Equol-containing food composition and method for producing same

Abstract

Provided are: an equol-containing food composition capable of further preventing microbial contamination; and a method for producing the equol-containing food composition. Also provided is a method for producing an equol-containing food composition by which the resulting equol can be efficiently recovered. The present invention provides a food composition obtained by a method for producing a liquid food composition, etc. This method for producing a liquid food composition comprises: (A) a step for culturing at least one equol raw material selected from the group consisting of daidzein glycosides, daidzein, and dihydrodaidzein with a microorganism that assimilates the equol raw material and produces equol; and (B) a step for adjusting the pH by adding a pH adjusting agent to the culture solution containing equol obtained in the culturing step, thereby obtaining a liquid food composition containing equol, and a pH-adjusted liquid food composition.

Description

Technical Field

[0001] The present invention relates to a food composition, which is a food composition containing equol and is a liquid food composition with adjusted pH, or a dried product thereof.

[0002] Furthermore, the present invention relates to a method for producing the food composition. Background Art

[0003] Isoflavones, which are abundant in leguminous plants such as soybeans and kudzu, are a type of polyphenols and are flavonoids with isoflavones as the basic skeleton. According to recent research, isoflavones have female hormone effects (estrogen) and antioxidant effects, and the intake of isoflavones has a preventive effect on breast cancer, prostate cancer, osteoporosis, hypercholesterolemia, heart disease, menopausal disorders, etc.

[0004] Isoflavones exist in soybeans, for example, as glycosides covalently bonded to sugars, such as daidzin, glycitin, and genistin, and exist only in a very small amount of aglycones. These glycosides also exist as malonylated and acetylated glycosides. When these glycosides enter the body of a human or animal, they are converted into daidzein, glycitein, and genistein by the action of digestive enzymes or enzymes produced by intestinal bacteria, such as β-glucosidase. Furthermore, it is known that daidzein is enzymatically converted into O-desmethylangolensin (O-DMA) or equol via dihydrodaidzein by the action of intestinal bacteria.

[0005] It is known that equol has the highest estrogenic activity among these metabolites. However, in the case of humans, the metabolism of isoflavones varies from person to person. As mentioned above, few people have intestinal bacteria that can ferment daidzein to produce equol. The rate of equol production is about 50% in Japanese and about 30% in Westerners. Therefore, people who do not have equol-producing bacteria have the problem of not being able to produce equol in their bodies even if they consume legumes such as soybeans.

[0006] In order to overcome these problems, attempts have been made to produce equol in vitro using anaerobic microorganisms such as lactic acid bacteria (Patent Documents 1 to 4), and methods for efficiently producing equol and / or efficiently recovering the produced equol have been sought.

[0007] Patent Document 5 aims to provide a composition containing equol-producing microorganisms, which contains equol-producing microorganisms that maintain the ability to produce equol in a live bacterial state, and can stably maintain the ability to produce equol even after storage, and discloses that a pH adjuster can be added to control the pH (Patent Document 5), but does not disclose a specific pH adjuster. In addition, the pH is adjusted during the anaerobic fermentation step, and the preferred pH is also set to 4.6 or above.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Patent Application Publication No. 2006-204296

[0011] Patent Document 2: Japanese Patent Application No. 2006-504409

[0012] Patent Document 3: Japanese Patent Application Publication No. 2008-61584

[0013] Patent Document 4: Japanese Patent Application Publication No. 2010-104241

[0014] Patent Document 5: Japanese Patent No. 5769419 Summary of the invention

[0015] Problems to be solved by the invention

[0016] Therefore, an object of the present invention is to provide a food composition containing equol and a method for producing the same which can further prevent microbial contamination.

[0017] Furthermore, in addition to or in addition to the above object, an object of the present invention is to provide a method for producing an equol-containing food composition that efficiently recovers the produced equol.

[0018] Solutions for solving problems

[0019] In order to solve the above-mentioned problems, the present inventors have found the following invention.

[0020] <1> A food composition comprising equol, which is a pH-adjusted liquid food composition or a dried product thereof.

[0021] <2> Above <1> The pH is preferably 3 to 5, preferably 3 to 4.

[0022] <3> Above <2> In the composition, the pH is adjusted by selecting one of the group consisting of organic acids and inorganic acids, wherein the organic acid is at least one selected from the group consisting of carbonic acid, bicarbonate, citric acid, succinic acid, fumaric acid, lactic acid, gluconic acid, acetic acid, malic acid, ascorbic acid and benzoic acid, and the inorganic acid is preferably at least one selected from the group consisting of hydrochloric acid, sulfuric acid and phosphoric acid.

[0023] <4> Above <2> Preferably, the composition contains at least one selected from the group consisting of hydrochloric acid, sulfuric acid and phosphoric acid.

[0024] <5> Above <1> The pH is 7 to 11, preferably 10 to 11.

[0025] <6> Above <5> Preferably, the pH of the composition is adjusted by using one selected from the group consisting of hydroxides of alkali metals and hydroxides of alkaline earth metals.

[0026] <7> Above <5> Preferably, the pH of the composition is adjusted by using one selected from the group consisting of sodium hydroxide, potassium hydroxide, calcium hydroxide, calcium oxide and magnesium hydroxide.

[0027] <8> A method for producing a liquid food composition, comprising the steps of obtaining a liquid food composition containing equol and having adjusted pH: (A) culturing at least one equol raw material selected from the group consisting of daidzein glycoside, daidzein and dihydrodaidzein with a microorganism that assimilates the equol raw material to produce equol; and (B) adding a pH adjuster to a culture solution containing the equol obtained in the culturing step to adjust the pH.

