Fermented composition and method for producing same

Abstract

This fermented composition comprises whey protein, a bacterium of the genus Bifidobacterium, a lactic acid bacterium, and acetic acid, wherein the content of acetic acid is 250 mg / 100 g or more with respect to the total mass of the fermented composition. This method for producing a fermented composition involves: adding a bacterium of the genus Bifidobacterium and a lactic acid bacterium to a raw material composition containing whey protein; and fermenting same until the acetic acid content reaches at least 250 mg / 100 g with respect to the total mass of the raw material composition, the bacterium of the genus Bifidobacterium, and the lactic acid bacterium.

Description

Fermented composition and method for producing same

[0001] The present invention relates to a fermentation composition and a method for producing the same.

[0002] In recent years, fermented compositions containing whey protein have been proposed. Patent Document 1 discloses a fermented composition obtained by high-temperature sterilization of an aqueous whey protein solution having a solids concentration of 11 to 35% by mass and a pH of 6.5 to 8, followed by lactic acid fermentation and homogenization. Patent Document 2 discloses a fermented composition containing whey protein, Bifidobacterium bacteria, and ash.

[0003] International Publication No. WO 2008 / 136309 International Publication No. WO 2021 / 200900

[0004] In recent years, vinegar drinks have been attracting attention due to the growing health consciousness. Lactic acid fermentation produces lactic acid, and fermentation by Bifidobacterium produces lactic acid and acetic acid, resulting in a sour taste in the fermented composition. However, the sour taste of conventional fermented compositions may be weaker than that of typical vinegar drinks. The present invention aims to provide a fermented composition having a vinegar drink-like flavor and a method for producing the same.

[0005] The present invention has the following aspects. [1] A fermented composition comprising whey protein, Bifidobacterium bacteria, lactic acid bacteria, and acetic acid, wherein the content of the acetic acid is 250 mg / 100 g or more relative to the total mass of the fermented composition. [2] The fermented composition according to [1], further comprising yeast extract. [3] The fermented composition according to [2], wherein the content of the yeast extract, calculated as solid content, is 0.01 mass % or more relative to the total mass of the fermented composition. [4] The content of the Bifidobacterium bacteria is 1.0 x 10 ６ [5] The fermentation composition according to any one of [1] to [3], wherein the lactic acid bacteria contain at least Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus, and the total content of the Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus is 1.0 x 10 ７[6] The fermented composition according to any one of [1] to [4], wherein the lactic acid bacteria contain at least Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus, and the ratio of the viable cell count of the Bifidobacterium bacteria to the total viable cell count of the Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus is 10:1 to 900:1. [7] The fermented composition according to [5] or [6], further containing Lactococcus lactis subsp. lactis as the lactic acid bacteria. [8] The fermented composition according to any one of [1] to [7], wherein the whey protein content is 0.8 to 1.3% by mass relative to the total mass of the fermented composition. [9] The fermented composition according to any one of [1] to [8], wherein the ratio of the mass of the whey protein to the total mass of protein is 60% by mass or more.

[10] The fermented composition according to any one of [1] to [9], wherein the content of vinegar is 0.1% by mass or less, relative to the total mass of the fermented composition.

[11] A method for producing a fermented composition, comprising adding Bifidobacterium bacteria and lactic acid bacteria to a raw material composition containing whey protein, and fermenting until the content of acetic acid relative to the total mass of the raw material composition, the Bifidobacterium bacteria, and the lactic acid bacteria reaches at least 250 mg / 100 g.

[12] The production method according to

[11] , wherein the raw material composition further contains yeast extract.

[0006] According to the present invention, a fermented composition having a flavor reminiscent of vinegar drink and a method for producing the same can be provided.

[0007] In the present invention, the methods for measuring each component are as follows. The acetic acid content is measured by the method described in the Examples below. The protein content (% by mass) is a value measured by the Dumas method. A total nitrogen analyzer (for example, the analytical instrument SUMIGRAPH NC-220F (manufactured by Sumika Chemical Analysis Center Co., Ltd.)) can be used to measure the protein content. The measurement conditions are as follows: Electric furnace temperature: Reactor 870°C, Reduction furnace: 600°C Oxygen purge: 0.2±0.02 L / min Column temperature: 70±5°C Detector: Detector temperature: 100°C, CURRENT: 160 mA Carrier gas: Helium flow rate 80±5 mL / min at column temperature 70±5°C Constituent reference substance: Aspartic acid Measurement sample amount: 500±100 mg Reference substance amount: 500±100 mg The moisture content is measured by the direct heating and drying method. The solid content is calculated by solid content (mass%) = 100 - water (mass%). pH is the value at 10°C. In this specification, the symbol "to" used for a range of values ​​means that the lower limit and upper limit are included.

[0008] [Fermented Composition] A fermented composition according to one embodiment of the present invention contains whey protein, Bifidobacterium bacteria, lactic acid bacteria, and acetic acid, and the acetic acid content is 250 mg / 100 g or more relative to the total mass of the fermented composition.

[0009] The fermented composition of the present embodiment typically contains a fermented product obtained by fermenting a raw material composition containing whey protein, Bifidobacterium bacteria, and lactic acid bacteria. The fermented composition containing the fermented product may consist of the fermented product alone, or may further contain raw materials other than the fermented product.

[0010] <Whey Protein> Examples of whey protein include whey protein derived from mammalian milk (for example, cow's milk, goat's milk, sheep's milk, or horse's milk). As the whey protein, whey protein derived from cow's milk is preferred.

[0011] Whey protein is typically blended as a whey protein-containing raw material. The whey protein-containing raw material is not particularly limited as long as it contains whey protein, but examples include whey powder, whey protein concentrate (WPC), whey protein isolate (WPI), skim milk powder, milk protein concentrate (MPC or TMP), micellar casein concentrate (MCC), desalted whey powder, and skim milk concentrate. The whey protein content in the whey protein-containing raw material is approximately 11 to 15% by mass for whey powder, approximately 30 to 85% by mass for WPC, approximately 85 to 95% by mass for WPI, and approximately 15 to 17% by mass for TMP, relative to the total mass of the whey protein-containing raw material. These whey protein-containing raw materials may be used alone or in combination.

