Fermentation composition and method for producing the same

Abstract

To provide a fermentation composition which includes viable cells such as lactic acid bacteria at a constant concentration (cfu / mL) or more, whose pH is a neutral region and in which "increase in acidity and acid odor", "decrease in pH" and / or "decrease in viable cell concentration (cfu / mL) such as lactic acid bacteria" during refrigerated storage after production are suppressed and to provide a production method of the fermentation composition.SOLUTION: The invention relates to a fermentation composition which includes (a) 1×106cfu / mL or more of one or more viable cells of bacteria selected from a group consisting of lactic acid bacteria and Bifidobacterium bacteria, (b) milk raw material and / or a fermented product of the milk raw material and (c) dead bacterial cells of Lactococcus bacillus and whose pH is 6.0 to 7.4, and a production method of the fermentation composition.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a fermentation composition containing live lactic acid bacteria and Bifidobacterium bacteria (hereinafter also referred to as "bifidobacteria," and hereinafter collectively referred to as "lactic acid bacteria, etc.") at a certain concentration (cfu / mL) or higher, and having a neutral pH, wherein the fermentation composition suppresses "increase in sourness and sour odor," "decrease in pH," and / or "decrease in the concentration of live lactic acid bacteria, etc. (cfu / mL)" during refrigerated storage after production, and to a method for producing the same. [Background technology]

[0002] Fermented milk and other fermented compositions obtained by fermenting dairy ingredients with lactic acid bacteria are not only nutritious foods rich in protein and calcium, but also contain lactic acid bacteria and their metabolites, which are expected to have various physiological effects and have been attracting increasing attention in recent years. Known physiological effects include improved immunity, alleviation of allergic diseases, improvement of autonomic nervous system function, and prevention and improvement of lifestyle-related diseases. Furthermore, lactic acid bacteria with superior functional effects are being widely researched, and consumer preference for actively consuming such superior lactic acid bacteria in foods and beverages such as fermented milk and lactic acid bacteria drinks has been increasing even more in recent years.

[0003] Fermented compositions such as fermented milk and lactic acid bacteria beverages are all manufactured by fermenting milk or other ingredients with live bacteria such as lactic acid bacteria. However, in such fermented compositions, although the acidity is not very strong immediately after the product is manufactured (for example, immediately after the milk raw materials have been fermented and cooled), during refrigerated storage after the product is manufactured (for example, refrigerated storage during the distribution process), the live lactic acid bacteria further produce lactic acid and acetic acid, causing the pH to decrease and the acidity and sour odor to increase. Towards the end of storage, the acidity and sour odor become excessive, resulting in a deterioration of flavor (the so-called "post-acidification problem during refrigerated storage") (see Patent Documents 1 and 2). As a method to improve such post-acid production, for example, Patent Document 1 discloses a method to suppress or reduce subsequent post-acid production by performing maturation in a sub-zero temperature zone after the completion of fermentation in the yogurt manufacturing process, and Patent Document 2 discloses a method to suppress post-acidification of fermented dairy products by using milk with reduced lactose as a raw material. However, these methods also had issues such as lack of simplicity.

[0004] Incidentally, as a technology using dead lactic acid bacteria, Patent Document 3 discloses a method for improving the richness (body) of coffee by incorporating dead lactic acid bacteria into a packaged coffee beverage.

[0005] However, it was previously unknown that adjusting the pH of the fermentation composition to a neutral range and adding dead Lactococcus bacteria would suppress the "increase in sourness and sour odor," "decrease in pH," and / or "decrease in the concentration of live lactic acid bacteria (cfu / mL)" during refrigerated storage of the fermentation composition product after production. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2003-259802 [Patent Document 2] Special Publication No. 2017-522012 [Patent Document 3] Japanese Patent Publication No. 2019-122316 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] The object of the present invention is to provide a fermentation composition containing live bacteria such as lactic acid bacteria at a certain concentration (cfu / mL) or higher and having a pH in the neutral range, wherein the "increase in sourness and sour odor," "decrease in pH," and / or "decrease in the concentration of live bacteria such as lactic acid bacteria (cfu / mL)" during refrigerated storage after production are suppressed, as well as a method for producing the same. [Means for solving the problem]

[0008] The inventors of this invention have conducted diligent studies in order to solve the problems of the present invention, (A) Step A, in which a fermented product is obtained by fermenting a milk raw material for fermentation product preparation with live bacteria of one or more bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria, and this fermented product is added to the milk raw material for fermentation composition production; or, (B) Step B: Adding live bacteria of one or more species selected from the group consisting of lactic acid bacteria and Bifidobacterium species to the milk raw material for the production of a fermentation composition and fermenting it; including, and, (C) By a manufacturing method including step C of adding dead bacteria of the genus Lactococcus, a fermentation composition with a pH of 6.0 to 7.4 can be produced (preferably by further adjusting the pH of the milk raw material for producing the fermentation composition using a pH adjusting agent), and thus the problems of the present invention can be solved, and the present invention has been completed.

[0009] In other words, the present invention is (1)(a) 1 × 10 6 A fermented composition containing (b) live bacteria of one or more species selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria in a concentration of cfu / mL or more, (b) a milk raw material and / or a fermented product of a milk raw material, and (c) dead cells of Lactococcus bacteria, with a pH of 6.0 to 7.4; (2) (A) Step A, in which a fermented product is obtained by fermenting a milk raw material for fermentation product preparation with live bacteria of one or more bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria, and is added to the milk raw material for fermentation composition production; or, (B) Step B: Adding live bacteria of one or more species selected from the group consisting of lactic acid bacteria and Bifidobacterium species to the milk raw material for the production of a fermentation composition and fermenting it; including, and, (C) A fermented composition with a pH of 6.0 to 7.4, produced by a manufacturing method including step C of adding dead cells of Lactococcus bacteria; (3) The content concentration of dead cells of Lactococcus bacteria is 1×10 8 ~1×10 10 cells / g, and the fermentation composition according to (1) or (2) above; (4) The fermentation composition according to any one of (1) to (3) above, wherein the fermentation composition further contains a pH adjuster, or the milk raw material for producing the fermentation composition is a milk raw material to which a pH adjuster is added; (5) The fermentation composition according to any one of (1) to (4) above, wherein the viable cells of one or more bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria are one or more viable cells selected from the group consisting of Lactococcus bacteria, Streptococcus bacteria, Lactobacillus bacteria, and Bifidobacterium bacteria; (6) The fermentation composition according to any one of (1) to (5) above, wherein the difference between the pH of the fermentation composition before refrigerated storage and the pH of the fermentation composition 14 days after refrigerated storage is less than 1; (7) In the method for producing a fermentation composition, (A) Step A of adding a fermented product obtained by fermenting a milk raw material for preparing a fermented product with viable cells of one or more bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria to the milk raw material for producing the fermentation composition; or (B) Step B of adding viable cells of one or more bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria to the milk raw material for producing the fermentation composition and fermenting; comprising, and (C) Step C of adding dead cells of Lactococcus bacteria; comprising characterized in that During refrigerated storage after production of the fermentation composition, the increase in sour taste, acid odor, decrease in pH, and / or decrease in the viable cell content concentration (cfu / mL) of the above-mentioned viable bacteria are suppressed, and the method for producing a fermentation composition with a pH of 6.0 to 7.4; or (8) In the method for producing a fermentation composition, (A) Step A of adding a fermented product obtained by fermenting a milk raw material for preparing a fermented product with viable cells of one or more bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria to the milk raw material for producing the fermentation composition; or (B) Step B of adding viable cells of one or more bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria to milk raw materials for producing a fermentation composition and fermenting them; and comprising (C) Step C of adding dead cells of Lactococcus bacteria; comprising characterized in that In a fermentation composition with a pH of 6.0 to 7.4, a method for suppressing an increase in sour taste, acid odor, a decrease in pH, and / or a decrease in the viable cell concentration (cfu / mL) of the viable cells during refrigerated storage after production of the fermentation composition; relates to.

