HK1186754A - Agent for improvement in survival of lactic acid bacterium and/or bifidobacterium - Google Patents

Description

Agent for improving survival ability of lactic acid bacteria and/or bifidobacteria

Reference to related applications

The present application is based on the prior Japanese patent application No. 2010-184086 (application date: 2010, 8/19) and claims the benefit of priority, the disclosure of which is incorporated herein by reference in its entirety.

Background

Field of the invention

The present invention relates to an agent for improving the survival ability of lactic acid bacteria and/or bifidobacteria, which comprises an amino acid as an active ingredient. The present invention also relates to a food composition containing such a survival ability-improving agent and lactic acid bacteria and/or bifidobacteria, and a method for producing the food composition. The present invention also relates to a method for improving the viability of lactic acid bacteria and/or bifidobacteria, which comprises adding the viability-improving agent to a food composition containing lactic acid bacteria and/or bifidobacteria.

Prior Art

Useful microorganisms capable of exerting an effect of improving the flora in the digestive tract or the like beneficial to the host are called probiotics (or probiotic bacteria). Examples of such useful microorganisms include lactic acid bacteria and/or bifidobacteria.

Functional lactic acid bacteria and/or bifidobacteria such as probiotics are often orally ingested in the form of various foods and/or medicines. In this case, fermented foods such as fermented milk are already in a low pH environment before being ingested, and such an environment is not suitable for survival (survival) of lactic acid bacteria and/or bifidobacteria in many cases. Even after ingestion, living bodies having a low pH value such as the inside of the stomach become an environment unsuitable for the survival of lactic acid bacteria and/or bifidobacteria. It is also important from the viewpoint of preventive medicine that the effect accompanying the function of the probiotic bacteria is expected to be improved if the viability of the lactic acid bacteria and/or bifidobacteria in the food and/or in the living body is improved.

Several proposals have been made so far for improving the viability of lactic acid bacteria in food products.

For example, int.Dairy journal7,435-443(1997), R.I.Dave et al (Rajiv I.Daveand Negendra P.Shah) ("effective connection of Ascorbic Acid as an Oxygen Scavenger in Improving Viability of lactic Acid bacteria (probiotics) in fermented milk by addition of the antioxidant active substance Ascorbic Acid (vitamin C). However, the addition of an antioxidant active substance or the like has a great influence on the flavor and/or physical properties of yogurt and/or fermented milk, and the use thereof is limited. Further, since the antioxidant active substance acts by autooxidation, the effect thereof cannot be expected to be sustained unless a considerable amount is used.

Japanese patent application laid-open No. 2002-017254 reports that the survival ability of lactic acid bacteria in fermented milk preserved under excessive light irradiation is improved by a compound selected from cysteine, vitamin C, red bayberry extract, rutin and fruit juice. However, there is no specific disclosure of the improvement of the survival ability in a low pH environment such as acidic environment.

Jp 2010-505390 a (WO2008/040872) describes that gum arabic is used in combination with a sulfur-containing amino acid (e.g., cysteine) as necessary to improve the survival ability of bifidobacteria in fermented milk products. However, gum arabic must be used, and sulfur-containing amino acids are used merely as additional ingredients.

Further, Japanese patent application laid-open No. 10-327751 discloses that the flavor of fermented milk can be improved by adding a mixed component of predetermined amino acids (glutamic acid, leucine, alanine, serine, arginine, tyrosine, phenylalanine, histidine, and methionine) at a predetermined concentration. However, there is no description or suggestion that the survival ability of lactic acid bacteria and the like in fermented milk can be improved by amino acids.

Disclosure of Invention

The present inventors have now succeeded in using amino acids for lactic acid bacteria and bifidobacteria, which are probiotics in an acidic (low pH) environment, to a large extentThe viability of these probiotics during storage is improved. The present inventors also found that Zn, folic acid, and MgCO were treated₃The same studies have been made on inorganic salts, and as a result, these substances can improve the survival ability of lactic acid bacteria and bifidobacteria as probiotics, similarly to amino acids. The present invention has been made based on these findings.

