JPS61130285A - Process for producing crude catechin from tea leaf - Google Patents

Abstract

PURPOSE:To obtain crude catechin containing catechin useful as an antioxidant, etc. in high concentration and high efficiency, by washing tea leaves with a specific mixed organic solvent to remove caffeine, etc., moistening the leaves with water, and extracting with an organic solvent. CONSTITUTION:Tea leaves are washed with a mixture of mutually compatible hydrophobic and hydrophilic organic solvents (preferably a combination of chloroform and methanol, etc.) to remove caffeine and pigments from the leaves, and said solvents are distilled out from the leaves. The treated leaves are moistened with water, and are made to contact with an organic solvent (preferably ethyl acetate) to extract the catechin-containing component to the solvent. The objective product containing a large amount of formula I (R1 is H or OH; R2 is H or group of formula II) can be produced by distilling out the organic solvent from the extract. The amount of water for moistening the tea leaves is preferably 0.65-1.3pts.wt. per 1pt.wt. of the treated tea leaves.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing crude catechins, and more particularly to a method for producing catechins from tea leaves as phase catechins with high efficiency and high concentration.

The present inventors have been conducting research on the pharmacological effects of tea components, and have confirmed the often strong physiological activity of tea catechins, which are the main components of tea tannins.

Patent Application No. 1982-120963, Patent Application No. 59-10980
As a result of further study, they discovered a method for efficiently producing catechins as crude catechins from tea leaves, and completed the present invention.

The present invention involves washing tea leaves with a compatible mixed organic solvent of hydrophobic and hydrophilic properties to remove caffeine and pigments, distilling off the mixed organic solvent from the tea leaves, and then adding an appropriate amount of water to the tea leaves. It is characterized by adding and moistening it, then contacting it with an organic solvent to transfer components including catechins into the organic solvent, and then distilling off this organic solvent; represented by Yin Shun H This is a method for producing crude catechin containing catechins in high concentration.

The tea leaves used as raw materials in the method of the present invention are unfermented teas such as green tea and semi-fermented teas such as oolong tea, and are used in the form of fresh leaves, dried products, powders, etc.

Specific examples of compatible hydrophobic and hydrophilic mixed organic solvents used to wash the tea leaves include:
Examples include appropriate combinations of hydrophobic organic solvents such as chloroform, hexane, methyl chloride, and ethyl chloride and wood-loving organic solvents such as methanol, ethanol, and acetone. Particularly suitable are combinations of chloroform and methanol and hexane and ethanol.

The hydrophobic organic solvent in the mixed organic solvent is used to extract oil-soluble components such as pigments, and is used in a larger amount than the hydrophilic organic solvent. On the other hand, the hydrophilic organic solvent has the effect of infiltrating the tea leaves and facilitating the elution of each component, and may be used in small amounts.

Kaffeif 1 pigments are removed by washing the tea leaves with the above mixed organic solvent. After the washing treatment, the solvent is distilled off from the tea leaves.

Next, water in an amount of 0.65 to 1.3 times the weight of the tea leaves is added to the tea leaves to moisten them, and then catechins are extracted using an organic solvent. Examples of the organic solvent used here include methanol, ethanol, n-propyl alcohol, and isopropyl alcohol.

n-butanol, acetone, methyl isobutyl ketone,
Examples include methyl acetate, ethyl acetate, butyl acetate, and among these, ethyl acetate is preferred.

Regarding the amount of organic solvent used, in the case of ethyl acetate,
4 times or more, preferably 5 times more than 1 part by weight of tea leaves without water added
After adding the organic solvent, stirring and mixing or refluxing are performed to extract the catechins into the organic solvent.

Thus, components including catechins migrate into the organic medium. Next, after distilling off the organic solvent, the remaining liquid is made into an aqueous solution. In this way, crude catechin containing a high concentration of catechins is obtained. Furthermore, a dry powder can be obtained by subjecting the aqueous solution to treatments such as spray drying and freeze drying.

The catechins obtained by the present invention have the following general formula % Formula % Specifically, there are the following four types of catechins.

(-) Epica chicken (in the general formula, R,=H.

Rz = H) (-) Epigallocatechin (in the general formula, R+ = OH.

Rz = H) (-)Epigallocatechin gallate (in the general formula, (-)epigallocatechin gallate (in the general formula) Although the above catechins are water-soluble, they can be mixed with fats and oils by dissolving them in a small amount of ethanol in advance. can be done.