[0028] <9> A method for producing a powdered food composition, comprising the following steps to obtain a powdered food composition containing equol and having adjusted pH: (A) a step of culturing at least one equol raw material selected from the group consisting of daidzein glycoside, daidzein and dihydrodaidzein using a microorganism that assimilates the equol raw material to produce equol; (B) a step of adding a pH adjuster to a culture solution containing the equol obtained in the culturing step to adjust the pH; and (C) a step of drying the liquid obtained in the pH adjustment step.

[0029] <10> Above <8> or <9> The adjusted pH is 3 to 5, preferably 3 to 4.

[0030] <11> Above <10> In the embodiment, the pH adjuster has one selected from the group consisting of an organic acid and an inorganic acid, the organic acid is at least one selected from the group consisting of carbonic acid, bicarbonate, citric acid, succinic acid, fumaric acid, lactic acid, gluconic acid, acetic acid, malic acid, ascorbic acid and benzoic acid, and the inorganic acid is preferably at least one selected from the group consisting of hydrochloric acid, sulfuric acid and phosphoric acid.

[0031] <12> Above <10> In the embodiment, the pH adjuster includes at least one selected from the group consisting of inorganic acids including hydrochloric acid, sulfuric acid, and phosphoric acid.

[0032] <13> Above <8> or <9> The adjusted pH is 7 to 11, preferably 10 to 11.

[0033] <14> Above <13> In the embodiment, the pH adjuster is preferably one selected from the group consisting of hydroxides of alkali metals and hydroxides of alkaline earth metals.

[0034] <15> Above <13> In the embodiment, the pH adjuster is preferably one selected from the group consisting of sodium hydroxide, potassium hydroxide, calcium hydroxide, calcium oxide and magnesium hydroxide.

[0035] Beneficial Effects

[0036] According to the present invention, an equol-containing food composition capable of further preventing microbial contamination and a method for producing the same can be provided.

[0037] Furthermore, according to the present invention, in addition to or in addition to the above effects, a method for producing an equol-containing food composition that efficiently recovers generated equol can be provided. DETAILED DESCRIPTION

[0038] The present application provides a method for producing a liquid food composition and a method for producing a powdered food composition, and a powdered food composition as a liquid food composition and a dried product thereof.

[0039] Hereinafter, a method for producing a liquid food composition and a method for producing a powdered food composition will be described, and then a powdered food composition as a liquid food composition and a dried product thereof will be described.

[0040] <Method for producing liquid food composition>

[0041] The method for producing a liquid food composition of the present invention obtains a liquid food composition containing equol and having adjusted pH by comprising the following steps: (A) a step of culturing at least one equol raw material selected from the group consisting of daidzein glycoside, daidzein and dihydrodaidzein using a microorganism that assimilates the equol raw material to produce equol; and (B) a step of adding a pH adjuster to a culture solution containing the equol obtained in the culturing step to adjust the pH.

[0042] <<(A) Process>>

[0043] Step (A) is a step of culturing at least one equol raw material selected from the group consisting of daidzein glycoside, daidzein and dihydrodaidzein, using a microorganism that assimilates the equol raw material to produce equol.

[0044] The conditions and the like of the culture step are not particularly limited as long as equol can be produced. For example, conventionally known conditions can be used, but the culture step is not limited to these conditions.

[0045] <<Equol Raw Materials>>

[0046] The form of the equol raw material used in the method of the present invention is not limited as long as it is literally used as a raw material of equol.

[0047] The equol raw material may contain at least one selected from the group consisting of daidzein glycoside, daidzein and dihydrodaidzein, and its form is not limited. For example, it may be daidzein glycoside itself, daidzein itself, or dihydrodaidzein itself, and substances containing them may also be listed, such as soybeans, soybean processed products, soybean hypocotyls, soybean hypocotyl processed products, such as soybean extracts, soybean hypocotyl extracts, and soybean hypocotyl extract purified products, and specifically, commercially available isoflavones.

[0048] <<Microorganisms>>

[0049] The method of the present invention uses a microorganism having the ability to assimilate an equol raw material to produce equol. It should be noted that in this specification, the "ability to assimilate an equol raw material to produce equol" may be simply referred to as "equol production ability".

[0050] The microorganism having the ability to produce equol used in the method of the present invention is not particularly limited as long as it is a microorganism having the ability to produce equol from the above-mentioned equol raw material.

[0051] It should be noted that the raw material of equol is determined in relation to the "equol production ability" of the microorganism. For example, when a certain microorganism A does not have the "equol production ability" for daidzein glycosides, but has the "equol production ability" for daidzein, the raw material of equol of the microorganism A is "daidzein". In addition, in this case, there may be a step of converting daidzein glycosides into daidzein before step (A). For example, when a certain microorganism B does not have the "equol production ability" for daidzein glycosides and daidzein, but has the "equol production ability" for dihydrodaidzein, the raw material of equol of the microorganism B is "dihydrodaidzein". In addition, in this case, there may be a step of converting daidzein glycosides into daidzein, and further converting daidzein into dihydrodaidzein before step (A).

[0052] Examples of the microorganisms include anaerobic microorganisms, which can produce equol at a temperature of, for example, around 37° C. (eg, 30 to 42° C.).

[0053] It should be noted that the equol production ability can be confirmed by quantitatively measuring daidzein, dihydrodaidzein, equol, etc. in the culture. For these quantitative measurements, those skilled in the art can, for example, perform the measurements based on the records of WO 2012 / 033150, Japanese Patent Application Laid-Open No. 2012-135217, Japanese Patent Application Laid-Open No. 2012-135218, Japanese Patent Application Laid-Open No. 2012-135219, etc. An example of these quantitative methods is shown below.

[0054] For example, ethyl acetate is added to the culture solution, and the solution is centrifuged after vigorous stirring to remove the ethyl acetate layer. The culture solution is subjected to the same operation several times as required, and the ethyl acetate layers are combined to obtain an equol extract. The extract is concentrated and dried under reduced pressure using an evaporator, and dissolved in methanol. The extract is filtered using a membrane such as a polytetrafluoroethylene (PTFE) membrane to remove insoluble matter, and the sample can be used as a high performance liquid chromatography sample. The conditions of high performance liquid chromatography can be exemplified by the following conditions, but are not limited thereto.

