KR100950780B1 - A sampling method for extracting to tea leaf - Google Patents

Abstract

The present invention comprises the steps of heat treating the harvested green leaves; Grinding while adding deionized water to the leaf which has been heat treated as described above; Adjusting the grinding liquid, which has been ground as the above, so that the pH is acidic, and then adding deionized water to leach the hot water, immediately cooling, and compressing and filtration; Restoring the pH of the supernatant obtained by centrifuging the filtrate filtered through compression as described above; Regarding the method of extracting a high quality extract from the green leaves of tea, comprising the step of adding beta-cyclodextrin (β-cyclodextrin) to the pH-restored extract as described above,

The extraction method is a novel tea extraction method that allows tea components to be easily extracted without separate processing process by enzymatically deactivating and then crushing the green leaves of the collected tea by enzymatic treatment. Since it does not go through complicated processing such as steaming or food, it can reduce the processing time drastically, thereby saving energy and cost, and destroying green tea components by not keeping in mind or direct high-temperature treatment during processing. It is less, the green tea component extraction efficiency is significantly improved, and color, flavor and the like can be obtained a high quality extract.

Tea, steaming, grinding, hydrothermal extraction, centrifugation

Description

A sampling method for extracting to tea leaf}

The present invention relates to a method for obtaining a high quality extract from the green leaves of tea, and more specifically, the green leaves of the harvested tea without enzymatic deactivation of the green leaves without going through complex processing such as thickening or food, and then crushed and enzyme A novel extraction method capable of extracting high quality tea components by treatment

Tea is a symbol and health drink that processed the shoots or leaves of Camellia sinensis O, Kuntze, which belongs to the Camellia family, and has been processed in various ways according to the taste and technology of each nation. , Semi-fermented tea, oolong tea, fermented tea, black tea, and post-fermented tea.

These teas contain catechins, caffeine, amino acids, fibrin, pectin and chlorophyll flavonol derivatives, plant pigments such as anthocyanin, and various components such as lipids, resins, essential oils and vitamins. Diuretic, antipyretic, astringent, and catechins include cholesterol suppression, amylase inhibition, blood sugar elevation inhibition, arteriosclerosis prevention, antioxidant activity, antibacterial action, blood pressure increase inhibition, enzyme activity inhibition, anti-ulcer Biological activity effects such as action and mutation suppression have been reported, and their consumption continues to increase.

In addition, in recent years, the tea is not only a beverage to drink, but also a functional ingredient is extracted from the tea leaves, and its use as an additive for food, medicine, health food, cosmetics, etc. has been expanded. In particular, high-quality green tea extract has been increasingly used as a diluent use as a food additive or direct beverage.

Tea for use in such a purpose is to make the dried tea by processing the green leaves of the tea by a thickening or food processing process and then extract the hot water to obtain an extract, and then the extract is concentrated under reduced pressure, ultrafiltration, reverse osmosis, freeze drying, etc. Tea concentrate or extract powder of tea has been prepared by using the above method alone or in combination.

At this time, the tea leaves used as raw materials for extraction are generally a thickening process consisting of steaming, crude oil, oil, heavy oil, essential oil, drying, flavor, etc. The same complicated machining process is carried out.

Therefore, the conventional tea extract concentrate manufacturing process as described above has a problem that the cost increase factor such as a complicated process, a large energy consumption by going through several processing steps. In addition, there was another problem that the quality is poor, such as browning of the tea leaves by browning the excessive heat treatment (within the moisture content 5%) to dry the tea leaves during the processing process.

Therefore, the present invention is to solve the above problems, it is possible to extract the green leaves of the collected tea directly from the green leaves without going through the existing complicated processing process, the process is simple and the cost is saved, green tea component extraction It is an object of the present invention to provide a method for extracting high-quality extracts from the green leaves of tea that can not only dramatically improve the performance but also improve the quality such as color and flavor.

