HK1117995A

HK1117995A - Fermented food containing bifidobacterium bacteria and method for producing the same

Info

Publication number: HK1117995A
Application number: HK08108954.9A
Authority: HK
Inventors: 星亮太郎; 小笠原伸浩; 芳川雅树; 工藤辰幸; 赤星良一; 水泽进; 君塚晴行; 铃木贵雄
Original assignee: 株式会社益力多本社
Priority date: 2005-06-02
Filing date: 2006-05-22
Publication date: 2009-01-30

Description

Fermented food containing bacteria of the genus Bifidobacterium and method for producing the same

Technical Field

The present invention relates to a fermented food containing bacteria of the genus bifidobacterium, and more particularly, to a fermented food containing viable bacteria of the genus bifidobacterium at a high concentration and having excellent survivability after storage, and a method for producing the same.

Background

Bacteria belonging to the genus bifidobacterium have been shown to have various effects such as improvement of intestinal flora, improvement of constipation, improvement of intestinal function, protection against infection, activation of immunity, and prevention of cancer, as well as lactic acid bacteria represented by bacteria belonging to the genus lactobacillus. Further, it is considered that these microorganisms contribute to human health by improving the intestinal environment.

In order to allow bacteria belonging to the genus bifidobacterium to exert such an effect, it is necessary to maintain a high viable cell count in products such as fermented milk. However, bacteria of the genus bifidobacterium are generally anaerobic bacteria, and therefore have poor viability and rapidly die particularly in the presence of oxygen.

In order to improve the viability of products such as fermented milk using bacteria of the genus bifidobacterium, for example, a method using sucrose (sucrose) or sorbitol (D-glucitol) has been proposed (patent document 1); a method using erythritol (patent document 2); a method using lactitol (patent document 3).

Further, in order to provide bacteria belonging to the genus bifidobacterium to consumers in a viable state, a method of completely blocking contact with oxygen by filling a container made of an oxygen-impermeable packaging material with a fermented product containing bacteria belonging to the genus bifidobacterium which has just been produced has been adopted, but the use of such an oxygen-impermeable container poses many problems in disposal and cost, and the degree of freedom of use thereof is limited.

Therefore, methods for maintaining the viability of bacteria belonging to the genus bifidobacterium even under aerobic conditions have been studied, and several reports have been reported. Specifically, methods of using N-acetylglucosamine, pantothenic acid or pantethine (pantethine), pantetheine, peptides, and lactulose have been reported for improving the viability of bacteria belonging to the genus bifidobacterium. However, for the reasons that the raw materials used in the above methods are expensive per se or have a large influence on the taste when applied to foods, a more excellent raw material including an effect on survivability has been demanded.

Further, it is considered that the viability of bacteria belonging to the genus bifidobacterium is easily affected by strains, pH of products (beverages, foods, etc.), amount of sugars and dissolved oxygen added as a sweetener, and the like, and in order to improve this, studies have been made on addition of yeast or lactic acid bacteria, combination use of vitamin C, material of product containers, and the like. However, in recent years, in order to further improve survivability in response to various consumer preferences, a more excellent raw material for use in survivability improvement is desired.

Patent document 1: japanese examined patent publication No. 57-4291

Patent document 2: japanese patent No. 2577692

Patent document 3: japanese patent No. 3261571

Disclosure of Invention

Accordingly, an object of the present invention is to obtain a novel raw material which is capable of improving the storage and survival properties of live bacteria belonging to the genus bifidobacterium, for which various physiological effects can be expected, and which does not affect the taste even when used in beverages, foods and the like, and to provide a fermented food containing the live bacteria belonging to the genus bifidobacterium, the viability of which is improved by the raw material, at a high concentration. Another object of the present invention is to provide a method for improving the survivability of fermented food containing bacteria belonging to the genus bifidobacterium during storage.

The present inventors have conducted intensive studies to solve the above problems, and as a result, have found that a fermented food capable of stably maintaining the viable cell count of bacteria belonging to the genus bifidobacterium after storage can be obtained by mixing extracts of specific plants, thereby completing the present invention.

That is, the present invention is a fermented food characterized by containing an extract of 1 or 2 or more plant materials selected from the group consisting of turmeric, houttuynia, eucommia, rice bran, persimmon leaf, perilla, clove, cinnamon, and hydrangea strigosa, and bacteria of the genus bifidobacterium.

The present invention also provides a fermented food containing bacteria belonging to the genus bifidobacterium and an extract of 1 or 2 or more plant materials selected from the group consisting of turmeric, houttuynia cordata, eucommia ulmoides, rice bran, persimmon leaf, perilla, clove, cinnamon, and sweet tea obtained by acid extraction, particularly the extract extracted under a condition of ph4.0 or less.

Further, the present invention is a method for producing a fermented food containing bacteria of the genus bifidobacterium, characterized in that in the production of the fermented food containing bacteria of the genus bifidobacterium, extract of 1 or more than 2 plant materials selected from the group consisting of turmeric, houttuynia cordata, eucommia ulmoides, rice bran, persimmon leaf, perilla, clove, cinnamon, and sweet tea are mixed at an arbitrary stage.

The present invention also provides a method for improving the viability of bacteria belonging to the genus bifidobacterium, characterized in that an extract of 1 or 2 or more plant materials selected from the group consisting of turmeric, houttuynia cordata, eucommia ulmoides, rice bran, persimmon leaf, perilla, clove, cinnamon, and sweet tea is mixed.

The extract of 1 or 2 or more plant materials selected from the group consisting of turmeric, houttuynia cordata, eucommia ulmoides, rice bran, persimmon leaf, perilla, clove, cinnamon, and sweet tea contained in the fermented food of the present invention imparts an excellent effect of improving the viability of bacteria belonging to the genus bifidobacterium, and hardly affects the taste. Therefore, the fermented food of the present invention using the extract has a good taste, does not deteriorate the viable cell count even when stored for a long period of time, and is useful for health promotion.

Detailed Description

The fermented food of the present invention is characterized by containing an extract (hereinafter, sometimes simply referred to as "extract") of 1 or 2 or more plant materials selected from the group consisting of turmeric, houttuynia cordata, eucommia ulmoides, rice bran, persimmon leaf, perilla, clove, cinnamon, and sweet tea.

Among the plant materials as the raw material of the above extract, Turmeric (Turmeric) is a rhizome of Turmeric (Curcuma longa L.) or Curcuma aromatica (Curcuma aromatica salisb.) belonging to a plant belonging to the genus Curcuma of the family zingiberaceae. In the present invention, among these plants of the genus curcuma, curcuma is particularly preferable. The turmeric is known to have the effects of improving liver function, preventing hangover every other day, inhibiting gastric acid secretion, improving gastrointestinal dysfunction, etc.