Accordingly, an object of the present invention is to provide a survival rate improver for lactic acid bacteria and/or bifidobacteria capable of improving the survival rate of lactic acid bacteria and bifidobacteria as probiotics in an acidic (low pH) environment, a food composition using the survival rate improver for lactic acid bacteria and/or bifidobacteria, and a method for producing the same.

According to the present invention, the following inventions are provided.

(1) An agent for improving the survival ability of lactic acid bacteria and/or bifidobacteria, which comprises an amino acid as an active ingredient;

(2) the survival rate-improving agent according to the above (1), wherein the amino acid is an amino acid selected from the group consisting of tyrosine, tryptophan, histidine, methionine, cysteine, alanine and a mixture thereof;

(3) the agent for improving survival ability according to the above (1) or (2), wherein the lactic acid bacterium and the bifidobacterium are probiotics;

(4) the agent for improving survival rate according to any one of the above (1) to (3), which improves survival rate of lactic acid bacteria and/or bifidobacteria in a low pH environment having a pH value in the range of 2.0 to 6.5;

(5) the agent for improving survival ability according to any one of the above (1) to (4), which improves survival ability of lactic acid bacteria and/or bifidobacteria in yogurt or fermented milk;

(6) the agent for improving survival ability according to any one of the above (1) to (5), wherein the lactic acid bacterium is a lactic acid bacterium belonging to the genus Lactobacillus;

(7) according to the above(1) The agent for improving survival ability according to any one of (1) to (6), further comprising Zn, folic acid, MgCO₃And inorganic salts in mixtures thereof;

(8) a composition comprising the survival rate-improving agent according to any one of (1) to (7) above, and a lactic acid bacterium and/or a bifidobacterium;

(9) the food composition according to the above (8), which is yogurt or fermented milk;

(10) the food composition according to the above (8) or (9), which comprises 50mg or more of an amino acid added as a survival ability-improving agent relative to 100g of the composition;

(11) a method for producing a food composition, which comprises adding an amino acid to a composition containing lactic acid bacteria and/or bifidobacteria in a low pH environment having a pH in the range of 2.0 to 6.5;

(12) the method according to the above (11), further comprising performing fermentation of the composition after adding an amino acid to the composition;

(13) the method according to the above (11) or (12), wherein the amino acid is an amino acid selected from the group consisting of tyrosine, tryptophan, histidine, methionine, cysteine, alanine and a mixture thereof;

(14) the method according to any one of the above (11) to (13), wherein the lactic acid bacteria and the bifidobacteria are probiotics;

(15) the method according to any one of the above (11) to (14), wherein the food composition is yogurt or fermented milk;

(16) the method according to any one of the above (11) to (15), wherein the lactic acid bacterium is a lactic acid bacterium belonging to the genus Lactobacillus;

(17) the method according to any one of the above (11) to (16), further comprising adding a compound selected from Zn, folic acid, MgCO₃And inorganic salts and amino acids in their mixturesAdding;

(18) the method according to any one of the above (11) to (17), wherein the amount of the amino acid added is 50mg or more per 100g of the composition;

(19) a method of improving the viability of lactic acid bacteria and/or bifidobacteria in a food composition comprising adding an amino acid to the composition comprising lactic acid bacteria and/or bifidobacteria.

(20) The method according to the above (19), wherein the composition to which the amino acid is added is in a low pH environment having a pH value in the range of 2.0 to 6.5;

(21) the method of (19) or (20) above, which comprises adding the amino acid to the composition prior to fermentation of the composition;

(22) the method according to any one of the above (19) to (21), wherein the amino acid is an amino acid selected from the group consisting of tyrosine, tryptophan, histidine, methionine, cysteine, alanine, and a mixture thereof;

(23) the use of amino acids for improving the viability of lactic acid bacteria and/or bifidobacteria in a low pH environment having a pH of 2.0 to 6.5;

(24) the use according to the above (23), wherein the amino acid is an amino acid selected from the group consisting of tyrosine, tryptophan, histidine, methionine, cysteine, alanine and a mixture thereof.

