HK1250605A1 - Tien-cha extract essence and application therefor - Google Patents

Abstract

The characteristics of sweet tea extract from sweet tea extract and the preparation method of fermented food made from sweet tea extract are characterized by the characteristics, which can replace the existing problems of sweet tea extract obtained from electrodialysis of sweet tea extract, maintain the proliferation of lactic acid bacteria and the survival of bifidobacteria, and do not affect flavor. It has the previously undiscovered effect of improving the proliferation of bifidobacteria, easy to manufacture and powdered technology.

Description

Sweet tea extract essence and application thereof

Technical Field

The present invention relates to an extract of sweet tea which can improve the proliferation properties of lactic acid bacteria and bacteria belonging to the genus Bifidobacterium and the survival properties of bacteria belonging to the genus Bifidobacterium, does not affect the flavor, can be easily produced and powdered, and to the use thereof.

Background

Lactic acid bacteria have various effects such as improvement of intestinal flora, improvement of stool properties, improvement of intestinal function, protection against infection, activation of immunity, and prevention of cancer, and are therefore used in the production of lactic acid bacteria preparations as medicines, fermented milk, lactic acid bacteria beverages, and foods and beverages such as cheese. For these uses, the most common is the culture of lactic acid bacteria using animal milk as a medium. However, since lactic acid bacteria generally have different nutritional requirements depending on the type, they do not proliferate much in a medium containing only animal milk, and even if they are strains having relatively excellent proliferation activity, in the case of fermented milk, lactic acid bacteria beverages, and the like produced using a medium containing only animal milk, it is necessary to perform cultivation for several days in order to obtain a fermented product having sufficient acidity.

However, long-term culture of lactic acid bacteria causes a decrease in the number of viable bacteria, and culture for producing lactic acid bacteria beverages, fermented milks, and the like, which are expected to have various physiological effects and in which the number of viable bacteria is regarded as important, cannot be said to be a preferable method. In addition, in the production of various foods and beverages which are subject to the flavor of a fermented product obtained by culturing lactic acid bacteria, the strain to be used cannot be selected from the viewpoint of only proliferation, and therefore lactic acid bacteria which have poor proliferation but can provide a fermented product with good flavor may be selected and used.

Therefore, in the culture of lactic acid bacteria, it is common practice to add various proliferation promoting substances to the culture medium in advance for the purpose of improving the culture efficiency. In general, if a substance effective as a growth promoting substance is exemplified, chlorella extract, iron salt, vitamins; protein hydrolysate containing amino acids/peptides, yeast extract, etc. The applicant also reported the following techniques: in order to improve the proliferation and the like of lactic acid bacteria, sweet tea extract and the like are added (patent document 1).

In addition, bacteria of the genus bifidobacterium, which are used in medicines, foods and beverages as in lactic acid bacteria, are generally anaerobic bacteria, and therefore have poor viability and rapidly die particularly in the presence of oxygen.

Heretofore, the present applicant has reported the following techniques: in order to improve the viability and the like of bacteria belonging to the genus bifidobacterium in products such as fermented milk using bacteria belonging to the genus bifidobacterium, sweet tea extract and the like are added to products such as fermented milk (patent document 2).

However, although the products such as fermented milk containing the sweet tea extract can improve the proliferation of lactic acid bacteria and the viability of bacteria belonging to the genus bifidobacterium, the products have a problem in taste and flavor due to the bitter taste of sweet tea.

Thus, the applicant has previously reported: it has been found that a culture having a good flavor and no bitterness derived from sweet tea can be obtained while promoting the proliferation of lactic acid bacteria by culturing lactic acid bacteria in a medium containing sweet tea extract obtained as a concentrated solution by adding an inorganic salt such as magnesium chloride to the sweet tea extract and subjecting the mixture to electrodialysis (patent document 3). In addition, it is reported that: bacteria belonging to the genus bifidobacterium are also cultured in a medium containing the above-mentioned rubus suavissimus essence, whereby the viability is improved and a culture having a good flavor and without bitterness derived from rubus suavissimus can be obtained (patent document 4).

However, since the above-mentioned sweet tea essence requires electrodialysis for a long period of time (day and night) during production, it takes time and requires a large amount of electric power (energy). In addition, although a large amount of inorganic salt such as magnesium chloride is added for the electrodialysis, the inorganic salt may cause precipitation of milk components and may hinder the production of the culture. Furthermore, especially in the case of using magnesium chloride as an inorganic salt, magnesium itself has a strong bitter taste, and therefore if magnesium remains in a sweet tea essence at a high concentration, the strong bitter taste may affect the flavor of the culture. Further, since magnesium chloride has deliquescence, even if it remains in the sweet tea essence in a small amount, when it is powdered in consideration of transportability and handling properties, there is a problem that the powder is deliquesced and liquefied after opening the seal.

Documents of the prior art

Patent document

Patent document 1: international publication No. WO2006/126476

Patent document 2: international publication No. WO2006/129508

Patent document 3: japanese patent laid-open No. 2012 and 75382

Patent document 4: japanese patent laid-open publication No. 2013-201898

Disclosure of Invention

Problems to be solved by the invention

Accordingly, an object of the present invention is to provide a technique for improving the proliferation of lactic acid bacteria and the viability of bacteria belonging to the genus bifidobacterium, which can replace the sweet tea essence obtained by subjecting a sweet tea extract to electrodialysis, which has the above-described various problems, and which can maintain the effects of the previous sweet tea extract and sweet tea essence, does not affect the flavor, and can be easily produced and powdered.

Means for solving the problems

The present inventors have conducted intensive studies to solve the above problems, and as a result, have found that the above problems can be solved by subjecting a sweet tea extract to activated carbon treatment instead of electrodialysis, and have completed the present invention.

That is, the present invention is the following inventions (1) to (16).

(1) Sweet tea extract essence is characterized by being obtained by performing activated carbon treatment on a sweet tea extract.

(2) The sweet tea extract essence according to (1), which is a dry powder.

(3) The sweet tea extract essence according to (1) or (2), wherein the activated carbon used in the activated carbon treatment is chemically activated carbon.

(4) The sweet tea extract essence according to any one of (1) to (3), wherein the amount of activated carbon added in the activated carbon treatment is 0.035% by weight or more in terms of dry weight per 1 Brix of the sweet tea extract.

(5) A preparation method of sweet tea extract essence is characterized in that the sweet tea extract is subjected to activated carbon treatment.

(6) The method for producing sweet tea extract essence according to (5), wherein the activated carbon used for the activated carbon treatment is chemically activated carbon.

(7) The method for producing a sweet tea extract essence according to (5) or (6), wherein the amount of activated carbon added in the activated carbon treatment is 0.035% by weight or more based on the dry weight per 1 brix of the sweet tea extract.