Houttuynia cordata (Houttuynia cordiata Thunb.) is a plant belonging to the genus Houttuynia of the family Saururaceae. The whole herb or branch of the aerial part can be used for extracting the extract from the houttuynia cordata, but the whole herb of the aerial part is particularly preferably used. The houttuynia cordata is known to have an effect of inhibiting mucosal inflammation.

Eucommia ulmoides (Eucommia ulmoides Oliv.) is a plant belonging to the genus Eucommia of the family Eucommiaceae. Leaves or branches can be used for extraction of the extract from eucommia ulmoides, but leaves are particularly preferably used. The eucommia ulmoides is known to have the effects of regulating blood pressure, relieving stress, preventing lifestyle-related diseases, and the like.

The Rice bran (Rice bran) refers to the pericarp, seed coat starch layer and germ of a seed (brown Rice) obtained by removing the outer skin (Rice hull) from Rice (Oryza sativa) which is a plant belonging to the family gramineae. The rice bran is known to have the effects of enhancing immunity, preventing fatty liver, and the like.

Persimmon leaves are leaves of persimmon (Diospyros Kaki Thunb.), black date (Diospyros lotus L.) or king emilia (Diospyros lotus L. var. glabra Makino) belonging to a plant belonging to the genus persimmon of the family Ebenaceae. In the present invention, persimmon is particularly preferable among these persimmon trees. The persimmon leaf is known to have the effect of suppressing sneezing, nasal obstruction, rhinorrhea, etc.

Perilla (Perilla) is a Perilla (perillabasttescens (L.) Britton var. acuta Kudo), green Perilla (perillabastescens (L.) Britton var. acuta Kudo) or tempering Perilla (perillabasttescens (L.) Britton var. crispa (thunnb) Decne) belonging to a plant belonging to the genus perillaof the family labiatae. In the present invention, among these plants of the genus perilla, perilla is particularly preferable. Further, leaves, branches, and seeds can be used for extraction of the extract from these perilla, but leaves are particularly preferably used. The perilla has been known to have antiallergic, hypoglycemic, youthful skin-caring effects.

Clove (cloves) is the flower bud of Clove (syzygiardia aromaticum (L.) merr. et Perry or Eugenia caryophyllata Thunb) belonging to the genus caryophylli of the family myrtaceae. The clove is known to have the effects of antisepsis, uterine contraction, toothache relief and the like.

Cinnamon (cinmamon) is the bark of Cinnamomum zeylanicum Nees or Cinnamomum cassia (cinmamum cassia Blume) belonging to Cinnamomum genus of lauraceae. Among these plants of the genus cinnamomum, cinnamomum zeylanicum is particularly preferred. Cinnamon is known to have antibacterial, cold-dispelling, antipyretic, analgesic, digestive system activating, cold-relieving, dyspepsia relieving, diarrhea relieving, and antiemetic effects.

Sweet tea (Rubus suavissimus s.lee (Rosaceae)) is a plant belonging to the genus Rubus of the family Rosaceae. When the extract is extracted from sweet tea, leaves or stems can be used, but leaves are particularly preferably used. In recent years, the sweet tea attracts attention for anti-inflammatory and anti-allergic effects.

When the extract is obtained from the above plant materials, more than 1 of the above plant materials are directly or optionally washed, peeled, dried and/or pulverized, and then extracted with solvent. These extracts may be used in a mixture of 1 or more of extracts obtained by extracting each plant material. Further, a mixed extract obtained by extracting a mixture obtained by mixing 2 or more plant materials may be used. Of these extracts, persimmon leaf extract and sweet tea extract are preferable.

Examples of the solvent used for producing the extract include lower alcohols having 1 to 5 carbon atoms such as water or ethanol, and organic solvents such as ethyl acetate, glycerin, and propylene glycol. These solvents may be used as a mixed solvent by mixing 2 or more kinds thereof. Among these solvents, water or an aqueous solvent such as water-lower alcohol is particularly preferable.

The method of extraction with the solvent is not particularly limited, but an acid extraction method is preferred because components that improve the effect of improving the viability of bacteria belonging to the genus bifidobacterium can be efficiently extracted from various plant materials by acid extraction, and sufficient effects can be obtained even when these extracts are added in a trace amount. The acid extraction is preferably carried out under acidic conditions of pH4.0 or less, more preferably pH3.0 to 4.0. The acid component used for adjusting the pH of the solvent in the acid extraction may be any acidic substance, and is not particularly limited. Preferable examples of the acid component include organic acids such as citric acid, malic acid, tartaric acid, succinic acid, lactic acid, and acetic acid.

Further, the extraction conditions for extracting the extract with the solvent are not particularly limited, but the extraction treatment is preferably performed at a temperature of, for example, 60 to 120 ℃, more preferably 80 to 100 ℃ for about 30 to 60 minutes.

The extract thus obtained may be used as it is, or a concentrated extract obtained by purifying and concentrating the obtained extract by ultrafiltration, centrifugation or the like, or a powdery extract obtained by drying the extract by spray drying, freeze drying or the like.

The amount of the above extract to be used in the fermented food of the present invention is preferably determined by experiments because the obtained effect may vary depending on the type of the bacterium belonging to the genus bifidobacterium or the like, and for example, in the case of an extract obtained by water extraction (hereinafter referred to as "water extract"), about 0.01 to 10.0% by mass (hereinafter referred to simply as "%") and preferably about 0.1 to 5.0% by mass is added as an extract having a brix of about 10. In the case of an extract obtained by acid extraction (hereinafter referred to as "acid extract"), about 0.001% to 10%, preferably about 0.01% to 1.0% is added as an extract having a brix of about 10.

In the fermented food of the present invention, even if the amount of the water extract or the acid extract used exceeds 10%, the effect of improving the viability of the bacterium belonging to the genus bifidobacterium may not be obtained in proportion to the amount of the water extract or the acid extract, and the taste of the fermented food may be adversely affected. On the contrary, if the amount of the water extract used is less than 0.01% or the amount of the acid extract used is less than 0.001%, the effect of improving the viability of bacteria belonging to the genus bifidobacterium cannot be sufficiently obtained, which is not preferable.