According to the present invention, the viability of lactic acid bacteria and/or bifidobacteria as probiotics in (refrigerated) storage in an acidic environment can be greatly improved. Therefore, the activity of these cells can be maintained for a long period of time. By using the agent for improving survival ability of the present invention in a food composition, the survival ability of the cells can be improved without affecting the flavor and/or physical properties of the food composition. Further, according to the present invention, since the activity of the microbial cells can be maintained for a long period of time at a high level, the amount of the microbial cells to be used (the amount to be added to a food composition such as fermented milk) can be reduced, and as a result, improvement in the flavor and/or physical properties of a food composition such as fermented milk (or suppression of quality deterioration) can be expected in addition to cost reduction.

It is known that the survival ability of lactic acid bacteria in fermented milk greatly varies depending on the tolerance of each strain to dissolved oxygen, hydrogen peroxide, low pH, and the like. If the viability of probiotic lactic acid bacteria in products can be improved by the present invention, the possibility that the bacterial strains cannot be used due to low viability in fermented milk although the physiological effect is excellent can be reduced, and the shelf life (freshness) of probiotic commercial products can be expected to be extended.

Detailed Description

Agent for improving survival ability

The agent for improving the survival ability of lactic acid bacteria and/or bifidobacteria of the present invention contains an amino acid as an active ingredient.

Here, the "agent for improving the survival ability of lactic acid bacteria and/or bifidobacteria" means an agent (including food additives) for improving the survival ability of both or at least either of lactic acid bacteria and bifidobacteria. In this context, a viability-improving agent may alternatively also be expressed as a viability-improving composition or a viability-improving additive.

Here, "improvement in viability" means that when lactic acid bacteria and/or bifidobacteria are present in an environment in which their bacterial cells can grow or be maintained, they act on the bacterial cells to inhibit their death, thereby maintaining or increasing the number of residual bacterial cells. Therefore, the expression of improvement in viability means typically suppression of decrease in the number of cells, and may be used in a concept including maintenance of the number of cells and promotion of growth.

In the present invention, the viability-improving agent is an agent capable of improving the viability of lactic acid bacteria and/or bifidobacteria when stored in an acidic (low pH) environment. In food compositions containing lactic acid bacteria and/or bifidobacteria, such as fermented milk, an acidic (low pH) environment is generally formed, and thus the proliferation and survival of lactic acid bacteria are often inappropriate. The agent for improving viability of the present invention can function to improve the viability of bacterial cells even in such an acidic (low pH) environment, and is therefore useful for improving the viability of lactic acid bacteria and/or bifidobacteria in food compositions such as fermented milk. Thus, the viability-enhancing agent of the present invention functions more effectively in an acidic (low pH) environment.

The acidic (low pH) environment mentioned here is typically a pH value in the range of 2.0 to 6.5, preferably a pH value in the range of 2.5 to 6.0, more preferably a pH value in the range of 3.0 to 5.5, further preferably a pH value in the range of 3.5 to 5.0, and further more preferably a pH value in the range of 3.8 to 4.8, in terms of pH value. Alternatively, when the acidic (low pH) environment is represented by acidity, the acidity of lactic acid is, for example, in the range of 0.1 to 1.3, preferably in the range of 0.3 to 1.2, more preferably in the range of 0.5 to 1.1, and still more preferably in the range of 0.7 to 1.1 in the case where the food composition is fermented milk or the like. Such acidity can be determined by quantifying lactic acid in the food composition by a known published method.

As described above, the viability-improving agent of the present invention can improve the viability of lactic acid bacteria and/or bifidobacteria stored in an acidic (low pH) environment. Herein, "preservation" means preservation under temperature conditions suitable for growth or maintenance of lactic acid bacteria and/or bifidobacteria. The storage conditions are preferably refrigerated storage conditions, and specific examples thereof include storage at a temperature of about 1 to 10 ℃, preferably 1 to 5 ℃, and more preferably about 4 ℃. The storage time for which improvement of survival ability is expected is, for example, a period of less than one month, preferably 1 to 4 weeks, more preferably 1 to 3 weeks, and still more preferably 2 to 3 weeks.

