JPH06184591A - Extraction of fragrant component of tea leaf - Google Patents

Abstract

PURPOSE:To extract only the fragrant component of the water-soluble fraction from tea leaves with supercritical carbon dioxide. CONSTITUTION:Water is added to tea leaves to such an extent that leaves are wet, and the fragrant component is then extracted with supercritical carbon dioxide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for extracting tea leaf aroma components, and more particularly to a method for extracting tea leaf aroma components using carbon dioxide in a supercritical state.

[0002]

2. Description of the Related Art As a conventional method for extracting a fragrance component with carbon dioxide in a supercritical state, Japanese Patent Laid-Open No. 59-232064 has been proposed.
As disclosed in Japanese Patent Publication, a method of treating a processed fish such as dried bonito and dried bonito with carbon dioxide in a supercritical state to extract and recover a natural aroma component in carbon dioxide. It has been known.

In the above-mentioned conventional techniques, all kinds of aroma components contained in the raw materials have been extracted regardless of whether they are water-soluble or oil-soluble. Therefore, regarding the production of instant seasonings using natural seasonings such as bonito flakes and dried sardines, it has been the conventional practice to extract all kinds of aroma components from the above-mentioned raw materials, as is the effect of the natural seasonings. That method was convenient. However, when only the aroma component of the water-soluble category is required, for example, in the case of extracting the aroma component from the tea leaf in order to produce instant tea that is close to tea prepared by pouring hot water into the tea leaf, the conventional method is used. It could not be used as it was. That is, when the conventional method is used as it is, not only does the aroma component of the oil-soluble category extracted from tea leaves adversely affect the aroma of tea,
At the same time, the extracted resin component adversely affects the taste of tea, which is not preferable.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for extracting only aroma components in a water-soluble fraction from tea leaves by using carbon dioxide in a supercritical state.

[0005]

According to the present invention, when water is added to tea leaves and carbon dioxide in a supercritical state is acted on to extract the aroma components, only the aroma components in the water-soluble category are mainly extracted. It was made based on knowledge.

That is, the present invention provides a method for extracting an aroma component of tea leaves, which comprises adding water to the extent that the tea leaves are wet and then extracting the aroma component with carbon dioxide in a supercritical state.

The tea leaves in the present invention are not particularly limited as long as they are teas that are generally extracted with hot water or water such as non-fermented tea such as green tea, semi-fermented tea such as oolong tea, fermented tea such as black tea, etc. Not done.

The water to be added in the present invention may be generally used as a beverage, but if the temperature is too high, the aroma component of the tea leaves is easily scattered, so it is preferable to use water having a temperature of 30 ° C. or less.

In the present invention, after adding water to tea leaves, carbon dioxide in a supercritical state is acted on to extract aroma components, but it is necessary to add water to the extent that the entire tea leaves are moistened. For this purpose, the amount of water added is appropriately 75 to 150% by weight, preferably about 100% by weight, based on the tea leaves. Further, the addition method is not particularly limited, for example, while mixing the tea leaves while dripping water,
After absorbing the water, a method of leaving it until the water has sufficiently penetrated into the tea leaves can be considered.

The carbon dioxide in the supercritical state in the present invention refers to carbon dioxide in a state exceeding the critical point, that is, a point peculiar to a substance, which is the maximum temperature and pressure at which gas and liquid can coexist. Corresponds to the part (a) in. The present invention is characterized in that the carbon dioxide in the supercritical state is applied to the tea leaves to which water has been added to the extent of being wet as described above to extract the aroma components, but the addition of water is conventional. The method of can be adopted. In the present invention,
The addition of water to tea leaves suppresses the extraction of aroma components and resin components in the oil-soluble category, and extracts preferable aroma components in the water-soluble category.

[0011]

EXAMPLES Next, examples of the present invention will be specifically described. Example 1 To 100 g of raw tea leaves (green tea), 100 g of water was added, and the mixture was stirred and mixed in a container, and sealed and left for about 30 minutes until surface water sufficiently penetrated into the tea leaves. Next, it was transferred to an extraction container and extracted with supercritical carbon dioxide under the extraction conditions (pressure, temperature) shown in Table 1. Separation conditions are 30 kg / cm ² ,
Carbon dioxide flow rate of 15 kg /
Each extract was obtained by performing circulation treatment for 2 hours with hr.

[0012]

[Table 1]

Next, each of the obtained extracts is 0.3
g was dissolved in 100 cc of hot water at 80 ° C. and sensory evaluation was performed. The results are shown in Table 2.

[0014]

[Table 2] It can be seen that the extract contains a scent during drinking regardless of the above conditions.

Example 2 100 g of water was added to 100 g of raw tea leaves (oolong tea), and the water was allowed to permeate the inside of the tea leaves in the same manner as in Example 1, and then transferred to an extraction container, and the temperature was 90 kg / cm ² at 35 ° C. It was extracted with carbon dioxide in the critical state. Separation condition is 50 kg / cm
^The temperature was set to 25 ° C. and the carbon dioxide flow rate was 15 kg / hr, and circulation extraction was performed for 2 hours to obtain 21.4 g of an extract. When 0.2 g of the extract thus obtained was dissolved in 100 cc of hot water at 90 ° C., it had the same aroma as that of oolong tea at the time of drinking.

Example 3 Extraction liquid was obtained in the same manner as in Example 2 except that 50 g of raw tea leaves (black tea) was added in an amount of 50 g to obtain 23.8 g of an extract. When 0.2 g of the extract thus obtained was dissolved in 100 cc of hot water at 90 ° C., it had the same aroma as that of black tea when drinking.

Comparative Example 1 The same procedure as in Example 1 was carried out except that water was not added to the raw tea leaves (green tea). As a result, the extract obtained under any of the extraction conditions was a trace amount of yellow oily substance and tar. When these oily substances were wiped off with filter paper and soaked in hot water at 80 ° C, sensory evaluation of the aroma was reminiscent of some of the aroma of tea when drinking, but not the aroma of the tea itself, rather the flowers of the tea leaves themselves. It had a scent and a citrus smell. An oil film was observed on the surface of the hot water.

From the above results, it can be seen that the aroma component like tea cannot be extracted without adding water to the tea leaves.

[0019]

EFFECTS OF THE INVENTION According to the method of the present invention, carbon dioxide in a supercritical state can be used to extract only a preferable aroma component in the water-soluble category from aroma components of tea leaves.

[0020]

[Brief description of drawings]

FIG. 1 is a pressure / temperature diagram of carbon dioxide, in which (a) represents a supercritical region and (b) represents a liquid region.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kensuke Yamaguchi 1-5-7 Mikitei-cho, Higashi-Osaka City, Osaka Prefecture House Food Industry Co., Ltd. (72) Inventor Jun Katada 1-chome, Mikitei-cho, Higashi-Osaka City, Osaka Prefecture No. 5-7 House Food Industry Co., Ltd.

Claims (2)

[Claims] 1. A method for extracting an aroma component of a tea leaf, which comprises adding water to such an extent that the tea leaf is moistened and then extracting the aroma component with carbon dioxide in a supercritical state. 2. The method for extracting an aroma component of tea leaves according to claim 1, wherein the tea leaves are selected from non-fermented tea, semi-fermented tea and fermented tea.