On the other hand, the species of Bifidobacterium bacteria used for the production of the fermented food of the present invention and contained in the food is not particularly limited as long as they are microorganisms belonging to the genus Bifidobacterium bacteria, and preferable examples thereof include Bifidobacterium breve (Bifidobacterium longum), Bifidobacterium longum (Bifidobacterium longum), Bifidobacterium infantis (Bifidobacterium infantis), Bifidobacterium adolescentis (Bifidobacterium adolescentis), Bifidobacterium bifidum (Bifidobacterium bifidum), Bifidobacterium catenulatum (Bifidobacterium catenulatum), Bifidobacterium pseudopetentium (Bifidobacterium anum), and Bifidobacterium angulus (Bifidobacterium angulus); bifidobacterium gallicum (Bifidobacterium gallicum) having a history isolated from the intestine of a human body; bifidobacterium lactis (Bifidobacterium lactis), Bifidobacterium animalis (Bifidobacterium animalis) and the like are used in foods. Of these bacteria belonging to the genus Bifidobacterium, Bifidobacterium breve, Bifidobacterium bifidum, and Bifidobacterium longum are particularly preferable from the viewpoint of the effect of improving the survivability when used in combination with the extract.

In addition, even when the fermented food of the present invention contains two or more other microorganisms in addition to the bacteria belonging to the genus bifidobacterium, the effect of improving the viability of the bacteria belonging to the genus bifidobacterium due to the extract can be obtained. Therefore, the fermented food product of the present invention may contain, in addition to the bifidobacterium bacteria, Lactobacillus casei (Lactobacillus casei), Lactobacillus acidophilus (Lactobacillus acidophilus), Lactobacillus helveticus (Lactobacillus helveticus), Lactobacillus salivarius (Lactobacillus salivarius), Lactobacillus gasseri (Lactobacillus gasseri), Lactobacillus fermentum (Lactobacillus fertilium), Lactobacillus reuteri (Lactobacillus reuteri), Lactobacillus crispatus (Lactobacillus crispatus), Lactobacillus bulgaricus (Lactobacillus delbrueckii subsp. bulgaricus), Lactobacillus delbrueckii (Lactobacillus delkis), Lactobacillus delbrueckii subsp. delbrueckii), Lactobacillus johnsonii, and the like; streptococcus bacteria such as Streptococcus thermophilus (Streptococcus thermophilus); lactococcus bacteria such as Lactococcus lactis subsp.lactis, Lactococcus lactis subsp.cremoris, Lactococcus plantarum (Lactococcus lactis), Lactococcus raffinosus (Lactococcus raffinosus), and the like; and lactobacillus such as Enterococcus bacteria such as Enterococcus faecalis (Enterococcus faecium) and Enterococcus faecium (Enterococcus faecium).

In the fermented food of the present invention, if the number of bacteria belonging to the genus Bifidobacterium is 1X 10, the effect of improving the survivability of the bacteria belonging to the genus Bifidobacterium, which is caused by the extract of the fermented food of the present invention, is obtained⁷More than ml, in particular 1X 10⁸At a concentration of more than ml, a remarkable effect can be obtained.

The fermented food of the present invention may be produced by a conventionally known method for producing a fermented food using bacteria of the genus bifidobacterium, in addition to the above-mentioned extract added at an arbitrary stage in the production process of a fermented food using the bacteria of the genus bifidobacterium (and lactic acid bacteria used as needed). For example, the extract may be added before or after the sterilization treatment of the skim milk powder solution, inoculated with a desired bifidobacterium bacterium or the like, cultured, homogenized to obtain a main agent for fermented milk, and then a syrup solution prepared separately may be added and mixed, and further a taste-improving agent or the like may be added to complete the final product. Alternatively, the sterilized skim milk powder solution may be inoculated with a desired bacterium belonging to the genus bifidobacterium and cultured, and homogenized to obtain a main agent of fermented milk, and then a syrup solution and an extract prepared separately may be added and mixed, and further a taste-improving agent may be added to complete the final product.

The fermented food of the present invention includes fermented milk prescribed by the general rule of the university of dairy products and the like, beverages such as dairy lactic acid bacteria beverages, solid yogurt (hard yogut), liquid yogurt (soft yogut), plain yogurt, goat cheese (Kefir), cheese, and the like. The fermented food of the present invention also includes various beverages and foods using lactic acid bacteria, for example, fermented milk of a primary taste type, a flavor type, a fruit taste type, a sweet taste type, a soft type, a beverage type, a solid (hard) type, a frozen type, etc., lactic acid bacteria beverage, goat cheese, etc.

Further, if necessary, a sweetener such as syrup and other various food materials may be added to the fermented food of the present invention, for example: various saccharides, thickeners, emulsifiers, various vitamin agents, and the like. Specific examples of these food materials include: sugars such as sucrose, glucose, fructose, palatinose, trehalose, lactose, xylose, and maltose; sugar alcohols such as sorbitol, xylitol, erythritol, lactitol, palatinol (パラチニツト), reduced syrup, and reduced maltose syrup; high-sweetness sweetening agents such as aspartame, thaumatin, sucralose, acesulfame potassium, stevia and the like; various thickening (stabilizing) agents such as agar, gelatin, carrageenan, guar gum, xanthan gum, pectin, locust bean gum, gellan gum, carboxymethyl cellulose, soybean polysaccharides, propylene glycol alginate, etc.; emulsifiers such as sucrose fatty acid ester, glycerin fatty acid ester, polyglycerin fatty acid ester, sorbitan fatty acid ester, lecithin and the like; cream such as cream, butter, sour cream, etc.; acidulants such as citric acid, lactic acid, acetic acid, malic acid, tartaric acid, gluconic acid, and the like; various vitamins such as vitamin A, B group vitamin and vitamin C, E group vitamin; mineral components such as calcium, magnesium, zinc, iron, and manganese; flavoring agents such as yogurt, berries, oranges, pears, perilla, citrus, apples, mints, grapes, apricots, pears, custard cake (custard cream), peaches, melons, bananas, tropical fruits, herbs, black tea, and coffee.

The reason why the addition of the mixed extract to the fermented food of the present invention as described above improves the survivability during storage as compared with the fermented food containing bacteria of the genus bifidobacterium in the past is not clear, but it is presumed that the extract extracted from each plant material contains a large amount of mineral components, and that these mineral components have a great effect on improving the survivability of bacteria of the genus bifidobacterium.

