JP3422973B2 - Method for increasing gamma-aminobutyric acid content in shredded grasses - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for increasing the content of γ-aminobutyric acid in a fragmented product of a Gramineae plant or its squeezed juice, a fragmented product or squeezed juice having an increased content, or a dried product thereof. The present invention relates to a powder, as well as a food material or a pharmaceutical raw material containing the dry powder.

[0002]

2. Description of the Related Art Since .gamma.-aminobutyric acid (hereinafter referred to as GABA) has a blood pressure lowering action, development of foods containing a large amount of GABA for people with hypertension has been studied. For example, so-called gabalon tea has been conventionally known in which tea leaves that have been plucked are placed under anaerobic conditions in the process of producing tea to accumulate GABA in large amounts in the tea leaves. Further, JP-A-8-173111 describes that coffee leaf tea having a high GABA concentration is obtained by a method of treating fresh coffee leaves in an oxygen-free state, followed by heat treatment at a high temperature of 110 ° C. or higher and drying treatment. There is. Furthermore, JP-A-9-205
Japanese Patent No. 989 describes that tea leaves are irradiated with infrared rays to improve the content of GABA.

On the other hand, green leaves of gramineous plants, such as young leaves of wheat, are rich in vitamins, minerals and insoluble dietary fiber, adsorb harmful substances, improve intestinal environment, suppress cholesterol absorption, and reduce postprandial blood glucose level. It has been attracting attention as a material for health foods that has effects such as prevention of sudden rise and activation of superoxide dismutase (SOD). When such a health food material contains GABA at a high concentration, an antihypertensive effect can be expected in addition to the above effects.

[0004]

Therefore, a food material derived from a grass family plant containing GABA at a high concentration is desired.

[0005]

Means for Solving the Problems As a result of investigations on novel useful components contained in grasses, the present inventors have found that GABA known as an antihypertensive component in grasses.
Was found to be included. Then, after the leaves or stems of these gramineous plants are fragmented or squeezed, glutamic acid and / or a salt thereof or another food material containing them is added, or heat insulation treatment and / or The present invention has been completed by finding that the anaerobic treatment can increase the GABA content in a fragmented product or a squeezed juice of a Gramineae plant.

Hereinafter, leaves and / or stems of grasses are collectively referred to as "Poaceae".

[0007] The present invention comprises the step of adding glutamic acid and / or a salt thereof or another food material containing them to a fragmented product or juice of a Gramineae plant, which comprises GABA.
The present invention relates to a method for producing a fragmented product or squeezed juice of a Gramineae plant having an increased content.

Further, the present invention produces a fragmented product or squeezed juice of a Gramineae plant having a high GABA content, which comprises a step of heat-retaining and / or anaerobically treating a fragmented product or squeezed juice of the Gramineae plant On how to do.

[0009] Preferably, the step is carried out by adding an inorganic chloride to a fragmented product or a squeezed juice of a Gramineae plant.

The present invention also provides GABA according to the above method.
The present invention relates to a method for producing a dry powder of a gramineous material or squeezed juice of a GA plant having an increased content of GABA, which comprises a step of dry-pulverizing a shredded material or squeezed juice of a Gramineous plant. .

[0011] In a preferred embodiment, the above-mentioned fragment is obtained by fragmenting green leaves so that 80% or more has an average diameter of 1 mm or less.

[0012] In a preferred embodiment, the gramineous plant is wheat.

Further, the present invention relates to a food material or a pharmaceutical material containing a fragmented product or squeezed juice of a Gramineae plant obtained by the above method and having an increased GABA content or a dry powder thereof.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION In the present specification, the Gramineae plant refers to all plants classified as Gramineae in the plant classification table. Specifically, barley, wheat, rye, oats,
Wheat, Italian ryegrass, Italian ace and other wheats; rice, fluff, bamboo grass, spine, acne, corn,
Examples thereof include, but are not limited to, sorghum and sugar cane. Of these, wheat is particularly preferable.

As described above, the Gramineae refers to leaves and / or stems of Gramineae, but in the present invention, green leaves are preferable, and young leaves harvested before maturation are more preferable.

