JP2000014356A - Production of gaba-containing beverage and food product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain beverage or food products in a low cost, containing γ- aminobutyric acid useful for improving hypertension and the like with excellent taste and color tone by inoculating a microorganism capable of producing protease to a specific food material and culturing it. SOLUTION: A food material that contains the peptide or protein including glutamic acid as a constituent amino acid, for example, powdered skim milk, soybean milk and the like is inoculated with a microorganism capable of producing protease, for example, a lactic acid bacterium that can liberate >=0.5 wt.% of glutamic acid after subtraction of its assimilated fraction based on the protein, when it is cultured in a 20% powdered skim milk substrate at 25-40 deg.C for 2 days and with a microorganism capable of producing glutamate decarboxylase, for example, a bacterium in Bifidobacterium, capable of producing >=600 mg/100 ml of γ-aminobutyric acid, when it is cultured in a culture medium containing 1,000 mg/100 ml of glutamic acid (glutamate salt) at 25-40 deg.C whereby the objective γ-aminobutyric acid-containing beverage or food products are obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a food or drink containing γ-aminobutyric acid (GABA).

[0002]

2. Description of the Related Art In mammals, GABA is an inhibitory neurotransmitter present in the brain and spinal cord. Its physiological effect is to increase brain blood flow and increase oxygen supply to the brain. Increases the metabolic function of blood, lowers blood pressure by acting on the vasomotor center of the spinal cord, suppresses the secretion of vasopressin, an antidiuretic hormone, dilates blood vessels and lowers blood pressure, necessary for the introduction of TCA cycle Involved in enhancing the activity of hexokinase and promoting glucose metabolism (New Brain Metabolism Activator, Eiichi Otomo, Pharmaceutical Journal (1987)), and used as a drug for the purpose of activating brain metabolism Have been.

[0003] Therefore, since hypertension can be expected to be improved by ingesting GABA as a food, some foods in which the GABA content is enhanced by applying appropriate treatment to the food have been proposed. For example, GA
BA-enriched rice germ (Oriza Yuka Co., Ltd.) (food that germ-treated rice germ to increase GABA content to 0.3%); GABARON tea (many companies) (tea leaves are anaerobically treated to reduce GABA content) Tea), which is several tens of times higher than that before treatment, and is increased to 220 mg%, etc., are known.

On the other hand, as a method for producing GABA-enriched foods using microorganisms, glutamic acid (salt) is added to milk, lactic acid bacteria capable of producing GABA are inoculated and cultured, and fermentation containing GABA is performed. A method for obtaining food (Japanese Patent Application Laid-Open No. 7-227245), and a method in which yeast or chlorella cell lysate is allowed to act on glutamic acid (sodium).
Method for producing food material enriched in BA
No. 38850).

[0005]

However, in conventional methods for producing GABA-containing foods and drinks using microorganisms, glutamic acid or a salt thereof is added,
Problems such as altering the taste of foods, glutamate and reducing sugars (sugars) causing aminocarbonyl reaction and discoloring when heat is applied during sterilization, etc., resulting in poor workability and high manufacturing costs was there. Accordingly, an object of the present invention is to provide a method for producing a GABA-containing food or drink having good taste and color tone.

[0006]

The inventors of the present invention have conducted various studies to solve the above-mentioned problems. As a result, the present inventors have used a food material containing a protein or peptide containing glutamic acid as a constituent amino acid, and produced a protease using the same. It has been found that, by inoculating and culturing a microorganism having an ability to produce glutamic acid decarboxylase and a microorganism having an ability to produce glutamate decarboxylase, foods and drinks having a good color tone can be obtained, which contain GABA abundantly and do not impair the taste. Was completed.

That is, the present invention is characterized in that a food material containing a protein or a peptide containing glutamic acid as a constituent amino acid is inoculated with a microorganism having a protease-producing ability and a microorganism having a glutamic acid decarboxylase-producing ability and cultured. The present invention also provides a method for producing GABA-containing food and drink, and a food and drink thus obtained.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The food or drink material of the present invention contains a protein or peptide containing glutamic acid as a constituent amino acid. Since proteins in many food materials contain glutamic acid as a constituent amino acid, the food materials are not particularly limited as long as they contain proteins. For example, meat, seafood, and milk can be mentioned. Casein protein contains about 20% of glutamic acid, and soy protein contains abundant glutamic acid. Processed products such as skim milk powder and soy milk are preferred.