Examples

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

Example 1

< preparation of extract 1>

Turmeric (rhizome of Curcuma longa L.), Houttuynia cordata (Houttuynia cordiatathunb.), whole herb of the aerial part of Houttuynia cordata (Houttuynia cordinata.), Eucommia ulmoides (leaf of Eucommia ulmoides Oliv.), pericarp, seed coat (brown rice) of seeds (brown rice) obtained by removing husk (rice husk) of rice obtained from Oryza sativa, seed coat starch layer, embryo bud), persimmon leaf (leaf of Diospyros Kaki Thunb), perilla (leaf of perillaflutescens (L.) Briton. Kudo), clove (flower of mern. et pery) and cinnamon (bark of cinammomum zeylanicum nees) are respectively peeled, pulverized and the like, and then hot water (10 times of each raw material) is used to extract 60 minutes, thereby preparing extracts of Curcuma longa, Eucommia ulmoides, perilla frutescens and Houttuynia cordata. The extracts were concentrated by an evaporator, and the Brix of each extract was adjusted to 10.

Example 2

< comparison of viability of bacteria belonging to the genus Bifidobacterium >

A 12% skim milk powder solution was used as a minimal medium, and 1% of the turmeric extract, houttuynia cordata extract, eucommia ulmoides extract, rice bran extract, persimmon leaf extract, perilla extract, clove extract, or cinnamon extract having a brix adjusted to 10, which was prepared in example 1, was added thereto, respectively, to prepare a sterile medium. These sterile media were inoculated with 1% of a starter of Bifidobacterium breve and cultured at 37 ℃ until the pH was about 4.8.

The number of viable bacteria in the culture after completion of the culture and after storage at 10 ℃ for 14 days was measured using TOS medium (prepared from ヤクルト pharmaceutical products manufactured by Yili chemical industries, Ltd.). Based on the number of viable bacteria measured, the survival rate of bacteria belonging to the genus Bifidobacterium was determined according to the following formula. The survival improvement rate in the medium to which each extract was added was determined according to the following formula, based on the survival rate in the minimal medium. The results are shown in Table 1.

[ Table 1]

	Minimal medium	Turmeric extract	Houttuynia cordata extract	Eucommia bark extract	Rice bran extract	Persimmon leaf extract	Perilla extract	Clove extract	Cortex Cinnamomi extract
	Minimal medium	Turmeric extract	Houttuynia cordata extract	Eucommia bark extract	Rice bran extract	Persimmon leaf extract	Perilla extract	Clove extract	Cortex Cinnamomi extract	Viable cell count (/ ml) at the end of culture	9.2×10⁸	9.9×10⁸	1.0×10⁹	9.7×10⁸	1.0×10⁹	1.1×10⁹	9.1×10⁸	8.9×10⁹	9.5×10⁸
Viable count after storage (/ ml)	5.3×10⁸	7.0×10⁸	6.8×10⁸	7.1×10⁸	7.3×10⁸	8.3×10⁸	6.2×10⁸	5.5×10⁸	6.1×10⁸	Viable cell count (/ ml) at the end of culture	9.2×10⁸	9.9×10⁸	1.0×10⁹	9.7×10⁸	1.0×10⁹	1.1×10⁹	9.1×10⁸	8.9×10⁹	9.5×10⁸
Viable count after storage (/ ml)	5.3×10⁸	7.0×10⁸	6.8×10⁸	7.1×10⁸	7.3×10⁸	8.3×10⁸	6.2×10⁸	5.5×10⁸	6.1×10⁸	Survival improvement rate (%)	-	31.0	23.8	35.7	35.7	40.1	23.8	9.5	14.3

Table 1 shows that the effect of improving the viability of bacteria of the genus bifidobacterium was confirmed in the medium supplemented with each of the extracts of turmeric, houttuynia cordata, eucommia ulmoides, rice bran, persimmon leaf, perilla, clove and cinnamon, as compared with the minimal medium.

Example 3

< verification of Effect of acid extract on improving survivability of Bifidobacterium bacteria >

Persimmon leaves were treated under the same conditions as in example 1 except that water and citric acid were used to prepare an aqueous solution having pH values of 3.0, 4.0 and 5.0 instead of hot water, thereby preparing persimmon leaf extracts each having a brix of 10. Inoculating 1% Bifidobacterium breve (YIT10001) starter to 12% skimmed milk powder culture medium containing 1% of each extract, and culturing at 37 deg.C until pH is about 4.8. The viable cell count of Bifidobacterium breve at the end of the culture and after the culture obtained was stored at 10 ℃ for 14 days was measured in the same manner as in example 2. Then, the survival rate was determined from the viable cell count in the same manner as in example 2, and the survival improvement rate was determined. The results are shown in Table 2.

[ Table 2]

	Minimal medium	Hot water	pH5.0	pH4.0	pH3.0
	Minimal medium	Hot water	pH5.0	pH4.0	pH3.0	Viable cell count (/ ml) at the end of culture	9.2×10⁸	9.5×10⁸	9.4×10⁸	9.8×10⁸	9.6×10⁸
Viable count after storage (/ ml)	5.3×10⁸	7.0×10⁸	7.4×10⁸	8.4×10⁸	8.3×10⁸	Viable cell count (/ ml) at the end of culture	9.2×10⁸	9.5×10⁸	9.4×10⁸	9.8×10⁸	9.6×10⁸
Viable count after storage (/ ml)	5.3×10⁸	7.0×10⁸	7.4×10⁸	8.4×10⁸	8.3×10⁸	Survival improvement Rate (%)	-	38.1	50.0	66.7	69.0

As is clear from Table 2, the effect of improving the viability of bacteria belonging to the genus Bifidobacterium is remarkable when an extract prepared at pH5.0 or less, particularly an extract prepared at pH4.0 or less is used.

Example 4

< preparation of extract 2>

After peeling and pulverizing turmeric (rhizome of Curcuma longa L.), Houttuynia cordata (Houttuynia cordiatathunb.), whole herb of overground part of Houttuynia cordata (Houttuynia cordinata.), pericarp, seed coat starch layer, embryo bud of seed (brown rice) from which husk (rice husk) of rice obtained from Oryza sativa is removed, persimmon leaf (leaf of Diospyros Kaki Thunb), perilla (leaf of perillaceae Kudo (L.) britt. Kudo), clove (flower bud of merr. et Perry) and cinnamon (bark of Cinnamomum zeylanicum nees) respectively, the extract of Curcuma longa, Eucommia ulmoides, perilla frutescens, and perilla frutescens are prepared by the same method as that of example 1, and the extract of perilla, perilla frutescens, and perilla frutescens are extracted under the same conditions as those of example 1. The extracts were concentrated separately by an evaporator to adjust the Brix to 10.