When the gramineous plant is a wheat, it is not particularly limited, but examples of the plant include wheat such as barley, wheat, rye, oats, hate, Italian ryegrass and Italian ace, and their young leaves. Can be preferably used. Preferably, these young leaves of barley are young leaves of barley harvested from the beginning of splitting to the early stage of heading (height of about 20 to 40 cm). More preferably, young barley leaves are used.

According to the present invention, the Gramineae plants are washed with water or the like to remove mud and the like and then fragmented, and then GA
The BA is processed so as to be increased (hereinafter referred to as GABA enrichment processing).

The fragmentation is carried out by a method commonly used by those skilled in the art, such as slicing, crushing, shredding and the like to fragment the gramineous plant. Slicing is also included in fragmentation. Slurrying is performed by treating with a juicer, blender, mass colloider, or the like. As a result, the gramineous plant becomes a muddy porridge (a suspension of liquid and solid particles). 80% or more of the gramineous plant is fragmented so that the average diameter is 1 mm or less, preferably 0.5 mm or less, more preferably 0.1 mm or less, and most preferably 0.05 mm, and fluidity To have.

GAB is a juice obtained by squeezing a fragmented Gramineae plant (hereinafter sometimes referred to as a fragment).
A enrichment processing may be performed.

Juice of Gramineae can be obtained by directly crushing Gramineae, or by squeezing Gramineae and then squeezing them, and further centrifuging or filtering them. The squeezed juice may be prepared after adding a solvent such as water, an ethanol solution or a buffer solution (including an isotonic solution) usually used by those skilled in the art, if necessary.

[0021] GABA enrichment treatment is carried out by adding glutamic acid and / or its salt to a fragment or squeezed juice of a Gramineae plant,
Alternatively, it can be carried out by adding a food material containing them or an extract thereof.

Examples of the salt of glutamic acid include salts of glutamic acid known to those skilled in the art, such as sodium glutamate, potassium glutamate, calcium glutamate and magnesium glutamate. Glutamic acid or its salt may be added directly, or a solution containing a high concentration may be added.

Glutamic acid and / or used in the present invention
Alternatively, the other food material containing a salt thereof refers to a food material containing glutamic acid or a salt thereof other than the fragmented product or squeezed juice of the Gramineae plant used. For example, seaweed such as kelp and wakame, mushrooms such as shiitake and maitake, fish such as bonito (including bonito flakes) and sardines, shellfish such as clams and shijimi, rice, wheat, soybean (including these germs), Examples thereof include tea leaves, mulberry leaves, vegetables (for example, tomato), citrus fruits (mesocarps, agate membranes) and the like, and food materials containing glutamic acid and / or a salt thereof in a relatively high concentration are preferably used. This includes those obtained by subjecting edible protein to enzyme treatment, heat treatment or the like to release or generate glutamic acid.

[0024] These food materials are added to shredded or squeezed juice of a Gramineae plant depending on its form. These food materials may be added as they are to the shredded product or squeezed juice, or the food material may be shredded, or the food material may be squeezed and added to the shredded product or squeezed juice. Further, dry powders of these food materials may be added to the shredded product or the squeezed juice. Alternatively, the ingredients contained in the food material may be added to water, ethanol solution, buffer solution (including isotonic solution),
If necessary, a solution that is heated and eluted may be added, or a dry powder of the eluted components may be added to the shredded product or squeezed juice. For example, when the food material containing glutamic acid is dried kelp, GABA can be efficiently increased by slicing the dried kelp and immersing it in the shredded product or squeezed juice of the Gramineae plant.

The temperature of the GABA enrichment treatment is carried out within a range in which the enzyme that catalyzes the conversion of glutamic acid to GABA is not inactivated, and preferably 20 to 50 ° C, more preferably 25 to 45 ° C.

It is also preferable to adjust the pH. The pH can be adjusted by adding a pH adjuster usually used by those skilled in the art, such as citric acid, succinic acid, tartaric acid, carbonic acid, phosphoric acid or salts thereof. Alternatively, foods or food additives such as vinegar and kansui can be used.
The pH of the GABA enrichment treatment is usually 3.5 to 9.0, preferably 4.0 to 8.0, more preferably 4.5 to 7.0,
Most preferably, it is carried out at 5.0 to 6.0. Even at pH-8, the amount of GABA is more than doubled, and when green leaves of Gramineae are used, a bright green color is exhibited as compared with those treated with acid and those whose pH is not adjusted.
At pH-4 or lower, the GABA enrichment efficiency decreases, and the green leaves of grasses turn brown, which is not preferable. In addition, after the GABA enrichment treatment, an alkaline substance or a solution thereof may be added to the fragmented product or squeezed juice of the Gramineae plant to make the green color bright.