[0012] The whey protein-containing raw material may be a commercially available product or may be produced by a known production method. Whey powder can be produced, for example, by drying whey produced as a by-product in the cheese or casein production process. Examples of whey include cheese whey and acid whey. Whey protein concentrate (WPC) and whey protein isolate (WPI) can be obtained, for example, by concentrating whey protein from whey produced as a by-product in the cheese or casein production process while partially removing lactose, minerals, and the like. The method for concentrating whey protein or removing lactose and the like is not particularly limited, and known protein concentration methods or known removal methods such as desalting can be used. More specifically, examples of such concentration and removal methods include ion exchange treatment and filtration (preferably ultrafiltration). The concentration and removal methods can be one or more selected from the group consisting of ion exchange treatment and filtration.

[0013] <Bifidobacterium> Bacteria of the genus Bifidobacterium (hereinafter also referred to as bifidobacteria) are not particularly limited, and any bifidobacteria known in the field of fermentation or the like can be used. For example, Bifidobacterium longum subsp. longum, Bifidobacterium longum subsp. infantis, Bifidobacterium breve, Bifidobacterium longum subsp. suis, Bifidobacterium animalis subsp. lactis, Bifidobacterium animalis subsp. lactis, Bifidobacterium longum subsp. longum, Bifidobacterium longum subsp. infantis, Bifidobacterium breve, Bifidobacterium longum subsp. suis, Bifidobacterium animalis subsp. lactis, Bifidobacterium longum subsp. longum ... lactis), Bifidobacterium animalis subsp. animalis, Bifidobacterium bifidum, Bifidobacterium adolescentis, Bifidobacterium angulatum, Bifidobacterium dentium, Bifidobacterium pseudocatenulatum Examples of Bifidobacterium longum include Bifidobacterium pseudocatenulatum, Bifidobacterium pseudolongum, and Bifidobacterium thermophilum. Note that Bifidobacterium longum subsp. longum is sometimes abbreviated simply as Bifidobacterium longum.Furthermore, Bifidobacterium longum subsp. infantis may be abbreviated simply as Bifidobacterium infantis.

[0014] The bifidobacterium is preferably at least one species selected from the group consisting of Bifidobacterium longum subsp. longum, Bifidobacterium longum subsp. infantis, and Bifidobacterium breve.

[0015] Examples of Bifidobacterium longum subsp. longum include NITE BP-02621, ATCC 15707, ATCC 25962, DSM 20219, and JCM 1217. Of these, NITE BP-02621 is preferred. Bifidobacterium longum subsp. longum may be used alone or in combination of two or more strains. The bacterium assigned the accession number NITE BP-02621 was internationally deposited under the Budapest Treaty on January 26, 2018, at the Patent Microorganisms Depositary Center of the National Institute of Technology and Evaluation (Room 122, 2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture, 292-0818) under the accession number NITE BP-02621. The bacterium is the same bacterium as Bifidobacterium longum subsp. longum BB536.

[0016] Examples of Bifidobacterium longum subsp. infantis include NITE BP-02623, ATCC 15697, ATCC 15702, DSM 20088, and JCM 1222. Of these, NITE BP-02623 is preferred. Bifidobacterium longum subsp. infantis may be used alone or in combination of two or more strains. The bacterium assigned the accession number NITE BP-02623 was internationally deposited under the Budapest Treaty on January 26, 2018, at the Patent Microorganisms Deposit Center of the National Institute of Technology and Evaluation (Room 122, 2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture, 292-0818) under the accession number NITE BP-02623. The bacterium is the same bacterium as Bifidobacterium longum subsp. infantis M-63.

[0017] Examples of Bifidobacterium breve include NITE BP-02622, FERM BP-11175, ATCC 15700, ATCC 15698, DSM 20213, DSM 24706, DSM 13692, DSM 24732, DSM 24736, DSM 16604, JCM 1192, NCC 2705, NCC 490, YIT 4010, YIT 4064, SBT 2928, UCC 2003, BBG-001, C50, R0070, and BG7. Among these, NITE BP-02622 is preferred. Bifidobacterium breve may be used alone or in combination with two or more strains. The bacterium assigned the accession number NITE BP-02622 was internationally deposited under the Budapest Treaty on January 26, 2018, with the Patent Microorganisms Depositary Center of the National Institute of Technology and Evaluation (Room 122, 2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture, 292-0818) under the accession number NITE BP-02622. The bacterium assigned the accession number FERM BP-11175 was internationally deposited under the Budapest Treaty with the Patent Organism Depositary of the National Institute of Advanced Industrial Science and Technology (currently the Patent Organism Depositary of the National Institute of Technology and Evaluation, Room 120, 2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture, 292-0818) on August 25, 2009. This bacterium is identical to Bifidobacterium breve MCC1274.

[0018] One type of bifidobacteria may be used, or two or more types may be used in combination. Bifidobacteria may be used in either live or dead form. From the viewpoint of probiotic effects, it is preferable to include live bacteria. Bifidobacteria may be used in the form of frozen, freeze-dried, or spray-dried forms. Furthermore, the bifidobacteria may be in the form of only bifidobacterial cells, or may contain bifidobacterial cells plus components other than the cells (e.g., cryoprotectants, freeze-drying protectants, spray-drying protectants, etc.). Furthermore, the bifidobacteria may be dispersed in a powder. Examples of the powder that can be used include starches such as corn starch, potato starch, and tapioca starch, starch hydrolysates, dextrin, and maltodextrin.

[0019] <Lactic acid bacteria> The lactic acid bacteria are not particularly limited, and lactic acid bacteria known in the field of fermented foods and the like can be used. For example, Lactobacillus bacteria, Streptococcus bacteria, Lactococcus bacteria, Enterococcus bacteria, and Leuconostoc bacteria can be mentioned. Note that, in the present invention, bifidobacteria are not considered to be lactic acid bacteria.

[0020] Examples of Lactobacillus bacteria include Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus gasseri, Lactobacillus acidophilus, Lactobacillus helveticus, Lacticaseibacillus paracasei, and Lacticaseibacillus casei. Lactobacillus delbrueckii subsp. bulgaricus may be simply referred to as Lactobacillus bulgaricus.