(8) A fermented food comprising a culture of lactic acid bacteria obtained by culturing lactic acid bacteria in a medium containing the extract of sweet tea according to any one of (1) to (4).

(9) A method for producing a fermented food containing a lactic acid bacterium, comprising the steps of: the sweet tea extract according to any one of (1) to (4) is added to a culture medium before culturing lactic acid bacteria.

(10) A fermented food characterized by containing a culture of a bacterium of the genus Bifidobacterium obtained by culturing the bacterium of the genus Bifidobacterium in a medium containing the essence extracted from sweet tea according to any one of (1) to (4).

(11) A method for producing a fermented food containing a bacterium belonging to the genus Bifidobacterium, comprising the steps of: the sweet tea extract according to any one of (1) to (4) is added to a culture medium before culturing the bacterium belonging to the genus Bifidobacterium.

(12) A method for promoting the proliferation of a lactic acid bacterium and/or a bacterium belonging to the genus Bifidobacterium, characterized by comprising adding the extract of Rubus suavissimus according to any one of (1) to (4) to a culture medium before culturing the lactic acid bacterium and/or the bacterium belonging to the genus Bifidobacterium in the culture of the lactic acid bacterium and/or the bacterium belonging to the genus Bifidobacterium.

(13) A proliferation promoter for lactic acid bacteria and/or bacteria belonging to the genus Bifidobacterium, comprising the extract of Rubus suavissimus of any one of (1) to (4) as an active ingredient.

(14) A method for improving the viability of a bacterium belonging to the genus Bifidobacterium, characterized by comprising adding the sweet tea extract described in any one of (1) to (4) to a culture medium before culturing the bacterium belonging to the genus Bifidobacterium in the culture medium.

(15) A survivability improving agent for bacteria belonging to the genus Bifidobacterium, comprising the extract of Rubus suavissimus of any one of (1) to (4) as an active ingredient.

(16) A method for improving the flavor of a sweet tea extract, characterized in that the sweet tea extract is subjected to an activated carbon treatment.

ADVANTAGEOUS EFFECTS OF INVENTION

The sweet tea extract essence of the present invention maintains the effects of the previous sweet tea extract and sweet tea essence on improving the proliferation of lactic acid bacteria and the viability of bacteria belonging to the genus bifidobacterium, and does not affect the flavor. In addition, it has an effect of improving the proliferation of bacteria belonging to the genus Bifidobacterium, which has not been found before. In addition, electrodialysis is required day and night in the conventional production of sweet tea extract, and the sweet tea extract of the present invention requires only about 30 minutes to 2 hours of activated carbon treatment instead of electrodialysis, thereby saving energy. Further, since the sweet tea extract of the present invention does not contain inorganic salts such as magnesium chloride, the problem of precipitation of fresh milk does not occur even when it is used for fermented foods. Further, even when the sweet tea extract essence of the present invention is powdered, problems such as deliquescence and liquefaction do not occur, and a powdered product excellent in transportability and handling properties can be stably stored for a long period of time.

Therefore, the sweet tea extract essence of the present invention can be suitably used for the production of fermented foods containing lactic acid bacteria and bacteria of the genus bifidobacterium.

Detailed Description

The sweet tea extract essence is obtained by performing activated carbon treatment on a sweet tea extract.

The sweet tea extract is not particularly limited as long as it is obtained by extracting any part of sweet tea (Rubussuavissimus S.Lee (Rosaceae)) belonging to Rubus of Rosaceae with a solvent, and examples thereof include an extract obtained by extracting leaves, stems, and preferably leaves of sweet tea with a solvent, either directly or after optionally washing, peeling, drying, crushing, etc.

The solvent used for the production of the sweet tea extract is not particularly limited, and examples thereof include: water, a lower alcohol having 1 to 5 carbon atoms such as ethanol, an organic solvent such as ethyl acetate, glycerin, propylene glycol, and the like, and these may be used alone or in combination of two or more. Among these solvents, water or an aqueous solvent such as water-lower alcohol is particularly preferable.

The extraction method of the sweet tea extract using the solvent is not particularly limited, and for example, an acid extraction method is preferable. The acid extraction is carried out under acidic conditions of pH4.0 or less, preferably pH3.0 to 4.0. In the acid extraction, the acid component used for adjusting the pH of the solvent is not particularly limited as long as it is an acidic substance, and preferable acid components include organic acids such as citric acid, malic acid, tartaric acid, succinic acid, lactic acid, and acetic acid.

Further, the extraction conditions of the sweet tea extract using the solvent are not particularly limited, and for example, the extraction is performed at a temperature of 0 ℃ to 100 ℃, more preferably 10 ℃ to 40 ℃ for about 30 to 60 minutes.

The sweet tea extract essence of the present invention is obtained by subjecting the above sweet tea extract to an activated carbon treatment of activated carbon. The method for bringing the sweet tea extract into contact with the activated carbon is not particularly limited, and examples thereof include: a batch system in which activated carbon is added to the sweet tea extract, a column system in which the sweet tea extract is passed through an activated carbon column, a cartridge system in which the sweet tea extract is passed through a cartridge containing activated carbon, and the like, and a batch system is particularly preferable.

The kind of the activated carbon used in the above is not particularly limited, and examples thereof include: chemically activated carbon chemically activated with zinc chloride, phosphoric acid, sulfuric acid, calcium chloride, sodium hydroxide, potassium hydroxide, or the like, gas activated carbon obtained with steam, carbon dioxide, oxygen, combustion exhaust gas, a mixed gas thereof, or the like. Among these activated carbons, chemically activated carbon obtained by using zinc chloride or steam activated carbon is preferable, and chemically activated carbon obtained by using zinc chloride is particularly preferable. As the chemical activated carbon obtained by zinc chloride, commercially available products such as TAIKO powdered carbon SA1000 to W65(futamura chemical co., Ltd.) can be used.

The amount of activated carbon used in the activated carbon treatment may be appropriately determined depending on the concentration of the sweet tea extract (brix) and the type of activated carbon, and for example, in the case of a batch method, 0.035% by weight (hereinafter simply referred to as "%") or more, preferably 0.05% to 0.5%, and more preferably 0.055% to 0.085% of activated carbon is added per 1 brix of the sweet tea extract, and for example, when the brix of the sweet tea extract is 2, 0.07% or more, preferably 0.1% to 1%, and more preferably 0.11% to 0.17% of activated carbon is added on a dry weight basis, and when the brix of the sweet tea extract is 20, 0.7% or more, preferably 1% to 10%, and more preferably 1.1% to 1.7% of activated carbon is added on a dry weight basis, and when the activated carbon extract is added, for example, the method for measuring the brix of the sweet tea extract may be measured by an optical refractive index (RX-7000 α), more preferably 1.1.7%, and when the activated carbon is added, and the amount of the activated carbon is particularly, and the activated carbon is not limited, and when the tea extract is added, the activated carbon is stirred for example, the time is 30 minutes, or so.