The GABA enrichment treatment is usually carried out for 10 minutes to 24 hours. GABA is more than doubled after 30 minutes.

The above-mentioned glutamic acid and / or its salt, or the food material containing them can be added in an arbitrary amount to the fragmented product of Gramineae plants or its juice. 0.01 for the volume of juice
To 40%, preferably 0.02 to 20%, and more preferably 0.05 to 10%. A food material containing glutamic acid and / or a salt thereof may be added in any amount, but even if the concentration of the salt of glutamic acid is 20% or more, no further effect can be expected. In this specification, the concentration of glutamic acid or a salt thereof is% by weight unless otherwise specified.

The GABA enrichment treatment can also be carried out by heat-retaining and / or anaerobically treating the fragmented Gramineae plant or its juice. This treatment may be carried out before or after the addition of the above-mentioned glutamic acid and / or salt thereof or a food material containing them, or at the same time, and further efficient GABA enrichment may be carried out.

Anaerobic treatment means treatment with a gas containing little or no oxygen. Including vacuum state. Nitrogen gas and carbon dioxide are preferably used as the gas. For example, it can be carried out by directly bubbling a gas such as nitrogen into the fragmentation or squeezed juice of the Gramineae plant, substituting the surrounding gas, or degassing.

The duration of the heat retention treatment and / or the anaerobic treatment is preferably 10 minutes to 24 hours, more preferably 1 to 6 hours. The temperature of the heat retention treatment and / or the anaerobic treatment is about 2
0 to 50 ° C is preferable, and about 30 to 45 ° C is more preferable.

Furthermore, by adding pyridoxal phosphoric acid, inorganic chlorides such as sodium chloride, etc., to the shredded or squeezed plants of Gramineae, and by removing inhibitors such as organic acids or ATP from the reaction system. , GABA enrichment efficiency can be increased.

Examples of the inorganic chloride include sodium chloride (salt), calcium chloride, potassium chloride, magnesium chloride and the like commonly used by those skilled in the art. You may use bittern, crude salt and the like. They are,
It can be added at any concentration, but usually a final concentration of 0.01
-20%, preferably 0.02-10%. For example, 10 divided into about 0.05 mm
To 0 g of barley young leaves, add 400 ml of water, and further add sodium glutamate to 3%, and add 30 ° C.
When incubating for 5 hours at room temperature, if sodium chloride is added to this to a final concentration of 0.5% by weight and incubated, GABA is compared to the case without addition.
Is increased by about 30%.

In this way, the mixture of the fragmented or squeezed of the GABA-enriched gramineous plant and the glutamic acid and / or its salt or the other food material containing them is contained in GABA. Compared to the quantity,
It can usually be increased 2-fold, preferably 3-fold, and more preferably 5-fold or more.

An extract can also be prepared from a fragment of a grass family plant that has been GABA-enriched. The Gramineae plant extract is obtained by adding a solvent commonly used by those skilled in the art, such as water, an ethanol solution, a buffer solution (including an isotonic solution), to the fragmented product, and heating the mixture as necessary (extraction). Products and their concentrates). In this specification, the extract is included in the juice.

The obtained GABA-enriched gramineous plant or squeezed juice can be further processed to be used as a food material or a pharmaceutical raw material.
When it is used as a food material, it is preferable that the fragmented or squeezed juice of the Gramineae plant maintains a green color. Pharmaceutical ingredients,
For example, when GABA is extracted and purified, it does not necessarily have to be green.

The GABA-enriched grits and squeezed grasses are enzymes (chlorophyllase, peroxidase, polyphenol oxidase) that can cause discoloration (including fading), deterioration, etc. as they are.
In order to inactivate, depending on the form, it is usually 2 to 180 at 80 to 150 ° C. under normal pressure, increased pressure or reduced pressure.
Processed for seconds.