In addition, another object of the present invention is to provide a high-quality tea extract with less destruction of tea components, significantly improved extraction efficiency, and improved color and flavor of the extract.

In addition, another object of the present invention is to provide a concentrate of tea prepared by concentrating the extract of the tea.

In addition, another object of the present invention is to provide an extract powder of tea prepared by powdering the extract of the tea.

According to an aspect of the present invention,

Heat treating the harvested leaves; Grinding while adding deionized water to the leaf which has been heat treated as described above; Adjusting the grinding liquid, which has been ground as the above, so that the pH is acidic, and then adding deionized water to leach the hot water, immediately cooling, and compressing and filtration; Restoring the pH of the supernatant obtained by centrifuging the filtrate filtered through compression as described above; It provides a method of extracting a high quality extract from the leaves of tea, characterized in that it comprises; adding a beta-cyclodextrin (β-cyclodextrin) to the pH-restored extract as described above.

In addition, the present invention provides a method for extracting a high-quality extract from the green leaves of the tea, characterized in that for the 40-120 seconds to increase the steam of 90 ~ 120 ℃.

In addition, the present invention provides a method for extracting a high quality extract from the green leaves of the tea, characterized in that the grinding is made through the chopper or colloid mill.

In addition, the present invention is a method of extracting a high-quality extract from the green leaves of tea, characterized in that the pH is adjusted to 4.0 ~ 6.0 by adding the selected one of the acetic acid (L-accorbic acid), malic acid, citric acid To provide.

In another aspect, the present invention provides a method for extracting a high quality extract from the leaves of tea, characterized in that the step of enzymatic treatment using a hemicellase-containing enzyme before the leaching in hot water after adjusting the pH of the grinding solution. .

In addition, the present invention is characterized in that the hemicellase-containing enzyme is a hemicellase enzyme, including hemicellase activity, hemicellulose agent enzyme having a pyrase activity or a hemicellulase enzyme agent having a pectinase activity and the like, and an enzyme agent having a hemicellulase activity. It provides a method for extracting high quality extracts from the green leaves of tea.

In addition, the present invention provides a method for extracting a high quality extract from the green leaves of tea, characterized in that the enzyme treatment is made for 20 to 50 ℃ for 0.5 to 4 hours.

In addition, the present invention provides a method for extracting a high quality extract from the green leaves of tea, characterized in that the enzyme is added 0.01 ~ 0.5% by weight based on the grinding liquid of tea leaves.

In addition, the present invention provides a method for extracting high quality extracts from the green leaves of tea, characterized in that the leaching is added to hot water to the enzyme-treated tea leaves grinding for 20 to 60 minutes at 70 ~ 97 ℃.

In addition, the present invention provides a method for extracting a high quality extract from the green leaves of tea, characterized in that the centrifugation is carried out for 10 to 30 minutes at 5,000 ~ 10,000rpm.

In addition, the present invention provides a method for extracting high-quality extracts from the leaves of tea, characterized in that the pH recovery of the supernatant is made by adding sodium ascorbate or sodium bicarbonate.

In addition, the present invention provides a high-quality tea extract, which is produced by the above-described manufacturing method, the destruction of tea components, the extraction efficiency is significantly improved, and the color and flavor of the extract is improved.

In addition, the present invention provides a concentrated solution of tea, characterized in that the extract of the tea produced by decompression concentration, RO concentration, ultra-concentration process alone or in parallel.

The present invention also provides an extract powder of tea, characterized in that prepared by lyophilizing the extract of the tea.

As described above, the method of extracting the high quality extract from the green leaves of the tea of the present invention enzymatically deactivates the green leaves of the collected tea by steaming, crushes and enzymatically immediately leaches the tea components without any additional processing. It is a new tea extraction method that enables extraction, which does not go through the complicated process such as the traditional cooking or food, so the process time can be drastically reduced and energy and cost can be saved. In the process of processing, it does not go through remarks or direct high-temperature treatment, so there is little destruction of green tea ingredients, and the green tea ingredient extraction efficiency is dramatically improved, and the color, flavor, etc. are improved and high quality extracts are obtained.