Here, the amino acid is not particularly limited as long as it can be ingested in use and can improve the survival ability of lactic acid bacteria or bifidobacteria, and preferred examples of the amino acid that can be used include tyrosine, tryptophan, histidine, methionine, cysteine, and alanine, and a mixture of two or more of these may also be used. More preferably, the amino acid is tyrosine, tryptophan, histidine, cysteine, or a mixture thereof. Further preferably, the amino acid is tyrosine, tryptophan, histidine or a mixture thereof. In addition, when cysteine is used, the effect of improving the survival ability of lactic acid bacteria and/or bifidobacteria is high, but the effect may be large on the flavor of food. On the other hand, as amino acids that can be used, amino acids having a large ORAC value (Oxygen Radical AbsorptionCapacity) are preferable.

When the survivability-improving agent of the present invention is added to a food composition, if an amino acid as an active ingredient is hardly soluble in the food composition, it can be dissolved and used by using water and/or a solvent commonly used in the food field, for example, alcohols, hydrocarbons, organic acids, organic bases, inorganic acids, inorganic bases, supercritical fluids, or the like, singly or in combination, as necessary. That is, the amino acid is hydrophobic, and the food composition is hydrophilic.

The survival ability-improving agent of the present invention is preferably applied to lactic acid bacteria and/or bifidobacteria as probiotics. That is, in food compositions such as fermented milk, there are, as lactic acid bacteria and/or bifidobacteria: used as starter and as probiotic for imparting functionality to food compositions, the viability-improving agent of the invention is primarily aimed at improving the viability of the latter probiotic. As the Bifidobacterium and/or lactic acid bacteria, commercially available bacteria can be used, and bacteria obtained from ordinary or public bacteria depositories, or bacteria obtained by culturing samples obtained from the intestine or the like can be used.

The lactic acid bacteria to which the viability-improving agent of the present invention can be applied are preferably lactic acid bacteria of the genus Lactobacillus (Lactobacillus), and more specific examples thereof include Lactobacillus bulgaricus (Lactobacillus gasseri), Lactobacillus amylovorus (Lactobacillus amylovorus), Lactobacillus bulgaricus (Lactobacillus bulgaricus), Lactobacillus lactis (Lactobacillus lactis), Lactobacillus mucosae (Lactobacillus mucosae), Lactobacillus salivarius (Lactobacillus salivarius), Lactobacillus acidophilus (Lactobacillus acidophilus), Lactobacillus caucasicus (Lactobacillus buccus), Lactobacillus kefir (Lactobacillus), Lactobacillus thermophilus (Lactobacillus), Lactobacillus plantarum (Lactobacillus), Lactobacillus crispatus (Lactobacillus), Lactobacillus brevis (Lactobacillus), Lactobacillus casei (Lactobacillus), Lactobacillus jejun (Lactobacillus), Lactobacillus plantarum (Lactobacillus), Lactobacillus casei), Lactobacillus plantarum (Lactobacillus), Lactobacillus plantarum (Lactobacillus), Lactobacillus plantarum (Lactobacillus), Lactobacillus (Lactobacillus), Lactobacillus plantarum (Lactobacillus), Lactobacillus (Lactobacillus), Lactobacillus plantarum (Lactobacillus), Lactobacillus (Lactobacillus), Lactobacillus (, Lactobacillus pentosus (Lactobacillus pentosus), and the like. Among them, preferable examples include Lactobacillus gasseri (Lactobacillus gasseri), Lactobacillus amylovorus (Lactobacillus amylovorus), and the like.

In addition, lactic acid bacteria other than lactobacillus include lactic acid bacteria belonging to the genus Streptococcus (Streptococcus), Leuconostoc (Leuconostoc), Pediococcus (Pediococcus), Enterococcus (Enterococcus), and Lactococcus (Lactococcus), and specific examples of these include Streptococcus thermophilus (Streptococcus thermophilus), Leuconostoc mesenteroides (leuconosteroids), Pediococcus pentosaceus (Pediococcus pentosaceus), Enterococcus faecalis (Enterococcus faecalis), Lactococcus lactis (Lactococcus lactis), Enterococcus faecium (Enterococcus faecium), Leuconostoc lactis (Leuconostoc lactis), and Lactococcus cremoris (Lactococcus cremoris).