Microwave treatment may be performed. Microwave treatment deactivates the enzymes involved in alteration, which are present in shredded or squeezed grass plants, or
It may be carried out within a range in which the green color is not lost by heating. Such a range can be appropriately adjusted depending on the wavelength of the microwave, the output of the microwave irradiation device, the irradiation time, and the like. For example, when a microwave of 2450 MHz and 500 W is applied, it is treated for 0.5 to 10 minutes, preferably 0.5 to 5 minutes, more preferably 0.5 to 1 minute per 100 g (wet weight) of young wheat leaves. . If it is less than 0.5 minutes, the inactivation of the enzyme is insufficient and the green leaves after the treatment are likely to be discolored. Further, if it is treated for 10 minutes or more, the color tends to fade and GABA tends to decrease.

Considering destruction of nutrients, it is desirable that these treatments be performed for a short time, and it is more preferable that the treatments be followed by rapid cooling. The cooling treatment can be performed by, for example, immersing in a water bath or an ice bath, or refrigerating. You can freeze it. The fragmented or squeezed juice of the Gramineae plant obtained by this treatment has inactivated enzymes related to the alteration contained in the Gramineae plant. Is possible. Moreover, since it retains a bright green color, it has a high commercial value when used as a health food or its original family.

The shredded or squeezed juice of the Gramineae plant obtained as described above can be further dried and powdered, if necessary.

The drying is carried out so that the water content is 10% or less, preferably 5% or less. For example, a fragment or squeezed juice of a Gramineae plant is dried by a method commonly used by those skilled in the art, such as hot air drying, high pressure steam drying, electromagnetic wave drying, spray drying, and freeze drying. Drying by heating is preferably 5
The heating can be performed at 0 ° C. to 80 ° C., more preferably 55 ° C. to 65 ° C. at a temperature and for a time at which the green color of the Gramineae plant does not change color. Of these, freeze drying and spray drying are preferably used. During spray drying, if necessary, dextrin, cyclodextrin, starch,
Excipients such as maltose can also be added.

The obtained dried product is further pulverized to obtain a dry powder. The pulverization can be performed according to a method commonly used by those skilled in the art, for example, using a crusher, a mill, a blender, a stone mill and the like. The dry powder is optionally sieved, and for example, one that passes through a 30 to 250 mesh sieve can be used. If the particle size is smaller than 250 mesh, it is difficult to perform further processing when it is used as a food material or a pharmaceutical material. If the particle size is larger than 30 mesh,
For example, it prevents uniform mixing with other food ingredients.

These can be further sterilized by any technique commonly used by those skilled in the art, such as air flow sterilization, high pressure sterilization, and heat sterilization.

The amount of GABA in the dry powder (whether green or not) of the fragmented gramineous plants prepared by the GABA enrichment treatment as described above is calculated as dry weight. 500 mg / 100 g or more, preferably 80
0 mg / 100 g or more, more preferably 1200 mg /
100g or more, most preferably 1600mg / 100g
That is all. On the other hand, when GABA enrichment treatment is not performed, the amount is at most about 400 mg / 100 g.

The GABA content of the squeezed powder (regardless of whether it is green or not) of the Gramineae plant prepared by the GABA enrichment treatment as described above is at least 80.
0 mg / 100 g or more, preferably 1200 mg / 10
The amount is 0 g or more, more preferably 1600 mg / 100 g or more, and most preferably 2000 mg / 100 g or more. On the other hand, when GABA enrichment processing is not performed,
It is about 600 mg / 100 g at most.

As described above, the fragmented grass, squeezed juice, or dry powder thereof of which the GABA content is increased may be used as it is, or as an excipient, a bulking agent, a binder, a thickener, It can be mixed with an emulsifier, a coloring agent, a flavor, a food additive, a seasoning and the like, and can be used as a raw material for foods, beverages and their materials, and pharmaceuticals, or feed for livestock and pets. For example, royal jelly, vitamins, proteins, calcium, chitosan, lecithin, etc. may be added, and sugar solution and seasonings may be added to adjust the taste. Alternatively, excess glutamic acid and / or its salt can be removed. And, if necessary, these can be formed into capsules such as hard capsules and soft capsules, tablets or pills, or formed into powder, granules, teas, tea bags, or candy. These may be eaten as they are, or may be dissolved in water, hot water, milk, or the like, or may be infused after infusing the components, depending on the shape or taste.

Further, it is also possible to purify a pure GABA product using the GABA-enriched material as a raw material by the method of the present invention.