Example 5

< verification of the Effect of improving the survivability of an extract against bacteria belonging to the genus Bifidobacterium >

15% of skimmed milk powder was used as a basic culture medium, and 1% of turmeric extract, houttuynia cordata extract, eucommia ulmoides extract, rice bran extract, persimmon leaf extract, perilla extract, clove extract or cinnamon extract with Brix adjusted to 10 in example 4 was added thereto, respectively, to prepare a culture medium. These media were inoculated with 1% of each of the bifidus bacteria as a starter and cultured at 37 ℃ for 48 hours. The number of viable cells of Bifidobacterium breve at the end of the culture and after the culture obtained was stored at 10 ℃ for 14 days was measured in the same manner as in example 2. Then, the survival rate was determined from the viable cell count in the same manner as in example 2, and the survival improvement rate was determined. The results are shown in Table 3.

In addition, bifidobacterium breve, bifidobacterium bifidum, and bifidobacterium longum were used as bacteria of the genus bifidobacterium in the culture.

[ Table 3]

Bacterium belonging to the genus Bifidobacterium	Minimal medium	Turmeric extract	Houttuynia cordata extract	Eucommia bark extract	Persimmon leaf extract	Perilla extract	Clove extract	Cortex Cinnamomi extract
Bacterium belonging to the genus Bifidobacterium	Minimal medium	Turmeric extract	Houttuynia cordata extract	Eucommia bark extract	Persimmon leaf extract	Perilla extract	Clove extract	Cortex Cinnamomi extract	Bifidobacterium breve	-(58^*)	60.0	52.4	57.1	66.7	54.8	50.0	47.6
Bifidobacterium bifidum	-(66^*)	65.0	67.6	55.9	70.6	44.1	55.9	50.0	Bifidobacterium breve	-(58^*)	60.0	52.4	57.1	66.7	54.8	50.0	47.6
Bifidobacterium bifidum	-(66^*)	65.0	67.6	55.9	70.6	44.1	55.9	50.0	Bifidobacterium longum	-(60^*)	47.5	52.4	52.4	57.1	50.0	47.5	52.5

^*Survival rate (%)

Table 3 shows that, although there are some differences depending on the types of strains, the effect of these extracts on the viability of various bacteria belonging to the genus bifidobacterium was confirmed in almost all strains. Particularly, significant effects are confirmed in turmeric extract, houttuynia cordata extract, eucommia ulmoides extract and persimmon leaf extract.

Example 6

< production of milk product 1>

The test medium was prepared by adding 0.1% of each of the extracts prepared in example 4 to 15% of a skim milk powder medium as a minimal medium. After these media were heat-sterilized, each of the media was inoculated with 1% of a starter of Bifidobacterium breve (YIT10001), 0.1% of a starter of lactococcus lactis (YIT2027) and 0.1% of a starter of Streptococcus thermophilus (YIT2021), and cultured at 35 ℃ for 24 hours to obtain a culture. The culture was homogenized at 15MPa, and 60 parts by weight of a 10% sugar solution sterilized at 100 ℃ for 5 minutes was added to 40 parts by weight of the homogenized product, and further 0.1% yogurt flavor (manufactured by Yakult Material Co., Ltd.) was added thereto to prepare a dairy product. The dairy products were subjected to taste testing by 5 experienced panelists, and no difference was found between each dairy product and the control containing the culture obtained using the minimal medium.

Further, the various extracts added to the medium were evaluated in such a manner that they did not exert an influence on the taste of the minimal medium and were mixed well, and it was confirmed that the taste was not deteriorated even when they were used for culturing drinks and foods such as dairy products.

Example 7

< influence of addition amount of persimmon leaf extract on taste and survivability improvement >

(1) Preparation method of folium kaki extract

Persimmon leaf extracts were prepared under the same conditions as in example 1, using aqueous solutions (10 times the amount) adjusted to ph4.0 with water and citric acid, respectively. The extracts were concentrated by an evaporator to adjust the Brix to 10.

(2) Confirmation of the amount added

Adding the persimmon leaf extract with the brix of 10 prepared in the step (1) into a 15% skimmed milk powder culture medium in a range of 0.001-10%, and sterilizing at 100 ℃ for 60 minutes to prepare a lactic acid bacteria culture medium. This culture medium was inoculated with 0.1% each of a starter of Bifidobacterium breve (YIT10001), a starter of lactococcus lactis (YIT2027) and a starter of Streptococcus thermophilus (YIT2021), and cultured at 35 ℃ for 24 hours to obtain a culture. Subsequently, the culture was homogenized at 15MPa, and 60 parts by weight of a 10% sugar solution sterilized at 100 ℃ for 5 minutes was added to 40 parts by weight of the homogenized product, and further 0.1% yogurt flavor (manufactured by Yakult Material corporation) was added thereto to prepare a dairy product. The dairy product was subjected to taste evaluation by 5 experienced panelists according to the following criteria. The number of viable bacteria of bacteria belonging to the genus bifidobacterium was measured after the preparation of the finished product and after the obtained product was stored at 10 ℃ for 14 days in the same manner as in example 2. Further, the survival rate was determined from the viable cell count in the same manner as in example 2, and the improvement rate of survivability was determined. The results are shown in Table 4.

< evaluation criteria >

(evaluation) (Contents)

Very good: is very good

O: good taste

+ -: in general

And (delta): difference (D)

X: very poor

[ Table 4]

	The addition amount (by mass%) of folium kaki extract)	The obtained product has Bifidobacterium bacteria count (/ ml)	Number of bacteria of Bifidobacterium (/ ml) after storage	Survival improvement Rate (%)	Taste evaluation
	The addition amount (by mass%) of folium kaki extract)		Number of bacteria of Bifidobacterium (/ ml) after storage	Survival improvement Rate (%)	Taste evaluation	Minimal medium	Without addition	1.2×10⁹	3.1×10⁸	-	◎
Water extraction	0.001	1.2×10⁹	3.2×10⁸	1.4	◎	Minimal medium	Without addition	1.2×10⁹	3.1×10⁸	-	◎
	0.001	1.2×10⁹	3.2×10⁸	1.4	◎	0.01	1.3×10⁹	4.2×10⁸	8.1	◎
	0.1	1.1×10⁹	4.4×10⁸	18.9	◎	0.01	1.3×10⁹	4.2×10⁸	8.1	◎
	0.1	1.1×10⁹	4.4×10⁸	18.9	◎	1	1.1×10⁹	4.6×10⁸	21.6	○
	5	1.2×10⁹	4.9×10⁸	20.3	○	1	1.1×10⁹	4.6×10⁸	21.6	○
	5	1.2×10⁹	4.9×10⁸	20.3	○	10	1.0×10⁹	3.8×10⁸	16.2	△
	Acid extraction (pH4.0)	0.001	1.2×10⁹	3.7×10⁸	6.8	10	1.0×10⁹	3.8×10⁸	16.2	△	◎
0.01		0.001	1.2×10⁹	3.7×10⁸	6.8	1.1×10⁹	4.2×10⁸	16.2	◎		◎
0.01		0.1	1.2×10⁹	5.0×10⁸	21.6	1.1×10⁹	4.2×10⁸	16.2	◎	◎
1		0.1	1.2×10⁹	5.0×10⁸	21.6	1.3×10⁹	5.2×10⁸	18.9	○	◎
1		5	1.3×10⁹	5.1×10⁸	17.6	1.3×10⁹	5.2×10⁸	18.9	○	○
10		5	1.3×10⁹	5.1×10⁸	17.6	1.1×10⁹	4.3×10⁸	17.6	△	○