[0021] Examples of Streptococcus bacteria include Streptococcus thermophilus. Examples of Lactococcus bacteria include Lactococcus lactis subsp. lactis, Lactococcus lactis subsp. cremoris, and Lactococcus plantarum. Lactococcus lactis subsp. lactis may be abbreviated simply as Lactococcus lactis, and Lactococcus lactis subsp. cremoris may be abbreviated simply as Lactococcus cremoris.

[0022] Examples of bacteria of the genus Enterococcus include Enterococcus faecalis and Enterococcus faecium. Examples of bacteria of the genus Leuconostoc include Leuconostoc mesenteroides and Leuconostoc mesenteroides subsp. cremoris.

[0023] One type of lactic acid bacterium may be used, or two or more types may be used in combination. Lactic acid bacteria may be any of live cells, dead cells, and cultures containing these, but live cells are preferred from the viewpoint of probiotic effect. From the viewpoint of fermentation efficiency, the fermentation composition preferably contains at least Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus as lactic acid bacteria. In addition to Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus, the fermentation composition may further contain other lactic acid bacteria. As the other lactic acid bacteria, Lactococcus lactis subsp. lactis is preferred from the viewpoint of improving the survival rate of bifidobacteria.

[0024] <Acetic Acid> At least a portion of the acetic acid contained in the fermented composition is produced by the bifidobacteria contained in the fermented composition. The fermented composition may contain vinegar in addition to the acetic acid produced by the bifidobacteria. Vinegar is a sour seasoning whose main component is acetic acid. Vinegar is classified as either brewed vinegar or synthetic vinegar according to the Vinegar Quality Labeling Standard established by the Ministry of Agriculture, Forestry and Fisheries. Brewed vinegar is a liquid seasoning obtained by acetic acid fermentation of at least one of grains, fruits, vegetables, other agricultural products (such as sugar cane), honey, and alcohol, and does not contain glacial acetic acid or acetic acid. Synthetic vinegar is obtained by adding at least one of sugars, acidulants, seasonings, and salt to glacial acetic acid or a diluted solution of acetic acid, or by adding brewed vinegar to these.

[0025] <Other Components> The fermented composition may further contain other components other than those described above, as necessary, within the scope that does not impair the effects of the present invention. Examples of other components include water, yeast extract, acidic components (excluding acetic acid), milk components (excluding whey protein), probiotics (excluding bifidobacteria and lactic acid bacteria), prebiotics, sweeteners, stabilizers such as pectin, flavor components, vegetable oils and fats, vegetable milks such as soy milk, thickening polysaccharides, oils and fats, proteins (excluding whey protein), amino acids, organic acids, vitamins, and inorganic salts. Any of these components can be used alone or in combination of two or more.

[0026] The yeast extract is a nutrient source obtained by moderately decomposing the raw material yeast using autolytic enzymes or the like. The yeast extract may be in liquid or powder form. A commercially available yeast extract (for example, Fuji Foods Co., Ltd. product name "Yeast Extract 21-NYP") can be used. The fermented composition preferably contains yeast extract. When a raw material composition containing whey protein, bifidobacteria, and lactic acid bacteria is fermented to produce a fermented composition, if the raw material composition contains yeast extract, the amount of acetic acid produced by bifidobacteria tends to be greater than when the raw material composition does not contain yeast extract, and the fermentation time required to reach the target acetic acid content tends to be shorter.

[0027] The acidic component is used as at least one of an acidulant and a pH adjuster. The acidic component can impart a sour taste to the fermentation composition or adjust the pH. Examples of the acidic component include citric acid, ascorbic acid, lactic acid, malic acid, maleic acid, adipic acid, succinic acid, fumaric acid, tartaric acid, gluconic acid, phytic acid, phosphoric acid, carbon dioxide, and salts thereof. These acidic components can be used alone or in combination of two or more. Furthermore, raw materials containing these acidic components may be used as the acidic component. For example, citrus juice may be used as the raw material containing the acidic component. This can also impart a flavor unique to fruit juice to the fermentation composition.

[0028] The milk component is not particularly limited, and common milk components can be used, but milk components derived from cow's milk are preferred. Examples of the milk component include raw milk, cow's milk, concentrated milk, condensed milk, whole milk powder, butter, cream, and cream powder. Any one of these milk components can be used alone, or two or more can be used.

[0029] Examples of the probiotics include acetic acid bacteria and Bacillus subtilis. These probiotics can be used alone or in combination. The probiotics may be live bacteria, killed bacteria, or cultures containing them, but live bacteria are preferred from the viewpoint of probiotic effects. Furthermore, the probiotic effects can be expected by incorporating bacteria, bacterial cultures, or fermented milk into the fermentation composition of the present invention.

[0030] Examples of the prebiotics include dietary fibers such as indigestible dextrin, insoluble oligosaccharides, and polydextrose; various proteins such as casein protein, soybean protein, and pea protein (pea protein); mixtures and hydrolyzates thereof; amino acids such as leucine, valine, isoleucine, and glutamine; vitamins such as vitamin B6 and vitamin C; creatine, citric acid, fish oil; and oligosaccharides such as isomaltooligosaccharides, galactooligosaccharides, xylooligosaccharides, soybean oligosaccharides, fructooligosaccharides, lactulose, and human milk oligosaccharides (HMO). These prebiotics may be used alone or in combination. The prebiotics may be produced by known production methods or commercially available products.

[0031] Examples of the human milk oligosaccharides include 2'-fucosyllactose, 3-fucosyllactose, 2',3-difucosyllactose, lacto-N-triose II, lacto-N-tetraose, lacto-N-neotetraose, lacto-N-fucopentaose I, lacto-N-neofucopentaose, lacto-N-fucopentaose II, lacto-N-fucopentaose III, lacto-N-fucopentaose V, and lacto-N-neofucopentaose. Examples of human milk oligosaccharides include neutral human milk oligosaccharides such as lacto-N-difucohexaose V, lacto-N-difucohexaose I, lacto-N-difucohexaose II, 6'-galactosyllactose, 3'-galactosyllactose, lacto-N-hexaose, and lacto-N-neohexaose, and acidic human milk oligosaccharides such as 3'-sialyllactose, 6'-sialyllactose, 3-fucosyl-3'-sialyllactose, and disialyl-lacto-N-tetraose. Any one of these human milk oligosaccharides may be used alone, or two or more may be used.

