JP2022136018A - Fermentation composition having improved shape retentivity, and method for producing the same - Google Patents

Abstract

To provide a fermentation composition having improved shape retentivity, and a method for producing the same.SOLUTION: A fermentation composition includes raw milk material fermented with viable cells of at least one kind of bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria. The fermentation composition may include killed cells of lactic acid bacteria added thereto. There is also provided a method for producing the same.SELECTED DRAWING: None

Description

In the present invention, live bacteria of lactic acid bacteria and Bifidobacterium (hereinafter also referred to as "bifidobacteria". Hereinafter, lactic acid bacteria and bifidobacteria are collectively referred to as "lactic acid bacteria etc.") are used to produce milk. The present invention relates to a fermented composition produced by fermenting raw materials and having improved shape retention, and a method for producing the same.

A fermented composition such as fermented milk obtained by fermenting milk raw materials with lactic acid bacteria is not only a nutritional food containing a large amount of protein and calcium, but also contains metabolites such as lactic acid bacteria, so various physiological effects are expected. and has received increasing attention in recent years. As such physiological effects, effects such as improvement of immunity, improvement of allergic diseases, improvement of autonomic nerve function, prevention and improvement of lifestyle-related diseases, etc. are known. In addition, lactic acid bacteria with excellent specific functional effects have also been extensively studied, and in recent years, there has been an increasing desire among consumers to actively ingest such excellent lactic acid bacteria in food and drink.

Lactobacillus bulgaricus (Lactobacillus delbrueckii subspecies bulgaricus) and Thermophilus (Streptococcus salivarius subspecies thermophilus) are known as lactic acid bacteria suitable for lactic acid fermentation in the production of the fermented composition. At present, these lactic acid bacteria are mainstream as lactic acid bacteria used in the production of fermented compositions such as fermented milk. The combination of Lactobacillus bulgaricus and Lactobacillus thermophilus is mainly used in the production of post-fermented milk called hard yogurt. Fermented milk with high shape retention tends to be obtained as compared with the case of using lactic acid bacteria. However, due to vibrations during transportation of fermented milk products and fluctuations in storage temperature from retailers to consumers, the yogurt structure collapses and the water called whey separates. There was a problem that the product value decreased. Even in the case of soft yoghurt, vibrations and fluctuations in storage temperature may reduce the viscosity and separate the whey, resulting in a decrease in commercial value.

In order to improve such problems, methods using a large amount of food materials such as agar and gelatin and food additives such as stabilizers such as carrageenan and xanthan gum are widely used. If the amount of stabilizer used is increased, the stability of fermented milk tends to improve and whey separation tends to be more suppressed. There are problems with the texture of the resulting fermented milk product, such as having a fragile structure that easily crumbles, and a problem that the flavor of the fermented milk may be reduced depending on the type and amount of the stabilizer used. In addition, considering that consumers tend to avoid food additives as much as possible these days, there is a problem in using many food additives such as stabilizers.
Therefore, attempts have been made to improve the shape retention of fermented milk by using a stabilizer in combination with other means, or by means other than the stabilizer. For example, Patent Document 1 describes a method for producing fermented milk having excellent shape retention and smooth texture by adding whey proteins and milk peptides having thermocoagulability to fermented milk. In Patent Document 2, by adding specific concentrations of gelatin, starch, and guar gum or xanthan gum to fermented milk so that it has a specific viscosity, it has a good texture, moderate viscosity, and shape retention. and methods for producing soft yogurt with stability. In addition, by using mesophilic bacteria of the genus Lactococcus, which are characterized by producing extracellular polysaccharides in the fermentation process and imparting viscosity to fermented milk products, together with thermophilic bacteria such as Bulgaria bulgaricus and Bacillus thermophilus, the production of fermented milk is improved. Methods to improve the stability are also known, but there are many problems in the production method, such as the difference in the optimum fermentation temperature between thermophilic and mesophilic bacteria.

By the way, it is known that the above-mentioned physiological activities of lactic acid bacteria and the like are generally exhibited not only by live bacteria such as lactic acid bacteria but also by dead bacteria (see, for example, Patent Document 3).
In addition, as a technique using dead cells such as lactic acid bacteria, Patent Document 4 discloses that dead cells of lactic acid bacteria or cultures containing dead cells of lactic acid bacteria are added during culturing of lactic acid bacteria to be grown. A method for promoting the growth of lactic acid bacteria to be grown and improving the viability of lactic acid bacteria in products is disclosed. Patent Document 5 discloses a method of blending dead bacteria such as lactic acid bacteria into a packaged coffee beverage. A method for improving the richness (feeling to drink) of coffee is disclosed.