Effect of the Invention

[0010] According to the present invention, a fermentation composition containing viable cells of lactic acid bacteria or the like at a concentration (cfu / mL) of a certain level or more and having a pH in the neutral range, in which "an increase in sour taste and acid odor", "a decrease in pH", and / or "a decrease in the viable cell concentration (cfu / mL) of viable cells such as lactic acid bacteria" during refrigerated storage after production are suppressed, and a method for producing the same can be provided. In addition, according to the present invention, it is possible to provide a new fermentation composition that appeals to consumers who do not prefer sour taste or acid odor although they wish to ingest a large amount of viable cells of lactic acid bacteria from a health perspective.

Brief Description of the Drawings

[0011] [Figure 1] Figure 1 is a diagram showing the relationship between Lactococcus lactis subsp. lactis JCM5805 strain and strains equivalent to this strain (strains derived from this strain and strains from which this strain is derived).

Modes for Carrying Out the Invention

[0012] The present invention [1](a) 1×10 6A fermented composition containing (b) live bacteria of one or more species selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria in a concentration of cfu / mL or more, (b) a milk raw material and / or a fermented product of a milk raw material, and (c) dead cells of Lactococcus bacteria, with a pH of 6.0 to 7.4; [2] (A) Step A, in which a fermented product is obtained by fermenting a milk raw material for fermentation product preparation with live bacteria of one or more bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria, and is added to the milk raw material for fermentation composition production; or, (B) Step B: Adding live bacteria of one or more species selected from the group consisting of lactic acid bacteria and Bifidobacterium species to the milk raw material for the production of a fermentation composition and fermenting it; including, and, (C) A fermented composition with a pH of 6.0 to 7.4, produced by a manufacturing method including step C of adding dead cells of Lactococcus bacteria; (The fermentation composition described in [1] and the fermentation composition described in [2] above are collectively referred to as "the fermentation composition of the present invention" below.) [3] In a method for producing a fermented composition, (A) Step A, in which a fermented product is obtained by fermenting a milk raw material for fermentation product preparation with live bacteria of one or more bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria, and this fermented product is added to the milk raw material for fermentation composition production; or, (B) Step B: Adding live bacteria of one or more species selected from the group consisting of lactic acid bacteria and Bifidobacterium species to the milk raw material for the production of a fermentation composition and fermenting it; including, and, (C) Includes step C of adding dead cells of Lactococcus bacteria; Characterized by, A method for producing a fermented composition with a pH of 6.0 to 7.4, in which the increase in sourness and sour odor, the decrease in pH, and / or the decrease in the concentration of the viable bacteria (cfu / mL) during refrigerated storage after the production of the fermented composition are suppressed (hereinafter also referred to as "the production method of the present invention"). [4] In a method for producing a fermented composition, (A) Step A, in which a fermented product is obtained by fermenting a milk raw material for fermentation product preparation with live bacteria of one or more bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria, and this fermented product is added to the milk raw material for fermentation composition production; or, (B) Step B: Adding live bacteria of one or more species selected from the group consisting of lactic acid bacteria and Bifidobacterium species to the milk raw material for the production of a fermentation composition and fermenting it; including, and, (C) Includes step C of adding dead cells of Lactococcus bacteria; Characterized by, A method for suppressing the increase in sourness and sour odor, the decrease in pH, and / or the decrease in the concentration of viable bacteria (cfu / mL) during refrigerated storage of a fermented composition with a pH of 6.0 to 7.4 after its production (hereinafter also referred to as "the suppression method of the present invention"). This includes embodiments such as the following.

[0013] (Milk raw material) In this specification, "dairy raw materials" is a concept that encompasses "dairy raw materials," "dairy raw materials for preparing fermented products," and "dairy raw materials for manufacturing fermented compositions" in the present invention, unless otherwise specified. In this specification, "dairy raw materials for preparing fermented products" means "dairy raw materials" used to prepare "fermented products" in this specification, and "dairy raw materials for manufacturing fermented compositions" means "dairy raw materials" used to prepare "fermented compositions" in this specification.

[0014] In this specification, "dairy raw materials" typically include "milk" as defined in the Ministerial Ordinance on Milk and Dairy Products, i.e., milk such as raw milk, cow's milk, special milk, raw goat's milk, pasteurized goat's milk, raw sheep's milk, adjusted milk, low-fat milk, non-fat milk, and processed milk, or materials containing an equivalent or greater amount of non-fat milk solids (i.e., 8% or more), but are not particularly limited as long as they are compositions containing milk components. In this specification, "dairy components" include one or more selected from the group consisting of milk fat derived from "milk" as defined in the Ministerial Ordinance on Milk and Dairy Products, and non-fat milk solids derived from said "milk" (e.g., proteins and / or sugars derived from said "milk").

[0015] The "milk raw material" in this specification can be prepared using milk, dairy products, etc. When using milk and / or dairy products as the "milk raw material", more specifically, it can be prepared using one or more selected from the group consisting of cow's milk, buffalo milk, sheep milk, goat milk, horse milk, condensed milk, skim milk, skim condensed milk, skim milk powder, whole milk powder, cream, butter, buttermilk, sweetened condensed milk, lactose, milk protein concentrate, whey protein concentrate, and water.

[0016] Examples of the "milk raw material" in this specification include those with a solid content concentration of milk components of, for example, 1 to 18% by weight, preferably 2 to 16% by weight, more preferably 4 to 12% by weight, and / or those with a concentration of non-fat milk solids of, for example, 1 to 18% by weight, preferably 2 to 16% by weight, more preferably 2 to 14% by weight, even more preferably 4 to 12% by weight, 6 to 10% by weight, or 7 to 9% by weight, and / or those with a concentration of milk fat of, for example, 0 to 8% by weight, preferably 0.1 to 7% by weight, more preferably 0.5 to 4% by weight, or 1 to 3% by weight.