[0032] The dietary fiber is preferably a carbohydrate that can be assimilated by one or both of Bifidobacterium bacteria and lactic acid bacteria. Examples of the dietary fiber include plant-derived carbohydrates and bacterial-derived carbohydrates. The carbohydrate is preferably one or both of polysaccharides and oligosaccharides (approximately 2 to 9 sugar residues). The dietary fiber is preferably water-soluble, and more specifically, one or both of polysaccharides and oligosaccharides soluble in water at approximately 4 to 30°C are more preferred. The dietary fiber is preferably one that is resistant to digestion by human enzymes. More specific examples of the dietary fiber include oligosaccharides such as galactooligosaccharides, fructooligosaccharides, soybean oligosaccharides, xylooligosaccharides, isomaltooligosaccharides, raffinose, lactulose, coffee bean mannooligosaccharides, and gluconic acid, as well as dietary fibers such as polydextrose, inulin, xylan, arabinan, pectin, galactan, cellulose, soybean fiber, dextrin, and dextran. These dietary fibers can be used alone or in combination of two or more.

[0033] The sweetener is not particularly limited, but examples thereof include saccharides such as isomerized sugar (so-called high fructose glucose liquid), sugar (so-called sucrose), glucose, fructose, lactose, maltose, palatinose, fructooligosaccharides, galactooligosaccharides, and raffinose; sugar alcohols such as sorbitol, mannitol, maltitol, xylitol, erythritol, and lactulose; natural sweeteners such as glycyrrhizin, stevioside, rebaudioside, sweet tea extract, and sweet tea extract; and artificial sweeteners such as saccharin, sucralose, acesulfame potassium, and aspartame. These sweeteners may be used alone or in combination. The sweeteners may also be used as nutritive substances. Furthermore, when preparing a low-calorie or non-calorie fermented composition, low-calorie or non-calorie sweeteners such as the artificial sweeteners described above may be used.

[0034] The stabilizer is not particularly limited, but examples thereof include high methoxyl pectin, sodium carboxymethylcellulose, and soybean polysaccharides. One or more stabilizers selected from the group consisting of these can be used. Soybean polysaccharides are polysaccharides obtained from soybeans, and their main component is hemicellulose. The stabilizer may be a commercially available product. Examples of commercially available stabilizers include high methoxyl pectin (SM-666, manufactured by San-Ei Gen F.F.I.), sodium carboxymethylcellulose (Cellogen FZ (product name), manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), and soybean polysaccharides (SM-1200, manufactured by San-Ei Gen F.F.I.), but are not particularly limited thereto. From the viewpoint of storage stability, it is preferable that the fermented composition contains a stabilizer. The content of the stabilizer can be appropriately adjusted depending on the form of the fermented composition and the type of stabilizer used. The content of the stabilizer is, for example, 0.05 to 0.30% by mass relative to the total mass of the fermented composition.

[0035] The flavor component is not particularly limited, and any component usable for flavoring and aromatizing beverages can be used. Examples of the flavor component include teas such as coffee, black tea, green tea, roasted green tea, bancha tea, sencha tea, and oolong tea, as well as extracts thereof; fruit juices such as citrus fruits (lemon, orange, etc.), apple, grape, strawberry, pineapple, banana, pear, peach, plum, blueberry, melon, guava, mango, acerola, and papaya; vegetable juices such as tomato and carrot, as well as powders and flavors thereof. These flavor components can be used alone or in combination of two or more.

[0036] <Characteristics of the fermented composition> The whey protein content is preferably 0.8% by mass or more and 1.3% by mass or less, based on the total mass of the fermented composition. When the whey protein content is equal to or greater than the lower limit, the vinegar flavor tends to be more excellent. When the whey protein content is equal to or less than the upper limit, the balance between the vinegar flavor and the milky taste tends to be better.

[0037] The mass ratio of whey protein to the total mass of proteins in the fermented composition is preferably 40% by mass or more, more preferably 60% by mass or more, even more preferably 80% by mass or more, and preferably 87% by mass or less, more preferably 85% by mass or less, and even more preferably 83% by mass or less. When the mass ratio of whey protein is above the lower limit, the appearance and physical properties become clean and the taste becomes more like a vinegar drink. When the mass ratio of whey protein is below the upper limit, the flavor balance between the milky taste and the vinegar taste tends to be better.

[0038] The content of bifidobacteria is 1.0 x 10 viable bacteria per 1 g of the fermented composition. ６ CFU / g or more is preferred, and 1.0 x 10 ７ CFU / g or more is more preferable, and 1.0 x 10 ８ CFU / g or more is more preferable, and 1.0 x 10 ９ The upper limit of the content of bifidobacteria is not particularly limited, but for example, 1.0 × 10 １０CFU / g or less, and even 5.0 x 10 １０ CFU / g or less. When the content of bifidobacteria is equal to or greater than the lower limit, the amount of acetic acid produced by bifidobacteria through fermentation during production of the fermentation composition is easily controlled to 250 mg / 100 g or more. The viable cell count (CFU / g) is determined by appropriately diluting the fermentation composition, culturing it in an appropriate medium, and counting the number of colonies that appear. Details are as described in the Examples below. CFU stands for colony forming unit.

[0039] The content of lactic acid bacteria is 1.0 x 10 in terms of the number of live bacteria per 1 g of the fermented composition. ７ CFU / g or more is preferred, and 5.0 x 10 ７ CFU / g or more is more preferable, and 1.0 x 10 ８ CFU / g or more is more preferable, and 2.0 x 10 ８ The upper limit of the content of lactic acid bacteria is not particularly limited, but for example, 2.0 × 10 ９ CFU / g or less, and even 1.0 x 10 ９ CFU / g or less.

[0040] When the fermentation composition contains Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus, the total content of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus is 1.0 x 10 in terms of the number of viable bacteria per 1 g of the fermentation composition. ７ CFU / g or more is preferred, and 5.0 x 10 ７ CFU / g or more is more preferable, and 1.0 x 10 ８ CFU / g or more is more preferable, and 2.0 x 10 ８ The upper limit of the total content of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus is not particularly limited, but for example, 2.0 × 10 ９ CFU / g or less, and even 1.0 x 10 ９CFU / g or less. When the total content of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus is equal to or more than the lower limit, the stability of the fermentation time tends to be better.