However, when dead cells of lactic acid bacteria are added to a fermented composition such as fermented milk, a fermented composition with improved shape retention, enhanced flavor inherent in milk, and improved smoothness in texture can be obtained. that was previously unknown.

Japanese Patent Application Laid-Open No. 2004-283047 Japanese Patent No. 3811631 JP 2019-216712 A JP-A-2008-5811 JP 2019-122316 A

An object of the present invention is to provide a fermented composition with improved shape retention, a method for producing the same, and the like.

The present inventors have made intensive studies to solve the problems of the present invention. The present inventors have found that the above problems can be solved by fermenting milk raw materials with viable bacteria and adding dead lactic acid bacteria, and have completed the present invention.

That is, the present invention
(1) A fermented composition produced by fermenting a raw milk material with one or more viable bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria,
The fermented composition, characterized in that dead cells of lactic acid bacteria are added;
(2) a group in which one or more live bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium are Lactobacillus, Streptococcus, and Bifidobacterium; The fermented composition according to (1) above, which is one or more viable bacteria selected from and the dead lactic acid bacteria are dead bacteria of the genus Lactococcus; (3) addition The fermented composition according to (1) or (2) above, wherein the dry weight of the dead lactic acid bacteria is 0.2% by weight or less with respect to the total amount of the fermented composition;
(4) The fermented composition according to any one of (1) to (3) above, wherein the content of dead lactic acid bacteria is 1×10 ⁸ to 1×10 ¹⁰ cells/g;
(5) Killed lactic acid bacteria are added to the raw milk material, and the raw milk material is fermented with live bacteria of one or more bacteria selected from the group consisting of lactic acid bacteria and bacteria of the genus Bifidobacterium. The fermented composition according to any one of (1) to (4) above, which is produced by;
(6) The fermentation composition according to any one of (1) to (5) above, wherein the content of exopolysaccharide is 5 to 60 μg glucose equivalent/g;
(7) Viscosity measured by a vibrating viscometer is 50 to 600 mPa s, or
The fermented composition according to any one of (1) to (6) above, wherein the maximum value of the complex elastic modulus measured by a viscoelasticity measuring device is 5×10 ² to 5×10 ³ Pa;
(8) The above (1) to wherein the dairy raw material is milk, the non-fat milk solid content of the dairy raw material is 8% by weight or more, and the milk fat content of the dairy raw material is 0.1% by weight or more. (7) the fermented composition according to any one;
(9) Any one of (1) to (8) above, wherein the one or more live bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria is Streptococcus thermophilus. the fermented composition of;
(10) In the method for producing a fermented composition,
It comprises a step of fermenting a raw milk material with live bacteria of one or more kinds of bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria, and adding dead cells of lactic acid bacteria. a method for producing a fermented composition with improved shape retention; and
(11) in the production of the fermented composition,
It comprises a step of fermenting a raw milk material with live bacteria of one or more kinds of bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria, and adding dead cells of lactic acid bacteria. do,
A method for improving shape retention in a fermented composition;
Regarding.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a fermented composition with improved shape retention, a method for producing the same, and the like.

FIG. 1 is a diagram showing the relationship between the Lactococcus lactis subspecies lactis JCM5805 strain and its equivalent strains (strains derived from and derived from the strain).

The present invention
[1] A fermented composition produced by fermenting a raw milk material with one or more viable bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria,
The fermented composition (hereinafter also referred to as "the fermented composition of the present invention") characterized by the addition of dead lactic acid bacteria;
[2] In the method for producing a fermented composition,
It comprises a step of fermenting a raw milk material with live bacteria of one or more kinds of bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria, and adding dead cells of lactic acid bacteria. a method for producing a fermented composition with improved shape retention (hereinafter also referred to as the "production method of the present invention");
[3] In the production of the fermented composition,
It comprises a step of fermenting a raw milk material with live bacteria of one or more kinds of bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria, and adding dead cells of lactic acid bacteria. do,
A method for improving shape retention in a fermented composition (hereinafter also referred to as "method for improving shape retention of the present invention");
and other embodiments.