[0017] (Fermented product of milk raw material) The "fermented product of milk raw material" in this specification means a product obtained by fermenting a milk raw material for fermented product preparation with lactic acid bacteria or the like. Such "fermented product of milk raw material" includes, for example, those with a viable cell concentration of lactic acid bacteria or the like of 1×10 7 cfu / mL or more, preferably 1×10 7 ~1×10 10 cfu / mL. Such "fermented product of milk raw material" can be produced by fermenting a milk raw material for fermented product preparation with viable cells of lactic acid bacteria or the like until the viable cell concentration of lactic acid bacteria or the like reaches 1×10 7 cfu / mL or more, preferably 1×10 7 ~1×10 10 cfu / mL. In addition, for the sake of convenience, the "fermented product of milk raw material" in this specification includes those obtained by isolating only lactic acid bacteria or the like from such a fermented product of milk raw material by centrifugation or the like.

[0018] (Dead cells of Lactococcus bacteria) In this invention, dead cells of Lactococcus bacteria are used. Lactococcus bacteria are classified as lactic acid bacteria. Examples of dead bacteria of the genus Lactococcus include dead bacteria of one or more species selected from the group consisting of Lactococcus bacteria, preferably dead bacteria of one or more species selected from the group consisting of Lactococcus lactis, more preferably Lactococcus lactis subsp. lactis (hereinafter also simply referred to as "Lactococcus lactis"), Lactococcus lactis subsp. lactis biovar diacetylactis, Lactococcus lactis subsp. cremoris, Lactococcus raffinolactis, Lactococcus spiscium, and Lactococcus plantarum. Examples include dead bacterial cells of one or more species selected from the group consisting of Lactococcus plantarum, Lactococcus garvieae, and Lactococcus lactis subsp. hordniae, more preferably dead bacterial cells of Lactococcus lactis, more preferably dead bacterial cells of one or more species selected from the group consisting of Lactococcus lactis JCM5805, Lactococcus lactis JCM20101, Lactococcus lactis NBRC12007, and Lactococcus lactis NRIC1150, and particularly preferably dead bacterial cells of Lactococcus lactis JCM5805.

[0019] With respect to the dead bacterial strains listed herein, equivalent strains are included as long as they possess the effects of the present invention. Here, equivalent strains refer to strains derived from the above strains, strains from which the above strains originate, or progeny strains of those strains. Equivalent strains may also be stored in other bacterial strain preservation institutions. Figure 1 shows strains derived from Lactococcus lactis subspecies lactis JCM5805, and strains from which Lactococcus lactis subspecies lactis JCM5805 originates. Equivalent strains of Lactococcus lactis subspecies lactis JCM5805 shown in Figure 1 can also be used as dead bacterial cells of the present invention as long as they possess the effects of the present invention. In this specification, when referring to Lactococcus lactis subspecies lactis JCM5805 (Lactococcus lactis JCM5805), these equivalent strains are also included.

[0020] In this specification, "dead cells of Lactococcus bacteria" are not particularly limited as long as they are dead cells of Lactococcus bacteria, and may be either dried or non-dried. However, from the viewpoint of storage stability of dead cells, they are preferably dried, and dried powder is a suitable example.

[0021] The method for preparing dead Lactococcus bacteria is not particularly limited. For example, methods include sterilizing the culture medium on which Lactococcus bacteria were cultured, and then collecting the bacteria by filtration, centrifugation, etc., or collecting the bacteria from the culture medium on which Lactococcus bacteria were cultured by filtration, centrifugation, etc., and then sterilizing the medium. Further drying or crushing treatments may be performed as needed. Furthermore, there are no particular restrictions on the sterilization methods; not only heating, but also conventional methods for killing bacteria, such as ultraviolet or gamma ray irradiation, can be used.

[0022] In the present invention, dead Lactococcus bacteria may be added at any step in the production of the fermentation composition. For example, when the fermentation composition in the present invention is produced by a production method including step B, the dead bacteria may be added to the milk raw material for fermentation preparation before the fermentation step of the milk raw material for fermentation preparation, or during the fermentation step of the milk raw material for fermentation preparation, or after the completion of the fermentation step of the milk raw material for fermentation preparation, but it is preferable to add the dead bacteria to the milk raw material for fermentation preparation before the fermentation step of the milk raw material for fermentation preparation, or to add the dead lactic acid bacteria to the milk raw material for fermentation preparation during the fermentation step of the milk raw material for fermentation preparation. Furthermore, when the fermentation composition in the present invention is produced by a production method including step A, dead Lactococcus bacteria may be added to the milk raw material for fermentation preparation, or to the milk raw material for producing the fermentation composition, but it is preferable to add them to the milk raw material for producing the fermentation composition.

[0023] The amount of dead Lactococcus bacteria used in this invention is not particularly limited as long as the effects of the present invention are obtained, but can be expressed in units of the number of dead lactic acid bacteria (cells / g) contained in the fermentation composition, for example, 1 × 10 8 ~1 × 10 10 pieces / g, preferably 5 x 10 8 ~1 × 10 10 The number of pieces / gram is a possible value. The number of dead Lactococcus bacteria in the fermentation composition can be measured by direct microscopy, particle electrophoresis, or PCR.

[0024] (pH) The pH of the fermentation composition in the present invention is 6.0 to 7.4, preferably 6.4 to 7.4. Unless otherwise specified in this specification, the pH of the fermentation composition is the pH of the fermentation composition immediately after production. The pH of the fermentation composition can be measured at 20°C using a known method, for example, a pH meter.

[0025] (pH adjuster) The "fermentation composition" in the present invention does not necessarily have to contain a pH adjuster, but from the viewpoint of obtaining more of the effects of the present invention, it is preferable that it contains a pH adjuster. The pH adjuster is not particularly limited as long as it is usable under the Food Sanitation Act and can adjust pH, but examples include sodium or potassium salts of organic acids such as sodium citrate (trisodium citrate), potassium citrate, sodium bicarbonate, sodium carbonate, potassium bicarbonate, potassium carbonate, disodium hydrogen phosphate, sodium acetate, potassium acetate, sodium L-ascorbate; bases such as sodium hydroxide and potassium hydroxide; and other pH adjusters usable under the Food Sanitation Act, among which trisodium citrate is preferred. One pH adjuster may be used, or two or more may be used in combination.

[0026] When a pH adjuster is included, the concentration of the pH adjuster is not particularly limited and can be adjusted as appropriate depending on the pH to be adjusted. For example, the concentration of the pH adjuster relative to the total amount of the fermentation composition may be 0.01 to 3% by weight or 0.1 to 2% by weight.