In addition to the above-mentioned activated carbon treatment, treatments such as centrifugal separation, diatomaceous earth filtration, microfiltration, concentration, and sterilization may be performed as necessary. Preferred examples of the production method of the sweet tea extract essence of the present invention include: after the sweet tea extract is treated by active carbon, the sweet tea extract is treated by centrifugal separation, diatomite filtration, microfiltration, concentration and sterilization in sequence; or performing microfiltration on the sweet tea extract, performing activated carbon treatment, and then performing centrifugal separation, diatomite filtration, concentration and sterilization in sequence. The conditions for the centrifugal separation are not particularly limited as long as the activated carbon can be removed, and examples thereof include 10000g and 2 minutes. The conditions for the diatomaceous earth filtration are not particularly limited, and examples thereof include conditions in which 0.1% of diatomaceous earth is added and filtration is performed using standard filter paper No. 131. The microfiltration conditions are not particularly limited, and for example, the microfiltration may be performed with a 0.2 μm microfilter, and the concentration conditions may be concentration of the brix to a desired value by an evaporator or the like. The sterilization conditions are not particularly limited, and examples thereof include a condition of reaching 90 ℃ and then cooling to 50 ℃ or lower.

The sweet tea extract essence obtained in the above manner is preferably made into a dry powder from the viewpoint of easy handling. Since the dry powder does not contain magnesium chloride, it has no deliquescence and can be stored stably. The fact that the dried powder was not deliquescent can be confirmed by the method described in examples.

The method for obtaining the above-mentioned dry powder is not particularly limited, and examples thereof include spray drying, freeze drying and the like, and a method for obtaining a dry powder by spray drying is preferable. The drying conditions for spray drying are not particularly limited, and examples thereof include conditions of an inlet temperature of 160 ℃, an outlet temperature of 80 to 100 ℃, and a flow rate of 10 mL/min. When drying is performed by spray drying, an excipient may be added as needed. Examples of the excipient include: dextrin, cyclodextrin, starch, maltose, etc., with dextrin being particularly preferred. The amount of the excipient is not particularly limited, and for example, when dextrin is used as the excipient, dextrin is added in an amount of 0.5 to 5 weight%, preferably 1 to 2 weight%, and more preferably 1.5 weight% to the solid content 1 of the sweet tea extract.

The sweet tea extract of the present invention is mixed with a culture medium and cultured with lactic acid bacteria, whereby a lactic acid bacteria culture can be obtained, and a fermented food containing the same can be obtained. As a medium for culturing lactic acid bacteria by blending the extract of sweet tea of the present invention, there can be mentioned: animal milk culture medium containing fresh milk such as cow milk, goat milk, horse milk, and sheep milk, or milk product such as skimmed milk powder, whole milk powder, and fresh milk oil, liquid milk derived from plants such as soybean milk, and various synthetic culture media. The medium may be supplemented with components used in a usual lactic acid bacterium medium. Examples of such components include: saccharides such as glucose, vitamins such as vitamin A, vitamin B, vitamin C, and vitamin E, various peptides, amino acids, and salts such as calcium and magnesium.

Furthermore, oleic acid may be added to the above medium. Examples of such oleic acids include oleic acid, salts of oleic acid such as sodium oleate and potassium oleate, and derivatives of oleic acid esters such as glyceryl oleate, polyglyceryl oleate and sucrose oleate. These oleic acids may be added in a concentration of 5 to 50ppm, preferably 5 to 25ppm, in the culture medium in terms of oleic acid.

The lactic acid bacteria to be cultured by adding the sweet tea extract of the present invention to a culture medium are not particularly limited as long as they are lactic acid bacteria generally used for food production, and examples thereof include: lactobacillus casei (Lactobacillus casei), Lactobacillus gasseri (Lactobacillus gasseri), Lactobacillus acidophilus (Lactobacillus acidophilus), Lactobacillus cremoris (Lactobacillus cremoris), Lactobacillus helveticus (Lactobacillus helveticus), Lactobacillus salivarius (Lactobacillus salivarius), Lactobacillus fermentum (Lactobacillus fermentum), Lactobacillus japonicus (Lactobacillus yoghurti), Lactobacillus bulgaricus (Lactobacillus delbrueckii subsp. Of these lactic acid bacteria, bacteria belonging to the genus Lactobacillus, bacteria belonging to the genus Streptococcus, and bacteria belonging to the genus lactococcus are preferable, and of these bacteria, Lactobacillus casei, Lactobacillus gasseri, lactococcus lactis, and Streptococcus thermophilus are preferable, and Lactobacillus casei YIT9029(FERM BP-1366, Collection date: Sho-56, 1-month and 12-month), Lactobacillus gasseri YIT0192(DSM20243), Lactobacillus lactis YIT2027(FERM BP-6224, Collection date: Flat 9 years, 2-month and 10-day), and Streptococcus thermophilus YIT2021(FERM BP-7537, Collection date: Flat 8 years, 11-month and 1-day) are particularly preferable. One or two or more of the above-mentioned various lactic acid bacteria may be used, and in addition, one or two or more of the below-mentioned various bacteria belonging to the genus bifidobacterium may be used in combination.

The amount of the sweet tea extract essence of the present invention added to the culture medium when culturing lactic acid bacteria is not particularly limited, and for example, is 0.0004% to 0.12% (0.0035% to 1% in terms of sweet tea extract essence having a brix of 11.5), preferably 0.0012% to 0.012% (0.01% to 0.1% in terms of sweet tea extract essence having a brix of 11.5) in terms of dry powder of the sweet tea extract essence (in terms of dry powder containing no excipient and only the sweet tea extract essence).

The culture conditions for obtaining the lactic acid bacteria culture are not particularly limited, and examples thereof include the following conditions: inoculating lactic acid bacteria into the culture medium so that the number of bacteria in the culture medium is 1.0X 10³～1.0×10⁹About cfu/ml, and culturing the cells at about 30 to 40 ℃ for about 1 to 7 days. The culture conditions in this case may be suitably selected from among standing, stirring, shaking, aeration, and the like, and a method suitable for culturing the lactic acid bacteria to be used may be used.