[0041] When the fermentation composition contains Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus, the ratio of the viable cell count of bifidobacteria to the total viable cell count of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus (viable cell count of bifidobacteria:total viable cell count of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus) is preferably 10:1 to 900:1, more preferably 10:1 to 500:1, even more preferably 10:1 to 250:1, and particularly preferably 10:1 to 125:1. When this ratio is within the above range, the survival rate of bifidobacteria increases, and the amount of acetic acid produced tends to increase.

[0042] The acetic acid content is 250 mg / 100 g or more, preferably 300 mg / 100 g or more, and more preferably 350 mg / 100 g or more, as a mass of acetic acid per 100 g of the fermented composition. The upper limit is not particularly limited, but is, for example, 500 mg / 100 g. When the acetic acid content is equal to or greater than the lower limit, the flavor becomes similar to that of a vinegar drink.

[0043] The content of vinegar is preferably 0.1% by mass or less, more preferably 0.05% by mass or less, and particularly preferably 0% by mass, relative to the total mass of the fermented composition. That is, it is particularly preferable that the fermented composition does not contain vinegar.

[0044] When the fermentation composition contains yeast extract, the content of the yeast extract in terms of solid content is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, even more preferably 0.03% by mass or more, and preferably 0.10% by mass or less. When the content of the yeast extract is equal to or greater than the lower limit, the amount of acetic acid produced tends to be better. When the content of the yeast extract is equal to or less than the upper limit, the flavor tends to be better.

[0045] The solid content of the fermentation composition is preferably less than 11% by mass, more preferably 10% by mass or less, and preferably 7.0% by mass or more, more preferably 8.0% by mass or more, and even more preferably 9.0% by mass or more, based on the total mass of the fermentation composition. When the solid content is less than the upper limit, the stability of physical properties tends to be better. When the solid content is more than the lower limit, the number of bifidobacteria and the amount of acetic acid produced tend to be better.

[0046] The fermented composition may be in any form, such as liquid, semi-solid, or solid. Specific examples of fermented compositions include, but are not limited to, yogurts, cheese, cream, dairy drinks, lactic acid bacteria drinks, and supplements. The fermented composition is preferably a fermented food or drink, more preferably a fermented liquid diet or fermented drink, and particularly preferably a fermented drink. Examples of fermented drinks include, but are not limited to, yogurt drinks and lactic acid bacteria drinks. The fermented composition is preferably a chilled food or drink, more preferably a chilled fermented liquid diet or chilled fermented drink, and particularly preferably a chilled fermented drink. In the present invention, "chilled" means refrigerated storage at 10°C or below (specifically, 0 to 10°C). Generally, a high water content in a composition tends to reduce the viable cell count and survival rate of bacteria. However, in this embodiment, even a fermented liquid diet or fermented drink with a high water content can maintain a high viable cell count and survival rate of bifidobacteria when stored in a refrigerator.

[0047] [Method for Producing Fermented Composition] The fermented composition of this embodiment can be produced, for example, by adding bifidobacteria and lactic acid bacteria to a raw material composition containing whey protein and fermenting until the acetic acid content reaches at least 250 mg / 100 g. The bifidobacteria and lactic acid bacteria added to the raw material composition are live bacteria and function as fermentation bacteria. In another aspect, the method for producing the fermented composition of this embodiment includes adding bifidobacteria and lactic acid bacteria to a raw material composition containing whey protein and fermenting until the acetic acid content relative to the total mass of the raw material composition, the bifidobacteria, and the lactic acid bacteria reaches at least 250 mg / 100 g. After fermentation, it is preferable not to perform sterilization such as heat sterilization or membrane sterilization so as not to impair the survival rate of bifidobacteria.

[0048] <Preparation of Raw Material Composition> The raw material composition can be prepared, for example, by mixing a whey protein-containing raw material, water, and, if necessary, other ingredients. The raw material composition typically does not contain acetic acid. The raw material composition preferably contains yeast extract in order to shorten the fermentation time required to reach the target acetic acid content. The amount of each raw material to be added is determined depending on the composition of the final fermented composition to be obtained.

[0049] After mixing, the resulting raw material composition is homogenized, heat sterilized, and cooled as necessary. Homogenization can be carried out by conventional methods. For example, a method using a homogenizer to homogenize the raw material composition at a temperature of 65 to 80°C and a pressure of 5 to 25 MPa can be exemplified, but is not limited to, these. Heat sterilization can be carried out by conventional heat sterilization methods. Sterilization can be carried out using a heat sterilization device such as a plate sterilizer, a tubular sterilizer, a direct heating sterilizer, or a jacketed tank. Sterilization can be carried out, for example, by heating to 80 to 150°C, or by heating to 80 to 120°C. The cooling temperature may be any temperature at which the bifidobacteria and lactic acid bacteria added to the raw material composition can survive, for example, 30 to 40°C.

[0050] Fermentation: Bifidobacteria and lactic acid bacteria are added to the raw material mixture and the mixture is cultured at a predetermined temperature, whereby fermentation proceeds. During this process, the bifidobacteria produce acetic acid, and the acetic acid content increases over time.

[0051] The method of adding bifidobacteria and lactic acid bacteria to the raw material mixture is not particularly limited, and they can be added in the form of bacterial powder or culture. The bacterial powder is a powdered product obtained by growing bacteria in an appropriate medium, separating them by centrifugation, mixing them with a freeze-drying protection agent, freeze-drying them, pulverizing the dried product, and then mixing it with a triturating agent as needed. The bacterial powder is 1 x 10 １１ It is preferable to use bacterial powder with a bacterial concentration of CFU / g or more. A culture is a liquid composition obtained by growing bacteria in an appropriate medium. As a culture, it is preferable to use a culture in which bacteria have been grown from the late logarithmic growth phase to the stationary phase, in order to promote efficient bacterial growth thereafter. As a guideline, a concentration of 1 x 10 ８ It is preferable to use a culture with a bacterial concentration of CFU / g or more. The temperature of the raw material mixture when adding bifidobacteria and lactic acid bacteria may be, similar to the cooling temperature described above, a temperature at which bifidobacteria and lactic acid bacteria can survive, for example, 30 to 40°C.