From table 4, it was confirmed that the addition of about 0.01% of persimmon leaf extract produced an effect of improving the viability of bacteria belonging to the genus bifidobacterium. On the other hand, even if about 10% of the persimmon leaf extract is added to the medium, no more excellent effect is obtained, but the taste derived from the persimmon leaf extract tends to affect the taste of the product. Further, the persimmon leaf extract brings about an effect of improving the survivability of bacteria belonging to the genus bifidobacterium, and a remarkable effect can be obtained with a smaller amount of addition in the acid extraction than in the water extraction.

Example 8

< influence of addition method of persimmon leaf extract on taste and survivability improvement >

(1) Preparation method of folium kaki extract

(2) Confirmation of addition method

After sterilizing 15% skimmed milk powder at 100 ℃ for 60 minutes, 1% of a starter of Bifidobacterium breve (YIT10001), 0.1% of each of a starter of lactococcus lactis (YIT2027) and a starter of Streptococcus thermophilus (YIT2021) were inoculated, and the resultant was cultured at 35 ℃ for 24 hours to obtain a culture. Then, the number of lactic acid bacteria in the culture was measured in the same manner as in example 2. Subsequently, the culture was homogenized at 15MPa, and to 40 parts by weight of the homogenized product, 60 parts by weight of a 10% sugar aqueous solution sterilized at 100 ℃ for 5 minutes or a solution sterilized at 100 ℃ for 5 minutes, which was obtained by mixing a 10% sugar aqueous solution with a 0.1% aqueous solution of each persimmon leaf extract prepared in (1), was added with 0.1% yogurt flavor (manufactured by Yakult Material corporation), to prepare a dairy product. The taste of the resulting dairy product was evaluated according to the same criteria as in example 7. The number of viable bacteria of bacteria belonging to the genus bifidobacterium was measured after the preparation of the finished product and after the obtained product was stored at 10 ℃ for 14 days in the same manner as in example 2. Further, the survival rate was determined from the viable cell count in the same manner as in example 2, and the improvement rate of survivability was determined. The results are shown in Table 5.

[ Table 5]

Persimmon leaf extract	The obtained product has Bifidobacterium bacteria (/ m1)	Number of bacteria of Bifidobacterium (/ ml) after storage	Survival improvement Rate (%)	Taste evaluation
Persimmon leaf extract	The obtained product has Bifidobacterium bacteria (/ m1)	Number of bacteria of Bifidobacterium (/ ml) after storage	Survival improvement Rate (%)	Taste evaluation	Without addition	1.2×10⁹	3.0×10⁸	-	◎
Water extraction	1.2×10⁹	4.2×10⁸	13.3	◎	Without addition	1.2×10⁹	3.0×10⁸	-	◎
Water extraction	1.2×10⁹	4.2×10⁸	13.3	◎	Acid extraction (pH4.0)	1.3×10⁹	4.9×10⁸	17.3	◎

As can be seen from table 5, even if the persimmon leaf extract was not added to the culture medium but added after the culture was obtained, the effect of improving the viability of bacteria belonging to the genus bifidobacterium was obtained. Moreover, even if the persimmon leaf extract is added after the culture is obtained, the taste of the dairy product is not adversely affected.

Example 9

< preparation of extract 3>

Folium hydrangeae strigosae (Rubus suavissimus S.Lee (Rosaceae)) is peeled and pulverized, and extracted with hot water (10 times of folium hydrangeae strigosae) at 90 deg.C for 60 min to obtain folium hydrangeae strigosae extract. Concentrating the obtained extract with evaporator to adjust Brix of the extract to 10.

Example 10

< verification of Effect of extract on Bifidobacterium bacteria >

A sterile medium was prepared by adding 1% of the sweet tea extract having a Brix adjusted to 10 prepared in example 9 to a 12% skimmed milk powder solution as a minimal medium. The sterile medium was inoculated with 1% of a starter of Bifidobacterium breve and cultured at 37 ℃ until the pH was about 4.8.

The number of viable bacteria in the culture at the end of the culture and after 14 days of storage at 10 ℃ was measured using TOS medium (manufactured by Yili Chemicals industries, Ltd.). Based on the number of viable bacteria measured, the survival rate of bacteria belonging to the genus Bifidobacterium was determined according to the following formula. The survival improvement rate in the medium containing the sweet tea extract was determined by the following formula based on the survival rate in the minimal medium. The results are shown in Table 6.

[ Table 6]

	Minimal medium	Sweet tea extract
	Minimal medium	Sweet tea extract	Viable cell count (/ ml) at the end of culture	1.2×10⁹	1.2×10⁹
Viable count after storage (/ ml)	6.1×10⁸	7.8×10⁸	Viable cell count (/ ml) at the end of culture	1.2×10⁹	1.2×10⁹
Viable count after storage (/ ml)	6.1×10⁸	7.8×10⁸	Survival improvement Rate (%)	-	40.8

As can be seen from table 6, the culture medium to which the rubus suavissimus extract was added had an excellent effect of improving the viability of bacteria belonging to the genus bifidobacterium, as compared with the minimal medium.

Example 11

< verification by acid extract 1>

Sweet tea extracts having a brix of 10 were produced by treating sweet tea under the same conditions except that water and an aqueous citric acid solution having a pH of 3.0, 4.0, or 5.0 were used instead of hot water in the production of the extract in example 9. Inoculating 1% Bifidobacterium breve (YIT10001) starter to 12% skimmed milk powder culture medium containing 1% of each extract, and culturing at 37 deg.C until pH is about 4.8. The number of viable cells of Bifidobacterium breve at the end of the culture and after the culture obtained was stored at 10 ℃ for 14 days was measured in the same manner as in example 10. Then, the survival rate was determined from the viable cell count in the same manner as in example 10, and the improvement rate of viability was determined. The results are shown in Table 7.

