformly fed into the respective spray rings 311 through the connection pipes 333 by pressurization of the pressurization pump 332, and the extraction liquid in a high pressure state can rapidly move along the pipeline path, so that the amount of the extraction liquid sprayed out from each spray head 312 is ensured to be approximately consistent, thereby guarantee that the extract after the blowout still can keep higher speed and pressure to guarantee the collision dynamics between extract and the thick liquid, make the mixed extraction effect between extract and the thick liquid better.

In the process of extracting tea, firstly, the crushed tea slurry and the extract liquid are respectively sent into the jet flow extraction mechanism 3 in the extraction tank body 1, in the practical use, the extract liquid includes but is not limited to water, ethanol and other conventional extracting agents, the tea slurry enters the device through the liquid inlet pipe 321 arranged at the top end of the annular curtain sprayer 32, the slurry flows out from the plurality of spraying nozzles 324 under the action of the annular curtain sprayer 32, the slurry forms a downward annular liquid curtain through the action of the plurality of spraying nozzles 324 which are integrally and uniformly distributed, meanwhile, the extracting agent is pressurized and respectively sent into the plurality of spraying rings 311 in the sprayer 31 under the action of the spraying pressurizer 33, the extracting agent is sprayed out from the plurality of spraying heads 312 uniformly distributed on the inner sides of the plurality of spraying rings 311 at high speed under the action of high pressure, and a plurality of strands of the extracting agent are sprayed out to be impacted and mixed with the annular liquid curtain formed by the slurry, the components in the tea cells are fully released through the impact action of the extracting agent while the extracting agent and the slurry are fully mixed, so that the cell walls of the tea are damaged through the impact action of the jet flow extraction mechanism 3, the extraction rate of the active components in the tea is improved, and the extraction effect is improved.

Further, the heating wire 41 is arranged inside the tank wall of the lower half part of the extraction tank body 1, the stirrer 42 penetrates from the tank cover 2 to the bottom end of the immersion extraction mechanism 4, the ultrasonic columns 43 are fixed at the bottom of the extraction tank body 1, and the ultrasonic columns 43 are uniformly distributed outside the stirrer 42.

Further, a shielding cover 44 is arranged at the top end of the plurality of ultrasonic columns 43, the shielding cover 44 separates the jet flow extraction mechanism 3 from the immersion liquid extraction mechanism 4, the shielding cover 44 is used for collecting liquid generated by jet flow extraction of the jet flow extraction mechanism 3 and collecting and guiding the liquid into the immersion liquid extraction mechanism 4, so that the jet flow extraction mechanism 3 and the immersion liquid extraction mechanism 4 inside the extraction tank body 1 are separated through the effect of the shielding cover 44, disordered state generated by impact of high-pressure extraction liquid in the upper jet flow extraction mechanism 3 is converted into relatively uniform state through collection of the shielding cover 44, and then the liquid is conveyed into the lower immersion liquid extraction mechanism 4 through diversion of the shielding cover 44 to perform relatively slow immersion liquid extraction process, so that the upper jet flow extraction process is prevented from disturbing the lower immersion liquid extraction process, and the effect of immersion liquid extraction is enhanced.

Further, a plurality of ultrasonic column 43 are inside to be provided with ultrasonic generrator, and a plurality of ultrasonic column 43 are used for releasing the immersion fluid extraction process of the supplementary immersion fluid extraction mechanism 4 of ultrasonic wave to through the effect of the inside ultrasonic generrator of a plurality of ultrasonic column 43, the inside ultrasonic wave that sends of immersion fluid extraction mechanism 4 on lower floor, make the inside high frequency vibrations that produce of liquid, tea cell breakage in high frequency vibrations, make the effect of improving the immersion fluid extraction through the supersound, in order to guarantee the extraction rate at the immersion fluid extraction in-process.

After the tea slurry and the extracting agent are subjected to the first-step extraction process in the jet flow extraction mechanism 3, the tea slurry and the extracting agent are collected by the action of a shielding cover 44 of the immersion liquid extraction mechanism 4 and then are sent to the lower half part of the extraction tank body 1, the collected liquid is sent to the immersion liquid extraction mechanism 4 and then is heated to a set temperature by the action of a heating wire 41, and stirring is periodically started by a stirrer 42, so that the components of the liquid in the immersion liquid extraction mechanism 4 are uniform, meanwhile, the non-uniform heating state caused by the fact that the center of the lower half part of the extraction tank body 1 is far away from the heating wire 41 is broken, the temperature uniformity of the liquid is improved, in the process of immersion liquid extraction, ultrasonic treatment is carried out on the liquid by the action of a plurality of ultrasonic columns 43, tea cells in the liquid are vibrated and crushed by the ultrasonic action, and a certain uniform mixing effect is increased by the vibration of the liquid, the extraction rate of the immersion extraction mechanism 4 is improved to a certain extent, and the low-temperature extraction effect on the tea is ensured.