Hereinafter, the present invention will be described in more detail.

The present invention is a method that can extract the components of tea directly from the leaves without going through the existing complex processing process, that is, after deactivation of enzymes in the leaves by the steaming process after harvesting finely crushed tea leaves and plant cell wall It is characterized in that the treatment with a degrading enzyme and then extracted with hot water.

In such a method, first, heat treatment is carried out with steam to deactivate the enzyme of the harvested leaves. Tea leaves of the present invention is a tea leaf obtained from the genus Camellia ( C. sinensis, C. assamica) or their hybrids, and the harvesting time is not limited to a young leaves or shaded cultivated soft leaves are preferred. Do.

The leaves are heat treated for 40 to 120 seconds with a 90-120 ° C. evaporation, and limiting the temperature of the evaporation is that the enzymes in the leaves cannot be completely deactivated when heat-treating at a temperature lower than 90 ° C. during the subsequent process. Polyphenols are oxidized by browning, and on the contrary, when heat treatment is performed at a temperature higher than 120 ° C., the tea leaves are excessively ripened, resulting in poor color and flavor. However, in general, when the leaves are thin, the heat treatment is relatively short, and the hardened leaves are long in heat treatment.

As a next step, after cooling the heated leaves in the previous step to room temperature immediately, the deionized water is added through 1 to 5 times the weight of the green leaves, and then crushed through a chopper or colloid mill.

 This grinding process is to facilitate the elution of the foliar constituents by destroying the foliar tissue, the conventional tea processing is easy to dissolve the foliar constituents after inactivation of enzymes in the green leaves in the case of thickening or steaming process In the present invention, the above step is omitted, and the present invention omits the above-described process and crushes the heated leaves by using a chopper or colloid mill to have an average particle size of 0.1 to 0.5 cm to facilitate the dissolution of the leaf components. do.

As a next step, after adjusting the pH of the teal ground grinding solution obtained in the previous step to be acidic, deionized water is additionally added, hot water is leached and immediately cooled, followed by compression filtration and centrifugation. This pH control is to minimize the browning of the tea leaves in the grinding fluid by maintaining the acidic state of pH 4.0 ~ 6.0 by adding a selected from acobic acid (L- accorbic acid), citric acid, malic acid.

On the other hand, after adjusting the pH of the grinding liquid before the hydrothermal leaching may be added to the enzyme treatment using a hemicellase-containing enzyme, by adjusting the pH from 4.0 to 6.0 in the previous step to optimize the conditions for the enzyme action Provide at the same time. Hemicellase-containing enzymes used in such enzymatic treatments include hemicellase, hemicellase enzymes having chisiase activity, hemicellulase enzymes having pectinase activity, and enzymes having hemicellulase activity. .

The above enzyme treatment is intended to facilitate the elution of the tea leaf components by insoluble solids such as hemicellulose, which is the constituent of the tea leaf cell wall, to facilitate the elution of the tea leaf components.

At this time, the enzyme treatment temperature is performed at 20-50 ° C. (preferably 30-40 ° C.), which is the optimum temperature of the enzyme, and the enzyme treatment time is preferably 0.5-4 hours. This is because if the enzyme treatment time is lower than 0.5 hours, the degradation effect by the enzyme treatment is inferior, and if it is more than 4 hours, quality deterioration such as color and flavor occurs.

In addition, the amount of enzyme added is preferably 0.01 to 0.5% by weight based on the grinding liquid of the tea leaves, the amount of the enzyme is added according to the enzyme titer, the type of enzyme, the degree of hardening of the tea leaves, the degree of grinding of the tea leaves, the concentration of the grinding material, etc. Adjusted.

The hydrolyzate treated by enzymatic treatment was added 1-5 times of hot water to leach at 70-97 ° C. for 20-60 minutes to obtain a leachate. The leachate was immediately cooled to 0-20 ° C. and then compressed with a filter cloth. It will be filtered.