The microorganism having protease-producing ability is not particularly limited as long as it is a protease-producing bacterium that can be added to foods. When cultured at 25 to 40 ° C. for 2 days using 20% nonfat dry milk as a substrate, glutamic acid is converted to It is preferable that the glutamate release at least 0.5% by weight or more, especially 0.7% by weight or more based on the protein after subtracting the amount of assimilation. Among them, those having not only high glutamic acid releasing activity but also low glutamic acid requirement, that is, low activity of assimilating free glutamic acid and using it for purposes other than GABA production are preferable. More specifically, bacteria such as Lactobacillus, Lactococcus, Bifidobacterium, and the like can be mentioned. Among these, Lactobacillus casei (hereinafter referred to as L. casei), Lactococcus lactis (Lactoco
ccus lactis (hereinafter referred to as L. lactis)), Lactococcus lactis subspecies. Cremoris (Lactococcus lactis ss. Cr
emoris (hereinafter referred to as L. cremolis)), and specifically L. cremoris. Casei YIT 9029 (FERM B
P-1366); Lactis YIT2027 (FE
RM BP-6224) and L.P. Cremoris YIT
2007 (ATCC 19257).

The microorganism having the ability to produce glutamic acid decarboxylase is not particularly limited as long as it is a glutamic acid decarboxylase-producing bacterium that can be added to foods.
When cultured at 25 to 40 ° C. in a medium supplemented with 00 mL, GABA is 600 mg / 100 mL or more, particularly 800 mg.
/ 100 mL or more is preferable. It is particularly preferable that this microorganism has a low glutamic acid requirement similarly to the above. When milk is used as a food material, a lactic acid bacterium or a bacterium belonging to the genus Bifidobacterium that produces glutamate decarboxylase is preferable. More specifically, bacteria such as Lactobacillus, Lactococcus, Bifidobacterium and the like can be mentioned. Among them, Lactococcus lactis is preferred. Specifically, YIT
2027.

[0011] In order to inoculate the above-mentioned food materials with the above two species and culture them, conditions suitable for the inoculated microorganisms may be selected. Alternatively, the above two microorganisms may be inoculated and cultured at the same time.
Then, a glutamic acid decarboxylase-producing bacterium may be inoculated and cultured. Also, microorganisms that produce both protease and glutamate decarboxylase, such as L. If Lactis YIT2027 is used, only one kind of microorganism may be used, but it is more preferable to mix and culture two or more strains from the viewpoint of GABA production ability and the like. In some microorganisms having both enzymes, the released glutamic acid was immediately replaced with GA.
It should be noted that in this case the protease activity is apparently lower, since some convert to BA.

A lactic acid bacterium or Bifidobacterium belonging to a protease-producing ability and a lactic acid bacterium or Bifidobacterium belonging to a glutamic acid decarboxylase-producing ability are simultaneously or sequentially inoculated into a food material containing milk. When culturing the cells, conditions suitable for the growth of the bacteria to be used, the production of enzymes, and the like may be set. Generally, 3
The culture may be performed at 0 to 37 ° C. for about 2 days to 1 week, and the milk concentration is 8% by weight or more, especially 8% by weight in terms of non-fat milk solids.
About 30% by weight is preferable in terms of GABA productivity, workability such as solubility of milk, and cost. The food thus obtained is a fermented milk food and drink containing GABA. This fermented milk food and drink contains a casein-degrading peptide, and it is known that not only GABA but also the casein-degrading peptide has various physiological activities including a blood pressure effect, and is particularly preferable.

According to the present invention, glutamic acid is released from a protein or peptide contained in a food material by the action of a protease-producing bacterium, and the released glutamic acid is converted into GABA by the action of a glutamic acid decarboxylase-producing bacterium. By using two kinds of microorganisms in this way, it is not necessary to add glutamic acid as a food additive, so that foods and drinks having a high GABA content without changing taste and color tone can be obtained at low cost.

The foods and drinks obtained include fermented milk foods, fermented soy milk foods, pickles, natto, liquors and the like.

[0015]

Next, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

Reference Example 1 Selection of Microorganism Having Protease-Producing Ability About 34% of skim milk powder is protein, of which glutamic acid is as high as about 20%. Therefore, a lactic acid bacterium having a high activity of releasing glutamic acid during the fermentation process of the skim milk solution is selected. Materials and Methods Strains Used The strains shown in Table 1 were used at 30 ° C. or 37 ° C. twice subcultured.

Culture conditions: 20% skim milk solution (121
(Sterilized at 15 ° C. for 15 minutes) at 30 ° C. or 37 ° C. for 3 days. Measurement method: Amino acid automatic analyzer (JCL-300 JEOL Ltd.) and data processor (LC30-DK1)
0 JEOL Ltd.) to determine GABA and glutamic acid. For separation of amino acids, a strongly acidic cation exchange resin (packed column LCR-6: a polystyrene resin having a sulfonic acid group introduced) was used, and quantification was performed using a ninhydrin coloring method. The 20% skim milk solution contains about 1000 mg / 100 mL of glutamic acid, and about 10 mg / 100 mL is released before culture.
For this reason, the glutamate release rate was calculated by the following equation.