(dairy raw material)
The "dairy ingredients" in the present specification typically include "milk" defined in the Ministerial Ordinance on Milk, i.e., raw milk, cow milk, special milk, raw goat milk, sterilized goat milk, raw sheep milk, ingredient adjustment milk, such as cow's milk, low-fat milk, non-fat milk and processed milk, or those containing an equivalent or higher non-fat milk solids content (i.e., 8% or more), especially so long as it is a composition containing a milk component Not restricted. The "milk component" in the present specification includes milk fat derived from "milk" defined in the Ministerial Ordinance for Milk, etc., and non-fat milk solids derived from the "milk" (e.g., proteins and proteins derived from the "milk" / or sugars derived from the "milk"), and for convenience, vegetable fats such as fats derived from soybeans (e.g., fats contained in soymilk), and soybeans One or two or more selected from the group consisting of solids other than fat derived from (e.g., protein contained in soymilk and / or sugar contained in soymilk) are also included, but are defined in the milk ministerial ordinance 1 selected from the group consisting of "milk"-derived milk fat and non-fat milk solids derived from the "milk" (e.g., the "milk"-derived protein and / or the "milk"-derived sugar) A species or two or more species are preferably mentioned.

The "dairy raw material" as used herein can be prepared using milk, dairy products, soy milk, soy milk products, soy raw materials, and the like. When using milk and / or dairy products as "dairy raw materials", more specifically, milk, buffalo milk, sheep milk, goat milk, horse milk, concentrated milk, skim milk, skim concentrated milk, skim milk powder, It can be prepared using one or more selected from the group consisting of whole milk powder, cream, butter, buttermilk, condensed milk, lactose, milk protein concentrate, whey protein concentrate, and water. Further, when using soymilk, soymilk products, soybean raw materials, etc. as the "milk raw material", more specifically, one or two selected from the group consisting of soymilk, soymilk products, soybean raw materials, and water It can be prepared using the above.

As used herein, the "dairy raw material" includes milk components having a solid content concentration of, for example, 1 to 18% by weight, preferably 2 to 16% by weight, more preferably 4 to 12% by weight, and / Or, the concentration of non-fat milk solids is, 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 the concentration of milk fat is, 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. In addition, as a dairy raw material, the concentration of non-fat milk solids is, for example, 8% by weight or more, preferably 8 to 18% by weight, 8 to 16% by weight, 8 to 14% by weight, 8 to 12% by weight, or 8% by weight. ~10% by weight, and/or the concentration of milk fat is, for example, 0.1% by weight or more, preferably 0.1-8% by weight, 0.1-7% by weight, or 0.1-4% Preference is given to milk in % by weight.
In addition, as the "dairy raw material" in the present specification, the concentration of soybean-derived solids other than fat is, for example, 1 to 18% by weight, preferably 2 to 16% by weight, more preferably 2 to 14% by weight, and further preferably 4-12% by weight, 6-10% by weight or 7-9% by weight, and/or the concentration of vegetable fat such as fat derived from soybean is, for example, 0-8% by weight, Preferably 0.1 to 7% by weight, more preferably 0.5 to 4% by weight or 1 to 3% by weight.

(fermented composition)
As used herein, the term "fermented composition" refers to the fermentation of dairy ingredients with live bacteria of one or more bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium in any of the production processes. means including the step of causing The "fermented composition" in the present specification includes, in any of the production processes, fermenting milk raw materials with live bacteria of one or more bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria. For example, as long as it includes the step of allowing the product to be processed, for example, "fermented milk", "dairy lactic acid drink", "lactic acid bacteria Beverages,” “foods mainly made from milk, etc.,” “natural cheeses,” fermented soymilk foods (namagashi), etc., but are not limited to these. For example, "fermented milk" defined in the milk ministerial ordinance includes raw milk, cow's milk, special milk, raw goat's milk, pasteurized goat's milk, raw sheep's milk, ingredient adjusted milk, low-fat milk, non-fat milk, processed milk, etc. milk; and dairy products such as cream, butter, cheese, and condensed milk; and foods made mainly from milk, etc.; (soft type) or liquid (drink type), or a frozen product thereof, but the "fermented composition" in this specification is limited to fermented milk defined in such a milk ministerial ordinance not. In addition, in the present specification, "foods containing milk as a main raw material" include one or more live bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium spp. As long as it includes the process of fermenting, it is not limited to "foods mainly made of milk, etc." specified in the Ministerial Ordinance on Milk, etc., and "milk" and/or "cream, butter, cheese, condensed milk, powdered milk, fermented milk Foods that use dairy products as main ingredients are also included. Sour cream, ricotta and the like are examples of such "foods containing milk as a main raw material".