The Bifidobacterium to which the survival rate improver of the present invention can be applied is a bacterium belonging to the genus Bifidobacterium, and specific examples thereof include Bifidobacterium lactis, Bifidobacterium bifidum, Bifidobacterium breve, Bifidobacterium infantis, Bifidobacterium adolescentis, Bifidobacterium longum, Bifidobacterium animalis, Bifidobacterium catenulatum, Bifidobacterium dentale, Bifidobacterium odonta, and Bifidobacterium odonta. Among them, preferred examples include Bifidobacterium lactis (Bifidobacterium lactis).

According to a preferred embodiment of the present invention, there is provided an agent for improving the survival ability of lactic acid bacteria and/or bifidobacteria, which comprises an amino acid selected from the group consisting of Zn, folic acid, and MgCO as an active ingredient₃And inorganic salts in mixtures thereof. As such an additive component, ascorbic acid is further exemplified.

According to other modes of the invention, Zn, folic acid and MgCO can be provided₃And an agent for improving the survival ability of a lactic acid bacterium and/or a bifidobacterium, which comprises an inorganic salt as an active ingredient in a mixture thereof.

Lactic acid bacteria are considered to have a defense mechanism against acid and/or oxygen, and depending on the strength, bacteria having high resistance to acid and/or oxygen and strains having low resistance are present. It is considered that the cell activity is increased and the survival ability is improved by an inorganic salt which can assist an intracellular enzyme reaction. These are, of course, theories and do not limit the invention. Thus, it can be said that the addition of these inorganic salts to amino acids is more advantageous in improving the survival ability.

Food composition and method for improving survival ability

According to still another aspect of the present invention, there is provided a composition containing the survival ability improver of the present invention and lactic acid bacteria and/or bifidobacteria. These compositions are preferably food compositions, and specific examples thereof include soft drinks, milk drinks, fermented milk, yogurt, and lactic acid bacteria drinks.

The composition containing the survival ability improver of the present invention and lactic acid bacteria and/or bifidobacteria may be used as it is, or may be further mixed with other foods and/or other ingredients, and used according to a conventional treatment method as in a conventional food composition. The properties thereof may be in the state and/or form of a generally used food or drink, for example, any of solid (powder, granule, and others), paste, liquid, and suspension.

According to a preferred embodiment of the present invention, there is provided a method for producing a food composition, which comprises adding an amino acid to a composition containing a lactic acid bacterium and/or a bifidobacterium in a low pH environment having a pH value in the range of 2.0 to 6.5. The resulting food composition has the viability-improving function of the present invention.

Here, the relationship between the time of adding the amino acid and the fermentation time of the food composition may be performed before, during, or after the fermentation of the composition, and the amino acid is preferably added before the fermentation of the composition, and the added amino acid is preferably managed in a hygienic manner, and the like, from the viewpoint of easily managing the effect and/or action, and the like, in the entire product, and more preferably before the sterilization of the composition.

That is, according to a more preferred embodiment of the present invention, the method for producing a food composition further comprises adding an amino acid to the composition, and then fermenting the composition.

According to a further preferred embodiment of the present invention, the method for producing a food composition further comprises adding a compound selected from the group consisting of Zn, folic acid, and MgCO₃And the inorganic salts in the mixture thereof are added together with the amino acid.

Examples of other components that can be added to the composition of the present invention include water, proteins, sugars, lipids, vitamins, minerals, organic acids, organic bases, fruit juices, and flavors. Further, additives such as gelling agents and stabilizers can be exemplified. These components may be used in combination of two or more.

In the composition of the present invention, the viability-improving agent is used as follows: the amino acid to be added as the survival ability improver is preferably contained in an amount of 50mg or more per 100g of the composition, more preferably 50mg to 300mg per 100g of the composition, and still more preferably 50mg to 200mg per 100g of the composition. The content of the amino acid in the composition is within the above range, and is advantageous in that the effect of improving the survival ability of the amino acid is sufficiently exhibited, and is effective in that the adverse effect on the flavor and/or physical properties of the composition due to the use of a large amount of the amino acid is avoided.

In the composition (preferably food composition) of the present invention, the lactic acid bacteria are preferably present in an amount of 10⁵CFU/g or more, more preferably 10⁶～10⁹CFU/g range, more preferably 10⁷～10⁸The content of the Bifidobacterium is preferably 10 in terms of CFU/g⁵CFU/g or more, more preferably 10⁶～10⁹CFU/g range, more preferably at 10⁷～10⁸The CFU/g range contains.