[0048]

The following examples are for purposes of illustration and are not intended to limit the invention.

Example 1 As a raw material, the height is about 30 cm.
Young barley leaves that had been cut in. This was washed with water to wash off the attached mud. Using a wet pulverizer (mass colloider), young wheat leaves were fragmented to an average diameter of about 0.05 mm (most of them were particles having an average diameter of 0.1 mm or less), and then pressed to obtain juice. Obtained. Next, this juice (10
To 0 ml), a 30 wt% sodium glutamate solution was added so that the final concentration was 3%, and the mixture was stirred at various temperatures shown in Table 1 for 4 hours. This was freeze-dried and then pulverized with a blender so that about 90% of it passed through 200 mesh to obtain a dry powder. The GABA content of these dry powders was measured under the following conditions using an amino acid automatic analyzer. The results are shown in Table 1. In the table, “untreated” is the GABA content of the squeezed juice obtained by squeezing, which was freeze-dried and pulverized in the same manner. The GABA enrichment ratio means “untreated”. It is the amount (%) of GABA when the GABA content in the dry powder is 100%.

[0050]   <Amino acid automatic analyzer operating conditions>   Model: JLC-500 / V (JEOL Ltd.)   Power Ram: LCR-6, 4mm x 90mm (JEOL Ltd.)   Mobile phase: Lithium citrate buffer (JEOL Ltd.)           P-21 (pH 2.98, Li 0.105 mol / l) 0 → 16.3 min           P-12 (pH 3.28, Li 0.26 mol / l) 16.3 → 36.1 min           P-13 (pH 3.46, Li 0.80 mol / l) 36.1 → 56.0 min           P-14 (pH 2.83, Li 1.54 mol / l) 56.0 → 63.4 min           P-15 (pH 3.65, Li 1.54 mol / l) 63.4 → 80.0 min   Reaction solution: Ninhydrin / hydridanthin reagent (Wako Pure Chemical Industries, Ltd.)   Temperature: Column 35 ℃ (0 → 16.3 min), 64 ℃ (15.3 → 31.0 min)                   44 ° C (31.0 → 44.4 min), 72 ° C (63.4 → 80.0 min)           Reaction tank 135 ℃   Flow rate: Mobile phase 0.50 ml / min           Reaction solution 0.30 ml / min   Measurement wavelength: 570 nm

[0051]

[Table 1]

The results in Table 1 show that GABA was obtained by adding sodium glutamate and treating at 20 to 50 ° C.
Is increased.

Example 2 To a juice (100 ml) obtained in the same manner as in Example 1 was added a 30 wt% sodium glutamate solution so that the final concentration was 3%, and then citric acid or sodium carbonate was added. The various p values listed in Table 2 were used.
Adjusted to H. This is stirred at 30 ° C. for 4 hours, freeze-dried, and then 200% of 90% is meshed with a blender.
The GABA content of the dry powder, which was ground to the extent that it passed, was measured. The results are shown in Table 2.

[0054]

[Table 2]

The results in Table 2 show that the addition of sodium glutamate increases GABA at pH -4.0 to 8.0.

Example 3 To the juice obtained in the same manner as in Example 1, sodium glutamate was added so that the final concentration could be various concentrations shown in Table 3. Then this is 30
After stirring at 4 ° C. for 4 hours, freeze-drying was performed, and the GABA content of the dry powder pulverized so that about 90% of it passed through 200 mesh was measured using a blender. The results are shown in Table 3.

[0057]

[Table 3]

The results in Table 3 show that the GABA content is sufficiently increased by the addition of sodium glutamate at a final concentration of 0.5% or more. Further, as shown in the 0% column, it is shown that the amount of GABA also increases by the heat retention treatment.

Example 4 To the juice obtained in the same manner as in Example 1, 30% by weight sodium glutamate was added so that the final concentration was 3%. This was stirred at 30 ° C. for various times shown in Table 4, freeze-dried, and pulverized with a blender so that about 90% of it passed through 200 mesh, and the GABA content of the dried powder was measured. The results are shown in Table 4.

[0060]

[Table 4]

The results shown in Table 4 show that the G
It shows that the ABA content is increased.