Catechins have various excellent effects such as antioxidant effects, anti-fading effects on natural pigments, and suppressive effects on increases in blood cholesterol, and are expected to have a wide range of uses.

Next, the present invention will be explained by examples.

Example 1 100 g of green tea powder was refluxed for 15 hours with 1.51 g of a chloroform-methanol mixture having various ratios to remove caffeine and pigments from the tea leaves, and then the chloroform-methanol mixture was distilled off from the tea leaves.

Next, an equal weight of water was added to the tea leaves to moisten them, and then the tea leaves were treated with 22 ethyl acetate to extract the catechins in the tea leaves into ethyl acetate. In this way, ethyl acetate was distilled off from the obtained ethyl acetate solution, water was added at the same time to form an aqueous solution, and this aqueous solution was freeze-dried to obtain a dry powder. Table 1 shows the results of measuring the weight of this dry powder, the amount of catechin contained in the powder (measured by the official tea tannin quantitative method using the total amount of chicken as the amount of tannin), and the amount of caffeine as an impurity. Further, a crude catechin powder obtained by carrying out the above refluxing procedure with only chloroform containing no methanol and a crude catechin powder obtained by carrying out the same procedure with chloroform:methanol = 9:1 or 15:1 were mixed with a certain amount of water. Figure 1 shows the results of measuring the absorbance.

Example 2 Table 2 shows the results of the final product obtained by using n-hexane and ethanol in place of chloroform and methanol as the mixed organic solvent in Example 1 and following the same procedure. An absorbance measurement diagram is shown in FIG.

Example 3 In Example 1, chloroform:methanol=15=1
After washing the tea leaves under reflux with a chloroform-methanol mixture to remove caffeine and pigments, the mixture was distilled off, and water was added in each amount to 200 g of the obtained tea leaves.

Next, this was subjected to the reflux operation with ethyl acetate 31 in the same manner as in Example 1, and the amount of water added and the amount of tannin were determined by using the official quantitative method to determine the amount of crude catechin in the resulting dry powder as the amount of tannin. The relationship is shown in Table 3.

Table 3 *When the amount of water exceeds 1.3 times the amount of tea N, water drips from the tea leaves and catechins are washed away.

Example 4 In Example 3, the same weight of water was added to 100 g of the pretreated tea leaves to moisten them, and the tea leaves were subjected to the following treatment in various organic solvents including reflux operation. Table 4 shows the results of measuring the dry matter content and tannin content (total chicken content) thus obtained.

Example 5 In Example 4, the extraction solvent was set as ethyl acetate, various tea leaves were appropriately selected, and the procedure was carried out according to the standard method.
The values of J amount and tannin amount per tea leaf roog are
Shown in the table.

[Brief explanation of drawings]

FIGS. 1 and 2 are graphs showing the absorbance of an aqueous solution of crude catechin powder. Procedural master's letter (spontaneous) December 26, 1981

Claims (1)

[Claims] 1. After washing tea leaves with a compatible mixed organic solvent of hydrophobic and hydrophilic properties to remove caffeine and pigments, the mixed organic solvent is distilled off from the tea leaves; General formula ▲ Mathematical formula characterized by adding an appropriate amount of water to moisten it, then contacting it with an organic solvent to transfer components including catechins into the organic solvent, and then distilling off this organic solvent, There are chemical formulas, tables, etc.▼ (Here, R_1 indicates H or OH, and R_2 indicates H or ▲There are mathematical formulas, chemical formulas, tables, etc.▼.) How to manufacture. 2. The method according to claim 1, wherein the tea leaves are unfermented tea or semi-fermented tea. 3. The compatible mixed organic solvent is a combination of a hydrophobic organic solvent selected from chloroform, hexane, methyl chloride and ethyl chloride and a hydrophilic organic solvent selected from methanol, ethanol and acetone. A method as claimed in claim 1. 4. Appropriate amount of water to moisten the tea leaves is 0% of the weight of pretreated tea leaves.
．． The method according to claim 1, which is 65 times to 1.3 times. 5. After adding an appropriate amount of water to the tea leaves, the organic solvent to be contacted is selected from methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol, acetone, methyl isobutyl ketone, methyl acetate, ethyl acetate, and butyl acetate. Claim 1 which is
The method described in section.