JPH05236872A - Food containing lactic acid bacterium - Google Patents

Abstract

PURPOSE:To obtain the subject food, comprising lactic acid bacteria having antimutagenicity against mutagens, excellent in safety and health retaining effects and useful as a fermented milk, a lactic acid bacteria beverage, etc. CONSTITUTION:The objective food comprises lactic acid bacteria such as Lactobacillus.casei having antimutagenicity against mutagens such as a base substitution type mutagen or a frame shift type mutagen.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a food containing lactic acid bacteria having antimutagenicity, and more specifically, it has a high antimutagenicity against mutagens and is a health food, a food for health use, etc. The present invention relates to foods such as fermented milk and lactic acid bacterium beverages that can be advantageously used as.

[0002]

2. Description of the Related Art The foods that we eat on a daily basis can be regarded as having a considerably low risk in terms of safety. However, many mutagens can be contained in foods, and these substances are of great interest today because they are deeply involved in the onset of cancer.

The currently known mutagen is 3-amino-, which is contained in the burnt parts of meat and fish.
1-Methyl-5H-pyrido [4,3-b] -indole (hereinafter abbreviated as "Trp-P-2"), nitroso compound produced by eating fish and vegetables, metabolism of mold growing in food Aflatoxins and the like produced as products.

It has already been found that many of these mutagens are carcinogens, and from the viewpoint of mutation toxicity, these mutagens that are deeply related to carcinogenesis and aging of human somatic cells are contained in foods. To be removed from

Conventionally, a method utilizing an enzyme has been known as a method for removing these mutagens from foods, for example, a method in which peroxidase is allowed to act on coffee (JP-A-60-62945), Method of causing catalase to act on coffee (Japanese Patent Laid-Open No. 59-232049)
No.), a method of allowing catalase to act on a vitamin C preparation (JP-A-60-54317), and the like.
Regarding the lactic acid bacterium food, there is a method for producing a lactic acid bacterium fermented food in which a system having a peroxidase and a thiocyanate ion and / or a halogenone ion is added to a lactic acid bacterium fermentation liquid at 10 ° C or lower (Japanese Patent Publication No. 62-228224). , It has been reported that this can remove mutagens and carcinogens.

On the other hand, based on the above-mentioned relationship between mutagens and carcinogenesis, the presence or absence of antimutagenic factors in foods determines the value of foods such as nutrition, digestibility, safety and flavor. It is said to be extremely important along with the factors.

In recent years, many researchers have reported various antimutagenic foods, such as milk, dairy products, raw vegetables, fruits, high fiber foods, and high vitamin content foods. ing. Further, these foods are regarded as foods having a high health-retaining function, rather than simply foods having a low risk of carcinogenicity.

In particular, it has been reported that fermented milk has a property of reducing the effect of mutagens contained in foods [Hosono Akiyoshi: Dairy Science / Food Research Vol.35 No.6 A-283].
~ A-289 (1986)].

However, when the presence or absence of antimutagenicity in fermented milk and beverages containing lactic acid bacteria, which are currently on the market, was examined, it was found to be little or very weak.

[0010]

Means for Solving the Problems Regarding the antimutagenicity reported in fermented milk, the present inventor searched for the cause and found that the cause of the mutagen caused simply by the pH decrease accompanying the lactic acid production of lactic acid bacteria. It was suggested that the bacterial cells used for fermentation are strongly involved, not the inactivation. As a result of further studies, it was found that a group of microorganisms having high antimutagenicity specifically exists in lactic acid bacteria, and that if they are added to foods such as fermented milk as lactic acid bacteria, high antimutagenicity can be obtained. It was found that a food having a positive effect as a health food or a health food can be obtained, and the present invention was completed.

That is, the present invention provides a food containing a lactic acid bacterium having antimutagenicity against a mutagen.

The lactic acid bacteria used in the food of the present invention (hereinafter,
The "anti-mutagenic lactic acid bacterium") can be isolated and collected from the nature or various fermented milks, for example, by the following screening method. In the present specification, "lactic acid bacterium" refers to all microorganisms capable of lactic acid fermentation, Lactobacillus microorganisms, Lactococcus microorganisms, Streptococcus microorganisms,
It includes a microorganism belonging to the genus Enterococcus, a microorganism belonging to the genus Bifidobacterium, and the like. In the present specification, the term "antimutagenicity" refers to all the effects of suppressing and reducing the effects of the mutagen, and also includes the effect of inactivating the mutagen itself.