The definitions and ingredient standards for fermented milk, etc. in the Ministerial Ordinance for Milk, etc. are as follows.
In the Ministerial Ordinance for Milk, etc., fermented milk is defined as "milk or milk containing non-fat milk solids equivalent to or higher than milk, fermented with lactic acid bacteria or yeast, and pasty or liquid, or frozen." It is The ingredient standard is "8% or more non-fat milk solid content, 10 million or more lactic acid bacteria or yeast count (per 1 ml), negative for coliform bacteria". In addition, in this specification, the unit of the number of lactic acid bacteria or the number of bifidobacteria is represented by CFU (colony forming unit).
In addition, in the Ministerial Ordinance for Milk, etc., lactic acid bacteria beverages are defined as “beverages (excluding fermented milk) that are processed or made mainly from milk fermented with lactic acid bacteria or yeast”. Its ingredient standards are "3% or more non-fat milk solids, 10 million or more lactic acid bacteria or yeast count (per 1 mL), negative for coliform bacteria".
In the Ministerial Ordinance on Milk, etc., lactic acid bacteria beverages for foods that use milk as the main ingredient are defined as "beverages (excluding fermented milk) that are processed or made from milk, etc. fermented with lactic acid bacteria or yeast as the main ingredient." is defined as Its ingredient standards are "less than 3% non-fat milk solids, 1 million or more lactic acid bacteria or yeast counts (per 1 mL), negative for coliform bacteria".

The "fermented composition" in the present invention is a method for producing a fermented composition in which one or more live bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria are used to ferment the raw milk material. It can be produced by including steps and adding dead cells of lactic acid bacteria.
As the production method of the present invention, a general method for producing a fermented composition such as fermented milk can be used, except that dead cells of lactic acid bacteria are added. As a general method for producing fermented milk, for example, as a method for producing fermented milk, a method of filling a container with milk raw materials and then fermenting with lactic acid bacteria (so-called post-fermentation type) may be used. is fermented with lactic acid bacteria, the resulting curd is crushed and filled into a container (so-called pre-fermentation type). Fermentation temperature and fermentation time can be appropriately set by those skilled in the art according to the optimum growth temperature and growth rate of the lactic acid bacteria to be used, or the type and product design of the desired fermentation composition. Fermentation time is, for example, 1 to 96 hours, preferably 2 to 72 hours, more preferably 3 to 48 hours. It is not possible to generalize how much the pH of the fermented composition is fermented, because it varies depending on the type of fermented composition, product design, etc. However, when the fermented composition is fermented milk, pH is, for example, 5 or less, preferably 4.8 to 4.5. The pH of the fermented composition can be measured by conventional methods.

In the "fermented composition" of the present invention, in any of the production steps, the raw milk material is fermented with one or more live bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria. comprising a step, and
dead cells of lactic acid bacteria are added, and
The concentration of non-fat milk solids is, for example, 1 to 18% by weight, preferably 2 to 16% by weight, more preferably 2 to 14% by weight, still more preferably 4 to 12% by weight, 6 to 10% by weight, or 7 to 9% by weight. % by weight and/or the milk fat concentration is for example 0-8% by weight, preferably 0.1-7% by weight, more preferably 0.5-4% by weight or 1-3% by weight are preferably included.
In addition, the "fermented composition" in the present invention includes one or more bacteria (preferably Streptococcus thermophilus) selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria in any of the production processes. and
dead cells of lactic acid bacteria are added, and
The concentration of non-fat milk solids is, for example, 8% by weight or more, preferably 8 to 18% by weight, 8 to 16% by weight, 8 to 14% by weight, 8 to 12% by weight, or 8 to 10% by weight, And/or the milk fat concentration is, for example, 0.1% by weight or more, preferably 0.1 to 8% by weight, 0.1 to 7% by weight, or 0.1 to 4% by weight. included.
In addition, the "fermented composition" in the present invention includes one or more live bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria in any of the production processes. comprising a step of fermenting, and
dead cells of lactic acid bacteria are added, and
Soybean-derived solids other than fat concentration is, 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 the concentration of vegetable fat such as soybean-derived fat is, for example, 0 to 8% by weight, preferably 0.1 to 7% by weight, more preferably Preferably included is 0.5 to 4% by weight or 1 to 3% by weight.

The concentrations of milk fat and non-fat milk solids contained in the fermented composition can be measured by conventional methods.

The content of exopolysaccharides such as lactic acid bacteria contained in the "fermented composition" in the present invention is not particularly limited, and varies depending on the type of fermentation composition and the type of lactic acid bacteria used. The unit of the content of exopolysaccharide contained in the composition (content of glucose equivalent: μg) is 3 to 100 μg glucose equivalent/g, and from the viewpoint of further improving shape retention, preferably 5 to 60 μg glucose equivalent/g, more preferably 9 to 55 μg glucose equivalent/g, still more preferably 12 to 52 μg glucose equivalent/g, still more preferably 17 to 50 μg glucose equivalent/g.
The content of exopolysaccharide in the fermented composition (μg glucose equivalent/g) can be measured, for example, by the method described in Test 1 in Examples below.