[0027] (Live bacteria such as lactic acid bacteria) In this specification, "live bacteria of one or more species selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria" is not particularly limited as long as it is live bacteria of one or more species selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria, but preferably, live bacteria of one or more species (preferably two or more, more preferably three or more) selected from the group consisting of Lactococcus, Streptococcus, Lactobacillus, and Bifidobacterium bacteria, and more preferably, live bacteria of one or more species (preferably one or two) of Lactococcus bacteria and one or more species (preferably one or two) of Streptococcus bacteria; Live bacteria of one or more species (preferably one or two species) of the genus Lactococcus and one or more species (preferably one or two species) of the genus Lactobacillus; or, One or more species (preferably one or two species) of Streptococcus bacteria and one or more species (preferably one or two species) of Lactobacillus bacteria; or, One or more (preferably one or two) live bacteria of the genus Lactococcus; or, One or more (preferably one or two) live bacteria of the genus Streptococcus; or, Examples include live bacteria of one or more species (preferably one or two species) of the genus Lactobacillus; more preferably, live bacteria of one or more species (preferably one or two species) of the genus Lactococcus; or live bacteria of one or more species (preferably one or two species) of the genus Streptococcus.

[0028] More specifically preferred embodiments of the live bacteria in the present invention include Lactococcus lactis, Lactococcus lactis biovariant diacetylactis, Lactococcus lactis subspecies cremoris, Lactococcus raffinolactis, Lactococcus pythium, Lactococcus plantarum, Lactococcus garvieae, and Lactococcus lactis subspecies heldniae, Streptococcus salivarius subsp. thermophilus, Lactobacillus acidophilus, Lactobacillus delbrueckii subsp. bulgaricus, and Lactobacillus delbrueckii subspecies delbrueckii. Lactobacillus delbrueckii subsp. delbrueckii), Lactobacillus delbrueckii subsp. lactis, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus gasseri, Lactobacillus helveticus, Lactobacillus johnsonii, Lactobacillus plantarum, Lactobacillus brevis, Lactobacillus casei subsp. rhamnosusLactobacillus rhamnosus, Lactobacillus pentosus, Lactobacillus fermentum, Bifidobacterium bifidum, Bifidobacterium breve, Bifidobacterium longum subsp. longum, Bifidobacterium longum subsp. infantis, Bifidobacterium animalis subsp. animalis, Bifidobacterium animalis subsp. Examples include one or more (preferably two or more, more preferably three or more) viable bacteria selected from the group consisting of Bifidobacterium lactis, Bifidobacterium adolescentis, Bifidobacterium angulatum, Bifidobacterium catenulatum, and Bifidobacterium pseudocatenulatum. Preferably, one or more (preferably two or more, more preferably three or more) live bacteria selected from the group consisting of Lactococcus lactis, Lactococcus lactis biovariant diacetylactis, Lactococcus lactis subspecies cremoris, Lactococcus raffinolactis, Lactococcus pythium, Lactococcus plantarum, Lactococcus garvieae, Lactococcus lactis subspecies heldniae, and Streptococcus salivarius subspecies thermophilus; or, Lactococcus lactis, Lactococcus lactis biovariant diacetylactis, Lactococcus lactis subspecies cremoris, Lactococcus raffinolactis, Lactococcus pythium, Lactococcus plantarum, Lactococcus garbieae, Lactococcus lactis subspecies heldniae, Lactobacillus acidophilus, Lactobacillus delbrookii subspecies bulgaricus, Lactobacillus delbrookii subspecies lactii Live bacteria of one or more species (preferably two or more, more preferably three or more) selected from the group consisting of Lactobacillus delbrueckii subspecies delbrueckii, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus gasseri, Lactobacillus helveticus, Lactobacillus johnsonii, Lactobacillus plantarum, Lactobacillus brevis, Lactobacillus casei subspecies rhamnosus, Lactobacillus pentosus, and Lactobacillus fermentum; or, Viable bacteria of one or more species (preferably two or more, more preferably three or more) selected from the group consisting of Streptococcus salivarius subspecies thermophilus, Lactobacillus acidophilus, Lactobacillus delbrookii subspecies bulgaricus, Lactobacillus delbrookii subspecies lactis, Lactobacillus delbrookii subspecies delbrookii, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus gasseri, Lactobacillus helveticus, Lactobacillus johnsoni, Lactobacillus plantarum, Lactobacillus brevis, Lactobacillus casei subspecies rhamnosus, Lactobacillus pentosus, and Lactobacillus fermentum; These are some examples.

[0029] (Classification based on the optimal growth temperature for lactic acid bacteria and bifidobacteria) Lactic acid bacteria and bifidobacteria used in the production of fermentation compositions are also classified according to their optimal growth temperature. Generally, lactic acid bacteria with an optimal growth temperature of approximately 25-30°C are called mesophilic bacteria, while those with an optimal growth temperature of 37-45°C are called thermophilic bacteria. Examples of thermophilic bacteria include Lactobacillus acidophilus, Lactobacillus delbruckii subspecies bulgaricus, Lactobacillus delbruckii subspecies lactis, Lactobacillus delbruckii subspecies delbruckii, Lactobacillus gasseri, Lactobacillus helveticus, Lactobacillus johnsoni, Lactobacillus brevis, Lactobacillus casei subspecies rhamnosus, Lactobacillus pentosus, and Streptococcus salivary. Examples of mesophilic bacteria include *Us subspecies thermophilus*, *Bifidobacterium bifidum*, *Bifidobacterium breve*, and *Bifidobacterium longum subspecies longum*. Mesophilic bacteria include, for example, *Lactobacillus casei*, *Lactobacillus paracasei*, *Lactobacillus plantarum*, *Lactococcus lactis subspecies lactis*, *Lactococcus lactis biovariant diacetylactis*, and *Lactococcus lactis subspecies cremoris*. Furthermore, as the lactic acid bacteria etc. used in the present invention, it is also possible to use live bacteria of one or more types of bacteria selected from the above-mentioned groups of thermophilic bacteria and mesophilic bacteria, or to use live bacteria of one or more types of bacteria selected from the above-mentioned group of thermophilic bacteria, and among these, it is preferable to use live bacteria of one or more types of bacteria selected from the above-mentioned group of thermophilic bacteria.

[0030] (How to obtain lactic acid bacteria, etc.) The live bacterial strains of lactic acid bacteria and other bacteria, as well as the dead bacterial strains of lactic acid bacteria used in this invention, can be obtained from depositary institutions such as the American Type Culture Collection (USA). Alternatively, commercially available starter cultures may be used as the live bacterial strains of lactic acid bacteria and other bacteria used in this invention.

[0031] The viable bacterial concentration of lactic acid bacteria, etc., in the fermentation composition of the present invention is 1 × 10⁻⁶ 6 There are no particular restrictions as long as it is above cfu / mL, for example, 1 × 10 6 ~1 × 10 9 cfu / mL or 1 × 10 6 ~5×10 8 A cfu / mL concentration is preferred. The viable bacterial concentration of lactic acid bacteria, etc., can be measured by determining the number of viable lactic acid bacteria, etc., in the fermented composition using methods such as the pour plate method. More specifically, the number of viable lactic acid bacteria in a fermented product can be measured according to the measurement method described in Appendix 2 of the Ministerial Ordinance on Milk and Dairy Products, Section (7) Test Methods for Component Standards of Milk and Dairy Products, (3) Fermented Milk and Lactic Acid Bacteria Beverages, 3. Method for Measuring the Number of Lactic Acid Bacteria.