In the screening of lactic acid bacteria used in the present invention, first, a lactic acid bacterium colony is separated from a sample containing lactic acid bacterium, for example, fermented milk, and then the bacterium is picked and the lactic acid bacterium is purely cultured to obtain a test lactic acid bacterium strain. Then, a test lactic acid bacterium strain is prepared in an appropriate number of bacteria, for example, about 300 to 300 million cells / ml, and a mutagen such as N-methyl-N′-nitro-N-nitrosoguanidine (hereinafter, referred to as “MNNG”) is prepared. For short), T
rp-P-2, aflatoxin, benzpyrene and the like are added, and further S9-mix is added if necessary. This is followed by a mutation test strain, such as Salmonella typhimurium TA100 strain or TA9.
8 strains or Escherichia coli WP2uv
After adding rA or the like and pre-incubating the mixture, the mixture is further cultured in a solid medium for an appropriate time. After completion of the culture, a revertant colony produced in the mutant assay strain may be detected, the antimutagenic action of each test lactic acid bacterium may be evaluated from the number of the colonies, and a lactic acid bacterium with high antimutagenicity may be selected.

In the above test, it is necessary to provide a positive control (mutagen, S9-mix, mutant test bacteria only), a standard control excluding the mutagen and a control of only the test lactic acid bacterium. ..

Further, the following formula may be used to calculate the rate of antimutagenicity from the above results. Antimutagenicity rate = [(BA) / (BC)] x 100 A: Number of revertant colonies when mutagen and lactic acid bacteria were added B: Revert when only mutagen was added Number of mutant colonies C: Number of revertant colonies when only lactic acid bacteria were added

Although the antimutagenic lactic acid bacterium can be detected, separated and collected by the above method, according to the results of the test conducted by the present inventors, even if the microorganisms belonging to the same lactic acid bacterium are antimutagenic, It has been revealed that the strains are largely different depending on the genus or species, and that the antimutagenicity of the antimutagenic microorganism also differs depending on the type of mutagen.

The antimutagenic activity of the lactic acid bacterium used in the present invention is preferably 40% to 55% or more with respect to at least one mutagen in terms of the above antimutagenicity, and a plurality of mutations More preferably it is for the raw material.

The food of the present invention is prepared by fermenting animal milk such as milk with the antimutagenic lactic acid bacterium obtained as described above, or in ordinary foods such as fruit juice and vegetable juice. It is prepared by adding the lactic acid bacterium to. Examples of the former food include fermented milk such as yogurt, fermented liquor such as kumisu and kefir, lactic acid bacterium beverage, and fermented food such as cheese. Examples of the latter food include juice containing lactic acid bacteria.

In the production of the food of the present invention, the number of antimutagenic lactic acid bacteria to be added is not limited, but a larger number of lactic acid bacteria is preferable because a better antimutagenic effect can be expected. In this sense, fermented foods that can increase the number of lactic acid bacteria by fermentation are more preferable.

The lactic acid bacterium used in the food of the present invention is more preferably a so-called intestinal-reachable lactic acid bacterium which is resistant to gastric acid of the human body, digestive enzyme system and bile acid. The reason why lactic acid bacteria that can reach the intestinal tract are preferable is that they become flora in these intestinal tracts and effectively protect the intestinal tissues from the mutagens existing in the intestinal tracts.
Examples of such lactic acid bacteria capable of reaching the intestinal tract include Lactobacillus casei, Lactobacillus acidophilus and Bifidobacterium.

The food of the present invention can be prepared by a usual method except that a lactic acid bacterium having antimutagenicity is used, and various components and additives such as milk and dairy products depending on the type of food are used. , Sugars such as sugar, fruit juices, vegetable juices, gelling agents, flavors and the like can be optionally added.

[0022]

Action: The mechanism of antimutagenicity of the food of the present invention has not been clarified, but it is considered to be due to some interaction existing between the mutagen and the antimutagenic lactic acid bacterium.

[0023]

EFFECTS OF THE INVENTION As will be apparent from the examples described below, the food of the present invention utilizing lactic acid bacteria having antimutagenicity is a fermented dairy product (eg yogurt) which has been conventionally provided.
It had a much higher ability to reduce mutagens compared to other foods. Thus, the food of the present invention has a high antimutagenic activity against mutagens, so by ingesting this daily, suppress the action of mutagens mixed in other foods, A safe and positive health maintenance effect becomes possible.

[0024] In particular, when an antimutagenic lactic acid bacterium having a high intestinal reach is used, it becomes possible for these lactic acid bacteria to exist as flora not only in the throat and oral cavity but also in the digestive tract. It can be fully expected to remove or suppress the causative mutagen.

[0025]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Example 1 Screening of anti-mutagenic lactic acid bacteria: Lactic acid bacteria having anti-mutagenicity were selected by the following screening method. (A) Each lactic acid bacterium sample was sampled in an appropriate amount, diluted and suspended in physiological saline, and then smeared and cultured on bromcresol purple plate count agar medium (BCP medium). From the colonies that grew on the medium, pick up the bacteria,
This was resuspended in physiological saline, and smear culture was repeated in BCP medium to perform pure isolation of the lactic acid bacterium strain. The resulting lactic acid bacterium strain was cultured in a liquid medium (MRS medium) at 30 ° C or 37 ° C for 17 hours. 300 times this culture
The cells were separated by centrifugation at 0 G and washed with a phosphate buffer (pH 7.4). Repeat this operation 3 times,
A lactic acid bacterium preparation liquid was obtained by adjusting the number of bacteria to 200 to 300 million / ml with the same buffer solution.