[0055] [HPLC Conditions]

[0056] Chromatographic column: Phenomenox Luna 5uC18, 2.0 mm × 150 mm (Shimadzu GLC).

[0057] Mobile phase: water / methanol [55:45, v / v].

[0058] Flow rate: 0.2mL / min.

[0059] Column temperature: 40°C.

[0060] Detection: UV 280nm.

[0061] Retention time: dihydrodaidzein 13.8 minutes, daidzein 19.6 minutes, glycitein 22.5 minutes, equol 25.6 minutes, genistein 35.0 minutes.

[0062] Examples of microorganisms capable of producing equol include microorganisms classified into the following genera, but are not limited to these microorganisms.

[0063] Adlercreutzia spp.

[0064] Bacteroides genus.

[0065] Bifidobacterium spp.

[0066] Clostridium spp.

[0067] Eggerthella genus.

[0068] Enterococcus spp.

[0069] Enterobacter (Enterorhabdus) genus.

[0070] Eubacterium spp.

[0071] Finegoldia spp.

[0072] Lactobacillus genus.

[0073] Lactococcus spp.

[0074] Paraeggerthella spp.

[0075] Pediococcus genus.

[0076] Proteus genus.

[0077] Sharpea spp.

[0078] Slackia spp.

[0079] Streptococcus spp.

[0080] Veillonella spp.

[0081] Specific examples of microorganisms capable of producing equol include the following microorganisms, but are not limited to these.

[0082] Adlercreutzia equolifaciens subsp.celatus.

[0083] Adlercreutzia equolifaciens subsp.equolifaciens.

[0084] Bacteroides ovatus.

[0085] Bifidobacterium breve.

[0086] Bifidobacterium longum.

[0087] Clostridium sp.

[0088] Eggerthella sp.

[0089] Enterococcus faecalis.

[0090] Enterococcus faecium.

[0091] Enterorhabdus mucosicola.

[0092] Eubacterium sp.

[0093] Finegoldia magna.

[0094] Lactobacillus fermentum.

[0095] Lactobacillus mucosae.

[0096] Lactobacillus paracasei.

[0097] Lactobacillus plantarum.

[0098] Lactobacillus rhamnosus.

[0099] Lactobacillus sp.

[0100] Lactococcus garvieae.

[0101] Lactococcus sp.

[0102] Paraeggerthella sp.

[0103] Pediococcus pentosaceus.

[0104] Proteus mirabilis.

[0105] Sharpea azabuensis.

[0106] Slackia equolifaciens.

[0107] Isoflavone-transforming Slackia isoflavoniconvertens.

[0108] Slackia sp.

[0109] Streptococcus constellatus.

[0110] Streptococcus intermedius.

[0111] Veillonella sp.

[0112] Among the microorganisms described above, for example, microorganisms classified into the Eggerthellaceae family, microorganisms classified into the Bifidobacteriaceae family, microorganisms classified into the Clostridiaceae family, microorganisms classified into the Coriobacteriaceae family, microorganisms classified into the Enterococcus family, microorganisms classified into the Eubacteriaceae family, microorganisms classified into the Morganellaceae family, microorganisms classified into the Peptoniphilaceae family, microorganisms classified into the Lactobacillaceae family, microorganisms classified into the Streptococcaceae family, microorganisms classified into the Veillonella family, or similar microorganisms thereof can be listed. Preferred are Adlercreutzia, Bacteroides, Bifidobacterium, Clostridium, Cochleobacterium, Eggerthella, Enterococcus, Eubacterium, Finegoldia, Lactobacillus, Lactococcus, Paraeggerthella, Pediococcus, Proteus, Sharpea, Slackia, Streptococcus, Veillonella, or microorganisms classified as similar microorganisms thereof.More preferably, Adlercreutzia equolifaciens subsp.celatus, Adlercreutzia equolifaciens subsp.equolifaciens, Bacteroides ovatus, Bifidobacterium breve, Bifidobacterium longum, Clostridium sp., Eggerthella sp., Enterococcus faecalis, Enterococcus faecium, Enterohabdus mucosicola, Eubacterium sp., Finegoldia magna, Lactobacillus fermentum, Lactobacillus intestinalis, Lactobacillus mucosae, Lactobacillus paracasei, paracasei), Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacillus sp., Lactococcus garvieae, Lactococcus sp., Paraeggerthella sp., Pediococcus pentosaceus, Proteus mirabilis, Sharpea azabuensis, Slackia equolifaciens, Slackia isoflavoniconvertens, Slackia sp., Streptococcus constellatus, Streptococcus intermedius, and Veillonellasp. are preferred.

[0113] More preferred anaerobic microorganisms include any of the microorganisms described above, particularly any of the microorganisms described below, or similar microorganisms having properties similar to these microorganisms.

[0114] Adlercreutzia equolifaciens subsp.celatus DSM 18785 strains.

[0115] Adlercreutzia equolifaciens subsp.equolifaciens DSM 19450 strains.

[0116] Bacteroides ovatus strain E-23-15.

[0117] Bifidobacterium breve ATCC 15700 strain.

[0118] Bifidobacterium longum BB536 strain.

[0119] Clostridium sp. strain HGH136.

[0120] Eggerthella sp. Julong 732 strain.

[0121] Eggerthella sp. strain YY7918.

[0122] Eggerthella sp. D1 strain.

[0123] Enterococcus faecalis INIA P333 strain.

[0124] Enterococcus faecium strain EPI1.

[0125] Enterohabdus mucosicola Mt1B8 strain.