At this time, the amount of deionized water is not particularly limited, but it is preferable to add 1 to 5 times the amount of tea leaves, which is too low when the amount of leaching yields due to excessive concentration, on the contrary, if too much amount is added to the leaching liquid This is because the concentration of is too thin, which will cost a lot in the future preparation of the concentrate.

In addition, the leaching temperature is less than 70 ℃ leaching ability is not only deterioration of the enzyme is not good deactivation problem and 97 ℃ or more because the problem of poor quality, such as browning of the extract is preferably leached within the above range. Do.

As a next step, after the leaching in the previous step, the filtrate obtained by compression filtration is centrifuged to restore the pH.

This centrifugation is to separate insoluble solids and turbid materials such as fine tea leaves fiber, even if the liquid filtered in the filter cloth in the previous step, and to separate them, the rotation speed is 5,000 ~ 10,000rpm for 10-30 minutes Will be implemented. This is because if the rotational speed is lower than 5,000rpm during centrifugation, the removal of insoluble solids such as fiber is insufficient, and if it is higher than 10,000rpm, the removal capacity does not increase any more.

The supernatant obtained by centrifugation as described above is added with sodium ascorbate or sodium bicarbonate to restore pH to neutrality.

As a next step, a high quality tea extract is obtained by adding 0.3-0.5% of beta-cyclodextrin to the extract which is restored to pH after filtration in the previous step. The beta-cyclodextrin (β-cyclodextrin) is to serve as a carrier that can contain a variety of tea components, in particular the fragrance-like component is effective in improving the flavor of the leaching and flavor retention during the preparation of the concentrate or extract powder.

The extract of the tea prepared in this way can be obtained in the form of a concentrated liquid by a single or parallel treatment of a conventional process such as concentrated under reduced pressure, RO concentration, ultra-concentration, etc. In addition, the extract of the tea can be lyophilized to prepare a powder form. It is a well known fact.

The present invention prepared through the above steps is enzymatically deactivated the green leaves of the collected tea, and then immediately crushed, enzymatically treated and then leached to extract a new tea that enables easy extraction of tea components without a separate processing step. As a method, such a method does not go through complicated processing processes such as a conventional thickening or food preparation, so that the processing time can be drastically reduced, thereby saving energy and cost. There is no destruction of the functional ingredients because it does not undergo high heat treatment, and the extractability of green tea components can be dramatically improved, and high-quality extracts with improved color and flavor can be prepared.

In addition, the present invention has been described for the leaf of the tea tree as an example, which is not limited to the leaf of the tea tree of the present invention, in addition to the mulberry leaf, lotus leaf, mugwort, it is found that it can be variously applied to the leaf of the leaves, such as herbs .

Hereinafter, the present invention will be described in more detail with reference to the following examples, which are presented to aid the understanding of the present invention, but the present invention is not limited thereto.

<Examples 1 to 9>

1,000 g of Boseong acid green tea leaves (about 75% water content) harvested in July was heated at 100 ° C. for 80 seconds, and then pulverized to around 0.3 cm in average particle size with chopper while adding 2,000 mL of deionized water. L-ascorbic acid was added to the liquid containing the dried tea leaves to adjust the pH to 5.0, and 0.1% of the enzyme (Rapidase TF, DSM Food Specialties, Netherlands) with hemicellase activity was treated. Temperature and time was performed as shown in Table 1 below.

Thus, 8,000 mL of deionized water was added to the ground product obtained after the enzymatic treatment, leached at 85 ° C. for 30 minutes, and then centrifuged at 8,000 rpm for 20 minutes after passing through a 200 mesh nylon filtration. The supernatant after centrifugation was restored to pH with sodium ascorbate after filtration, and 0.3% of β-cyclodextrin was added to prepare green tea extract.