(B) To a sterilized test tube, take 0.1 ml of this lactic acid bacterium preparation, add MNNG, which is a typical base-substitution mutagen as a mutagen, to 5 μg / ml, and further add Mutation assay bacterium Salmonella typhimurium TA100 strain was added and shaken at 37 ° C. for 20 minutes in a shaking culture constant temperature water bath,
Pre-incubated. Top agar was then added and mixed, poured onto minimal glucose medium and spread evenly. After shading and culturing at 37 ° C. for 48 hours, the number of colonies of Salmonella typhimurium non-histidine-requiring strains generated by reversion was counted, and the antimutagenicity rate was calculated.

In a similar manner, the antimutagenicity rate of Trp-P-2 (0.05 μg / ml), which is a typical frame-substitution mutagen, was tested, and the antimutagenic performance of each lactic acid bacterium sample was tested. Was measured.

(C) As a result, although the mutagenicity rate of each lactic acid bacterium varied from 0% to 77.1%, MNNG and Tr were obtained from lactic acid bacterium specimens of 11 strains of 150 strains or more.
The following 7 lactic acid bacterium strain was obtained as a representative bacterial strain having high antimutagenicity to both p-P-2. For comparison, 5 lactic acid bacterium strains isolated from commercially available yogurt also show the antimutagenicity rate measured by the same method.

[0029]

Example 2 Production of fermented milk (yogurt) and its antimutagenicity test: As a starter of yogurt, the lactic acid bacterium Lactobacillus casei LA2 strain showing the highest antimutagenicity in Example 1 was used. 1% was added to milk sterilized at 120 ° C. for 2 seconds and fermented at 37 ° C. for 16 hours to produce yogurt. For this yogurt, MNNG (5.0 μg /
ml) and Trp-P-2 (0.05 μg / ml) were examined for antimutagenicity according to the following method. For comparison, the antimutagenicity rate was similarly measured for commercially available yogurt. The results are shown below.

(Anti-mutagenicity test of yogurt) (1) 0.1 ml of yogurt sample was placed in a sterilized test tube.
Then, add 5 μg / ml of MNNG as a mutagen.
To be added. (2) To this, 100 strains of Salmonella typhimurium TA, which is a mutation test bacterium, were added and shaken at 37 ° C. for 20 minutes in a shaking culture constant temperature water bath,
Pre-incubate. (3) Next, top agar is added and mixed, and the mixture is poured onto a minimal glucose medium and spread evenly. (4) Protect from light and incubate at 37 ° C for 48 hours. (5) Count the number of colonies of Salmonella typhimurium non-histidine-requiring strains generated by the back mutation. (6) For Trp-P-2, an antimutagenicity test is performed in the same manner as (1) to (5). However, in (2), the amount of Trp-P-2 was adjusted to 0.05 μl / ml, and 0.1 ml of S9-mix was further added.

[0032]

Example 3 Production of juice and its antimutagenicity test: physiological saline was added to the cells of the Lactobacillus casei LA2 strain collected by centrifugation in the same manner as in Example 1 to obtain 2.6 billion. Pieces / ml
Was prepared. This prepared liquid was added to sterilized and cooled juice having the following composition to adjust the number of lactic acid bacteria to 260 million / ml.

(Juice composition) Apple juice 880 g Glucose 10 g Skim milk powder 10 g Lactobacillus casei LA2 strain containing liquid 100 g ────────────────────────── ─── (total) 1,000g

0.1 ml of this apple juice containing lactic acid bacteria
The antimutagenicity of MNNG and Trp-P-2 was measured according to Example 2. As a result, the antimutagenicity rate of the juice of the present invention for MNNG was 71.3.
%, That for Trp-P-2 was 75.2%. that's all

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuuji Morita 5 Honjuku-cho, Asahi-ku, Yokohama-shi, Kanagawa Takanashi Milk Products Co., Ltd. Product Research Laboratory

Claims (5)

[Claims] 1. A food containing a lactic acid bacterium having antimutagenic activity against a mutagen. 2. The food according to claim 1, which is a beverage. 3. The food according to claim 1, which is fermented milk or a lactic acid bacterium beverage. 4. The food according to claim 1, wherein the lactic acid bacterium is Lactobacillus casei. 5. The method according to claim 1, wherein the mutagen is both a base substitution type mutagen and a frameshift type mutagen.
Item food.