[0126] Eubacterium sp. strain D2.

[0127] Finegoldia magna EPI3 strain.

[0128] Lactobacillus fermentum DPPMA114 strain.

[0129] Lactobacillus intestinalis KTCT13676BP strain.

[0130] Lactobacillus mucosae strain EPI2.

[0131] Lactobacillus paracasei strain JS1.

[0132] Lactobacillus plantarum DPPMA24W strain.

[0133] Lactobacillus plantarum DPPMASL33 strain.

[0134] Lactobacillus rhamnosus DPPMAAZ1 strain.

[0135] Lactobacillus rhamnosus INIA P540 strain.

[0136] Lactobacillus sp. Niu-O16 strain.

[0137] Lactococcus garvieae strain 20-92.

[0138] Paraella sp. SNR40-432 strain.

[0139] Pediococcus pentosaceus strain CS1.

[0140] Proteus mirabilis strain LH-52.

[0141] Sharpea azabuensis ST18 strain.

[0142] Slackia equolifaciens DSM 24851 strains.

[0143] Isoflavone-transforming Slackia isoflavoniconvertens DSM 2200

[0144] 6 strains.

[0145] Slackia sp. strain FJK1.

[0146] Slackia sp. NATTS strain.

[0147] Slackia sp. strain YIT11861.

[0148] Slackia sp. strain TM-30.

[0149] Streptococcus constellatus strain E-23-17.

[0150] Streptococcus intermedius strain A6G-225.

[0151] Veillonella sp. EP strain.

[0152] It should be noted that the above-mentioned anaerobic microorganisms can be obtained from the depository institutions indicated by their depository numbers. Each depository number indicates that the anaerobic microorganisms are deposited in the following depository institutions.

[0153] FERM Patent Organism Depository; International Patent Organism Depositary (IPOD).

[0154] http: / / unit.aist.go.jp / pod / ci / index.html

[0155] DSM German Collection of Microorganisms and Cell Cultures (DSMZ).

[0156] http: / / www.dsmz.de /

[0157] KCCM Korean Culture Center of Microorganisms.

[0158] In the present invention, anaerobic microorganisms having the ability to produce equol are cultured under conditions suitable for the production of equol. The conditions suitable for the production of equol in the present invention refer to conditions that maintain the survival and activity of anaerobic microorganisms having equol-producing activity. More specifically, it refers to maintaining gas phase conditions (anaerobic conditions) that enable anaerobic microorganisms to survive, and providing nutrients for supporting the activity and proliferation of the anaerobic microorganisms. Various culture medium compositions suitable for the survival of anaerobic microorganisms are well known. Therefore, for anaerobic microorganisms having the above-mentioned equol-producing ability, those skilled in the art can select appropriate culture medium compositions. For example, BHI culture medium manufactured by Difco, culture medium used in the examples, etc. can be used, but are not limited to these.

[0159] A water-soluble organic substance may be added to the culture medium used in the present invention as a carbon source. Examples of the water-soluble organic substance include the following compounds, but are not limited to these compounds.

[0160] Sugars such as sorbitol, fructose, and glucose; alcohols such as methanol; organic acids such as valeric acid, butyric acid, propionic acid, acetic acid, and formic acid, or salts thereof.

[0161] The concentration of the organic matter added to the culture medium as a carbon source can be appropriately adjusted so that the anaerobic microorganisms in the culture medium can grow efficiently.

[0162] A nitrogen source may be added to the culture medium. In the present invention, various nitrogen compounds that can be used for conventional fermentation may be used as the nitrogen source. Preferred inorganic nitrogen sources are ammonium salts and nitrates. More preferred inorganic nitrogen sources are ammonium sulfate, ammonium chloride, ammonium phosphate, ammonium hydrogen phosphate, potassium nitrate and sodium nitrate. On the other hand, preferred organic nitrogen sources are amino acids, yeast extracts, peptones, meat extracts, liver extracts, digested serum, etc. More preferred organic nitrogen sources are arginine, cysteine, cystine, citrulline, lysine, yeast extracts, and peptones.

[0163] Furthermore, in addition to the carbon source and the nitrogen source, other organic or inorganic substances suitable for producing equol may be added to the culture medium. For example, sometimes the proliferation and activity of anaerobic microorganisms can be enhanced by adding cofactors such as vitamins, various inorganic compounds such as salts, etc. to the culture medium. For example, the following can be listed as inorganic compounds, vitamins, and microbial proliferation cofactors derived from animals and plants.

[0164]

[0165]

[0166] As a method for adding these inorganic compounds, vitamins or growth cofactors to prepare a culture solution, a conventionally known method can be used. The culture medium can be liquid, semisolid or solid. In the present invention, the preferred form of the culture medium is a liquid culture medium.

[0167] The culture medium used in the present invention may contain dextrins. If anaerobic microorganisms are cultured in a culture medium containing dextrins, a liquid containing equol and dextrins can be prepared without bringing dextrins into contact with the culture medium again after the culture.

[0168] Dextrins may be added to the medium before or during the cultivation of the microorganisms.

[0169] The culture medium used in the present invention may contain a defoaming agent, preferably soybean oil, more preferably soybean oil to which vitamin E is added.

[0170] In the method of the present application, microorganisms, particularly anaerobic microorganisms, can be cultured according to known microorganism culture methods. In industrial production, a continuous fermentation system that can continuously supply a culture medium and a substrate gas and has a mechanism for recovering the culture product can also be used.

[0171] In the method of the present application, when using anaerobic microorganisms, it is better to prevent oxygen from mixing into the fermentation tank. The fermentation tank can directly utilize a commonly used fermentation tank. By replacing the oxygen mixed into the fermentation tank with an inert gas such as nitrogen, an anaerobic atmosphere can be produced.