According to another aspect of the present invention, there is provided a method for improving the viability of lactic acid bacteria and/or bifidobacteria in a food composition, which comprises adding the viability-improving agent of the present invention to a composition containing lactic acid bacteria and/or bifidobacteria. Here, the time for adding the survival ability improver may be any time before, during, or after the fermentation of the composition, from the viewpoint of facilitating uniform management of the effect and/or action and the like in the whole product, preferably from the viewpoint of facilitating hygienic management of the amino acid and the like added before the fermentation of the composition, and more preferably before the sterilization of the composition.

In the present specification, the expression "about" and/or "approximately" is used to include the variation of the value that can be allowed by a person skilled in the art in achieving the purpose of setting the value.

Examples

The present invention is explained in detail by the following examples, but the present invention is not limited to these examples.

(1) Test strain and culture method

As lactic acid bacteria, strains having different viability in a low pH environment (e.g., in fermented milk) are used: lactobacillus gasseri OLL203195(l.gasseri OLL203195) (FERM BP-11005), lactobacillus gasseri MEP22040001(l.gasseri MEP22040001), lactobacillus gasseri MEP22040002(l.gasseri MEP22040002), lactobacillus gasseri JCM1131T (l.gasseri JCM1131T) and lactobacillus amylovorus OLL2880(l.amylovorus OLL2880) (FERM BP-11006). In this case, l.gasseri OLL203195 is used as a representative of a cell having a low viability under a low pH environment, l.gasseri MEP22040001 is used as a representative of a cell having a medium viability under a low pH environment, l.gasseri MEP22040002 is used as a representative of a cell having a high viability under a low pH environment, and l.gasseri JCM1131T is used as a representative of a lactic acid bacterium belonging to the genus Lactobacillus (Lactobacillus) or a representative of Lactobacillus gasseri (Lactobacillus gasseri).

Further, l.gasseri OLL203195(Lactobacillus gasseri OLL203195) was deposited by the patent organism depositary center of the institute of advanced industrial and technology, independent administrative corporation on 2.9.2008, and the present microorganism was deposited under accession number FERM BP-11005.

In addition, l.amylovorus OLL2880(Lactobacillus amylovorus OLL2880) was deposited by the patent organism depositary of the institute of advanced industrial and technology, independent administrative law, p.2008, p.2, and this microorganism was deposited under accession number FERM BP-11006.

Moreover, JCM refers to the microbial systems preservation facility of institute of physical and chemical sciences (Japan Collection Microorganisms), and is now becoming the biological resource center of independent administrative sciences institute of physical and chemical sciences (RIKEN BRC) microbial material development room.

Each strain was anaerobically cultured in MRS medium using an anaerobic culture system (アネロパツク (trade name, Mitsubishi ガス chemical Co., Ltd.)Then, the mixture is cultured (37 ℃ for 24 hours). Then, the resulting culture solution was concentrated to 10 times, and suspended in 0.85% physiological saline to prepare a concentrated cell solution (cell concentration: about 10)¹⁰CFU/g)。

(2) Preparation of working starter

A10 wt% aqueous solution of skim milk powder was sterilized at 95 ℃ for 10 minutes, and then inoculated with 0.15 wt% of a starter (a mixed starter separated from Mingzhi yoghurt) and fermented at 37 ℃ until the acidity reached 0.75, and then cooled to 4 ℃ as a working starter.

(3) Determination of viability in fermented milk

Yogurt mix (yogurtmix) (raw milk) (table 1) was sterilized at a maximum temperature of 95 ℃, inoculated with 3 wt% of the above working starter and 1 wt% of each lactic acid bacterium, and fermented at 43 ℃ until the acidity reached 0.75.

As the survival ability improving agent or its comparative example, amino acids (tyrosine, tryptophan, histidine, methionine, cysteine, alanine) (each 100mg/100g), vitamin C (100mg/100g), and MgCO were used₃(200mg/100g), folic acid (200. mu.g/100 g), zinc (Zn) (1mg/100 g). In principle, these viability-improving agents and comparative examples were added in prescribed amounts before the above-mentioned fermentation and before sterilization (among them, vitamin C and folic acid were added after sterilization because of poor heat resistance). After fermentation, each sample was placed in a semi-resistant cup baffle container, cooled to 4 ℃, and then covered with an aluminum lid using a heat sealer.