The fermented food containing the lactic acid bacteria culture obtained by culturing lactic acid bacteria by adding the sweet tea extract essence of the present invention to a culture medium can be produced by a conventionally known method for producing fermented food, except that the sweet tea extract essence is added to the culture medium before culturing lactic acid bacteria. Here, the fermented food containing the lactic acid bacteria culture includes, for example, fermented milk, milk products, lactic acid bacteria beverages, and the like specified in fermented soybean milk, and the like. The fermented food includes various foods and drinks using lactic acid bacteria, for example, fermented milk such as plain type (plain type), flavored type (flavoured type), fruit type (fruity type), sweet type (sweet type), liquid type (soft type), drinkable type (drinkable type), set type (hard type), frozen type (frozen type), lactic acid bacteria drink, goat cheese (kefir), and the like.

In addition, fermented foods containing a culture of lactic acid bacteria can be prepared as follows: if necessary, various food materials other than the sweetener such as syrup, for example, various sugars, thickeners, emulsifiers, various vitamins, and other optional ingredients are blended. Specific examples of such food materials include: saccharides such as sucrose, glucose, fructose, palatinose, trehalose, lactose, xylose, and maltose; sugar alcohols such as sorbitol, xylitol, erythritol, lactitol, palatinose alcohol, reduced maltose and reduced maltose; high-sweetness sweeteners such as aspartame, thaumatin, sucralose, acesulfame and stevia rebaudiana; agar, gelatin, carrageenan, guar gum, xanthan gum, pectin, locust bean gum, gellan gum, carboxymethyl cellulose, soybean polysaccharides; various thickening (stabilizing) agents such as propylene glycol alginate; emulsifiers such as sucrose fatty acid ester, glycerin fatty acid ester, polyglycerin fatty acid ester, sorbitan fatty acid ester, lecithin, etc.; 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, vitamin B, vitamin C, vitamin E, and the like; mineral components such as calcium, magnesium, zinc, iron, and manganese; a yogurt system; berry (berry) lines; orange (orange) line; quince (quince) series; the perilla (perilla) line; citrus (citrus) lines; an apple line; a mint family; a grape line; apricot (apricot) line; pear, custard cream, peach, melon, banana, tropical; a vanilla line; black tea, coffee series, etc.

In addition, by mixing the sweet tea extract essence of the present invention in a culture medium and culturing bacteria of the genus bifidobacterium, a culture of bacteria of the genus bifidobacterium can be obtained, and a fermented food containing the same can be obtained. The culture medium for culturing bacteria of the genus bifidobacterium by adding the extract essence of sweet tea of the present invention to the culture medium includes, in the same manner as the culture medium for culturing lactic acid bacteria described in the last paragraph on page 7: animal milk culture medium containing fresh milk such as cow milk, goat milk, horse milk, and sheep milk, or milk product such as skimmed milk powder, whole milk powder, and fresh milk oil, liquid milk derived from plants such as soybean milk, and various synthetic culture media. The medium may be supplemented with components of a medium generally used for bacteria of the genus bifidobacterium. Examples of such components include: saccharides such as glucose, vitamins such as vitamin A, vitamin B, vitamin C, and vitamin E, various peptides, amino acids, and salts such as calcium and magnesium.

Furthermore, as in the case of the medium for culturing lactic acid bacteria, oleic acids described in the page 7, last but 1 st to page 8, first paragraph 1 may be added to the medium for culturing bacteria of the genus Bifidobacterium, and the addition amount thereof may be such that the concentration thereof in terms of oleic acid is approximately 5 to 50ppm, preferably 5 to 25ppm, in the medium, as described in the page 7, last but 1 st to page 8, first paragraph 1.

The Bifidobacterium bacteria cultured by mixing the sweet tea extract of the present invention in a culture medium are not particularly limited, and examples thereof include Bifidobacterium breve (Bifidobacterium breve), Bifidobacterium bifidum (Bifidobacterium bifidum), Bifidobacterium longum (Bifidobacterium longum), Bifidobacterium infantis (Bifidobacterium infantis), Bifidobacterium adolescentis (Bifidobacterium adolescentis), Bifidobacterium catenulatum (Bifidobacterium catenulatum), Bifidobacterium pseudocatenulatum (Bifidobacterium pseudocatenulatum), Bifidobacterium horn (Bifidobacterium angulus), Bifidobacterium galobum (Bifidobacterium gallicum), Bifidobacterium lactis (Bifidobacterium lactis), and Bifidobacterium animalis (Bifidobacterium animalis). Among these bacteria belonging to the genus Bifidobacterium, Bifidobacterium breve, Bifidobacterium bifidum and Bifidobacterium longum are preferable, and Bifidobacterium breve YIT12272(FERM BP-11320, Collection date: 22 years, 2 months and 16 days) and Bifidobacterium bifidum YIT10347(FERM BP-10613, Collection date: 17 years, 6 months and 23 days) are particularly preferable. One or two or more species of the above-mentioned various bacteria belonging to the genus bifidobacterium may be used, and in addition, one or two or more species of the above-mentioned various lactic acid bacteria may be used in combination.

The above-mentioned lactic acid bacteria and bacteria belonging to the genus Bifidobacterium on the day of preservation are all deposited in the patent deposit center on the basis of the national institute of technology for evaluation of the independent administrative sciences (〒 292 0818, 2 Digites, 5-Fadi 8120, Japan) in Gentianjin, Japan, Katazu, Katakutaki county.

The amount of the sweet tea extract essence of the present invention added to the culture medium when culturing bacteria of the genus bifidobacterium is not particularly limited, and for example, when the proliferation of bacteria of the genus bifidobacterium is to be improved, the amount is 0.001% to 1%, preferably 0.35% to 0.55%, in terms of the sweet tea extract essence having a brix of 11.5. When the viability of bacteria belonging to the genus bifidobacterium is to be maintained at a high level, the content of the dried extract of rubus suavissimus (dry powder of rubus suavissimus extract without a vehicle) is 0.0004% to 0.12% (0.0035% to 1% as the dried extract of rubus suavissimus having a brix of 11.5), preferably 0.0012% to 0.012% (0.01% to 0.1% as the dried extract of rubus suavissimus having a brix of 11.5).

In addition, the method for obtaining Bifidobacterium bacteriaThe culture conditions of the bacterial culture are not particularly limited, and examples thereof include the following conditions: inoculating bacteria of the genus Bifidobacterium into the culture medium so that the number of bacteria in the culture medium is 1.0X 10³～1.0×10⁹About cfu/ml, and culturing the cells at about 30 to 40 ℃ for about 12 hours to 7 days or until the pH reaches about 4 to 5.5. The culture conditions in this case may be suitably selected from among static culture, agitation, shaking, and the like, and are preferably performed under anaerobic conditions, as appropriate for the culture of the bacterium belonging to the genus Bifidobacterium to be used.

