JPH09205989A - Gamma-aminobutyric acid accumulating method in tea - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accumulate a large amount of γ-aminobutyric acid which is important as nervus inhibiting transmitter and showing the vasodepressor activity in the leaves of tea by irradiating the leaves of tea before steaming with infrared rays in the range of a wavelength with heating ability. SOLUTION: The leaves of tea before steaming are irradiated with infrared rays in the range of a wavelength (normally 650 to 2500nm) with heating ability. To pout it in the concrete, the leaves are irradiated with infrared rays while stirring tea leaves in the raw state by using a roughly crumpling device provided with the radiation source of infrared rays such as an infrared lamp, a far infrared heater, e.g. In addition the irradiating temp. of infrared rays is desirably controlled to make the temp. of the irradiated tear 40 to 50 deg.C. An irradiating time is desirably 20 to 60min in the above temp. condition.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to γ-in tea.
The present invention relates to a method for accumulating aminobutyric acid.

[0002]

BACKGROUND OF THE INVENTION γ-Aminobutyric acid (hereinafter referred to as GABA) is one of the non-protein-constituting amino acids widely existing in the living world, and is important as a major inhibitory transmitter of nerves in higher animals. At the same time, it is known to exhibit a blood pressure lowering action.

While trying to improve the process of processing green tea, Tsushida et al. Found that a large amount of GABA was accumulated in the tea leaves when the extracted tea leaves were placed under anaerobic conditions. The resulting green tea will be called "Gabalon tea" (Tojida Tsushida et al., Agriculturalization, 6
1, 817-822 (1987)). It was confirmed that this Gabalon tea has a blood pressure lowering effect (Agriculture, 6
1, 1449 to 1451 (1987)), which is one of the functional foods.

[0004] Table 3 shows the results of examining changes in amino acids in tea leaves after plucking fresh tea leaves and leaving them under anaerobic conditions for 5 to 10 hours, which was made clear by the report of Toshiro Tsushida and others. It is what

[0005]

[Table 3]

As is clear from Table 3, GABA is accumulated in a large amount of 170 mg% to 290 mg% by anaerobic treatment of tea leaves.

[0007]

However, the anaerobic treatment of tea leaves must be performed by replacing the air atmosphere with nitrogen gas, carbon dioxide gas or the like. For this reason, the conventional GABA storage method has a problem that not only time and effort are required for anaerobic treatment, but also cost is high.

The present invention has been made in view of the above conventional problems, and a large amount of GABA can be accumulated in tea leaves only by irradiating the tea leaves before steaming with infrared rays.
It is an object to provide a method for accumulating GABA in tea.

[0009]

A method for accumulating GABA in tea provided by the present invention is characterized by irradiating tea leaves before steaming with infrared rays in a wavelength range having a heating effect.

[0010]

It has been conventionally confirmed that GABA can be accumulated in tea leaves by placing fresh leaves under anaerobic conditions. In this invention, it was revealed that the irradiation of infrared rays promotes the accumulation of GABA. This fact is
This is a completely new finding, and its chemical reaction route and the like are not clear, but it could be clarified in Examples described later.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION While a tea leaf in a raw state is being stirred, it is irradiated with infrared rays.

[0012] The tea leaves mentioned here include first tea, second tea, tea immediately after plucking or temporarily stored tea, and the variety is not limited. Stirring is performed, for example, with a rough kneader. The infrared radiation source may be of any type as long as it emits infrared rays such as an infrared lamp and a far infrared heater. If a radiant source is used, it will be installed in it.

The infrared wavelength range is 650 nm to 2500.
nm is the practical range. The point is that the band has a heating effect.

The infrared irradiation temperature is controlled so that the temperature of the irradiated tea becomes 40 ° C to 50 ° C. This can be achieved by setting the internal temperature of the rough kneader at 40 ° C to 50 ° C.

The irradiation time of infrared rays is such that the temperature of tea is 40 ° C.
20 minutes or more is desirable in the range of 50 ° C. One upper limit is about 60 minutes.

Embodiments 1 to 6 of the present invention will be described below.

[I] Production of rough tea by infrared irradiation (Example 1) First tea is placed in the chamber of a coarse kneading machine of a small amount tea making machine, irradiated with infrared rays with an infrared lamp while stirring, and then ordinary sencha The rough tea was obtained by the tea making method.

The process will be described below in the order of steps.

(1) 2 kg of the first tea just collected after being collected in May was placed in the chamber of the rough kneader, and while stirring, it was irradiated with infrared rays by an infrared lamp installed in the chamber.

The infrared lamp has a wavelength range shown in FIG. 1, that is, 650 nm to 2500 n.
3 of m were used. These infrared lamps were installed at a position where the infrared rays could be uniformly radiated from a distance of about 50 cm above the tea leaves leveled in the refrigerator.

The infrared irradiation temperature is about 45 for tea leaves.
It controlled so that it might become ℃ -46 ℃.

The control was carried out by measuring the temperature of the tea leaves with a thermocouple and blinking the infrared lamp as necessary.

The irradiation time of infrared rays depends on the temperature of the tea leaves at about 45.
It was carried out for 10 minutes while maintaining (controlling) at ℃ to 46 ℃.