[0052] The culture temperature (i.e., fermentation temperature) may be within a range in which bifidobacteria and lactic acid bacteria can grow efficiently, and is preferably about 30 to 50°C, more preferably about 34 to 38°C. Fermentation may be carried out until the acetic acid content relative to the total mass of the raw material composition, Bifidobacterium bacteria, and lactic acid bacteria is at least 250 mg / 100 g. In other words, fermentation may be carried out until the acetic acid content relative to the total mass of the fermented composition is at least 250 mg / 100 g. The preferred range for the acetic acid content is as described above. From the viewpoint of the acetic acid content, the fermentation time is preferably 6 hours or more, more preferably 7 hours or more, and from the viewpoints of the viability of bifidobacteria and the productivity of the fermented composition, it is preferably 11 hours or less, more preferably 10 hours or less.

[0053] <Other Steps> After fermentation, the obtained fermented product may be used as a fermented composition as is, or other components may be added to form a fermented composition. For example, when a stabilizer is added to enhance the storage stability of the fermented composition, the stabilizer can be added before and / or after fermentation. The stabilizer may be dissolved in water and added in the form of an aqueous solution.

[0054] The obtained fermentation composition may be filled into a container to form a container-packed fermentation composition. Packaging the fermentation composition in a container facilitates low-temperature storage, such as refrigeration or freezing, and thus facilitates stable storage over long periods of time. Furthermore, even when the fermentation composition has a high water content, such as in a liquid or semi-liquid state, a decrease in the viable cell count and survival rate of bifidobacteria can be suppressed over a longer period of time. The container is preferably one with low oxygen permeability, and in particular, a paper container composed of a laminate having a paper base material and an oxygen barrier layer, a glass container, or a plastic container (e.g., made of polypropylene, polyethylene terephthalate (PET), polystyrene, or polyethylene) is preferred. An example of the oxygen barrier layer of the paper container is a layer of ethylene-vinyl alcohol copolymer (EVOH). The capacity of the container is not particularly limited, but may be, for example, 80 to 1000 mL, or even 350 to 1000 mL.

[0055] [Effects] The fermented composition of this embodiment contains whey protein, bifidobacteria, lactic acid bacteria, and acetic acid. The acetic acid content is 250 mg / 100 g or more relative to the total mass of the fermented composition, resulting in a vinegar drink-like flavor. The fermented composition of this embodiment also exhibits good bifidobacterial viability and productivity. Generally, bifidobacteria grow poorly in milk-based media and have poor survival rates under acidic conditions. Therefore, when fermenting a raw material composition containing whey protein with bifidobacteria, increasing the amount of acetic acid produced to a level that would result in a vinegar drink-like flavor can require a long fermentation time or can reduce the viability of the bifidobacteria. In this embodiment, the use of lactic acid bacteria in combination can increase the amount of acetic acid produced by bifidobacteria, achieving an acetic acid content of 250 mg / 100 g or more relative to the total mass of the fermented composition in a fermentation time comparable to conventional methods without compromising the viability of the bifidobacteria. The above effects are particularly excellent when yeast extract is further contained, or when the ratio of the viable cell count of bifidobacteria to the total viable cell count of Lactobacillus bulgaricus and Streptococcus thermophilus is 10: 1 to 900: 1. Furthermore, since the fermented composition of this embodiment contains bifidobacteria and lactic acid bacteria and has excellent viability of bifidobacteria, it can be expected to have probiotic effects that are beneficial to human health, such as intestinal regulation, mineral absorption promotion, and prevention and improvement of inflammatory bowel disease.

[0056] The present invention will be described in more detail below using examples. However, the present invention is not limited to these examples. Unless otherwise specified, "%" and "parts" mean "% by mass" and "parts by mass", respectively. "E + n" in the number of bacteria is "×10 ｎ ", for example, "E+09" means "×10 ９ The viable cell count of lactic acid bacteria (L. lactis and lactic acid bacteria (1)) was determined by measuring the number of lactic acid bacteria using a plate count agar medium containing BCP.

[0057] <Measurement of Acetic Acid Content> The acetic acid content was measured using high-performance liquid chromatography (HPLC). The specific measurement method and HPLC conditions are as follows. [Measurement Method] (1) Sodium acetate (special grade, ≥98.5%, Kanto Chemical Co., Inc.) was dissolved in water to prepare a standard stock solution of 1.0 mg / mL acetic acid. This standard stock solution was diluted with water to prepare standard solutions of 0.5, 0.2, and 0.01 mg / mL. (2) Approximately 2 g of sample was accurately weighed, 5 mL of 5% perchloric acid was added, and the solution was mixed and then diluted to 50 mL with water. After the volume was adjusted to the required volume, the solution was filtered through a membrane filter (pore size 0.45 μm) to obtain the test solution. (3) 10 μL of each of the standard solution and test solution was injected into the HPLC. The acetic acid in the test solution was identified (qualified) based on the peak retention time of the acetic acid in the standard solution, and the peak height of acetic acid was measured. (4) A calibration curve was created from the peak height and concentration of the standard solution measured in (3) above. (5) The acetic acid concentration in the test solution was determined from the peak height obtained from the test solution and the calibration curve, and the content was calculated using the following formula: Acetic acid content (g / 100g) = S x V / W x D / 10 S: acetic acid concentration in the test solution (mg / mL) V: fixed volume of test solution (mL) W: sample amount (g) D: dilution ratio of the test solution

[0058] [HPLC conditions] Detector: Electrical conductivity meter Column: Shim-pack SCR-102H x 2, φ8.0 mm x 300 mm [Shimadzu Corporation] Column temperature: 45°C Mobile phase: 5 mmol / L p-toluenesulfonic acid Reaction solution: 5 mmol / L p-toluenesulfonic acid containing 0.1 mmol / L EDTA and 20 mmol / L Bis-TriS Flow rate: Mobile phase 0.8 mL / min, reaction solution 0.8 mL / min