[0032] The method for adjusting the concentration of live bacteria such as lactic acid bacteria in the fermentation composition in the present invention is not particularly limited. If the method for producing the fermentation composition includes step A, examples include a method for adjusting the concentration of lactic acid bacteria in the fermented product or a method for adjusting the amount of fermented product added. If the method for producing the fermentation composition includes step B, examples include a method for adjusting the amount of live bacteria such as lactic acid bacteria added or a method for adjusting fermentation conditions such as the fermentation time.

[0033] (Fermented composition) In this specification, "fermented composition" means a composition whose manufacturing process includes either (A) step A, in which a fermented product obtained by fermenting a milk raw material for fermentation with live bacteria of one or more species of bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium species is added to the milk raw material for manufacturing the fermented composition, or (B) step B, in which live bacteria of one or more species of bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium species are added to the milk raw material for manufacturing the fermented composition and fermented, and whose pH is 6.0 to 7.4, preferably 6.4 to 7.4. In this specification, "fermented composition" includes, but is not limited to, "fermented milk," "dairy product lactic acid bacteria beverage," "lactic acid bacteria beverage," and "food products mainly made from milk" as defined in the "Ministerial Ordinance Concerning Standards for Ingredients of Milk and Dairy Products" (hereinafter referred to as the "Milk and Dairy Products Ordinance"). For example, "fermented milk" as defined in the Milk and Dairy Products Ordinance refers to milk such as raw milk, cow's milk, special milk, raw goat's milk, pasteurized goat's milk, raw sheep's milk, adjusted milk, low-fat milk, non-fat milk, and processed milk; or dairy products such as cream, butter, cheese, and condensed milk; or food products mainly made from milk; which are fermented with lactic acid bacteria or yeast to become solid (hard type), paste (soft type), or liquid (drink type), or frozen. However, "fermented composition" in this specification is not limited to such fermented milk as defined in the Milk and Dairy Products Ordinance. Furthermore, the term "foods primarily made from milk, etc." in this specification includes, as long as any of the manufacturing processes includes process (B) or (A) described above and the pH is between 6.0 and 7.4, not only "foods primarily made from milk, etc." as defined in the Ministerial Ordinance on Milk, etc., but also foods primarily made from "milk" and / or "dairy products such as cream, butter, cheese, condensed milk, powdered milk, and fermented milk." Examples of such "foods primarily made from milk, etc." include sour cream.

[0034] The definitions and ingredient standards for fermented milk and other dairy products in the Ministerial Ordinance are as follows: In the Ministerial Ordinance on Milk and Dairy Products, fermented milk is defined as "milk or milk products containing an equivalent or greater amount of non-fat milk solids fermented with lactic acid bacteria or yeast, resulting in a paste-like or liquid form, or frozen form thereof." The component standards are "8% or more of non-fat milk solids, 10 million or more lactic acid bacteria or yeast counts (per 1 ml), and negative for coliform bacteria." In this specification, the unit for lactic acid bacteria count or bifidobacteria count is expressed in CFU (colony forming unit). Furthermore, the Ministerial Ordinance on Milk and Dairy Products defines a dairy product lactic acid bacteria beverage as "a beverage (excluding fermented milk) that is processed from milk or other dairy products fermented with lactic acid bacteria or yeast, or that uses such products as its main ingredient." Its ingredient standards are "3% or more non-fat milk solids, 10 million or more lactic acid bacteria or yeasts per 1 mL, and negative for coliform bacteria." Furthermore, the Ministerial Ordinance on Milk and Dairy Products defines lactic acid bacteria beverages, which are foods that use milk and dairy products as their main ingredients, as "beverages that are processed from milk and dairy products fermented with lactic acid bacteria or yeast, or beverages that use milk and dairy products as their main ingredient (excluding fermented milk)." The ingredient standards are "less than 3% non-fat milk solids, 1 million or more lactic acid bacteria or yeast counts (per 1 mL), and negative for coliform bacteria."

[0035] The "fermented composition" in the present invention may contain stabilizers, sweeteners, dietary fiber, vitamins, minerals, flavorings, etc., to the extent that it does not impair the effects of the present invention. The above-mentioned stabilizers are not particularly limited and include, for example, carrageenan and xanthan gum. The above-mentioned sweeteners are not particularly limited and include, for example, sugars, sugar alcohols, high-intensity sweeteners, etc., and one or more of these sweeteners can be used in combination. Furthermore, if the "fermented composition" in the present invention contains a stabilizer, such stabilizer may be present in an amount of 0.01 to 0.5% by weight or 0.1 to 0.3% by weight relative to the total amount of the fermented composition. In addition, the "fermented composition" in the present invention may contain agar and gelatin, and the total amount of agar and gelatin (dry weight) may be present in an amount of 0.1 to 1% by weight or 0.2 to 0.5% by weight relative to the total amount of the fermented composition.

[0036] The "fermented composition" in the present invention preferably includes a non-fat milk solids concentration of, for example, 1 to 18% by weight, preferably 2 to 16% by weight, more preferably 2 to 14% by weight, even more preferably 4 to 12% by weight, 6 to 10% by weight, or 7 to 9% by weight, and / or a milk fat concentration of, for example, 0 to 8% by weight, preferably 0.1 to 7% by weight, more preferably 0.5 to 4% by weight, or 1 to 3% by weight.

[0037] The fermentation composition in this invention is preferably packaged in a container. "Packaged" means that the product has been filled into a container and sealed. The container is preferably one commonly used in the production of fermented milk, such as plastic, glass, or paper containers.

[0038] (Method for producing the fermented composition of the present invention) The present invention relates to a method for producing a fermented composition, (A) Step A, in which a fermented product is obtained by fermenting a milk raw material for fermentation product preparation with live bacteria of one or more bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria, and this fermented product is added to the milk raw material for fermentation composition production; or, (B) Step B: Adding live bacteria of one or more species selected from the group consisting of lactic acid bacteria and Bifidobacterium species to the milk raw material for the production of a fermentation composition and fermenting it; including, and, (C) A manufacturing method comprising step C of adding dead cells of Lactococcus bacteria, wherein the pH of the fermented composition produced is 6.0 to 7.4, preferably 6.4 to 7.4, and is not particularly limited as long as the manufacturing method is such that.

[0039] The above-mentioned step A is not particularly limited as long as it is a step A in which a fermented product, obtained by fermenting a milk raw material for fermentation product preparation with live bacteria of one or more bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria, is added to a milk raw material for fermentation composition production. There are no particular restrictions on the amount of fermented product to be added, obtained by fermenting milk raw materials for fermentation preparation. However, when fermented product obtained by fermenting milk raw materials for fermentation preparation is added to milk raw materials for fermentation composition production, the concentration of viable bacteria such as lactic acid bacteria in the milk raw materials for fermentation composition production should be, for example, 1 × 10⁻⁶. 6 cfu / mL or higher, preferably 1 × 10⁶ 6 ~1 × 10 9 cfu / mL or 1 × 10 6 ~5×10 8 A preferred amount to add is one that results in a concentration of cfu / mL.