(2) The tea leaves irradiated with infrared rays were placed in a steamer, steamed for about 30 to 40 seconds, and cooled immediately.

(3) Tea leaves softened by steaming
The mixture was roughly kneaded at about 70 ° C to 80 ° C for about 15 minutes.

(4) After rough kneading, kneading was performed for about 15 minutes.

(5) After the kneading, medium kneading was performed at about 30 to 35 ° C. for about 10 minutes.

(6) After the medium was rubbed, it was rubbed at about 70 ° C. for 30 to 40 minutes.

(7) After being rubbed, it was dried at about 80 ° C. to obtain rough tea having a water content of about 20%.

Example 2 A crude tea was produced in the same manner as in Example 1 except that the infrared irradiation time was 20 minutes.

Example 3 A crude tea was produced in the same manner as in Example 1, except that the infrared irradiation time was 30 minutes.

(Example 4) A rough tea was produced in the same manner as in Example 1 except that the irradiation time of infrared rays was 40 minutes.

(Example 5) A crude tea was produced in the same manner as in Example 1 except that the infrared irradiation time was 50 minutes.

Example 6 A crude tea was produced in the same manner as in Example 1 except that the infrared irradiation time was 60 minutes.

(Comparative Example 1) Ichibancha, which had just been collected and collected in May, was placed in a steamer without being irradiated with infrared rays and steamed for about 30 to 40 seconds. saved.

(Comparative Example 2) In a manner substantially similar to the tea manufacturing method disclosed in Japanese Patent Laid-Open No. 62-32843,
Raw leaves were processed. Explaining the processing method in the order of steps,
It is as follows.

(1) A microwave heating device (NJ manufactured by New Japan Radio Co., Ltd.) equipped with a far-infrared heater and 1 Kg of second tea leaves
E2407: with thermocouple), and irradiated with far infrared rays for 60 minutes. At this time, the temperature of the tea leaves was maintained at 30 ° C to 40 ° C by the far infrared heater controller.

(2) The tea leaves irradiated with far infrared rays were withered at room temperature for a short time until the weight of the tea leaves decreased by about 10% to 20% after the irradiation of far infrared rays was completed.

(3) The withered tea leaves were steamed for about 20 seconds with a steam amount of about 300 g per 1 kg of fresh leaves.

(4) The steamed tea leaves were dried in a dryer and stored in a cool dark place until they were analyzed.

Comparative Example 3 (1) Using fresh leaves plucked at the same time as Comparative Example 2, infrared rays were irradiated in the same manner as in Example 6.

(2) The tea leaves irradiated with infrared rays were placed in a steamer and steamed for about 30 to 40 seconds, followed by rapid cooling.

(3) The steamed tea leaves were dried in a dryer and stored in a cool dark place until they were analyzed.

[II] Amino acid analysis of crude tea and fresh leaves The amino acids of Examples 1 to 6 and Comparative Examples 1 to 3 were analyzed according to the following procedure.

Hot water was added to 400 mg of tea powder, and the mixture was extracted by heating in a water bath at 80 ° C. for 30 minutes, cooled and then dissolved in 100 ml. 20 μl of this extract diluted 2-fold with HP
Quantitative analysis was carried out by the LC method.

The HPLC conditions and the like are as follows.

Apparatus: JASCO 800 series, column:
AApack (manufactured by JASCO Corporation) Reaction solution: OPA solution, sodium hypochlorite solution, Eluent: lithium citrate buffer solution (0.15N to 1.23)
N) Flow rate: 0.8 ml / min, column temperature: 40 ° C. Detector: FP-210 type Excitation wavelength: 345 nm, fluorescence wavelength: 445 nm [III] Results of amino acid analysis and its evaluation Table 1 shows Examples 1 to 6. And the result of the amino acid analysis of Comparative Examples 1-3 is shown.

[0048]

[Table 1]

As is clear from Table 1, the composition ratio of GABA was higher when irradiated with infrared rays, and the tendency was remarkable when the irradiation time was 20 minutes or longer. Further, the composition ratio of the theanine, which is a umami component, is about 50% as in the case of sencha, so it is considered that there is no deterioration in quality due to infrared irradiation.

In Comparative Example 2 and Comparative Example 3, the second tea leaves were used for the respective treatments and subjected to the analysis. Even if the first tea leaves were used, the GABA composition ratios were almost the same. It is considered possible. Therefore, G
It seems that ABA can be accumulated more effectively than the method disclosed in JP-A-62-32843.

For reference, the amino acid composition of ready-made oolong tea etc. is shown in Table 2.

[0052]

[Table 2]

[0053]

As described above, according to the present invention, tea leaves before steaming are irradiated with infrared rays in a wavelength range having a heating effect, so that a large amount of GABA can be accumulated in the tea leaves.

[Brief description of drawings]

FIG. 1 is a graph showing a wavelength range of infrared lamps used in Examples 1 to 6.

Claims (1)

[Claims] 1. A γ in tea characterized in that tea leaves before steaming are irradiated with infrared rays in a wavelength region having a heating effect.
-Aminobutyric acid accumulation method.