Further, feed liquor pipe 321 runs through out tank cover 2, and one side that tank cover 2 kept away from feed liquor pipe 321 is provided with air duct 21, and air duct 21 is used for carrying out decompression or pressurization operation to the extraction jar body 1 inside extraction gas or leading-in gas to can carry out decompression or pressurization operation with the extraction jar body 1 inside through setting up of air duct 21, thereby make this extraction device can adapt to the requirement of carrying out the extraction at the pressure of difference.

When in use, firstly, the selected extract is added into the containing cylinder 331, the pressure pump 332 pressurizes the extract in the containing cylinder 331 and then conveys the extract to the connecting pipe 333, the extract is evenly injected into the plurality of injection rings 311 under the action of the plurality of branch ports 334 of the connecting pipe 333, so that the extract is conveyed in the injection rings 311 and is injected out through each injection head 312, then the crushed tea slurry enters the device through the liquid inlet pipe 321 arranged at the top end of the ring curtain sprayer 32, the slurry fed in through the liquid inlet pipe 321 is evenly guided into the ring pipe 323 through the liquid branch pipe 322, the slurry is conveyed in the ring pipe 323 to flow out through each spraying nozzle 324, so that the liquid flows out from each spraying nozzle 324, and the liquid is continuously discharged from the plurality of spraying nozzles 324 because the plurality of spraying nozzles 324 are evenly distributed at the bottom end of the ring pipe 323, so that the ring liquid curtain is formed at the upper half part of the extraction tank body 1, thereby uniformly scattering the slurry into the interior of the extraction tank body 1.

In the process of evenly spraying the size and evenly spraying the extraction liquid, because the equal slope of a plurality of shower nozzles 312 upwards sets up, the shower nozzle 312 all points to the center of the extraction jar body 1, upwards just point to the center of the extraction jar body 1 through the slope of shower nozzle 312, make a plurality of the liquid of shower nozzle 312 blowout evenly points to the position on the upper left of the equal altitude center of the extraction jar body 1, thereby make the extraction liquid that erupts upwards spout to one side, form the offset between the annular liquid curtain downwards, thereby improve the collision dynamics between extraction liquid and the size, make in the collision process between extraction liquid and the size, the cell wall atress of tealeaves is ruptured, impel the active ingredient in the tealeaves to release from inside the cell, improve the extraction efficiency in the efflux extraction. And in the collision process between the extraction liquid and the slurry, a plurality of strands of extraction agents are sprayed out to impact and mix with the annular liquid curtain formed by the slurry, so that a certain extraction effect is generated in the mixing process.

After the pulp and the extractant are subjected to the first-step extraction process in the jet flow extraction mechanism 3, the jet flow extraction mechanism 3 and the immersion liquid extraction mechanism 4 in the extraction tank body 1 are separated by the action of the shielding cover 44, the disordered state generated by the impact of the high-pressure extraction liquid in the upper jet flow extraction mechanism 3 is converted into a relatively uniform state through the collection of the shielding cover 44, and then the disordered state is conveyed into the lower immersion liquid extraction mechanism 4 through the diversion of the shielding cover 44 to perform a relatively slow immersion liquid extraction process, so that the upper jet flow extraction process is prevented from disturbing the lower immersion liquid extraction process.

After the liquid after gathering sends into immersion fluid extraction mechanism 4, effect through heater strip 41 heats to the settlement temperature, and start the stirring regularly through agitator 42, when guaranteeing that the composition of the inside liquid of immersion fluid extraction mechanism 4 is even, make extraction jar body 1 the latter half central authorities broken because the inhomogeneous state of being heated that leads to far away from heater strip 41, promote the temperature homogeneity of liquid, and at the in-process of immersion fluid extraction, effect through a plurality of ultrasonic columns 43, carry out ultrasonic treatment to liquid, shake the breakage through the tea cell of ultrasonic action in to liquid, and through the effect of ultrasonic wave, make liquid vibrations increase certain mixing effect, improve the extraction rate of immersion fluid extraction mechanism 4 to a certain extent, guarantee the low temperature extraction effect to tealeaves.