The fermented food containing a culture of bacteria of the genus bifidobacterium obtained by culturing bacteria of the genus bifidobacterium while adding the sweet tea extract essence of the present invention to a culture medium can be produced by a conventionally known method for producing fermented food, except that the sweet tea extract essence is added to the culture medium before culturing the bacteria of the genus bifidobacterium. The fermented food containing the bifidobacterium bacterial culture includes, for example, fermented milk, milk product lactic acid bacteria beverage, and the like prescribed in fermented soybean milk, and the like, and includes various foods and drinks utilizing bifidobacterium bacteria, as in the fermented food containing the lactic acid bacteria culture described in page 9, paragraph 3. The fermented food can be obtained by blending the sweeteners described in the last 1 th to 10 th paragraphs on page 9 and various food materials other than the sweeteners, similarly to the fermented food containing the lactic acid bacteria culture.

The fermented food containing the culture of lactic acid bacteria to which the extract of rubus suavissimus of the present invention is added thus obtained can improve the proliferation of lactic acid bacteria, and the fermented food containing the culture of bifidobacterium bacteria to which the extract of rubus suavissimus of the present invention is added can improve the proliferation and viability of bifidobacterium bacteria. Further, these fermented foods have no bitterness derived from sweet tea and are excellent in flavor. Therefore, these fermented foods are highly useful and contribute to health promotion. The survival rate can be determined by the method described in examples.

Examples

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

Reference example 1

Preparation of sweet tea extract 1:

after leaf of sweet tea (scientific name: Rubus suavissimus s. lee (Rosaceae)) was subjected to pulverization treatment, water in an amount 15 times that of sweet tea leaves and citric acid in an amount corresponding to 5% of sweet tea leaves were added to adjust pH to 3.8, and the mixture was stirred at 25 ℃ for 60 minutes to extract, thereby obtaining a sweet tea extract having a brix of 2.0. The obtained sweet tea extract having a brix of 2.0 was concentrated by an evaporator by about 10.3 times to obtain a sweet tea extract having a brix of 20.6.

Example 1

Preparation of sweet tea extract essence dry powder:

(1) selection of activated carbon

The amounts of rubusoside (rubusoside) and polyphenol remaining in the sweet tea extract and the high brix value of the sweet tea extract were measured because they affected the flavor of the fermented food.

The sweet tea extract having a brix of 20.6 produced in reference example 1 was added according to the kind and amount of activated carbon described in table 1, and after stirring for 30 minutes, the brix of the solution was measured with an RX-7000 α digimatic refractometer (atagaco., Ltd.) and the rubusoside contained in the solution was measured by HPLC method.

The device comprises the following steps: waters alliance 2690

A detector: PDA detector W2996

Measuring wavelength: 210nm

Column: YMC-Pack ODS-A150 x 4.6mm I.D. S-5 μm

Column temperature: 25 deg.C

Mobile phase: line A (0.17% phosphoric acid aqueous solution), line B (0.17% phosphoric acid/acetonitrile)

Liquid feeding conditions: gradient elution at a flow rate of 1.0 ml/min

Gradient conditions:

(time) (line A) (line B)

0 → 5 min (composition fixed) 75% 25%

5 → 30 min (Linear gradient) 30% 70%

The amount of polyphenol contained in the solution was measured by the iron tartrate method. The polyphenol amount was calculated by converting to ethyl gallate. Further, the results of brix, rubusoside and polyphenol contents when each activated carbon was used are shown in table 1.

[ Table 1]

*1: TAIKO powdered carbon SA1000-W65(Futamura Chemical Co., Ltd.). This product contained 65% of water, but the amount added in table 1 was calculated as the dry weight excluding water. .

*2: TAIKO powdered charcoal K (Dry) (Futamura Chemical Co., Ltd.)

*3: TAIKO powdered carbon M (W50) (Futamura Chemical co., Ltd.). This product contained 50% of water, but the amount added in table 1 was calculated on a dry weight basis without water.

As a result, the brix was highest without adding activated carbon, and the residual amounts of rubusoside and polyphenol were also the highest. The use of the chemical process activated carbon and the steam activated carbon reduces the contents of brix, rubusoside and polyphenol, and particularly in the case of the chemical process activated carbon, the contents of brix, rubusoside and polyphenol are reduced more than those in the case of the steam activated carbon, although the amount of the added activated carbon is smaller than that in the case of the steam activated carbon.

When the amount of the activated carbon is large, it takes more time in the activated carbon removal step than when the amount is small, and therefore, it is preferable to reduce the amount of these substances by a small amount of addition, and it is known that the activated carbon is more suitable than the steam-activated carbon for the chemical method using zinc chloride.

(2) Preparation of sweet tea extract

To the sweet tea extract having a brix of 2.0 produced in reference example 1, 0.14% (dry weight equivalent) of Chemical activated carbon (TAIKO powdered carbon SA1000-W65(Futamura Chemical co., Ltd.)) was added, and the mixture was stirred for 30 minutes. After stirring, the mixture was centrifuged at 10,000 Xg for 2 minutes, and the supernatant was subjected to celite filtration (0.1% of celite (manufactured by Tokyo Jinye Co., Ltd.) was added, followed by filtration through a No.131 filter paper). The resulting solution filtered through celite was microfiltered through a 0.2 μm microfilter (manufactured by Toyo Filter paper Co., Ltd.), and the filtrate was concentrated to a Brix of 11.5 by an evaporator. Concentrating, heating to 90 deg.C for sterilization, and cooling to below 50 deg.C to obtain folium hydrangeae strigosae extract.

(3) Powdering of sweet tea extract

Dextrin (manufactured by Cargill Japan) was added to the solid content 40 of the sweet tea extract obtained in (2) at a weight ratio of 60, mixed with water and dissolved, and then powdered by a spray dryer (manufactured by Nihon Buchi corporation). The pulverization is carried out under the conditions of 160 ℃ at the inlet, 80 to 100 ℃ at the outlet and 10 mL/min at the flow rate.

The dried powder of the obtained sweet tea extract essence was confirmed to be not deliquesced by visual observation even when left at room temperature for 2 hours.