[0172] In the step (A) of the present invention, the gas phase is preferably composed of one or more gases containing hydrogen. The gas constituting the gas phase is not particularly limited as long as it is composed of one or more gases containing hydrogen, but it is preferably composed of hydrogen and one or more gases other than hydrogen. Examples of the gas other than hydrogen include carbon dioxide, nitrogen, carbon monoxide, etc., without particular limitation.

[0173] The hydrogen concentration of the gas is not particularly limited, and examples thereof include 30% or less, 10% or less, and 4% or less.

[0174] In addition, the step (A) in the present invention can also be carried out in a closed system such as a bottle or a test tube which is not ventilated but tightly sealed with a rubber stopper.

[0175] In order to efficiently recover equol, the permeation rate of the mixed gas constituting the gas phase into the culture tank can be set to 0.001-2.0 V / V / M gas volume / liquid volume / minute, for example 0.01-2.0 V / V / M gas volume / liquid volume / minute, but is not limited to this.

[0176] Depending on the shape of the culture tank, a stirrer or the like may be used to fully stir the culture medium. By stirring the culture in the culture tank, the opportunity for contact between the culture medium components, the matrix gas and the anaerobic microorganisms can be increased, thereby optimizing the production efficiency of equol. In addition, the matrix gas may also be supplied in the form of nanobubbles.

[0177] In the present invention, the culture of microorganisms can also be carried out under normal pressure. When pressurized, the pressurization conditions are not particularly limited as long as the microorganisms can grow. As preferred pressurization conditions, the range of 0.2 MPa or less, for example, the range of 0.02 to 0.2 MPa can be listed, but it is not limited thereto.

[0178] In order to increase the amount of equol produced, the temperature of the culture tank is not particularly limited, but preferably 30°C to 40°C, more preferably 33°C to 38°C.

[0179] The culture time can be appropriately set according to the amount of equol produced and the amount of isoflavones remaining, etc. For example, 8 to 120 hours, preferably 12 to 72 hours, and particularly preferably 16 to 60 hours can be exemplified, but it is not limited thereto.

[0180] <<(B) Process>>

[0181] The step (B) is a step of adding a pH adjuster to the culture solution containing equol obtained in the step (A), that is, the culturing step, to adjust the pH.

[0182] In step (B), the pH of the culture solution is preferably adjusted to the acidic side, specifically, to 3 to 5, preferably to 3 to 4. By adjusting the pH of the culture solution to the acidic side, specifically, to 3 to 5, especially to 3 to 4, the microorganisms used in step (A) can be easily separated, and the recovery efficiency of equol can be improved.

[0183] In addition, in step (B), the pH of the culture solution is preferably adjusted to the alkaline side, specifically, the pH is adjusted to 7 to 11, preferably 10 to 11. By adjusting the pH of the culture solution to the alkaline side, specifically, by adjusting the pH to 7 to 11, especially 10 to 11, the microorganisms used in step (A) can be dissolved, and the recovery efficiency of equol can be improved.

[0184] In the step (B), when the pH is adjusted to the acidic side, the pH adjuster preferably contains at least one selected from the group consisting of organic acids and inorganic acids.

[0185] Examples of the organic acid include carbonic acid, hydrogen carbonate, citric acid, succinic acid, fumaric acid, lactic acid, gluconic acid, acetic acid, malic acid, ascorbic acid, and benzoic acid, but are not limited thereto.

[0186] In addition, examples of the inorganic acid include hydrochloric acid, sulfuric acid, and phosphoric acid, but are not limited thereto.

[0187] In the step (B), when the pH is adjusted to the alkaline side, the pH adjuster preferably includes one selected from the group consisting of hydroxides of alkali metals and hydroxides of alkaline earth metals.

[0188] Specifically, examples of the pH adjuster for adjusting the pH to the alkaline side include sodium hydroxide, potassium hydroxide, calcium hydroxide, calcium oxide, and magnesium hydroxide, but the pH is not limited to these.

[0189] Through the above-mentioned steps (A) and (B), a liquid food composition can be obtained, but the method of the present invention for obtaining a liquid food composition may also include steps other than the above-mentioned steps (A) and (B). For example, steps for removing microorganisms capable of producing equol, such as a centrifugal separation step and a membrane filtration step, may be cited, but are not limited thereto.

[0190] <Method for producing powdered food composition>

[0191] The present application also provides a method for producing a powdered food composition.

[0192] This method includes the step (C) of drying the liquid obtained in the step (B) of adjusting pH after the steps (A) and (B), thereby obtaining a powdered food composition containing equol and having adjusted pH.

[0193] <<(C) Process>>

[0194] The step (C) is a step of drying the liquid obtained in the pH adjustment step (B).

[0195] (C) The drying step can be performed by a conventionally known method, for example, heat drying, spray drying, freeze drying, fluidized bed drying, fluidized layer drying, etc., but the drying process is not limited to these.

[0196] The heat drying treatment can be performed using, for example, a rotary drum dryer, the spray drying treatment can be performed using, for example, a spray dryer, and the freeze drying treatment can be performed using a freeze dryer. The drying method may be any dryer as long as it can dry a liquid.

[0197] The substance obtained by the drying treatment can be subjected to a pulverization treatment as necessary.

[0198] The method of the present invention may further include steps other than the above-mentioned steps (A), (B) and (C).

[0199] For example, after step (B) and before step (C), there may be a step of heating the liquid obtained in step (B) and a centrifugation step and / or a filtration step of removing unnecessary solid components from the obtained liquid after the heating step. It should be noted that in step (B), when the pH is adjusted to the alkaline side, especially when the pH is adjusted to 10 to 11, there may be no centrifugation step, which is preferred from the perspective of reducing the number of steps.

[0200] When a centrifugation step and / or a filtration step for removing unnecessary solid components is included, a clear liquid can be obtained, and thus the liquid food composition is suitable for use in beverages and the like.