The viscosity (mPa s) of the "fermented composition" in the present invention as measured by a vibration viscometer is not particularly limited, and varies depending on the type of fermented composition and the type of lactic acid bacteria used, etc., but is 5 to 500 mPa. s and 50 to 600 mPa s, preferably 50 to 590 mPa s, more preferably 60 to 570 mPa s, and still more preferably 70 to 550 mPa s from the viewpoint of further improving shape retention. be done.
Such viscosity can be measured, for example, using a vibrating viscometer such as FVM72A-VM-200T2 manufactured by Sekonic.

The maximum value of the complex elastic modulus (Pa) of the “fermented composition” in the present invention is not particularly limited, and varies depending on the type of the fermented composition and the type of lactic acid bacteria used, etc., but is 3 × 10 ² to 3. × 10 ⁵ Pa, preferably 5 × 10 ² to 5 × 10 ³ Pa, more preferably 6 × 10 ² to 4.5 × 10 ³ Pa, still more preferably from the viewpoint of further improving shape retention. is 1×10 ³ to 4×10 ³ Pa, and more preferably 2×10 ³ to 3.6×10 ³ Pa.
The maximum value of such a complex elastic modulus can be measured, for example, by the method described in Test 3 of Examples below.

The "fermented composition" in the present invention may contain stabilizers, sweeteners, dietary fibers, vitamins, minerals, fermentation-promoting ingredients, etc., as long as the effects of the present invention are not impaired. The above stabilizer is not particularly limited, and examples thereof include carrageenan, xanthan gum, and the like. Moreover, the above-mentioned sweetener is not particularly limited, and examples thereof include saccharides, sugar alcohols, high-intensity sweeteners, and the like, and these sweeteners can be used singly or in combination of two or more.
In addition, the "fermented composition" in the present invention may contain a stabilizer, but from the viewpoint of reducing the amount of food additives, etc., the stabilizer is preferably 0.5 % by weight or less, more preferably 0.3% by weight or less, and more preferably containing no stabilizer. In addition, the "fermented composition" in the present invention may contain agar and gelatin, but the total amount (dry weight) of agar and gelatin is preferably 0.5% by weight with respect to the total amount of the fermented composition. Below, it is more preferably 0.3% by weight or less, and more preferably contains neither agar nor gelatin.

The fermented composition in the present invention is preferably packed in a container.
"Contained" means filled (inside) a container and sealed. The container is preferably a container commonly used in the production of fermented milk and the like, and examples thereof include plastic, glass and paper containers.

(Dead cells of lactic acid bacteria)
In the present invention, dead cells of lactic acid bacteria are used.

"Lactic acid bacteria" is a general term for all taxonomically recognized lactic acid bacteria, and is not limited by genus, species, strain, or the like. Examples of such "lactic acid bacteria" include bacteria that produce a large amount of lactic acid (preferably 50% or more of the sugar consumed) by lactic acid fermentation of sugar, and include bacteria of the genus Lactobacillus and Streptococcus. Bacteria, bacteria belonging to the genus Lactococcus, bacteria belonging to the genus Leuconostoc, bacteria belonging to the genus Pediococcus, and bacteria belonging to the genus Enterococcus.

Although the genus and species of the killed lactic acid bacteria used in the present invention are not particularly limited, the group consisting of bacteria of the genus Lactobacillus, bacteria of the genus Streptococcus, bacteria of the genus Lactococcus, bacteria of the genus Pediococcus, and bacteria of the genus Enterococcus. One or two or more bacteria selected from, preferably one or two or more bacteria selected from the group consisting of bacteria belonging to the genus Lactococcus, more preferably Lactococcus lactis One or two or more bacteria selected from the group consisting of