Example Enzyme Treatment Condition Temperature (℃) Time (min) One 25 120 2 30 120 3 37 120 4 45 120 5 50 120 6 45 60 7 45 180 8 45 240 9 45 300

 Comparative Example 1

Adds 50 times the amount of deionized water to the tea leaves obtained in July through Boseongsan green tea leaves (about 75% water content) harvested in July through conventional process (heat, oil, oil, oil, essential oil, drying, flavor). After extracting for 20 minutes at 60 ℃ filtered and then the same amount of L-ascorbic acid, sodium ascorbate, β-cyclodextrin was added as in Examples 1 to 9 to prepare a green tea extract.

Experimental Example 1

 Soluble solids, total polyphenols, and total amino acids were analyzed for green tea extracts prepared in Examples 1 to 9 and Comparative Examples, and the results are shown in Table 2 below. The results are shown in Table 3 below, respectively.

Soluble solids content

After each extract to room temperature measured by a digital refractometer (PR-101, Atago co. Ltd.) was shown as ° brix, the results are shown in Table 2 below.

Total Polyphenol Content

Total polyphenol quantitation was determined according to the Folin-Ciocalteu variant. That is, 6 mL of distilled water and 0.5 mL of folin-Ciocalteu reagent were added and mixed with 0.1 mL of the sample. After 8 minutes, 2 mL of 15% Na ₂ CO ₃ was added thereto, followed by 10 mL. Then, after standing for 2 hours at room temperature, the absorbance was measured at 765 nm and quantified in terms of (+) catechin, and the results are shown in Table 2 below.

Total amino acid content

The sample filtrate was shaken with polyvinylpolypyrrolidone, allowed to stand for 30 minutes, and then 1 mL of the filtered filtrate was added to a screw-cap tube. 0.5 mL of the pH 5.2 citric acid buffer solution adjusted with the mixture) and 0.5 mL of SnCl ₂ solution (SnCl _{2 ·} 2H ₂ O 50 mg dissolved in 25 mL of the pH 5.2 citric acid buffer solution) were added and mixed well. After warming for 30 minutes in a constant temperature bath, 5 mL of diluted solution (iso-prophylalcohol: H2O = 1: 1) was added thereto, shaken well, and absorbance was measured at 570 nm. At this time, the amino acid content was converted into a calibration curve after using theanine, and the results are shown in Table 2 below.

Sensory test

The green tea extract was mixed with hot water at 60 ° C, diluted to 0.1 ° brix, and tasted by 20 trained professional panelists. The sensory test was performed on a nine-point scale for color, aroma, taste, and overall preference. It is shown in Table 3 below.

Treatment Soluble solids (° Brix) Total Polyphenols (mg / mL) Total amino acid (mg / mL) Example 1 1.85 ± 0.07 3.882 ± 0.177 0.217 ± 0.001 Example 2 1.87 ± 0.04 3.944 ± 0.094 0.227 ± 0.001 Example 3 1.90 ± 0.01 4.306 ± 0.046 0.224 ± 0.001 Example 4 1.90 ± 0.00 4.401 ± 0.055 0.230 ± 0.000 Example 5 1.90 ± 0.01 4.400 ± 0.098 0.246 ± 0.001 Example 6 1.90 ± 0.08 4.298 ± 0.049 0.219 ± 0.002 Example 7 2.18 ± 0.04 4.414 ± 0.056 0.234 ± 0.001 Example 8 2.22 ± 0.04 4.413 ± 0.033 0.234 ± 0.001 Example 9 2.22 ± 0.08 4.348 ± 0.020 0.233 ± 0.002 Comparative Example 1 1.64 ± 0.08 3.216 ± 0.002 0.213 ± 0.002