The fermented milk of each sample covered with the aluminum lid obtained was stored at 4 ℃.

The viability of the fermented milk was confirmed for 72 hours (storage temperature: 4 ℃) after 1 day and 16 days from the start of storage by aerobic culture in BL (+) medium (culture under aerobic conditions in BL medium supplemented with 5% defibrinated horse blood) and anaerobic culture with LBS (culture under anaerobic conditions in LBS medium using anaerobic culture system (アネロパツク (trade name, Mitsubishi ガス chemical Co., Ltd.)).

Specifically, the viable cell count of each sample was determined, and the survival rate was determined by dividing the number of cells after 16 days by the number of cells after 1 day in% conversion. The number of bacteria used herein is the average value of the number of bacteria in the medium used.

TABLE 1 simple mix of yoghurt mixes (without homogenization treatment)

The results of the experiment are shown in tables 2 and 3 below.

In addition, in table 2 and table 3, the survival rate difference in the control group was due to the experimental error per day because of the difference in the production date.

TABLE 2.4 survival rate of each lactic acid bacterium in fermented milk at preservation temperature (%: 16 days/1 day)

TABLE 3.4 survival rate of each lactic acid bacterium in fermented milk at preservation temperature (%: 16 days/1 day)

In addition, for vitamin C, MgCO₃The results of the experiments for each of folic acid, and zinc (Zn) are shown in tables 4 and 5 below.

TABLE 4 survival rate of L.gasseri MEP22040001 in fermented milk at 4.4 ℃ preservation (%: 8 or 16 days/1 day)

	1 day	8 days	16 days
				Control group	100	2.0	0.3
Zn additive group	100	26.5	0.2
				Folic acid addition group	100	23.8	0.5
MgCO3 addition group	100	27.5	3.0

TABLE 5 survival rate (%: 8 or 16 days/1 day) of L.gasseri OLL203195 in fermented milk at 4 ℃ storage

	1 day	8 days	16 days
				Control group	100	5.7	0.7
Zn additive group	100	10.4	0.5
				Folic acid addition group	100	6.6	0.6
MgCO3 addition group	100	14.7	3.1

(4)Determination of the viability (influence due to the difference in the amount of amino acids)

Survival ability (survival rate) was determined in the same manner as in the experiment (3) except that l.gasseri OLL2680 was used as lactic acid bacteria and the kind and amount of amino acids added as the survival ability-improving agent were as shown in the following table.

The results are shown in Table 6 below.

TABLE 6 survival rate of L.gasseri JCM1131T in fermented milk at 4 ℃ storage (%: 16 days/1 day)

(5)Determination of the viability (influence due to the difference in the amount of amino acids)

The survival rate was determined in the same manner as in the experiment (3) except that l.gasseri OLL2802 and l.gasseri OLL2680 were used as lactic acid bacteria, and amino acid (tryptophan) was used as a survival rate improver at addition amounts of 1, 10, 50 and 100mg/100 g.

The results of the experiment are shown in table 7 below.

TABLE 7.4 survival rate of each lactic acid bacterium in fermented milk at preservation temperature (%: 16 days/1 day)

From the above results, when the tryptophan concentration (amino acid) was added to exceed 50mg/100g, the effect of improving the survival ability of lactic acid bacteria was confirmed.

(6)Determination of the viability (in the case of mixtures of amino acids)

The survival rate was determined in the same manner as in the experiment (3) except that l.gasseri OLL2802 and l.gasseri OLL2680 were used as lactic acid bacteria, and the following combination (mixture) of 2 kinds of amino acids was used as a survival ability improving agent.

The amino acid combinations tested are as follows.

(a) Tryptophan: 50mg/100g + histidine: 50mg/100g

(b) Tryptophan: 50mg/100g + tyrosine: 50mg/100g

(c) Tryptophan: 50mg/100g + cysteine: 50mg/100g

The results of the experiment are shown in table 8 below.