(Embodiment 5) As in Embodiment 1, 0.0
20 g of 100 g of barley young leaves sliced to about 5 mm
0 ml of water was added. To this, 90% of 200 mesh
After adding 3 g of a commercially available dry kelp crushed to such an extent that the degree of passing was reached, the pH was adjusted to pH-6.0 and the mixture was stirred at 30 ° C. for 4 hours. This was freeze-dried, and the GABA content of the dry powder pulverized so that about 90% of it passed through 200 mesh was measured. The results are shown in Table 5. In addition, dry kelp and GAB
A was not included.

[0063]

[Table 5]

The results in Table 5 show that the GABA enrichment treatment of the present invention is carried out by adding a food material containing glutamic acid.

(Embodiment 6) As in Embodiment 1, 0.0
200 to 100g of barley young leaves that have been shredded to about 5mm
30 ml by weight sodium glutamate solution and 10% by weight sodium chloride (salt) were added.
The solution was added so that the final concentrations were 3% and 0.5%, respectively, and the mixture was stirred at 30 ° C. for 4 hours. Further, the same treatment was carried out for the one to which the sodium chloride solution was not added. These are freeze-dried and 20 using a blender.
The GABA content of the dry powder pulverized to the extent that 90% of it passed through 0 mesh was measured. The results are shown in Table 6.

[0066]

[Table 6]

The results in Table 6 show that GABA enrichment is efficiently performed by adding sodium chloride in addition to sodium glutamate.

(Example 7) Young leaves of barley cut at a height of about 30 cm and green leaves of Italian ryegrass and rice (Koshihikari) cut at a height of about 20 cm were made to have a particle size of about 0.05 mm in the same manner as in Example 1. It was fragmented. 200 ml of water was added to these pieces, and a 30 wt% sodium glutamate solution was further added so that the final concentration was 3%, followed by stirring at 30 ° C. for 5 hours. These are freeze-dried and then blended using a blender.
The GABA content of the dry powder crushed so that about 90% of it passed through 00 mesh was measured. The results are shown in Table 7.

[0069]

[Table 7]

The results in Table 7 show that the GABA enrichment treatment of the present invention can also be performed on Italian ryegrass which is a grass family plant and on green leaves of rice.

[0071]

INDUSTRIAL APPLICABILITY By adding glutamic acid and / or a salt thereof or a food material containing them to a fragmented product or squeezed plant of Gramineae, the GABA content in the fragmented product or squeezed juice can be increased. In addition, a food material derived from a Gramineae plant containing a high concentration of GABA or a raw material for a drug can be obtained from this as a raw material.

─────────────────────────────────────────────────── --- Continuation of the front page (56) Reference JP-A-11-155508 (JP, A) JP-A-3-236763 (JP, A) JP-A-3-244366 (JP, A) JP-A-9- 238650 (JP, A) JP 7-241176 (JP, A) JP 9-135671 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) A23L 1/30-1 / 305 A23L 1/212 A61K 35/78 A61P 9/12 JISST file (JOIS)

Claims (7)

(57) [Claims] 1. A Gramineae plant having an increased γ-aminobutyric acid content, which comprises a step of adding glutamic acid and / or a salt thereof or another food material containing them to a fragmented product or juice of a Gramineae plant. A method of producing shreds or juices of the body. 2. A fragmented product or squeezed juice of a Gramineae plant comprising a step of heat-retaining and / or anaerobically treating a fragmented product or squeezed juice of a Gramineae plant. how to. 3. The method according to claim 1 or 2, wherein the step according to claim 1 or 2 is performed by adding an inorganic chloride to the shredded material or squeezed juice of the gramineous plant. 4. A step of dry-pulverizing a fragment or squeezed juice of a Gramineae plant having an increased γ-aminobutyric acid content by the method according to any one of claims 1 to 3,
A method for producing a dried powder of a fragment or squeezed juice of a Gramineae plant having an increased γ-aminobutyric acid content. 5. The method according to claim 1, wherein the debris is obtained by treating green leaves such that 80% or more of the debris has an average diameter of 1 mm or less. 6. The plant according to claim 1, wherein the gramineous plant is wheat.
5. The method according to any one of items 5 to 5. 7. A shredded product or squeezed juice of a Gramineae plant having an increased γ-aminobutyric acid content obtained by the method according to any one of claims 1 to 5 or a dry powder thereof. Food ingredients or pharmaceutical ingredients.