Example 2

Production of fermented food containing lactic acid bacteria:

the dried powder of the sweet tea extract essence manufactured in example 1 was added to the minimal medium in the amount described in table 2, using 10% skimmed milk powder solution as the minimal medium. The medium was inoculated with 0.1% starter (initial number of fermentation bacteria: 1.5X 10) of Lactobacillus casei YIT9029⁶cfu/ml) at 37 ℃ for 24 hours to obtain a lactic acid bacteria culture, and then cooled to 10 ℃ or less to obtain fermented milk. The pH, acidity and viable cell count of the fermented milk were measured. The pH was determined using a pH meter (HORIBAF-52). With respect to the acidity, 9g of the fermented milk was sampled, and the titration value (unit: ml) at pH8.5 by neutralization titration with 0.1N sodium hydroxide was measured. The viable cell count was measured using BCP medium (product of Rongji chemical Co., Ltd.). Further, the flavor of the obtained fermented milk was evaluated by 3 panelists according to the following evaluation criteria. The results are shown in Table 2.

[ Table 2]

*: the equivalent of the dried powder of the sweet tea extract essence alone without dextrin is shown. The numbers in parentheses indicate: dextrin was added to the solid content 40 of the sweet tea extract in an amount of 60 wt% and then powdered to obtain a dry powder.

< evaluation Standard of flavor >

Evaluating content

5: no bitter and astringent taste is felt

4: hardly any bitter or astringent taste is felt

3: slight bitter and astringent taste

2: the bitter and astringent taste was felt

1: strongly felt bitter and astringent taste

The fermented milk containing the lactic acid bacteria culture obtained by culturing the dried powder containing the sweet tea extract (containing no dextrin and containing only the dried powder containing the sweet tea extract) in an amount of 0.0004% or more (0.0035% or more in terms of the sweet tea extract having a brix of 11.5) showed a higher viable cell count (5.0 × 10) and promoted culture of lactobacillus casei compared with the fermented milk containing no dried powder containing the sweet tea extract⁸cfu/ml or more). The fact that the culture of Lactobacillus casei was promoted was also confirmed by the decrease in pH and the increase in acidity.

In particular, when 0.0012% to 0.012% of dried powder of rubus suavissimus extract (dried powder containing only rubus suavissimus extract dried powder without dextrin) was added (0.01% to 0.1% in terms of rubus suavissimus extract having a brix of 11.5), the effect of promoting the culture of lactobacillus casei was remarkable, and the flavor was also good.

Example 3

Production of fermented food containing bacteria of the genus bifidobacterium (1):

the 20% skim milk powder solution was used as a minimal medium, and the dried powder of the sweet tea extract essence manufactured in example 1 was added to the minimal medium in the amount described in table 3. The culture medium was inoculated with 1% starter (initial number of fermentation bacteria: 1.0X 10) of Bifidobacterium breve YIT12272⁷cfu/ml), and cultured at 37 ℃ for 24 hours to obtain fermented milk. The fermented milk was filled into a glass container and sealed with a butyl rubber stopper, and then stored at 10 ℃ for 21 days. Viable cell counts before and after storage were measured using TOS medium (Yakult Pharmaceutical Industry Co., Ltd.). Note that the flavor after storage was evaluated in the same manner as in example 2. Further, the survival rate ((number of viable cells after storage/number of viable cells at the time of production) × 100 (%) was determined from the number of viable cells before and after storage. The results are shown in Table 3.

[ Table 3]

*: the equivalent of the dried powder of the sweet tea extract essence alone without dextrin is shown. The numbers in parentheses indicate: dextrin was added to the solid content 40 of the sweet tea extract in an amount of 60 wt% and then powdered to obtain a dry powder.

Fermented milk containing a bifidobacterium bacterial culture obtained by culturing bifidobacterium breve in a medium containing not less than 0.0004% (not less than 0.0035% in terms of dried powder of rubus suavissimus extract having a brix of 11.5) of dried powder of rubus suavissimus extract (dried powder containing not dextrin but only dried powder of rubus suavissimus extract) was improved in the survival rate of bifidobacterium breve as compared with fermented milk containing no dried powder of rubus suavissimus extract.

In particular, when 0.0012% to 0.012% of dried powder of rubus suavissimus extract (dried powder containing only rubus suavissimus extract powder without dextrin) was added (0.01% to 0.1% in terms of rubus suavissimus extract having a brix of 11.5), the effect of improving the survival of bifidobacterium breve was remarkable, and the flavor was also good.

Example 4

Production of fermented food containing Bifidobacterium bacteria (2)

As a minimal medium, 18% milk powder solution (or milk powder solution with a non-fat milk solid content (SNF) of 14%) was prepared: to the minimal medium were added a medium containing 0.44% of the extract of sweet tea having a brix of 11.5, which was produced in example 1(2), and a medium not added. Whey peptide (LE80GF-US) was added to the medium, and 3% starter (initial number of fermentation bacteria: 2.8X 10) of Bifidobacterium bifidum YIT10347 was inoculated thereto⁷cfu/ml), incubated at 37 ℃ to pH 4.9, and then cooledCooling to below 10 deg.C to obtain fermented milk. The number of viable bacteria in the fermented milk was measured. The results are shown in Table 4.

[ Table 4]

Fermented milk obtained by culturing bifidobacterium bifidum in a medium containing 0.44% of sweet tea extract having a brix of 11.5 showed a shorter culture time and a higher viable count of fermented milk, compared to fermented milk without the addition of sweet tea extract, although the pH was the same as the conditions of the whey peptide added.

Although the effect of the sweet tea extract on slightly shortening the culture time of bifidobacterium bifidum (the effect of shortening to about 92%) has been known (patent document 2), the culture time of bifidobacterium bifidum YIT10347 is shortened to about 73% by adding 0.44% of sweet tea extract, and the proliferation promoting effect is confirmed. Thus, although the reason is not clear, it is known that: by subjecting the sweet tea extract to activated carbon treatment, the effect of promoting the proliferation of Bifidobacterium bifidum becomes remarkable.

Example 5

Preparation of sweet tea extract essence dry powders a and B:

(1) preparation of sweet tea extract A

The sweet tea extract having a brix of 2.0 produced in reference example 1 was microfiltered with a 0.2 μm microfilter (manufactured by toyoyo filter paper co., Ltd.), and 0.14% (dry weight equivalent) of Chemical activated carbon (TAIKO powdered carbon SA1000-W65(Futamura Chemical co., Ltd.) was added to the resulting solution, followed by stirring for 30 minutes. After stirring, the mixture was centrifuged at 10,000 Xg for 2 minutes, and the supernatant was subjected to celite filtration (0.1% of celite (manufactured by Tokyo Jinye Co., Ltd.) was added, followed by filtration through a No.131 filter paper). The resulting solution was concentrated to a brix of 11.5 with an evaporator. Concentrating, heating to 90 deg.C for sterilization, and cooling to below 50 deg.C to obtain sweet tea extract A.

Dextrin (manufactured by cargill japan) was added to the solid content 40 of the sweet tea extract essence a obtained above at a weight ratio of 60, and the mixture was mixed with water and dissolved, and then the mixture was powdered by a spray dryer (manufactured by Nihon Buchi corporation). The powdering conditions were the same as those in (3) of example 1. The obtained powder was used as sweet tea extract dried powder A.