[0040] If the manufacturing method of the present invention includes step A, it may or may not include a step of fermenting the milk raw material for the production of the fermented composition after step A. Note that fermentation may gradually progress during refrigerated storage after the production of the fermented composition, but such fermentation is not included in the fermentation step as defined herein. If the process includes a step of fermenting the milk raw materials for the fermented composition after step A, the fermentation can be carried out in a relatively short time such that the pH of the fermented composition does not fall below 6. Furthermore, if the manufacturing method of the present invention includes step A, in addition to adding the fermented product, live bacteria such as lactic acid bacteria may be separately added to the milk raw material for preparing the fermented product.

[0041] The above-mentioned step B is not particularly limited as long as it is a step B in which one or more live bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria are added to the milk raw material for the production of the fermentation composition and fermented. There are no particular restrictions on the amount of live bacteria, such as lactic acid bacteria, that can be added, and it can be adjusted as appropriate. The fermentation temperature and time can be appropriately set by a person skilled in the art, depending on the optimal growth temperature and growth rate of the lactic acid bacteria used, or the type of fermented composition and product design. While there are no particular limitations on the fermentation time, a fermentation time such that the pH of the fermented composition is 6.0 to 7.4, preferably 6.4 to 7.4, is recommended. Examples of such fermentation times include 1 to 10 hours and 1 to 6 hours.

[0042] The milk raw materials for producing the fermentation composition in steps A and B described above are not particularly limited as long as they are milk raw materials as specified herein, but from the viewpoint of obtaining more of the effects of the present invention, it is preferable that they further contain a pH adjuster. When a milk raw material for the production of a fermented composition contains a pH adjuster, the concentration of the pH adjuster is not particularly limited and can be adjusted as appropriate depending on the pH to be adjusted. For example, the concentration of the pH adjuster relative to the total amount of the fermented composition may be 0.01 to 3% by weight or 0.1 to 2% by weight. The pH of the milk raw material for the production of the fermented composition is not particularly limited, but 7 to 8.5 is preferred.

[0043] The above-mentioned step C is not particularly limited as long as it is a step C in which dead cells of the genus Lactococcus are added. As mentioned above, dead Lactococcus bacteria may be added at any stage in the production of the fermentation composition. For example, the dead bacteria may be added to the milk raw material before the fermentation process, during the fermentation process, or after the fermentation process is completed. However, it is preferable to add the dead bacteria to the milk raw material before the fermentation process or to add the dead lactic acid bacteria to the milk raw material during the fermentation process. In addition, the dead cells of Lactococcus bacteria may be added to the milk raw material alone, or they may be added to the milk raw material together with other raw materials. Furthermore, in this specification, adding dead cells of Lactococcus bacteria to the milk raw material also includes, for convenience, adding the milk raw material to the dead cells of Lactococcus bacteria. It is also preferable to mix after adding the dead cells of Lactococcus bacteria. Furthermore, in this invention, when adding dead cells of Lactococcus bacteria, it is preferable to sterilize the milk raw material to which the cells are to be added, the milk raw material during fermentation, or the fermented composition after fermentation beforehand.

[0044] (Other optional steps) The manufacturing method of the present invention may include any other step in addition to steps A and C, or step B or C. Such optional steps include filling a container with a fermentation composition or milk raw materials for preparing a fermented product. If the manufacturing method of the present invention includes step B (fermentation step), examples include a method in which milk raw materials for fermentation preparation (or live bacteria such as lactic acid bacteria) are filled into a container and then fermented (so-called post-fermentation type), or a method in which milk raw materials for fermentation composition production are fermented with lactic acid bacteria, etc., the resulting curd is crushed and filled into a container (so-called pre-fermentation type). On the other hand, if the manufacturing method of the present invention includes step A, examples include a method of simultaneously or sequentially filling a container with a fermented product obtained by fermenting a milk raw material for fermentation preparation and a milk raw material for manufacturing a fermented composition, or a method of filling a container with a milk raw material for manufacturing a fermented composition to which a fermented product obtained by fermenting a milk raw material for fermentation preparation has been added.

[0045] In the manufacturing method of the present invention, the fermented composition is produced so that its pH is 6.0 to 7.4, preferably 6.4 to 7.4. There are no particular limitations on the factors that cause the pH of the fermented composition to fall within this range, but regardless of whether the manufacturing method of the present invention includes step A or step B, one or more factors selected from the group consisting of a lower degree of fermentation compared to general fermented milk, the use of a predetermined amount of pH adjusting agent, and the addition of dead bacteria of the genus Lactococcus may be considered.

[0046] (Inventive suppression method of the present invention) As a method of suppression according to the present invention, in a method for producing a fermentation composition, (A) Step A, in which a fermented product is obtained by fermenting a milk raw material for fermentation product preparation with live bacteria of one or more bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria, and this fermented product is added to the milk raw material for fermentation composition production; or, (B) Step B: Adding live bacteria of one or more species selected from the group consisting of lactic acid bacteria and Bifidobacterium species to the milk raw material for the production of a fermentation composition and fermenting it; including, and, (C) Includes step C of adding dead cells of Lactococcus bacteria; Characterized by, In a fermentation composition with a pH of 6.0 to 7.4, the method is not particularly limited as long as it suppresses an increase in sourness and sour odor, a decrease in pH, and / or a decrease in the concentration of viable bacteria (cfu / mL) during refrigerated storage after the production of the fermentation composition, and may further include other optional steps.

[0047] Steps A to C described above, as well as other optional steps, are the same as those described in the manufacturing method of the present invention.

[0048] (A fermentation composition in which the increase in sourness and sour odor is suppressed.) The fermentation composition of the present invention is preferably a fermentation composition in which the increase in sourness and sour odor during refrigerated storage after production of the fermentation composition is suppressed. In this specification, a fermentation composition in which the increase in sourness and sour odor is suppressed is defined as a fermentation composition in which the increase in sourness and sour odor is suppressed compared to a fermentation composition produced using the same type of milk raw material and the same manufacturing method (hereinafter also referred to as "control fermentation composition in the present invention"), except that no dead lactic acid bacteria are added and / or no pH adjusters (preferably one or more pH adjusters selected from sodium or potassium salts of organic acids and bases) are added (preferably, the pH of the milk raw material for producing the fermentation composition is not adjusted to 7 or higher).