[0201] <Food composition>

[0202] The present application provides a food composition, which is a food composition containing equol and is a liquid food composition after adjusting pH or a dried product thereof.

[0203] The food composition of the present invention can also be obtained by the above method, but is not limited thereto.

[0204] <<Liquid Food Composition>>

[0205] When the liquid food composition is on the acidic side, the pH thereof is preferably 3 to 5, preferably 3 to 4.

[0206] When the liquid food composition is on the alkaline side, the pH thereof is preferably 7 to 11, and preferably 10 to 11.

[0207] <<Dried liquid food composition>>

[0208] The present application also provides a food composition containing equol and a dried product of a liquid food composition having adjusted pH.

[0209] In the dry form, pH is defined as follows.

[0210] That is, the pH when 50 g of the dried product is dissolved or suspended in 1 L of water is within the above range, that is, on the acidic side, the pH is 3 to 5, preferably 3 to 4, or on the alkaline side, the pH is 7 to 11, preferably 10 to 11.

[0211] A glass diaphragm electrode can be preferably used for pH measurement, but a simple electrode such as pH test paper can also be used.

[0212] When the food composition of the present invention is adjusted to the acidic side, the pH is preferably adjusted with one selected from the group consisting of organic acids and inorganic acids.

[0213] In this case, the food composition of the present invention has one selected from the group consisting of an organic acid and an inorganic acid.

[0214] Here, examples of the organic acid include carbonic acid, hydrogen carbonate, citric acid, succinic acid, fumaric acid, lactic acid, gluconic acid, acetic acid, malic acid, ascorbic acid, and benzoic acid, but are not limited thereto.

[0215] In addition, examples of the inorganic acid include hydrochloric acid, sulfuric acid, phosphoric acid, and the like, but are not limited thereto.

[0216] When the food composition of the present invention is adjusted to the alkaline side, the pH is preferably adjusted with one selected from the group consisting of hydroxides of alkali metals and hydroxides of alkaline earth metals.

[0217] In this case, the food composition of the present invention contains one selected from the group consisting of hydroxides of alkali metals and hydroxides of alkaline earth metals.

[0218] Examples of the one selected from the group consisting of hydroxides of alkali metals and hydroxides of alkaline earth metals include sodium hydroxide, potassium hydroxide, calcium hydroxide, calcium oxide, and magnesium hydroxide, but are not limited thereto.

[0219] Hereinafter, the present invention will be described based on examples, but the scope of the present invention is not limited to the following examples.

[0220] Example

[0221] [Example 1]

[0222] (Preparation of pre-culture medium)

[0223] Anaerob Basal Broth (manufactured by Thermo Scientific, catalog number CM0957B) was dissolved in a predetermined amount of distilled water (ABB medium), and 1 L was dispensed into a 2 L pressure fermentation tank. The atmosphere was then replaced with nitrogen and sterilized at 121° C. for 15 minutes.

[0224] (Preparation of formal culture medium)

[0225] The enzyme-treated soybean germ extract (containing aglyconed isoflavones: daidzein, glycitein, and genistein) was added to ABB medium containing β-cyclodextrin at a final concentration of 6 g / L, and 1 L was dispensed into a 2 L fermentation tank. The atmosphere was then replaced with nitrogen and sterilized at 121° C. for 15 minutes.

[0226] (Pre-cultivation)

[0227] Adlercreutzia equolifaciens DSM 19450 strain was inoculated into the preculture medium, and then cultured at 37°C for one day while continuously supplying hydrogen-containing anaerobic gas sterilized by a sterilizing filter (pore size: 0.2 μm, material: polyvinylidene fluoride (PVDF)).

[0228] (Formal training)

[0229] The precultured strain was inoculated into a main culture medium and then cultured at 37°C for two days while continuously supplying an anaerobic gas containing hydrogen sterilized by a sterilizing filter (pore size: 0.2 μm, material: PVDF).

[0230] The production of equol was confirmed by HPLC analysis.

[0231] (pH adjustment process)

[0232] The main culture solution in which the production of equol was confirmed was collected in a glass container, pH was adjusted, and sterilized by heating. For comparison, pH adjustment was not performed, but sterilization was performed by heating.

[0233] 1) Citric acid was added to the main culture solution to lower the pH to 3, 4, or 5, and sterilization was performed by heating.

[0234] 2) In addition, hydrochloric acid was added to the main culture solution to lower the pH to 3, 4, or 5, and sterilization was performed by heating.

[0235] 3) Furthermore, sodium hydroxide was added to the main culture solution to raise the pH to 8, 9, 10, or 11, and sterilization was performed by heating.

[0236] (Confirmation of antibacterial effect)

[0237] The heat sterilized solution obtained in the pH adjustment step was left to stand at room temperature for one week. Then, a portion of the solution was spread equally on a standard agar medium, cultured at 37°C for one day, and the number of colonies was counted.

[0238] The results are shown in Table 1.

[0239] As can be seen from Table 1, in the case of no adjustment, the number of colonies increases to the point where it is impossible to count. On the other hand, the pH adjustment step makes the solution acidic or alkaline, thereby suppressing bacterial growth.

[0240] It is understood that by providing the pH adjustment step of the present invention, the pH-adjusted liquid food composition of the present invention or its dried product can prevent microbial contamination.

[0241] [Table 1]

[0242] Table 1. Colony count results

[0243]

[0244]

[0245] ※1: Too many to count.

[0246] Note: In the table, the values ​​represent the number of colonies.

[0247] [Example 2]

[0248] In Example 1, after the pH adjustment step was carried out, the following steps were carried out.

[0249] (Centrifugal Sedimentation Process)

[0250] The culture solution after heat sterilization was placed in a 2 mL Eppendorf tube, the insoluble components were precipitated using a centrifuge, the supernatant was removed, and the amount of the sediment was confirmed. At this time, the centrifugal separation conditions (speed, time) were changed to observe the effect on the sedimentation.