Note that, even when the dried powder a of the sweet tea extract essence was left at room temperature for 2 hours, no deliquescence was observed by visual observation.

(2) Preparation of dried powder B of sweet tea extract

Sweet tea extract dry powder B was produced in the same manner as in (2) and (3) of example 1.

Reference example 2

Preparation of dried powder of sweet tea extract and dried powder of electrodialysis material of sweet tea extract:

(1) preparation of dried powder of sweet tea extract

The sweet tea extract having a brix of 2.0 produced in reference example 1 was concentrated to a brix of 11.5 with an evaporator, heated to 90 ℃ for sterilization, and cooled to 50 ℃ or lower. Dextrin (manufactured by Cargill Japan) was added to the obtained solid content 40 of the sweet tea extract having a brix of 11.5 in a weight ratio of 60, and the mixture was mixed with water and dissolved, and then powdered by a spray dryer (manufactured by Nihon Buchi corporation). The powdering conditions were the same as those in (3) of example 1. The obtained powder was used as a dry powder of sweet tea extract.

Even when the dried powder of the sweet tea extract was left at room temperature for 2 hours, no deliquescence was observed by visual observation.

(2) Preparation of electrodialytic dried powder of sweet tea extract

The sweet tea extract having a brix of 2.0 prepared in reference example 1 was microfiltered with a 0.2 μm microfilter (available from Toyo Filter paper Co., Ltd.), and magnesium chloride hexahydrate was added to the resulting solution in an amount of 1% magnesium chloride. Then, the extract was placed in a desalting chamber of an electrodialysis apparatus (electrodialysis membrane: AC220-50, product name: Micro Acilyzer S-3, manufactured by ASTOMCorporation), and water corresponding to 17% of the extract solution was added to the concentration chamber to conduct electrodialysis treatment until the conductivity of the desalting chamber reached an equilibrium (2 milliSiemens per centimeter (mS/cm)), thereby recovering a concentrated solution. The concentrated solution was concentrated to a brix of 11.5 by an evaporator. Heating the concentrated solution with Brix of 11.5 to 90 deg.C, sterilizing, and cooling to below 50 deg.C to obtain electrodialysis material.

Dextrin (manufactured by Cargill Japan) was added in an amount of 60 parts by weight based on 40 parts by weight of the solid content of the electrodialysis material having a brix of 11.5 obtained above, and the resulting mixture was mixed with water and dissolved, and then powdered by a spray dryer (manufactured by Nihon Buchi corporation). The powdering conditions were the same as those in (3) of example 1. The resulting powder was used as an electrodialysis dry powder.

Even when the dry powder of the electrodialysis material was left at room temperature for 2 hours, the powder was partially liquefied, and deliquescence was visually observed.

Example 6

Production of fermented food containing lactic acid bacteria (1):

the dry powders a and B of the extract of sweet tea produced in example 5 and ginseng were added to a minimal medium containing 15% of skim milk powder containing 4% of glucose in an amount of 0.012% in terms of dry powder containing no dextrin (0.1% in terms of a concentrate before powdering having a brix of 11.5) relative to the minimal mediumThe sweet tea extract dry powder and the electrodialysis material dry powder manufactured in example 2 were examined. The culture medium was inoculated with 0.5% starter of Lactobacillus casei YIT9029 (initial number of fermentation bacteria: 7.5X 10)⁶cfu/ml) was cultured at 37 ℃ for 24 hours to obtain a lactic acid bacteria culture, and then cooled to 10 ℃ or lower to obtain fermented milk. The pH, acidity, viable cell count and flavor of the fermented milk were measured. Each target measurement method was performed in the same manner as in example 2. The results are shown in Table 5.

[ Table 5]

The fermented milk has less viable count (less than 5.0 × 10) when no additive is added⁸cfu/ml), nor was it confirmed that the proliferation is promoted by pH and acidity.

On the other hand, in the case of the dried sweet tea extract powder, the dried electrodialysis material powder, and the dried sweet tea extract essence powders a and B, the number of viable bacteria is large, and the proliferation promoting effect is also remarkably exhibited in terms of pH and acidity.

In addition, when the dry powder of sweet tea extract was used, the flavor of fermented milk was poor, but in the case of the dry powder of electrodialysis material and the dry powders a and B of sweet tea extract essence, no influence on the flavor was observed.

Therefore, it was found that the dried powders a and B of the sweet tea extract essence had the same growth promoting effect of lactobacillus casei as the dried powder of the electrodialysis material, and did not affect the flavor of the fermented milk.

Example 7

Production of fermented food containing lactic acid bacteria (2):

instead of Lactobacillus casei YIT9029, Lactobacillus gasseri YIT 01920.5% (initial number of fermentation bacteria: 4.5X 10) was inoculated⁶cfu/ml), the same strips as in example 6 were used except thatThe test was performed. The results are shown in Table 6.

[ Table 6]

Similarly to the results of example 6, the number of viable bacteria in the fermented milk was small (less than 5.0X 10) without the additive⁸cfu/ml), the growth acceleration was not confirmed from the pH and acidity, but the number of viable bacteria was large in the case of the sweet tea extract dry powder, the electrodialysis material dry powder, and the sweet tea extract essence dry powders a and B, and the growth acceleration effect was also remarkably exhibited from the pH and acidity side.

In addition, in the case of using the dried powder of sweet tea extract, the flavor of the fermented milk was poor, but in the case of the dried powder of electrodialysis material and the dried powder of sweet tea extract a and B, no influence on the flavor was observed.

Therefore, it was found that the dried powders a and B of the sweet tea extract essence had not only the growth promoting effect of lactobacillus casei but also the growth promoting effect of lactobacillus gasseri, and did not affect the flavor of fermented milk, as in the case of the electrodialysis material dried powder.