TABLE 8.4 survival rate of each lactic acid bacterium in fermented milk at preservation temperature (%: 16 days/1 day)

(7)Determination of viability (in the case of Bifidobacterium)

The survival rate was determined in the same manner as in the experiment (3) except that bifidobacterium b.animalis subsp.lactis JCM10602T (bifidobacterium animalis subsp.lactis JCM10602T) was used in place of lactic acid bacteria, and amino acid (tryptophan) was used as a survival rate improving agent in the amounts of 50, 100 and 200mg/100 g.

The results of the experiment are shown in table 9 below.

TABLE 9.4 survival rate of Bifidobacterium in fermented milk at preservation: (16 days/1 day)

Claims (24)

1. An agent for improving the survival ability of lactic acid bacteria and/or bifidobacteria, which comprises an amino acid as an active ingredient.

2. The survivability-improving agent according to claim 1, wherein the amino acid is an amino acid selected from the group consisting of tyrosine, tryptophan, histidine, methionine, cysteine, alanine and a mixture thereof.

3. The survivability-improving agent according to claim 1 or 2, wherein the lactic acid bacteria and the bifidobacteria are probiotics.

4. The agent for improving survival ability according to any one of claims 1 to 3, which improves the survival ability of lactic acid bacteria and/or bifidobacteria in a low pH environment having a pH value in the range of 2.0 to 6.5.

5. The agent for improving survival ability according to any one of claims 1 to 4, which improves the survival ability of lactic acid bacteria and/or bifidobacteria in yogurt or fermented milk.

6. The agent for improving survival rate according to any one of claims 1 to 5, wherein the lactic acid bacterium is a lactic acid bacterium belonging to the genus Lactobacillus.

7. The agent for improving survival ability according to any one of claims 1 to 6, further comprising Zn, folic acid, MgCO₃And inorganic salts in mixtures thereof.

8. A composition comprising the survival ability-improving agent according to any one of claims 1 to 7, and lactic acid bacteria and/or bifidobacteria.

9. Food composition according to claim 8, which is a yoghurt or a fermented milk.

10. The food composition according to claim 8 or 9, wherein 50mg or more of the amino acid added as a survival ability-improving agent is contained per 100g of the composition.

11. A method for producing a food composition, which comprises adding an amino acid to a composition containing a lactic acid bacterium and/or a bifidobacterium in a low pH environment having a pH value in the range of 2.0 to 6.5.

12. The method of claim 11, further comprising fermenting the composition after adding the amino acid to the composition.

13. The method of claim 11 or 12, wherein the amino acid is an amino acid selected from the group consisting of tyrosine, tryptophan, histidine, methionine, cysteine, alanine, and mixtures thereof.

14. The method according to any one of claims 11 to 13, wherein the lactic acid bacteria and bifidobacteria are probiotics.

15. A method according to any one of claims 11 to 14 wherein the food composition is yoghurt or fermented milk.

16. The method according to any one of claims 11 to 15, wherein the lactic acid bacteria are lactic acid bacteria of the genus lactobacillus.

17. The method of any one of claims 11-16, further comprising adding a compound selected from Zn, folic acid, MgCO₃And the inorganic salts in the mixture thereof are added together with the amino acid.

18. The method according to any one of claims 11 to 17, wherein the amount of the amino acid added is 50mg or more per 100g of the composition.

19. A method of improving the viability of lactic acid bacteria and/or bifidobacteria in a food composition comprising adding an amino acid to the composition comprising lactic acid bacteria and/or bifidobacteria.

20. The method according to claim 19, wherein the composition to which the amino acid is added is in a low pH environment having a pH in the range of 2.0 to 6.5.

21. The method of claim 19 or 20, comprising adding the amino acid to the composition prior to fermentation of the composition.

22. The method of any one of claims 19 to 21, wherein the amino acid is an amino acid selected from the group consisting of tyrosine, tryptophan, histidine, methionine, cysteine, alanine and mixtures thereof.

23. Use of an amino acid for improving the viability of lactic acid bacteria and/or bifidobacteria in a low pH environment having a pH in the range of 2.0 to 6.5.

24. The use according to claim 23, wherein the amino acid is an amino acid selected from the group consisting of tyrosine, tryptophan, histidine, methionine, cysteine, alanine and mixtures thereof.