[0251] The results are shown in Table 2.

[0252] As can be seen from Table 2, when the pH is acidic, the amount of precipitation does not change even if the rotation speed of centrifugal separation is reduced, but at pH 7 or higher, the apparent amount of precipitation increases.

[0253] It was confirmed that pH adjustment affects the separation characteristics in the centrifugal separation step.

[0254] [Table 2]

[0255] Table 2. Precipitation amount (values ​​in the table represent mg)

[0256]

[0257] [Example 3]

[0258] In Example 1, after the pH adjustment step was carried out, the following steps were carried out.

[0259] (Centrifugal Sedimentation Process)

[0260] After pH adjustment, the culture solution after heat sterilization was placed in a 40 mL centrifugal sedimentation tube, and the insoluble components were precipitated using a centrifuge to recover the supernatant.

[0261] (Filtration process)

[0262] The supernatant recovered by centrifugal sedimentation separation was filtered through a PVDF MF membrane (pore size 0.2 μm) to recover the filtrate, and the equol and isoflavones in the filtrate were analyzed by HPLC.

[0263] The results are shown in Table 3.

[0264] As can be seen from Table 3, by setting the pH to alkaline in the pH adjustment step, the isoflavone concentration can be increased, and the recovery rate of isoflavones in the filtrate can be improved. Isoflavones other than equol can also be expected to have physiological activities, so by increasing the isoflavone concentration, effects that cannot be achieved by equol alone can be expected.

[0265] [Table 3]

[0266] Table 3. Filtrate recovery and analysis results

[0267]

[0268] [Example 4]

[0269] In Example 1, after the pH adjustment step was performed, the following drying step was performed.

[0270] In Example 3, after the filtration step was performed, the following drying step was performed.

[0271] (Drying process)

[0272] The filtrate was subjected to freeze drying to recover a powder.

[0273] (Confirmation of antibacterial effect)

[0274] The recovered powder was spread on a petri dish and left to stand at room temperature for one week. Then, a portion of it was used as an agar medium by a pouring method using a standard agar medium, cultured at 37°C for one day, and the number of colonies was counted.

[0275] No colonies were detected in any powder, and it is believed that the antibacterial effect can be maintained even after drying.

[0276] It should be noted that the pH measurement results of the liquid obtained by dissolving or suspending 50 g of the recovered powder in 1 L of water or an equivalent ratio are shown in Table 4. From Table 4, it was confirmed that the pH of the liquid obtained by redissolving the recovered powder (the value of "after drying" in Table 4) was substantially the same as the pH used in the pH adjustment step of Example 1 (the value of "before drying" in Table 4).

[0277] [Table 4]

[0278] Table 4. pH measurement results of recovered powder redissolution

[0279] Before drying 3 4 5 6.6 (no adjustment) 8 9 10 11 After drying 3.1 4.2 5.1 6.7 8.2 9.0 9.9 10.8

[0280] [Example 5]

[0281] The same procedure as in Example 1 was carried out except that Asaccharobacter celatus DSM 18785 was used instead of Adlercreutziaequolifaciens DSM 19450.

[0282] The results are shown in Table 5.

[0283] It can be confirmed from Table 5 that, similarly to Example 1, in the absence of pH adjustment, the number of colonies is so large that it cannot be counted. On the other hand, by the pH adjustment process, the pH becomes acidic or alkaline, thereby inhibiting the proliferation of bacteria. It is known that by providing the pH adjustment process of the present invention, in addition, the liquid food composition or its dried product having adjusted pH of the present invention can prevent microbial contamination.

[0284] [Table 5]

[0285] Table 5. Bacterial count results

[0286]

[0287] ※1: Too many to count.

[0288] Note: In the table, the values ​​represent the number of colonies.

[0289] [Example 6]

[0290] In Example 3, the same procedure as in Example 3 was carried out except that Asaccharobacter celatus DSM 18785 was used instead of Adlercreutziaequolifaciens DSM 19450.

[0291] The results are shown in Table 6.

[0292] As can be seen from Table 6, by making the pH adjustment step alkaline, the isoflavone concentration can be increased, and the recovery rate of isoflavones in the filtrate can be improved. Isoflavones other than equol can also be expected to have physiological activities, so by increasing the isoflavone concentration, effects that cannot be achieved by equol alone can be expected.

[0293] [Table 6]

[0294] Table 6. Filtrate recovery and analysis results

[0295]

[0296] [Example 7]

[0297] (Preparation of pre-culture medium)

[0298] Anaerob Basal Broth (manufactured by Thermo Scientific, catalog number CM 0957B) was dissolved in a predetermined amount of distilled water (ABB medium), and 1 L was dispensed into a 2 L pressure fermentation tank. The atmosphere was then replaced with nitrogen and sterilized at 121°C for 15 minutes.

[0299] (Preparation of formal culture medium)

[0300] After the soybean germs were pulverized, tap water was added to make it 100 g / L, and 1 L was dispensed into a 2 L fermentation tank. Then, enzymes were added, and the mixture was stirred at 50°C overnight to convert the isoflavone glycosides contained therein into aglycones, and then arginine was added to make it 1 g / L, and the gas was replaced with nitrogen, and sterilized at 121°C for 15 minutes.

[0301] (Pre-cultivation)

[0302] Adlercreutzia equolifaciens DSM 19450 strain was inoculated into the preculture medium, and then cultured at 37°C for 1 day while continuously supplying anaerobic gas of hydrogen sterilized by a sterilizing filter (pore size: 0.2 μm, material: polyvinylidene fluoride (PVDF)).

[0303] (Formal training)

[0304] The precultured strain was inoculated into a main culture medium and then cultured at 37°C for two days while continuously supplying an anaerobic gas containing hydrogen sterilized by a sterilizing filter (pore size: 0.2 μm, material: PVDF).