[ Table 7]

	Minimal medium	Hot water	pH5.0	pH4.0	pH3.0
	Minimal medium	Hot water	pH5.0	pH4.0	pH3.0	Viable cell count (/ ml) at the end of culture	1.2×10⁹	1.2×10⁹	1.1×10⁹	1.2×10⁹	1.2×10⁹
Viable count after storage (/ ml)	6.1×10⁸	7.8×10⁸	7.6×10⁸	8.8×10⁸	8.9×10⁸	Viable cell count (/ ml) at the end of culture	1.2×10⁹	1.2×10⁹	1.1×10⁹	1.2×10⁹	1.2×10⁹
Viable count after storage (/ ml)	6.1×10⁸	7.8×10⁸	7.6×10⁸	8.8×10⁸	8.9×10⁸	Survival improvement Rate (%)	-	29	37	45	47

As shown in table 7, it was confirmed that the lower the pH of the sweet tea extract extraction solvent, the higher the improvement effect on the viability of bacteria belonging to the genus bifidobacterium.

Example 12

< preparation of extract 4>

After the leaves of Rubus suavissimus s.lee (Rosaceae) were peeled and pulverized, the extract was extracted under the same conditions as in example 9 using water and an aqueous citric acid solution (10 times the amount of Rubus suavissimus leaves) adjusted to ph 4.0. The obtained extract was concentrated by an evaporator to adjust the Brix to 10.

Example 13

< verification by acid extraction of extract 2>

A culture medium was prepared by adding 1% of the sweet tea extract having a brix adjusted to 10 of example 12 to 15% of skimmed milk powder as a minimal medium. This medium was inoculated with 1% of various strains of Bifidobacterium bacteria and cultured at 37 ℃ until the pH was about 4. The number of viable bacteria of bacteria belonging to the genus Bifidobacterium was measured at the end of the culture and after the culture obtained was stored at 10 ℃ for 14 days in the same manner as in example 10. Then, the survival rate was determined from the viable cell count in the same manner as in example 10, and the improvement rate of viability was determined. The results are shown in Table 8.

[ Table 8]

Bacterium belonging to the genus Bifidobacterium	Minimal medium				Sweet tea extract
	Minimal medium				Sweet tea extract				Viable cell count (/ ml) at the end of culture	Viable count (/ m) after storagel)	Survival improvement Rate (%)	Incubation time (h)	Viable cell count (/ ml) at the end of culture	Viable count after storage (/ ml)	Survival improvement Rate (%)	Incubation time (h)
	Bifidobacterium breve	1.2×10⁹	6.1×10⁸	-	41	1.1×10⁹	8.1×10⁸	47	Viable cell count (/ ml) at the end of culture	Viable count (/ m) after storagel)	Survival improvement Rate (%)	Incubation time (h)	Viable cell count (/ ml) at the end of culture	Viable count after storage (/ ml)	Survival improvement Rate (%)	Incubation time (h)	40
Bifidobacterium bifidum	Bifidobacterium breve	1.2×10⁹	6.1×10⁸	-	41	1.1×10⁹	8.1×10⁸	47	1 0×10⁹	4.8×10⁸	-	48	1.2×10⁹	9.8×10⁸	65	44	40
Bifidobacterium bifidum	Bifidobacterium longum	1.1×10⁹	5.6×10⁸	-	45	1.2×10⁹	8.4×10⁸	39	1 0×10⁹	4.8×10⁸	-	48	1.2×10⁹	9.8×10⁸	65	44	44

Table 8 shows that the effect of sweet tea extract on improving the viability of bacteria belonging to the genus bifidobacterium was confirmed in almost all the strains, although the strains were somewhat different. Further, the effect of shortening the culture time was also confirmed for some strains.

Example 14

< production of milk product 2>

A20% nonfat dry milk medium was used as a minimal medium, and 0.1% of the sweet tea extract prepared in example 12 was added thereto to prepare a test medium. The culture medium was heat-sterilized, and then inoculated with 1% of a starter of Bifidobacterium breve (YIT10001), 0.1% of starter of lactococcus lactis (YIT2027) and 0.1% of starter of Streptococcus thermophilus (YIT2021), and cultured at 35 ℃ for 24 hours to obtain a culture. The culture was homogenized at 15MPa, and 40 parts by weight of the homogenized product was added with 60 parts by weight of a 10% sugar solution sterilized at 100 ℃ for 5 minutes, and further added with 0.1% yogurt flavor (manufactured by YakultMaterial Co., Ltd.) to prepare a dairy product. Taste testing of the milk products was performed by 5 experienced judges and no difference was found between each of the lactic acid bacteria beverages and the control containing the culture obtained using the minimal medium.

Further, the sweet tea extract added to the medium was evaluated in such a manner that the taste was not affected by the minimal medium and the mixing was very consistent, and it was confirmed that the taste was not deteriorated even when the extract was used for culturing beverages such as dairy products and foods.

Example 15

< influence of the amount of sweet tea extract added on the taste, the growth activity and the survival improvement >

(1) Preparation method of sweet tea extract

Sweet tea extract was prepared under the same conditions as in example 9 using water and an aqueous solution (10 times the amount) of citric acid adjusted to ph 4.0. The obtained extract was concentrated by an evaporator to adjust the Brix to 10.

(2) Confirmation of the amount added

Adding the sweet tea extract with the brix of 10 prepared in the step (1) into a 20% skimmed milk powder culture medium in a range of 0.001-10%, and sterilizing at 100 ℃ for 60 minutes to prepare the culture medium. This culture medium was inoculated with 0.1% each of a starter of Bifidobacterium breve (YIT10001), a starter of lactococcus lactis (YIT2027) and a starter of Streptococcus thermophilus (YIT2021), and cultured at 35 ℃ for 24 hours to obtain a culture. Thereafter, the number of lactic acid bacteria in the culture was measured in the same manner as in example 10. Subsequently, the culture was homogenized at 15MPa, and 60 parts by weight of a 10% sugar solution sterilized at 100 ℃ for 5 minutes was added to 40 parts by weight of the homogenized product, and further 0.1% yogurt flavor (manufactured by Yakult Material corporation) was added thereto to prepare a dairy product. The resulting dairy products were subjected to taste evaluation by 5 experienced panelists according to the following criteria. The number of viable bacteria of bacteria belonging to the genus bifidobacterium after the preparation of the finished product and after the storage of the obtained product at 10 ℃ for 14 days was measured in the same manner as in example 10. Further, the survival rate was determined from the viable cell count in the same manner as in example 10, and the improvement rate of survivability was determined. The results are shown in Table 9.