[0018]

(Equation 1)

Results Table 1 shows the release of glutamic acid, and Table 2 shows the GABA concentration at that time.

[0020]

[Table 1]

[0021]

[Table 2]

Glutamate-releasing activity was determined by culturing at 30.degree. Casei YIT 9029 was the highest, and 1.2% by weight of free glutamic acid was observed after 3 days of culture. Y
IT9029 has one amino acid from the N-terminus of the peptide chain.
It was considered that the activity of aminopeptidase released by each residue was high and the required amount of glutamic acid was small. L. Cremoris YIT 2007 (ATCC 19257 ^T ) or L. Helveticas YIT 0083 (ATC
C15009 ^T ) also had high glutamate releasing ability.
On the other hand, L. Lactis YIT 2027 and Strept
Glutamic acid was not observed in the culture of C. cucus thermophilus (S. thermophilus) YIT 2001, but this was because the released glutamic acid was converted to GABA in the former, and it was considered that the latter was assimilated and metabolized. Since about 0.7 g of GABA is usually produced from 1 g of glutamic acid, the actual glutamic acid release rate of YIT2027 is considered to be about 7.14% on the second day of culture. From the above examination results, L. as a strain that releases glutamic acid from milk protein. Casei YIT 9029 and L. Cremoris YIT 2007 and L. Lactis YIT
2027 is preferable since it releases 0.5% by weight or more of glutamic acid when cultured for 2 days.

REFERENCE EXAMPLE 2 The strains shown in Table 3 were added to a 20% skim milk solution containing 1000 mg / 100 mL of sodium glutamate at 30 ° C. (Y
IT 2027 only) or 37 ° C (all other strains)
For 3 days. Table 3 shows the results. As a strain that converts glutamic acid to GABA, L. glutamic acid is used. Lactis YIT2
027 is preferable.

[0024]

[Table 3]

Example 1 Heat-sterilized 30% skim milk solution was mixed with L. fermented milk. Lactis YIT 2027 (FERM BP-624
4) and cheese-derived L. Cremoris YIT 2007
(ATCC 19257) at a ratio of 10: 1,
The cells were cultured at 30 ° C. for 3 days. GABA was not confirmed before fermentation, but after the fermentation, 30 mg / 100
mL.

Example 2 Lactose derived from fermented milk was added to soymilk to which heat-sterilized lactose was added. Lactis YIT 2027 and cheese-derived L. Inoculate Cremoris YIT 2007 at a ratio of 10: 1 and 30
C. for 3 days. GABA was not confirmed before fermentation, but increased to 32 mg / 100 mL after fermentation.

Comparative Example 1 Glutamic acid (Na) was added to a 30% skim milk solution to a final concentration of 15 g / L, and the mixture was sterilized by heating at 100 ° C. for 30 minutes. lactis YIT 2027, and cultured at 30 ° C. for 3 days. GABA after fermentation
The concentration was 105 mg / 100 mL.

Test Example 1 Using the fermented milk obtained in Example 1 and Comparative Example 1, a sample having the following formulation was prepared. These flavors and colors were sensory evaluated by five expert panelists.

[0029]

(Formulation) Fermented milk 30 (% by weight) 30% sucrose solution 30 Stabilizer (pectin) 0.3 Flavor 0.1 Water Remaining amount

The flavor evaluation is an index including an amino acid smell and a burnt smell, and the like: +1: delicious, 0: normal, -1: unsatisfactory, color tone: +1: good color tone, 0: slightly poor color tone No, -1: poor color tone. as a result,
The fermented milk beverage of the present invention had better flavor and color tone than the sample to which glutamic acid was added. The sample of the comparative example had a slightly glutamic acid flavor.

[0031]

[Table 5]

Comparative Example 2 In the same medium as in Example 1, S. cerevisiae having a low glutamate releasing activity was used. L. thermophilus YIT 2001 and L. glutamic acid decarboxylase with high activity. Lactis YIT 20
27 was inoculated at a ratio of 1: 1 and cultured at 30 ° C. for 3 days. GABA was not confirmed before fermentation, but increased to 4 mg / 100 mL after fermentation.

Comparative Example 3 In the same medium as in Example 1, L. cerevisiae having high glutamate releasing activity was added. Lactobacillus acidophilus with low activity of casei YIT2029 and glutamate decarboxylase
s) YIT 0168 was inoculated at a ratio of 1: 1 at 30 ° C.
For 3 days. GABA was not confirmed before fermentation, but increased to 0.5 mg / 100 mL after fermentation.