[0059] <Method for Measuring Viable Bacterial Count of Bifidobacteria> The viable count of bifidobacteria was measured using TOS propionic acid agar medium (manufactured by Yakult Pharmaceutical Co., Ltd.). The specific measurement method is described below. [Measurement Method] (1) Medium Preparation: TOS propionic acid agar medium was prepared according to the manufacturer's protocol and stored at 48°C until use. The prepared medium was used only on that day. (2) Mupirocin Solution Preparation: Mupirocin lithium salt (manufactured by Merck) was dissolved in water to prepare a 1 mg / mL aqueous solution, which was then sterilized by filtration using a sterilization filter with a pore size of 0.22 μm or less. (3) Dilution Solution Preparation: 2.25 g of sodium chloride, 0.105 g of potassium chloride, 0.06 g of calcium chloride (anhydrous), 0.05 g of sodium bicarbonate, and 1000 mL of distilled water were mixed and sterilized by heating at 121°C for 15 minutes to prepare a ¼-strength Ringer's solution, which was then stored at room temperature or below until use. (4) Homogenization of the sample: The sample was shaken repeatedly to thoroughly mix the contents. (5) Preparation of the first dilution: 10 g of the homogenized sample was aseptically placed in a sterilized container, and sterilized dilution solution was added to make 100 mL. The container was then sealed and shaken 10 times. (6) Preparation of the 10-fold dilution: 1 mL of the first dilution was sampled and added to 9 mL of sterilized dilution solution and mixed thoroughly. These procedures were repeated until 30 to 300 colonies were obtained per Petri dish. (7) Inoculation and cultivation: 1 mL of the solution prepared in (6) above was dispensed into two or more sterilized Petri dishes per sample. 5% of the mupirocin solution was added to TOS propionic acid agar medium kept at 48°C and stirred to distribute the mupirocin evenly. 12 to 15 mL of this medium was poured into the Petri dishes containing the diluted samples. The Petri dish was gently stirred to ensure uniformity of the diluted solution and medium, and then placed on a flat table and left to stand until the medium solidified. After the medium solidified, the Petri dish was placed in an anaerobic culture device (Hirasawa Corporation, device name: Teha type Anaerobox ANX-3) as quickly as possible. The process from the start of dilution to the addition of medium was completed within 45 minutes. The culture was performed anaerobically at 37°C for 72±3 hours. (8) Counting and Calculation The number of colonies on plates that produced 30 to 300 colonies was counted.The average value obtained by multiplying the colony count by the dilution factor was taken as the viable cell count of bifidobacteria.

[0060] <Sensory evaluation of flavor> Nine panelists evaluated the vinegar flavor, milky flavor, appearance and physical properties of the fermented composition on a 5-point scale from 1 to 5, and the average of the ratings from each panelist was calculated. "Vinegar flavor" 5: Has a strong, tingly sour taste typical of a vinegar drink. 4: Has a tingly sour taste typical of a vinegar drink. 3: Has a sour taste typical of a vinegar drink. 2: Does not have much of a flavor (sourness) typical of a vinegar drink. 1: Has almost no flavor (sourness) typical of a vinegar drink. "Milkiness" 5: Has a strong, milky taste (mild flavor) typical of yogurt. 4: Has a milky taste (mild flavor) typical of yogurt. 3: Has a slight milky taste typical of yogurt. 2: Does not have much of a milky taste typical of yogurt. 1: Does not have a milky taste typical of yogurt. "Appearance and physical properties" 5: In terms of appearance and physical properties, the taste is clean and refreshing, with a strong flavor typical of a vinegar drink. 4: In terms of appearance and physical properties, it has a clean mouthfeel and a flavor typical of a vinegar drink. 3: In terms of appearance and physical properties, it has a somewhat clean mouthfeel and a slightly vinegar drink flavor. 2: In terms of appearance and physical properties, it does not feel very refreshing and does not taste like a vinegar drink. 1: In terms of appearance and physical properties, it does not feel refreshing and does not taste like a vinegar drink.

[0061] <Ingredients> Whey powder: manufactured by Morinaga Milk Industry Co., Ltd., whey protein content 12.5%. Skim milk powder: manufactured by Morinaga Milk Industry Co., Ltd., whey protein content 6.8%, casein protein content 27.2%. Yeast extract: powder, Fuji Foods Co., Ltd., product name "Yeast Extract 21-NYP". Pectin: San-ei Gen F.F.I., product name "SM-MN-2779". Bifidobacterium: manufactured by Morinaga Milk Industry Co., Ltd., Bifidobacterium longum BB536 (NITE BP-02621 strain) bacterial culture. L. lactis: Lactococcus lactis, isolated from Bifidus Yogurt Sweetened Type (product name, manufactured by Morinaga Milk Industry Co., Ltd.). Lactic acid bacteria (1): a mixed culture of Streptococcus thermophilus (S. thermophilus) and Lactobacillus bulgaricus (L. bulgaricus) (manufactured by Danisco).

[0062] <Test Example 1> This test was carried out for the purpose of evaluating the influence of the acetic acid content and the ratio of whey protein to the total mass of protein on the flavor of the fermented composition.

[0063] [Preparation of Fermented Composition] Using a mixer, the amounts of whey powder, skim milk powder, and sodium carbonate shown in Table 1, 0.04 parts of yeast extract, and room temperature water were mixed and dissolved by heating to 70°C. The amount of water was adjusted so that the total amount of raw material composition became 100 parts. The resulting raw material solution was homogenized using a homogenizer at a pressure of 15 MPa, heat-sterilized at 90°C for 10 minutes, and cooled to 38°C. Bifidobacterium, L. lactis, and lactic acid bacteria (1) were added thereto so that the cell counts of these bacteria after fermentation would be the values ​​shown in Table 1, thereby obtaining a raw material composition. The resulting raw material composition was fermented at 38°C for 6 to 10 hours, and then cooled to 10°C or below to terminate the fermentation. The pH of the fermented product immediately before the termination of fermentation was shown in Table 1 as the acidity after fermentation. A previously prepared sterilized aqueous pectin solution (pectin concentration: 1%) was added to the obtained fermented product (sour milk), and the mixture was homogenized using a homogenizer (pressure: 15 MPa) to obtain fermented compositions (Examples 1 to 4) that were mixtures of sour milk in which the milk protein curd had been crushed and the pectin solution. The amount of pectin solution added was such that the pectin content was 0.1% relative to the total mass of the fermented composition. The viscosity of the fermented product after mixing with the pectin solution at 10°C was measured using a B-type viscometer. The results are shown in Table 1 as B-type viscosities.