[0305] The production of equol was confirmed by HPLC analysis.

[0306] (pH adjustment process)

[0307] The main culture solution in which the production of equol was confirmed was collected in a glass container, pH was adjusted, and sterilized by heating. For comparison, pH adjustment was not performed and sterilization was performed by heating.

[0308] Furthermore, sodium hydroxide was added to the main culture solution to raise the pH to 8, 9, 10, or 11, followed by heating for sterilization, and the insoluble components were precipitated by a centrifuge to recover the supernatant in the same manner as in Example 3. The precipitate was directly subjected to isoflavone analysis.

[0309] The results are shown in Table 7.

[0310] As can be seen from Table 7, when soybean germ is used as the raw material, equol and isoflavones are also present on the precipitate side, but by setting the pH adjustment process to alkaline, the isoflavone concentration and equol concentration in the precipitate are reduced, and the isoflavone concentration and equol concentration in the supernatant are increased, which can improve the recovery rate of isoflavones.

[0311] Since the recovery rate of equol can be improved and isoflavones other than equol can also be expected to have physiological activities, by increasing the isoflavone concentration, effects that cannot be achieved by equol alone can be expected.

[0312] By removing the water-insoluble soybean germs through centrifugal separation, a clear aqueous solution can be recovered, which can improve the adaptability to beverages and the like.

[0313] [Table 7]

[0314] Table 7. Filtrate recovery and analysis results

[0315]

[0316]

[0317] [Example 8]

[0318] In Example 7, the same procedure as in Example 7 was carried out except that Asaccharobacter celatus DSM 18785 was used instead of Adlercreutziaequolifaciens DSM 19450.

[0319] The results are shown in Table 8.

[0320] It can be seen that, similar to Example 7, when soybean germ is used as the raw material, equol and isoflavones are also present on the precipitate side, but by setting the pH adjustment process to alkaline, the isoflavone concentration and equol concentration in the precipitate are reduced, and the isoflavone concentration and equol concentration in the supernatant are increased, which can improve the recovery rate of isoflavones.

[0321] Since the recovery rate of equol can be improved and isoflavones other than equol can also be expected to have physiological activities, by increasing the isoflavone concentration, effects that cannot be achieved by equol alone can be expected.

[0322] By removing the water-insoluble soybean germs through centrifugal separation, a clear aqueous solution can be recovered, which can improve the adaptability to beverages and the like.

[0323] [Table 8]

[0324] Table 8. Filtrate recovery and analysis results

[0325]

Claims

1. A food composition comprising equol and being a liquid food composition having adjusted pH or a dried product thereof.

2. The food composition according to claim 1, wherein The pH is 3-5.

3. The food composition according to claim 2, wherein The pH of the composition is adjusted by one selected from the group consisting of an organic acid and an inorganic acid, The organic acid is at least one selected from carbonic acid, bicarbonate, citric acid, succinic acid, fumaric acid, lactic acid, gluconic acid, acetic acid, malic acid, ascorbic acid and benzoic acid, The inorganic acid is at least one selected from the group consisting of hydrochloric acid, sulfuric acid, and phosphoric acid.

4. The food composition according to claim 2, wherein The composition comprises at least one selected from the group consisting of hydrochloric acid, sulfuric acid, and phosphoric acid.

5. The food composition according to claim 1, wherein The pH is 7-11.

6. The food composition according to claim 5, wherein The pH of the composition is adjusted by one selected from the group consisting of alkali metal hydroxides and alkaline earth metal hydroxides.

7. The food composition according to claim 5, wherein The pH of the composition is adjusted by one selected from the group consisting of sodium hydroxide, potassium hydroxide, calcium hydroxide, calcium oxide, and magnesium hydroxide.

8. A method for producing a liquid food composition, comprising the steps of obtaining a liquid food composition containing equol and having a pH adjusted therein: (A) a step of culturing at least one equol raw material selected from the group consisting of daidzein glycoside, daidzein and dihydrodaidzein with a microorganism that assimilates the equol raw material to produce equol; and (B) a step of adding a pH adjuster to the culture solution containing equol obtained in the culturing step to adjust the pH.

9. A method for producing a powdered food composition, comprising the steps of obtaining a powdered food composition containing equol and having adjusted pH: (A) a step of culturing at least one equol raw material selected from the group consisting of daidzein glycoside, daidzein and dihydrodaidzein with a microorganism that assimilates the equol raw material to produce equol; (B) a step of adding a pH adjuster to the culture solution containing equol obtained in the culturing step to adjust the pH; and (C) A step of drying the liquid obtained in the pH adjustment step.

10. The method according to claim 8 or 9, wherein: The adjusted pH is 3-5.

11. The method according to claim 10, wherein: The pH adjuster is one selected from the group consisting of an organic acid and an inorganic acid. The organic acid is at least one selected from carbonic acid, bicarbonate, citric acid, succinic acid, fumaric acid, lactic acid, gluconic acid, acetic acid, malic acid, ascorbic acid and benzoic acid, The inorganic acid is at least one selected from the group consisting of hydrochloric acid, sulfuric acid, and phosphoric acid.

12. The method according to claim 10, wherein: The pH adjuster includes at least one selected from the group consisting of inorganic acids including hydrochloric acid, sulfuric acid, and phosphoric acid.

13. The method according to claim 8 or 9, wherein: The adjusted pH is 7-11.

14. The method according to claim 13, wherein: The pH adjuster includes one selected from the group consisting of hydroxides of alkali metals and hydroxides of alkaline earth metals.

15. The method according to claim 13, wherein: The pH adjuster is one selected from the group consisting of sodium hydroxide, potassium hydroxide, calcium hydroxide, calcium oxide, and magnesium hydroxide.

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