[0049] The degree to which the sourness and sour odor increase during refrigerated storage after the production of a fermentation composition, and how this degree of increase compares to that of the control fermentation composition in the present invention (e.g., whether it is suppressed), can be easily and clearly determined by a trained panel. General methods can be used for evaluation criteria and for summarizing evaluations among the panel members. The number of panel members evaluating the degree of increase in sourness and sour odor in a fermentation composition may be one, but from the viewpoint of obtaining a more objective evaluation, the minimum number of panel members can be set to, for example, three or more, preferably five or more, and from the viewpoint of conducting the evaluation test more simply, the maximum number of panel members can be set to, for example, seven or less. When there are two or more panel members, the evaluation of the degree of increase in sourness and sour odor in a fermentation composition may be based on the average of the evaluations of all panel members regarding the degree of increase in sourness and sour odor in that fermentation composition.

[0050] (Fermentation composition in which pH decrease is suppressed) The fermentation composition of the present invention is preferably a fermentation composition in which the decrease in pH during refrigerated storage after production of the fermentation composition is suppressed. In this specification, a fermentation composition in which the decrease in pH is suppressed compared to the "control fermentation composition of the present invention" described above.

[0051] In the present invention, a fermented composition in which the decrease in pH is suppressed is preferably a fermented composition in which the degree of decrease in pH of the fermented composition after 14 days of refrigeration, compared to the pH of the fermented composition immediately after production and before refrigeration, is 1 or less, preferably 0.6 or less.

[0052] (A fermented composition in which the decrease in the concentration of live bacteria such as lactic acid bacteria is suppressed.) The fermentation composition of the present invention is preferably a fermentation composition in which the decrease in the content concentration of live bacteria such as lactic acid bacteria is suppressed during refrigerated storage after the production of the fermentation composition. In this specification, a fermentation composition in which the decrease in the content concentration of live bacteria such as lactic acid bacteria is suppressed means a fermentation composition in which the decrease in the content concentration of live bacteria such as lactic acid bacteria is suppressed compared to the "control fermentation composition of the present invention" described above.

[0053] In the present invention, a fermented composition in which the decrease in the content concentration of live bacteria such as lactic acid bacteria is suppressed is preferably a fermented composition in which the content concentration (cfu / mL) of one or more bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria in the fermented composition after 14 days of refrigerated storage is 0.2 times or more, preferably 0.2 to 30 times or 0.2 to 25 times, compared to the content concentration (cfu / mL) of the live bacteria in the fermented composition before refrigerated storage.

[0054] (Store in the refrigerator) In this specification, "refrigerated storage" refers to, for example, a temperature of 1 to 10°C, preferably 4 to 10°C, or 10°C.

[0055] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. [Examples]

[0056] [Test 1: Comparative Example 1] Confirmation of changes in pH and lactic acid bacteria concentration during refrigerated storage The following tests were conducted to investigate the changes in pH and lactic acid bacteria concentration during refrigerated storage of the fermentation composition.

[0057] (method) After adding live Lactococcus bacteria to the substrate (milk raw material for preparing fermented products), fermentation was carried out at 30°C until the bacterial concentration reached an order of 10^9 (cfu / mL) to prepare the fermented product. In all tests of the embodiments of this application, the number of lactic acid bacteria in the fermented product was measured according to the measurement method described in Appendix 2 of the Ministerial Ordinance on Milk and Dairy Products, Section (7) Test Methods for Component Standards of Milk and Dairy Products, (3) Fermented Milk and Lactic Acid Bacteria Beverages, 3. Measurement Method for the Number of Lactic Acid Bacteria.

[0058] Next, 3% or 7% by weight of the aforementioned fermented product (fermented product containing live Lactococcus bacteria at a bacterial concentration of the order of 10^9 (cfu / mL)) was added to the substrate milk (milk raw material for fermentation composition production) and mixed to prepare each fermentation composition sample. Subsequently, each fermentation composition sample was refrigerated and stored at 10°C. pH measurements and live Lactococcus bacteria concentration measurements were performed on each fermentation composition sample "before refrigeration," "14 days after the start of refrigeration," and "28 days after the start of refrigeration." In addition, seven panelists performed sensory evaluations of sourness and sour odor for each fermentation composition sample, and the average evaluation was used as the overall comment for that fermentation composition sample. These results are shown in Table 1 below.

[0059] [Table 1]

[0060] (result) As can be seen from Table 1, in all fermentation composition samples, the pH decreased during refrigeration, and after 14 days of refrigeration, the pH was 1.3 or more lower than before refrigeration. Furthermore, sourness and sour odor were detected after 14 days of refrigeration, and these became even stronger after 28 days of refrigeration. Moreover, in all samples, the viable bacterial concentration of Lactococcus species was higher than the viable bacterial concentration before refrigeration, and this was maintained at both the 14-day and 28-day mark after refrigeration.

[0061] [Test 2: Comparative Example 2] Confirmation of changes in the concentration of viable lactic acid bacteria in a fermented composition with an acidic pH during refrigerated storage. The following tests were conducted to confirm the change in the concentration of viable lactic acid bacteria when a fermentation composition with an acidic pH was stored under refrigeration.

[0062] (method) Live Lactococcus bacteria were added to milk (milk raw material for fermentation composition production), which served as the substrate, and fermented at 30°C until the bacterial concentration reached the order of 10^9 (cfu / mL), preparing a fermentation composition sample with a pH of 4.3. This fermentation composition sample was refrigerated and stored at 10°C. The concentration of live Lactococcus bacteria in the fermentation composition sample was measured "before refrigeration," "14 days after the start of refrigeration," and "28 days after the start of refrigeration." The results are shown in Table 2 below.

[0063] [Table 2]

[0064] (result) The results in Table 2 show that when fermentation composition samples with an acidic pH are stored under refrigeration, the concentration of viable lactic acid bacteria decreases.

[0065] [Test 3: Example 1] Confirmation of the effects of adding dead lactic acid bacteria and pH adjusters on changes in pH and live lactic acid bacteria concentration during refrigerated storage. To investigate the effects of adding dead lactic acid bacteria cells or pH adjusters to fermentation compositions on changes in pH and live lactic acid bacteria concentration during refrigerated storage, the following tests were conducted.

[0066] (method) After adding live Lactococcus bacteria to the substrate (milk raw material for fermentation preparation), fermentation was carried out at 30°C until the bacterial concentration reached the order of 10^9 (cfu / mL) to prepare the fermented product. Next, 1 × 10⁶ dead Lactococcus bacteria are added to the substrate, which is milk (milk raw material for fermentation composition production). 9 After adding the required amount per gram and adjusting the pH by adding 1% by weight of trisodium citrate, a pH adjuster, each fermentation composition sample was prepared by adding and mixing 0.5% by weight, 1.0% by weight, or 1.5% by weight of the aforementioned fermented product (fermented product containing live Lactococcus bacteria at a bacterial concentration of the order of 10^9 (cfu / mL)) and then refrigerating it at 10°C. pH and the concentration of live Lactococcus bacteria were measured for each fermentation composition sample "before refrigeration" and "14 days after the start of refrigeration." In addition, seven panelists performed sensory evaluations of sourness and sour odor for each fermentation composition sample, and the average evaluation was used as the overall comment for that fermentation composition sample. These results are shown in Table 3 below.