[0064] The resulting fermented composition was stored at 10°C, and the amount of acetic acid was measured by the method described above. In addition, the viable cell count of bifidobacteria was measured by the method described above on the day after production (initial test). The results are shown in Table 1.

[0065]

[0066] As shown in Table 1, it was confirmed that a higher ratio of whey protein to protein tends to result in a cleaner mouthfeel and a stronger vinegar drink-like flavor.

[0067] <Test Example 2> This test was carried out for the purpose of evaluating the effect of the amount of yeast added on the amount of acetic acid produced.

[0068] [Preparation of Fermented Composition] Using a mixer, 9.5 parts whey powder, 0.5 parts skim milk powder, 0.07 parts sodium carbonate, yeast extract, and room temperature water were mixed and heated to 70°C to dissolve. The yeast extract was added in an amount such that the yeast extract content in the raw material composition would be the value shown in Table 1. The water was added in an amount such that the total raw material composition would be 100 parts. The resulting raw material solution was homogenized using a homogenizer at a pressure of 15 MPa, heat-sterilized at 90°C for 10 minutes, and cooled to 38°C. Bifidobacterium, L. lactis, and lactic acid bacteria (1) were added to the mixture so that the bacterial counts of these bacteria after fermentation would be the values ​​shown in Table 2, thereby obtaining a raw material composition. The resulting raw material composition was fermented at 38°C for 7 to 10 hours, cooled to below 10°C, and fermentation was stopped to obtain fermented compositions (Examples 5 to 8). The pH of the fermented product immediately before the stop of fermentation was shown in Table 2 as the acidity after fermentation.

[0069] The resulting fermented composition was stored at 10°C, and the amount of acetic acid was measured by the method described above. The viable cell count of bifidobacteria was also measured by the method described above on the day after production (initial test) and 20 days later (D+20). The results are shown in Table 2.

[0070]

[0071] As shown in Table 2, it was confirmed that the inclusion of yeast extract increased the amount of acetic acid produced during fermentation.

[0072] <Test Example 3> This test was carried out for the purpose of evaluating the effect of the ratio of bifidobacteria to lactic acid bacteria (1) in the final fermentation product on the survival rate of bifidobacteria and the amount of acetic acid produced.

[0073] [Preparation of Fermented Composition] Using a mixer, 8.5 parts of whey powder, 0.5 parts of skim milk powder, 0.06 parts of sodium carbonate, 0.04 parts of yeast extract, and room temperature water were mixed and heated to 70°C to dissolve. The amount of water was adjusted to 100 parts of the raw material composition. The resulting raw material solution was homogenized using a homogenizer at a pressure of 15 MPa, heat-sterilized at 90°C for 10 minutes, and cooled to 38°C. Bifidobacterium, L. lactis, and lactic acid bacteria (1) were added thereto so that the bacterial counts of these bacteria after fermentation were the values ​​shown in Table 3, to obtain a raw material composition. The resulting raw material composition was fermented at 38°C for the fermentation time shown in Table 3, and then cooled to 10°C or below to stop the fermentation. The pH of the fermented product immediately before the stop of fermentation was shown in Table 3 as the acidity after fermentation. A previously prepared sterilized aqueous pectin solution (pectin concentration: 1%) was added to the obtained fermented product (sour milk), and the mixture was homogenized using a homogenizer (pressure: 15 MPa) to obtain fermented compositions (Examples 9 and 10) that were mixtures of sour milk in which the milk protein curd had been crushed and the pectin solution. The amount of pectin solution added was such that the pectin content was 0.1% of the total mass of the fermented composition.

[0074] The resulting fermented composition was stored at 10°C, and the amount of acetic acid was measured using the method described above. The viable cell count of bifidobacteria was also measured using the method described above on the day after production (initial test) and 18 days later (D+18). The results are shown in Table 3.

[0075]

[0076] As shown in Table 3, Example 10, in which the ratio of the viable cell count of bifidobacteria (initial test) to the viable cell count of lactic acid bacteria (1) was within the range of 10:1 to 900:1, produced acetic acid equivalent to that of Example 9 in a shorter fermentation time than Example 9. Furthermore, the ratio of the viable cell count of the initial test to the viable cell count of bifidobacteria D+18 was approximately 0.1% in Example 9 and approximately 8.3% in Example 10, indicating that Example 10 had superior survival of bifidobacteria during storage.

Claims

1. A fermented composition comprising whey protein, Bifidobacterium, lactic acid bacteria and acetic acid, wherein the content of the acetic acid is 250 mg / 100 g or more relative to the total mass of the fermented composition.

2. The fermented composition of claim 1, further comprising yeast extract.

3. The fermented composition according to claim 2, wherein the content of the yeast extract in terms of solid content is 0.01% by mass or more relative to the total mass of the fermented composition.

4. The content of the Bifidobacterium genus bacteria is 1.0 x 10 ６ The fermentation composition of claim 1 , wherein the fermentation composition has a cell count of 1000 or more CFU / g.

5. The lactic acid bacteria include at least Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus, and the total content of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus is 1.0 x 10 ７ The fermentation composition of claim 4, wherein the fermentation composition has a CFU / g or higher.

6. The fermentation composition according to claim 4, wherein the lactic acid bacteria comprise at least Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus, and the ratio of the viable cell count of the Bifidobacterium bacteria to the total viable cell count of the Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus is 10:1 to 900:

1.

7. The fermentation composition according to claim 5 or 6, further comprising Lactococcus lactis subsp. lactis as the lactic acid bacterium.

8. The fermented composition according to claim 1, wherein the whey protein content is 0.8 to 1.3% by mass relative to the total mass of the fermented composition.

9. The fermented composition according to claim 7, wherein the ratio of the mass of the whey protein to the total mass of proteins is 60% by mass or more.

10. The fermented composition according to claim 1, wherein the vinegar content is 0.1% by mass or less based on the total mass of the fermented composition.

11. A method for producing a fermented composition, comprising adding Bifidobacterium bacteria and lactic acid bacteria to a raw material composition containing whey protein, and fermenting the composition until the acetic acid content relative to the total mass of the raw material composition, the Bifidobacterium bacteria, and the lactic acid bacteria reaches at least 250 mg / 100 g.

12. The method of claim 11, wherein the raw material composition further comprises yeast extract.

Images