Treatment color incense flavor Overall preference Example 1 6.6 5.6 5.2 5.3 Example 2 6.5 5.6 5.3 5.3 Example 3 6.3 6.0 5.3 5.5 Example 4 6.3 6.2 5.8 5.9 Example 5 6.1 6.1 5.4 5.5 Example 6 6.4 6.2 5.5 5.6 Example 7 5.8 5.7 5.1 5.1 Example 8 5.5 5.4 4.5 4.5 Example 9 5.0 4.8 4.2 4.2 Comparative Example 1 5.0 5.6 5.2 5.2

As shown in Table 2, Examples 1 to 9 produced by the manufacturing method of the present invention was found to have a higher soluble solids and total polyphenol content than the comparative example prepared by the conventional thickening process. In addition, the total amount of amino acid is slightly different, but it can be seen that it is relatively high, which can be seen that the easy elution of components and high quality green tea extract can be obtained by the process of the present invention.

However, within the results of Examples 1 to 9, the soluble solid content was not affected by the enzyme treatment temperature and showed a tendency to increase as the enzyme treatment time became longer, and the total polyphenol content was determined by the enzyme treatment concentration and treatment time. When the enzyme treatment temperature was different and the enzyme treatment temperature was increased, it increased as the temperature increased, but it did not increase any more than 45 ℃, and when the enzyme treatment temperature and concentration were constant and the treatment time was different, Similar results were found in the treatments. However, the total amino acid content was found to be no significant difference between treatments.

In addition, as shown in Table 3, as a result of the sensory test, the test spheres produced by each example had little effect on the enzyme treatment concentration and temperature, but the color, flavor, taste, and overall acceptability when the enzyme treatment time was 60 minutes or more. It was found to fall, and when the extract was prepared with dried leaves, it was found to be low in color, taste and overall acceptability.

<Examples 10-15>

Prepared in the same manner as in Example 4, deionized water was added to the grinding obtained after the enzyme treatment and leached under the conditions as shown in Table 4 to prepare a green tea extract.

Treatment Leaching condition Temperature (℃) Time (min) Example 10 75 30 Example 11 85 30 Example 12 95 30 Example 13 85 20 Example 14 85 60 Example 15 85 80

Experimental Example 2

Soluble solids, total polyphenols, and total amino acid analysis were performed on the green tea extracts prepared in Examples 10 to 15, and the results are shown in Table 5 below.

Treatment Soluble solids (° Brix) Total Polyphenols (mg / mL) Total amino acid (mg / mL) Example 10 1.78 ± 0.04 3.857 ± 0.007 0.186 ± 0.001 Example 11 1.90 ± 0.08 4.346 ± 0.006 0.219 ± 0.002 Example 12 1.92 ± 0.08 4.350 ± 0.004 0.220 ± 0.001 Example 13 1.72 ± 0.04 3.873 ± 0.033 0.208 ± 0.005 Example 14 1.92 ± 0.08 4.348 ± 0.020 0.223 ± 0.002 Example 15 1.92 ± 0.12 4.384 ± 0.025 0.227 ± 0.007

As shown in Table 5, the soluble solids, total polyphenols and total amino acid content according to the leaching temperature was found to be no significant difference at 85 ℃ or more at the same leaching time of 30 minutes leaching, the same temperature 85 ℃ The leaching showed little increase over 30 minutes.

<Examples 16-21>

Prepared in the same manner as in Example 4, without deionized water was added to deionized water obtained in the previous step and leached under the conditions shown in Table 6 to prepare a green tea extract.

Treatment Leaching condition Temperature (℃) Time (min) Example 16 75 30 Example 17 85 30 Example 18 95 30 Example 19 95 20 Example 20 95 40 Example 21 95 60

Experimental Example 3

 Soluble solids, total polyphenols and total amino acids were analyzed for green tea extracts prepared in Examples 16 to 21 in the same manner as in Experimental Example 1, and the results are shown in Table 7. In addition, the sensory test was also performed in Experimental Example 1 and The same procedure was followed and the results are shown in Table 8, respectively.