More specific preferred embodiments of the dead cells of the present invention include Lactobacillus acidophilus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus delbrueckii subsp. 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. rhamnosus, Lactobacillus pentosus, Lactobacillus fermentum, Streptococcus salivarius subsp. thermophilus (hereinafter also simply referred to as "Streptococcus thermophilus"), Lactococcus lactis - Subspecies lactis (Lactococcus lactis subsp. lactis) (hereinafter also simply referred to as "Lactococcus lactis"), Lactococcus lactis biovariant diacetylactis (Lactococcus lactis subsp. lactis biovar diacetylactis), Lactococcus lactis subsp. Lactococcus lactis subsp. cremoris, Lactococcus raffinolactis, Lactococcus piscium, Lactococcus plantarum, Lactococcus garviae garvieae), Lactococcus lactis subsp. hordniae, Leuconostoc mesenteroides subsp. consisting of Pediococcus damnosus, Pediococcus pentosaceus, Pediococcus acidilactici, Enterococcus faecalis and Enterococcus faecium One or two or more killed bacteria selected from the group, preferably Lactobacillus acidophilus, Lactobacillus delbrueckii subspecies bulgaricus, Lactobacillus delbrueckii subspecies lactis, Lactobacillus・Delbruecki Subspecies Delbrueckii, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus gasseri, Lactobacillus helveticus, Lactobacillus johnsonii, Lactobacillus plantarum, Lactobacillus brevis, Lactobacillus casei Subspecies rhamnosus, Lactobacillus ・Pentosus, Lactobacillus fermentum, Streptococcus salivarius subspecies thermophilus, Lactococcus lactis subspecies lactis, Lactococcus lactis biovariant diacetylactis, Lactococcus Cass lactis subspecies cremoris, Lactococcus raffinolactis, Lactococcus pythium, Lactococcus plantarum, Lactococcus garbieae, Lactococcus lactis subspecies holdiae, Leuconostoc mesentroides subspecies Dead cells of one or more bacteria selected from the group consisting of Cremoris and Leuconostoc lactis, more preferably Lactococcus lactis, Lactococcus lactis biovariant die selected from the group consisting of Acetylactis, Lactococcus lactis subspecies cremoris, Lactococcus raffinolactis, Lactococcus pythium, Lactococcus plantarum, Lactococcus garbieae, and Lactococcus lactis subspecies foldiae More preferably, killed cells of Lactococcus lactis, more preferably Lactococcus lactis JCM5805, Lactococcus lactis JCM20101, One or two or more killed bacteria selected from the group consisting of Lactococcus lactis NBRC12007 and Lactococcus lactis NRIC1150, particularly preferably killed bacteria of Lactococcus lactis JCM5805 mentioned.

The term “dead cell of lactic acid bacteria” as used herein is not particularly limited as long as it is a dead cell of lactic acid bacteria, and may be a dried product or a non-dried product. From the viewpoint of stability, it is preferably a dry product, and for example, a dry powder is suitable.

The method for preparing the dead lactic acid bacteria is not particularly limited. For example, after sterilizing the medium in which the lactic acid bacteria are cultured, the bacterial cells are collected by filtration, centrifugation, etc., or from the medium in which the lactic acid bacteria are cultured, the , a method of collecting the cells by centrifugation or the like, and then sterilizing them, and if necessary, a drying treatment or a crushing treatment can be further performed.
The means of sterilization is not particularly limited, and not only heating but also conventional means such as ultraviolet rays and γ-ray irradiation can be used.

In the present invention, the dead lactic acid bacteria may be added in any step during the production of the fermented composition. Alternatively, dead lactic acid bacteria may be added to the milk raw material during the fermentation process of the dairy raw material, or dead lactic acid bacteria may be added to the fermented composition after the completion of the dairy raw material fermentation process. However, from the viewpoint of further improving the shape retention of the fermented composition, dead cells of lactic acid bacteria may be added to the milk raw material before the fermentation process of the milk raw material, or during the fermentation process of the milk raw material, It is preferable to add dead cells of lactic acid bacteria to the raw milk material, and it is more preferable to add dead cells of lactic acid bacteria to the raw milk material before the fermentation process of the raw milk material.
As for the dead lactic acid bacteria, only the dead lactic acid bacteria may be added to the dairy raw material, or the dead lactic acid bacteria may be added to the dairy raw material together with other raw materials. In addition, in the present specification, addition of dead lactic acid bacteria to the raw milk material includes adding the dead lactic acid bacteria to the raw milk material for the sake of convenience. Moreover, it is preferable to mix after adding the killed lactic acid bacteria. In addition, in the present invention, when adding dead lactic acid bacteria, it is preferable to previously sterilize the raw milk material to be added, the raw milk material during fermentation, or the fermented composition after fermentation.

The amount of dead lactic acid bacteria used in the present invention is not particularly limited as long as the effects of the present invention can be obtained. 0.01% by weight or more by weight, preferably 0.025% by weight or more, more preferably 0.05% by weight or more, and still more preferably 0.1% by weight from the viewpoint of further improving shape retention. The above are mentioned.
The upper limit of the amount of dead lactic acid bacteria used in the present invention is not particularly limited, but the dry weight of dead lactic acid bacteria relative to the total amount of milk raw materials or the total amount of fermentation composition is 0.25% by weight or less, 0.2% by weight. Below, 0.1 weight% or less is mentioned.
These lower and upper limits can be combined arbitrarily.