Example 3 L. with high activity to release glutamic acid from milk protein GA from casei YIT9029 and glutamic acid
L. having high activity to convert to BA. Lactis YIT 20
27 were singly and mixedly cultured. Both strains were inoculated in a 30% non-fat dry milk solution heat-sterilized at a ratio of 1: 1.
Cultured for days. FIG. 1 shows the time course of GABA production at this time.

After 3 days of culture, L. Lactis YI
T 2027 alone has a GABA production concentration of 15 mg / 1
00 mL was reached. L. Casei YIT 9029
More than double 38mg / 100 by performing mixed culture with
It increased to mL, confirming the usefulness of mixed culture. The glutamic acid concentration at this time was 1 mg / 100 mL.

Further, GABA production was examined by changing the inoculation ratio of the strain exponentially. As a result, L. Casey Y
IT 9029 and L.E. It was found that the GABA concentration increased when the ratio of Lactis YIT2027 was 1: 1 to 10: 1 (Table 6).

[0037]

[Table 6]

From the above examination results, L. Casei YIT
9029 and L.E. Inoculation and cultivation of Lactis YIT2027 simultaneously at a ratio of 1: 1 proved to be an effective method for increasing the GABA content.

Reference Example 2 Changes in blood pressure when fermented milk was administered to spontaneously hypertensive mice (SHR) Conditions: 14-week-old, male, 5 / group, 10% lyophilized fermented milk of the present invention (feed) In Example 3, both strains were:
1 and inoculated and adjusted) and allowed to eat freely. 1% of salt was added to the feed for both the control group and the fermented milk group. The results are shown in FIG. By administering the GABA-containing fermented milk prepared this time, a tendency to suppress the increase in blood pressure was observed. On the 21st day of administration, it can be seen that the increase in blood pressure was significantly (p <0.05) suppressed.

[0040]

According to the present invention, GAB having good taste and color tone
A-containing food and drink can be obtained efficiently.

[Brief description of the drawings]

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a diagram showing a time-dependent change in GABA concentration for one strain and two strains.

FIG. 2 shows changes in blood pressure when the fermented milk of the present invention is administered to spontaneously hypertensive mice.

[Procedure amendment]

[Submission date] May 11, 1999 (1999.5.1
1)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction contents]

[0018]

(Equation 1)

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0022

[Correction method] Change

[Correction contents]

Glutamate-releasing activity was determined by culturing at 30.degree. Casei YIT 9029 was the highest, and 1.2% by weight of free glutamic acid was observed after 3 days of culture. Y
IT9029 has one amino acid from the N-terminus of the peptide chain.
It was considered that the activity of aminopeptidase released by each residue was high and the required amount of glutamic acid was small. L. Cremoris YIT 2007 (ATCC 19257 ^T ) or L. Helveticas YIT 0083 (ATC
C15009 ^T ) also had high glutamate releasing ability.
On the other hand, L. Lactis YIT 2027 and Strept
Glutamic acid was not observed in the culture of C. cucus thermophilus (S. thermophilus) YIT 2001, but this was because the released glutamic acid was converted to GABA in the former, and it was considered that the latter was assimilated and metabolized. Since about 0.7 g of GABA is usually produced from 1 g of glutamic acid, the actual glutamic acid release rate of YIT2027 is considered to be about 0.714% on the second day of culture. From the above examination results, L. as a strain that releases glutamic acid from milk protein. Casei YIT 9029 and L.
Cremoris YIT 2007 and L. Lactis YI
T2027 is preferable because it releases 0.5% by weight or more of glutamic acid when cultured for 2 days.

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Claims (6)

[Claims] 1. A γ-amino acid characterized in that a food material containing a protein or a peptide containing glutamic acid as a constituent amino acid is inoculated with a microorganism having a protease-producing ability and a microorganism having a glutamic acid decarboxylase-producing ability and cultured. A method for producing butyric acid-containing food or drink. 2. The method according to claim 1, wherein the microorganism capable of producing protease and the microorganism capable of producing glutamate decarboxylase are lactic acid bacteria or bacteria of the genus Bifidobacterium. 3. A microorganism having protease-producing ability,
2. The method of claim 1, wherein when culturing at 25 to 40 ° C. for 2 days using 20% nonfat dry milk as a substrate, at least 0.5% by weight or more of glutamic acid with respect to protein is released by subtracting the amount that assimilates glutamic acid. Or the production method according to 2. 4. A microorganism capable of producing glutamic acid decarboxylase, wherein glutamic acid or a salt thereof is dissolved in 1000
4. The method according to claim 1, which has the ability to produce γ-aminobutyric acid in an amount of 600 mg / 100 mL or more when cultured at 25 to 40 ° C. in a medium supplemented with mg / 100 mL. 5. The food or drink is a fermented milk food or drink.
5. The production method according to any one of 4. 6. A γ-aminobutyric acid-containing food or drink obtained by the method according to any one of claims 1 to 5.