Comparative example of Effect

To further illustrate the technical effects of the method for extracting the organic selenium-rich tea extract of the present invention, the following experimental examples were set up to measure the product obtained by the method of the present invention:

(1) the experimental steps are as follows:

the residues after the water-soluble, alcohol-soluble, water-soluble and alcohol-soluble active ingredients and proteins are extracted in examples 1 to 3, the residues after the water-soluble, alcohol-soluble, water-soluble and alcohol-soluble active ingredients and proteins are extracted in comparative examples 1 to 3, the fresh Enshi natural selenium-enriched tea leaves used in examples 1 to 3 and comparative examples 2 to 3, and the ordinary fresh tea leaves without selenium used in comparative example 1 are respectively dried in a vacuum oven at 50 to 60 ℃ until the moisture content is less than 1.0%, and the content of the tea polyphenol, theophylline, chlorophyll, protein, selenium and theanine contained in each of the fresh tea leaves is measured.

(2) The experimental results are as follows:

(3) and (4) conclusion: according to the experimental results, the extraction rate of the tea polyphenol reaches more than 73%, the extraction rate of the theophylline reaches more than 98%, the extraction rate of the green tea can reach 65% -70%, the extraction rate of the protein reaches more than 52%, the extraction rate of the theanine reaches more than 88%, and the extraction rate of each effective component is obviously superior to that of the comparative example; in the embodiment, the extraction rate of selenium is 56-58%, compared with the common fresh tea without selenium, the organic selenium content in the extract is high, and the extract can be used as a good selenium supplement product.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. A method for extracting active ingredients in tea leaves is characterized by comprising the following steps:

1) picking fresh tea leaves, cleaning and crushing;

5) leaching the tea residue obtained in the step 3) by a salt extraction method, and filtering to obtain a leaching solution containing protein after leaching is finished;

6) precipitating protein from the protein-containing leaching liquor, centrifuging, collecting precipitate, washing the precipitate, and freeze-drying to obtain tea protein.

2. The method for extracting active ingredients from tea leaves according to claim 1, wherein the specific operation of the step 2) is as follows:

a) placing the ethanol water solution in a jet flow extraction mechanism (3) at the upper part inside an extraction tank body (1) of an extraction device, and spraying the ethanol water solution to the center of the extraction tank body (1) through a spraying pressurizer (33) and a sprayer (31);

b) adding the crushed tea leaves into the jet flow extraction mechanism (3), and downwards spraying the tea leaves in an annular shape through an annular curtain spraying device (32) to form an annular liquid curtain which collides with the ethanol water solution sprayed in the step a);

c) after being collided with the ethanol water solution, the crushed tea leaves enter an immersion liquid extraction mechanism (4) at the lower half part of the interior of the extraction tank body (1) to form a mixed liquid;

d) starting a stirrer (42) and an ultrasonic column (43) in the immersion extraction mechanism (4), leaching the mixed liquor formed in the step c), and heating the mixed liquor by a heating wire (41).

3. The method according to claim 2, wherein the mixed solution is heated in step d) at a temperature of 40-60 ℃ for 8-12 hours.

4. The method according to claim 1, wherein the leaching solution used in the salt extraction in the step 5) is a neutral salt solution; the concentration of the neutral salt solution is 0.3-0.7 mol/L; the dosage of the neutral salt solution is 1-5 times of the fresh tea; the neutral salt solution is a sodium chloride solution or a potassium chloride solution.

5. An extraction apparatus used in the extraction method of active ingredients from tea leaves according to any one of claims 1 to 4, characterized by comprising an extraction tank (1) and a tank cover (2), wherein the upper half part of the inside of the extraction tank (1) is provided with a jet extraction mechanism (3), and the lower half part of the inside of the extraction tank (1) is provided with an infusion extraction mechanism (4);

jet-flow draws mechanism (3) including sprayer (31), ring curtain drenches sprayer (32) and sprays presser (33), sprayer (31) be used for with the extract to draw jar body (1) center department blowout, ring curtain drenches sprayer (32) and is used for being cyclic annular downward blowout with the raw materials, it is used for providing to spray presser (33) sprayer (31) sprays the required pressure of extract.