Another lower limit for the amount of dead lactic acid bacteria used in the present invention is 1×10 ⁸ /g in units of the number of dead lactic acid bacteria (pieces/g) contained in the fermented composition. g to 1×10 ¹⁰ /g.
The number of dead lactic acid bacteria in the fermented composition can be measured by a direct microscopy method, a particle electric detection zone method, or a PCR method.

(Viable bacteria such as lactic acid bacteria in the present invention)
The fermented composition in the present invention is a fermentation produced by fermenting a raw milk material with one or more live bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria (such as lactic acid bacteria). The composition is a fermented composition to which dead cells of lactic acid bacteria have been added.
In the present invention, the one or more live bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium are selected from the group consisting of lactic acid bacteria and Bifidobacterium. Although not particularly limited as long as it is one or more types of viable bacteria, preferably bacteria of the genus Lactobacillus, bacterium of the genus Streptococcus, bacterium of the genus Lactococcus, bacterium of the genus Leuconostoc, bacterium of the genus Pediococcus, and bacterium of the genus Enterococcus , and one or more (preferably two or more, more preferably three or more) viable bacteria selected from the group consisting of bacteria of the genus Bifidobacterium, more preferably Lactobacillus One or two or more (preferably two or more, more preferably three or more) live bacteria selected from the group consisting of bacteria of the genus Streptococcus, and bacteria of the genus Bifidobacterium. more preferably, one or two or more (preferably one or two) Lactobacillus bacteria, one or two or more (preferably one or two) Streptococcus bacteria, and one or two or more (preferably one or two) live bacteria of the genus Bifidobacterium;
1 or 2 or more (preferably 1 or 2) Lactobacillus bacteria and 1 or 2 or more (preferably 1 or 2) Streptococcus bacteria; and
1 or 2 or more (preferably 1 or 2) Lactobacillus bacteria and 1 or 2 or more (preferably 1 or 2) Bifidobacterium bacteria; and
1 or 2 or more (preferably 1 or 2) Streptococcus bacteria and 1 or 2 or more (preferably 1 or 2) Bifidobacterium bacteria; and
1 or 2 or more (preferably 1 or 2) live bacteria of the genus Streptococcus; and 1 or 2 or more (preferably 1 or 2) live bacteria of the genus Lactobacillus;
One or more (preferably one or two) live bacteria of the genus Bifidobacterium;
is mentioned.

More specific preferred embodiments of viable bacteria in the present invention include Lactobacillus acidophilus, Lactobacillus delbrueckii subspecies bulgaricus, Lactobacillus delbrueckii subspecies lactis, Lactobacillus delbrueckii subspecies delbrueckii , lactobacillus casei, lactobacillus paracasei, lactobacillus gasseri, lactobacillus helveticus, lactobacillus johnsonii, lactobacillus plantarum, lactobacillus brevis, lactobacillus casei subspecies rhamnosus, lactobacillus pentosus, lactobacillus fermentum, streptococcus salivarius subspecies thermophilus, lactococcus lactis subspecies lactis, lactococcus lactis biovariant diacetylactis, lactococcus lactis subspecies cremoris, lactococcus raffinolactis, lactococcus pythium, lactococcus・Plantarum, Lactococcus garbieae, Lactococcus lactis subspecies holdniae, Leuconostoc mesentroides subspecies cremoris, Leuconostoc lactis, Pediococcus damnosus, Pediococcus pentosaceus, Pedio Coccus acidilactici, Enterococcus faecalis, Enterococcus faecium, Bifidobacterium bifidum, Bifidobacterium breve, Bifidobacterium longum subspecies longum longum subsp. longum), Bifidobacterium longum subsp. infantis, Bifidobacterium animalis subsp. animalis, Bifidobacterium - Animalis subspecies lactis (Bifidobacterium animalis subsp. lac tis) (hereinafter simply referred to as "Bifidobacterium lactis". ), Bifidobacterium adolescentis, Bifidobacterium angulatum, Bifidobacterium catenulatum, and Bifidobacterium pseudocatenulatum ( Bifidobacterium pseudocatenulatum), and one or more (preferably two or more, more preferably three or more) viable bacteria selected from the group consisting of
Preferably, Lactobacillus acidophilus, Lactobacillus delbrueckii subspecies bulgaricus, Lactobacillus delbrueckii subspecies lactis, Lactobacillus delbrueckii subspecies delbrueckii, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus gasseri , Lactobacillus helveticus, Lactobacillus johnsonii, Lactobacillus plantarum, Lactobacillus brevis, Lactobacillus casei subspecies rhamnosus, Lactobacillus pentosus, Lactobacillus fermentum, Streptococcus salivarius subspecies thermophilus, Bifidobacterium Bifidum, Bifidobacterium breve, Bifidobacterium longum subspecies longum, Bifidobacterium longum subspecies infantis, Bifidobacterium animalis subspecies animalis, Bifidobacterium selected from the group consisting of Umm animalis subspecies lactis, Bifidobacterium adrecentis, Bifidobacterium angularum, Bifidobacterium catenulatum, and Bifidobacterium pseudocatenulatum 1 or 2 or more (preferably 2 or more, more preferably 3 or more) viable bacteria,
More preferably, Lactobacillus acidophilus, Lactobacillus delbrueckii subspecies bulgaricus, Lactobacillus delbrueckii subspecies lactis, Lactobacillus delbrueckii subspecies delbrueckii, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus casei Gasseri, Lactobacillus helveticus, Lactobacillus johnsonii, Lactobacillus plantarum, Lactobacillus brevis, Lactobacillus casei subspecies rhamnosus, Lactobacillus pentosus, Lactobacillus fermentum, and Streptococcus salivarius subspecies thermophilus One or two live bacteria selected from, or
Bifidobacterium bifidum, Bifidobacterium breve, Bifidobacterium longum subspecies longum, Bifidobacterium longum, and one or two live bacteria selected from the group - One or two viable bacteria selected from the group consisting of Subspecies infantis, Bifidobacterium animalis Subspecies animalis, and Bifidobacterium animalis Subspecies lactis A combination with
More preferably, Lactobacillus acidophilus, Lactobacillus delbrueckii subspecies bulgaricus, Lactobacillus delbrueckii subspecies lactis, Lactobacillus delbrueckii subspecies delbrueckii, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus casei Gasseri, Lactobacillus helveticus, Lactobacillus johnsonii, Lactobacillus plantarum, Lactobacillus brevis, Lactobacillus casei subspecies rhamnosus, Lactobacillus pentosus, Lactobacillus fermentum, and Streptococcus salivarius subspecies thermophilus One or two live bacteria selected from
More preferably, one or two live bacteria selected from the group consisting of Lactobacillus gasseri and Streptococcus salivarius subspecies thermophilus are included.
In the present invention, the type of lactic acid bacteria used for dead cells and the type of lactic acid bacteria used for viable cells may be the same or different, and some species may overlap. good.