[0067] [Table 3]

[0068] (result) As can be seen from Table 3, in all fermentation composition samples, although the pH decreased slightly during refrigeration, the pH remained in the neutral range of 6.4 or higher. In other words, the pH after 14 days of refrigeration decreased by only 0.6 or less compared to before refrigeration. Furthermore, in the fermentation composition samples after 14 days of refrigeration, there was no sourness or sour odor, or only a very faint one. In addition, in all fermentation composition samples, the viable bacterial concentration of Lactococcus species was higher than the viable bacterial concentration before refrigeration, even after 14 days of refrigeration. These findings indicate that adding dead Lactococcus bacteria or pH adjusters suppresses the decrease in pH and the increase in sourness and sour odor during refrigerated storage.

[0069] [Test 4: Example 2] Confirmation of the effect when using other types of lactic acid bacteria The following tests were conducted to confirm whether adding dead Lactococcus bacteria could suppress the "decrease in pH" and the "increase in sourness and sour odor" during refrigerated storage, even when using live Lactococcus species other than Lactococcus.

[0070] Live Streptococcus bacteria were added to the milk substrate (milk raw material for fermentation preparation), and then fermentation was carried out at 40°C until the bacterial concentration reached the order of 10^8 (cfu / mL) to prepare the fermented product. Next, 1 × 10⁶ dead Lactococcus bacteria are added to the substrate, which is milk (milk raw material for fermentation composition production). 9Each fermentation composition sample was prepared by adding and mixing 3% by weight, 6% by weight, and 9% by weight of the aforementioned fermented product (a fermented product containing live Streptococcus lactic acid bacteria at a bacterial concentration of the order of 10^8 (cfu / mL)) and then storing them under refrigeration at 10°C. pH measurements and live Streptococcus lactic acid bacteria concentrations were performed on each sample at "before refrigeration," "14 days after the start of refrigeration," and "28 days after the start of refrigeration." In addition, seven panelists performed sensory evaluations of sourness and sour odor for each fermentation composition sample, and the average evaluation was used as the overall comment for that fermentation composition sample. These results are shown in Table 4 below.

[0071] [Table 4]

[0072] (result) As can be seen from Table 4, in all fermentation composition samples, the pH was maintained in the neutral range of 6.5 or higher during refrigerated storage. Furthermore, no sour taste or sour odor was detected in any of the fermentation composition samples after 14 or 28 days of refrigerated storage. In addition, in all fermentation composition samples, the viable bacterial concentration of Streptococcus lactic acid bacteria was higher than the viable bacterial concentration before refrigerated storage, and this was maintained even after 14 and 28 days of refrigerated storage. These findings indicate that even when live lactic acid bacteria of species other than Lactococcus are used, adding dead Lactococcus bacteria suppresses the "decrease in pH" and the "increase in sourness and sour odor" during refrigerated storage. [Industrial applicability]

[0073] According to the present invention, it is possible to provide a fermentation composition containing live bacteria such as lactic acid bacteria at a certain concentration or higher, and having a pH in the neutral range, in which the "increase in sourness and sour odor," "decrease in pH," and / or "decrease in the concentration of live bacteria such as lactic acid bacteria (cfu / mL)" during refrigerated storage after production are suppressed, as well as a method for producing the same.

Claims

1. (a) 1 x 10 ６ (b) live bacteria of one or more species selected from the group consisting of lactic acid bacteria and Bifidobacterium species, in a concentration of cfu / mL or higher; (c) fermented milk raw materials and / or milk raw materials; and (d) dead Lactococcus bacteria at a concentration of 1 × 10⁸ to 1 × 10¹⁰ cells / g. The pH is 6.0 to 7.4, and The difference between the pH of the fermented composition before refrigeration and the pH of the fermented composition after 14 days of refrigeration is less than 1. Fermentation composition.

2. (A) Step A, in which a fermented product is obtained by fermenting a milk raw material for fermentation product preparation with live bacteria of one or more bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria, and is added to the milk raw material for fermentation composition production; or, (B) Step B of adding live bacteria of one or more species selected from the group consisting of lactic acid bacteria and Bifidobacterium species to milk raw materials for the production of fermentation composition and fermenting them; including, and, (C) Manufactured by a manufacturing method including step C, which involves adding dead Lactococcus bacteria such that the concentration of dead Lactococcus bacteria is 1 × 10⁸ to 1 × 10¹⁰ cells / g; The pH is 6.0 to 7.4, and The difference between the pH of the fermented composition before refrigeration and the pH of the fermented composition after 14 days of refrigeration is less than 1. Fermentation composition.

3. The fermented composition according to claim 1 or 2, wherein the fermented composition further contains a pH adjuster, or the milk raw material for producing the fermented composition is a milk raw material to which a pH adjuster has been added.

4. The fermentation composition according to any one of claims 1 to 3, wherein the viable bacteria of one or more species selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria are one or more viable bacteria selected from the group consisting of Lactococcus, Streptococcus, Lactobacillus, and Bifidobacterium bacteria.

5. In a method for producing a fermented composition, (A) Step A, in which a fermented product is obtained by fermenting a milk raw material for fermentation product preparation with live bacteria of one or more bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria, and is added to the milk raw material for fermentation composition production; or, (B) Step B of adding live bacteria of one or more species selected from the group consisting of lactic acid bacteria and Bifidobacterium species to milk raw materials for the production of fermentation composition and fermenting them; including, and, (C) A step C comprising adding dead Lactococcus bacteria to the fermentation composition such that the concentration of dead Lactococcus bacteria in the fermentation composition is 1 × 10⁸ to 1 × 10¹⁰ cells / g; A method for producing a fermented composition having a pH of 6.0 to 7.4, characterized by the following: The manufacturing method wherein, during refrigerated storage after the production of the fermented composition, an increase in sourness and sour odor, a decrease in pH, and / or a decrease in the concentration of live bacteria (cfu / mL) are suppressed, and the difference between the pH of the fermented composition before refrigerated storage and the pH of the fermented composition 14 days after refrigerated storage is less than 1.

6. In the production of fermentation compositions, (A) Step A, in which a fermented product is obtained by fermenting a milk raw material for fermentation product preparation with live bacteria of one or more bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria, and is added to the milk raw material for fermentation composition production; or, (B) Step B of adding live bacteria of one or more species selected from the group consisting of lactic acid bacteria and Bifidobacterium species to milk raw materials for the production of fermentation composition and fermenting them; including, and, (C) A step C comprising adding dead Lactococcus bacteria to the fermentation composition such that the concentration of dead Lactococcus bacteria in the fermentation composition is 1 × 10⁸ to 1 × 10¹⁰ cells / g; Characterized by, A method for suppressing an increase in sourness, sour odor, a decrease in pH, and / or a decrease in the concentration of live bacteria (cfu / mL) during refrigerated storage of the fermented composition having a pH of 6.0 to 7.4 after its production, The method wherein the difference between the pH of the fermented composition before refrigeration and the pH of the fermented composition 14 days after refrigeration is less than 1.

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