Example 8

Production of fermented food containing bacteria of the genus bifidobacterium (1):

the dried powder of sweet tea extract essence a and B produced in example 5, and the dried powder of sweet tea extract and the dried powder of electrodialysis material produced in reference example 2 were added to a minimal medium of 15% skimmed milk powder so that the dry powder containing no dextrin was 0.012% in terms of (0.1% in terms of the concentrated solution before powdering having a brix of 11.5) in terms of the minimal medium. The culture medium was inoculated with 1% starter (initial number of fermentation bacteria: 1.0X 10) of Bifidobacterium breve YIT12272⁷cfu/ml), lactococcus lactis YIT2027 and Streptococcus thermophilus YIT20210.1% of each starter (initial fermentation bacteria number: 1.0X 10 respectively)⁶cfu/ml、1.2×10⁶cfu/ml), cultured at 35 ℃ until pH reached 4.4. To 40 parts by weight of the product obtained by homogenizing the culture at 15MPa, 60 parts by weight of a 10% sucrose solution sterilized at 100 ℃ for 5 minutes was added to produce fermented milk. The fermented milk thus produced was filled in a glass container, sealed with a butyl rubber stopper, and then stored at 10 ℃ for 21 days under anaerobic conditions, and the viable cell count before and after storage was measured in the same manner as in example 3. Note that the flavor after storage was evaluated in the same manner as in example 2. Further, the survival rate was determined from the number of viable bacteria before and after storage in the same manner as in example 3. The results are shown in Table 7.

[ Table 7]

Viable count and survival rate represent the values of bifidobacterium breve YIT 12272.

The survival rate of Bifidobacterium breve was low without additives.

On the other hand, in the case of the sweet tea extract dry powder, the electrodialysis material dry powder, and the sweet tea extract essence dry powders a and B, the survival rate of bifidobacterium breve was high, and the viability-improving effect was remarkably exhibited.

In addition, when the dry powder of sweet tea extract was used, the flavor of fermented milk was poor, and in the case of the dry powder of electrodialysis material and the dry powders a and B of sweet tea extract essence, no effect on flavor was observed.

Therefore, it was found that the dried powders a and B of the sweet tea extract essence had the same effect of improving the viability of bifidobacterium breve as the dried powder of the electrodialysis material, and did not affect the flavor of the fermented milk.

Example 9

Production of fermented food containing bacteria of the genus bifidobacterium (2):

in place of 1% of starter for Bifidobacterium breve YIT12272, 0.1% of starter for lactococcus lactis YIT2027 and Streptococcus thermophilus YIT2021, and 2% of starter for inoculating Bifidobacterium bifidum YIT10347 (initial number of fermentation bacteria: 2.2X 10)⁷cfu/ml) and starter 0.01% of streptococcus thermophilus YIT2021 (initial number of fermentation bacteria: 1.2X 10⁵cfu/ml), the test was carried out under the same conditions as in example 8 except that the amount of cfu/ml was changed. The results are shown in Table 8.

[ Table 8]

Viable count and survival rate represent the values of bifidobacterium bifidum YIT 10347.

Similarly to the results of example 8, the survival rate of bifidobacterium bifidum was low without additives, and the survival rate of bifidobacterium bifidum was high and the viability-improving effect was remarkably exhibited in the case of the dried sweet tea extract powder, the dried electrodialysis material powder, and the dried sweet tea extract powder a and B.

In addition, in the case of using the dried powder of sweet tea extract, the flavor of fermented milk was poor, while the electrodialysis material dried powder, the dried powder of sweet tea extract a and B did not find the influence on the flavor.

Therefore, it was found that the dried powders a and B of the sweet tea extract had the same effect of improving the viability of bifidobacterium breve as that of the dried powder of the electrodialysis material, and also had the effect of improving the viability of bifidobacterium bifidum without affecting the flavor of the fermented milk.

Industrial applicability

The sweet tea extract essence of the present invention maintains the effect of the sweet tea extract in improving the proliferation of lactic acid bacteria and the viability of bacteria belonging to the genus bifidobacterium without affecting the flavor, has an effect of improving the proliferation of bacteria belonging to the genus bifidobacterium, which has not been found before, and is easy to produce and pulverize.

Therefore, the sweet tea extract essence of the present invention can be preferably used for the production of fermented foods containing lactic acid bacteria and bacteria of the genus bifidobacterium.

PCT/RO/134 Table

Claims (16)

1. Sweet tea extract essence is characterized by being obtained by performing activated carbon treatment on a sweet tea extract.

2. The sweet tea extract essence according to claim 1, which is a dry powder.

3. The sweet tea extract essence according to claim 1 or 2, wherein the activated carbon used in the activated carbon treatment is chemically activated carbon.

4. The sweet tea extract essence according to any one of claims 1 to 3, wherein the amount of activated carbon added in the activated carbon treatment is 0.035 wt% or more in terms of dry weight per 1 brix of the sweet tea extract.

5. A preparation method of sweet tea extract essence is characterized in that the sweet tea extract is subjected to activated carbon treatment.

6. The method for producing sweet tea extract essence according to claim 5, wherein the activated carbon used for the activated carbon treatment is chemically activated carbon.

7. The method for producing sweet tea extract essence according to claim 5 or 6, wherein the amount of activated carbon added in the activated carbon treatment is 0.035 wt% or more in terms of dry weight per 1 brix of the sweet tea extract.

8. A fermented food comprising a culture of lactic acid bacteria obtained by culturing lactic acid bacteria in a medium containing the extract of sweet tea according to any one of claims 1 to 4.

9. A method for producing a fermented food containing a lactic acid bacterium, comprising the steps of: before culturing lactic acid bacteria, the sweet tea extract according to any one of claims 1 to 4 is added to a culture medium.

10. A fermented food comprising a culture of bacteria of the genus Bifidobacterium obtained by culturing the bacteria of the genus Bifidobacterium in a medium containing the essence extracted from sweet tea according to any one of claims 1 to 4.

11. A method for producing a fermented food containing a bacterium belonging to the genus Bifidobacterium, comprising the steps of: before culturing bacteria belonging to the genus Bifidobacterium, the extract essence of sweet tea according to any one of claims 1 to 4 is added to a culture medium.

12. A method for promoting the proliferation of lactic acid bacteria and/or bacteria belonging to the genus Bifidobacterium, characterized in that the extract of Rubus suavissimus of any one of claims 1-4 is added to a culture medium before culturing lactic acid bacteria and/or bacteria belonging to the genus Bifidobacterium in the culture of lactic acid bacteria and/or bacteria belonging to the genus Bifidobacterium.

13. A proliferation promoter for lactic acid bacteria and/or bacteria belonging to the genus Bifidobacterium, which comprises the extract of Rubus suavissimus of any one of claims 1 to 4 as an active ingredient.

14. A method for improving the viability of bacteria belonging to the genus Bifidobacterium, characterized in that the sweet tea extract according to any one of claims 1 to 4 is added to a culture medium before culturing the bacteria belonging to the genus Bifidobacterium in the culture medium of the bacteria belonging to the genus Bifidobacterium.

15. A survivability improving agent for bacteria belonging to the genus Bifidobacterium, comprising the sweet tea extract essence according to any one of claims 1 to 4 as an active ingredient.

16. A method for improving the flavor of a sweet tea extract, characterized in that the sweet tea extract is subjected to an activated carbon treatment.