< evaluation criteria >

(evaluation) (Contents)

Very good: is very good

O: good taste

+ -: in general

And (delta): difference (D)

X: very poor

[ Table 9]

	Sweet tea extract weight (mass%)	The obtained product has Bifidobacterium bacteria (/ m1)	Number of bacteria of Bifidobacterium (/ ml) after storage	Survival improvement Rate (%)	Taste of the product
	Sweet tea extract weight (mass%)	The obtained product has Bifidobacterium bacteria (/ m1)	Number of bacteria of Bifidobacterium (/ ml) after storage	Survival improvement Rate (%)	Taste of the product	Minimal medium	Without addition	1.3×10⁹	3.1×10⁸	-	◎
Hot water extraction	0.001	1.2×10⁹	3.3×10⁸	5	◎	Minimal medium	Without addition	1.3×10⁹	3.1×10⁸	-	◎
	0.001	1.2×10⁹	3.3×10⁸	5	◎	0.01	1.3×10⁹	4.5×10⁸	14	◎
	0.1	1.4×10⁹	4.9×10⁸	15	◎	0.01	1.3×10⁹	4.5×10⁸	14	◎
	0.1	1.4×10⁹	4.9×10⁸	15	◎	1	1.3×10⁸	4.9×10⁸	18	○
	5	1.2×10⁹	5.1×10⁸	24	±	1	1.3×10⁸	4.9×10⁸	18	○
	5	1.2×10⁹	5.1×10⁸	24	±	10	1.2×10⁹	4.3×10⁸	16	△
	Acid extraction (pH4.0)	0.001	1.2×10⁹	3.7×10⁸	9	10	1.2×10⁹	4.3×10⁸	16	△	◎
0.01		0.001	1.2×10⁹	3.7×10⁸	9	1.2×10⁹	4.5×10⁸	18	◎		◎
0.01		0.1	1.2×10⁹	5.3×10⁸	27	1.2×10⁹	4.5×10⁸	18	◎	◎
1		0.1	1.2×10⁹	5.3×10⁸	27	1.3×10⁹	5.6×10⁸	25	○	◎
1		5	1.3×10⁹	5.6×10⁸	25	1.3×10⁹	5.6×10⁸	25	○	±
10		5	1.3×10⁹	5.6×10⁸	25	1.2×10⁹	4.8×10⁸	21	△	±

From table 9, it was confirmed that the effect of improving the survival of bacteria belonging to the genus bifidobacterium was obtained by adding about 0.01% of the sweet tea extract. On the other hand, even if about 10% of the sweet tea extract is added to the medium, a more excellent effect cannot be obtained, but the taste of the product tends to be affected. Further, the sweet tea extract obtained by acid extraction showed a more significant effect on improving the viability of bacteria belonging to the genus bifidobacterium than that obtained by hot water extraction.

Example 16

< verification of the Effect of adding sweet tea extract on improving the survivability of bacteria belonging to the genus Bifidobacterium >

(1) Preparation method of sweet tea extract

Sweet tea extract was prepared under the same conditions as in example 9 using water and an aqueous solution (10 times in amount) of citric acid adjusted to ph 4.0. The extract was concentrated by an evaporator to adjust the Brix to 10.

(2) Confirmation of addition method

After sterilizing 20% skim milk powder at 100 ℃ for 60 minutes, 1% of a starter of Bifidobacterium breve (YIT10001), 0.1% of each of a starter of lactococcus lactis (YIT2027) and a starter of Streptococcus thermophilus (YIT2021) were inoculated, and the resultant was cultured at 35 ℃ for 24 hours to obtain a culture. Subsequently, the culture was homogenized at 15MPa, and to 40 parts by weight of the homogenized product, 60 parts by weight of a 10% sugar solution sterilized at 100 ℃ for 5 minutes or a solution sterilized at 100 ℃ for 5 minutes, which was obtained by mixing a 0.1% aqueous solution of the sweet tea extract prepared in (1) with a 10% sugar solution, was added, and further 0.1% yogurt flavor (manufactured by Yakult Material corporation) was added to produce a dairy product. The number of viable bacteria of bacteria belonging to the genus bifidobacterium was measured on the obtained dairy product at the end of production and after the obtained product was stored at 10 ℃ for 14 days in the same manner as in example 2. Further, the survival rate was determined from the viable cell count in the same manner as in example 10, and the improvement rate of survivability was determined. The results are shown in Table 10.

[ Table 10]

Sweet tea extract	The obtained product has Bifidobacterium bacteria count (/ ml)	Number of bacteria of Bifidobacterium (/ ml) after storage	Survival improvement Rate (%)
Sweet tea extract		Number of bacteria of Bifidobacterium (/ ml) after storage	Survival improvement Rate (%)	Without addition	1.3×10⁹	3.1×10⁸	-
Hot water extraction	1.2×10⁹	4.0×10⁸	12	Without addition	1.3×10⁹	3.1×10⁸	-
Hot water extraction	1.2×10⁹	4.0×10⁸	12	Acid extraction (pH4.0)	1.3×10⁹	4.8×10⁸	17

The results in table 10 show that the viability-improving effect of the extract on bacteria belonging to the genus bifidobacterium can be obtained whenever the sweet tea extract is added.

Industrial applicability

The fermented food of the present invention contains bacteria belonging to the genus Bifidobacterium, but has good taste even when stored for a long period of time, maintains the viable count, and is beneficial for health promotion.

Claims

1. A fermented food characterized by containing an extract of 1 or 2 or more plant materials selected from the group consisting of turmeric, houttuynia cordata, eucommia ulmoides, rice bran, persimmon leaf, perilla, clove, cinnamon and sweet tea, and bacteria belonging to the genus Bifidobacterium.

2. The fermented food according to claim 1, wherein the extract is obtained by acid extraction.

3. The fermented food according to claim 2, wherein the acid extraction is performed under a condition of ph4.0 or less.

4. The fermented food according to any one of claims 1 to 3, wherein the fermented food further contains lactic acid bacteria.

5. A method for producing a fermented food containing bacteria of the genus Bifidobacterium, characterized in that in the production of a fermented food containing bacteria of the genus Bifidobacterium, extract of 1 or more than 2 kinds of plant materials selected from the group consisting of Curcuma longa, houttuynia cordata, eucommia ulmoides, rice bran, persimmon leaf, perilla, clove, cinnamon and hydrangea strigosa are mixed at an arbitrary stage.

6. A method for improving the viability of bacteria belonging to the genus Bifidobacterium, characterized in that extracts of 1 or more than 2 kinds of plant materials selected from the group consisting of Curcuma longa, houttuynia cordata, eucommia ulmoides, rice bran, persimmon leaf, perilla, clove, cinnamon and hydrangea strigosa are mixed.