Treatment Soluble solids (° Brix) Total Polyphenols (mg / mL) Total amino acid (mg / mL) Example 16 1.04 ± 0.06 3.766 ± 0.106 0.180 ± 0.012 Example 17 1.06 ± 0.05 3.806 ± 0.067 0.204 ± 0.025 Example 18 1.14 ± 0.05 3.929 ± 0.004 0.214 ± 0.008 Example 19 1.10 ± 0.12 3.903 ± 0.012 0.214 ± 0.021 Example 20 1.42 ± 0.10 4.084 ± 0.024 0.217 ± 0.013 Example 21 1.78 ± 0.08 4.101 ± 0.009 0.220 ± 0.014

Treatment color incense flavor Overall preference Example 16 6.4 5.7 5.6 5.5 Example 17 6.2 5.9 5.7 5.7 Example 18 6.0 5.9 5.7 5.7 Example 19 6.2 6.1 5.8 5.8 Example 20 5.8 5.5 5.3 5.4 Example 21 5.6 5.3 5.2 5.2

As shown in Table 7, the content of soluble solids, total polyphenols and total amino acids according to leaching temperature was not significantly different at 85 ° C. after leaching for 30 minutes. When leaching to the same temperature of 95 ℃, it showed little increase over 30 minutes. This showed a similar tendency to the case of enzyme treatment, but the optimum leaching temperature was 95 ℃, slightly higher than that of enzyme treatment, and higher in all treatments than in the case of dry leaf leaching.

In addition, as shown in Table 8, the sensory test results showed similar tendency in color, aroma, taste, and overall acceptability except in Examples 20 and 21.

Claims (13)

Heat treating the harvested leaves; Grinding the heated leaves as described above while adding deionized water; Adjusting the grinding liquid, which has been ground as the above, so that the pH is acidic, and then adding deionized water to leach the hot water, immediately cooling, and compressing and filtration; Restoring the pH of the supernatant obtained by centrifuging the filtrate filtered through compression as described above; Adding beta-cyclodextrin (β-cyclodextrin) to the pH-restored extract as described above; Method of extracting a high quality extract from the green leaves of tea. The method of extracting high quality extract from the green leaves of tea according to claim 1, wherein the step of increasing heat is performed by adding a heat of 90 to 120 ° C. for 40 to 120 seconds. The method of extracting high quality extract from the green leaves of tea according to claim 2, wherein the grinding step is performed through chopper or colloid mill. The method of extracting a high quality extract from the green leaves of tea according to claim 3, wherein the pH is adjusted to be 4.0-6.0 by adding a selected one from acobic acid, citric acid and malic acid. . The method of extracting high quality extract from the green leaves of tea according to claim 4, further comprising the step of enzymatic treatment using hemicellase-containing enzyme prior to hydrothermal leaching after adjusting the pH of the grinding solution. The method according to claim 5, wherein the hemicellase-containing enzyme is characterized in that hemiscellase, including hemicellase enzyme having a chisiase activity or hemicellulase enzyme having a pectinase activity, etc. Method of extracting high quality extract from the green leaves of tea. The method of claim 5, wherein the enzyme treatment is performed at 20-50 ° C. for 0.5-4 hours. The method according to claim 5, wherein the enzyme is a high-quality extract from the green leaves of tea, characterized in that the addition of 0.01 to 0.5% by weight relative to the grinding liquid of tea leaves. The method of claim 5, wherein the leaching is performed by adding hot water to the enzyme-treated tea leaves and leaching at 70-97 ° C. for 20 to 60 minutes. The method of claim 9, wherein the centrifugation is performed at 5,000 to 10,000 rpm for 10 to 30 minutes. A high quality tea extract, which is prepared by the method of any one of claims 1 to 10, wherein the tea components are less disrupted, the extraction efficiency is remarkably improved, and the color and flavor are improved. Tea concentrate of claim 11, characterized in that the tea extract was prepared by the sole or parallel treatment of reduced pressure, RO concentration, ultra-concentration. Tea extract powder, characterized in that prepared by lyophilizing tea extract of claim 12.