(Classification by optimum growth temperature for lactic acid bacteria and bifidobacteria)
Lactic acid bacteria and bifidobacteria used in the production of fermented compositions are also classified according to the difference in optimum growth temperature. In general, lactic acid bacteria with an optimum growth temperature of about 25-30°C are called mesophilic bacteria, and lactic acid bacteria with an optimum growth temperature of 37-45°C are called thermophilic bacteria.
Thermobacteria include, for example, Lactobacillus acidophilus, Lactobacillus delbrueckii subspecies bulgaricus, Lactobacillus delbrueckii subspecies lactis, Lactobacillus delbrueckii subspecies delbrueckii, Lactobacillus gasseri, Lactobacillus helveticus , Lactobacillus johnsonii, Lactobacillus brevis, Lactobacillus casei subspecies rhamnosus, Lactobacillus pentosus, Streptococcus salivarius subspecies thermophilus, Bifidobacterium bifidum, Bifidobacterium breve, Bifidobacterium Longum subspecies longum, and mesophilic bacteria include, for example, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus plantarum, Lactococcus lactis subspecies lactis, Lactococcus lactis biovariant diacetylactis , Lactococcus lactis subspecies cremoris, and Leuconostoc mesentroides subspecies cremoris.
In the production of container-packed yogurt, live thermophilic bacteria are often used, but viable mesophilic bacteria are sometimes used, and thermophilic and mesophilic live bacteria are used in combination. There is also Mesophilic bacteria are often used in the production of cheese.
Regarding the relationship between the type of lactic acid bacteria and the type of fermented composition, Lactococcus bacteria are often used for cheese production, Streptococcus thermophilus is often used for fermented milk such as yogurt, and Lactobacillus bacteria are It is used to produce a wide range of fermented compositions such as fermented milk such as yogurt and cheese.

(How to obtain lactic acid bacteria, etc.)
Strains of viable bacteria such as lactic acid bacteria used in the present invention and strains of dead cells of lactic acid bacteria are obtained from RIKEN BioResource Center Microbial Material Development Office (3-1-1 Takanodai, Tsukuba City, Ibaraki Prefecture), American type culture collection (USA), National Institute of Technology and Evaluation (2-5-8 Kazusa Kamatari, Kisarazu City, Chiba Prefecture), Tokyo University of Agriculture, Strain Storage Room (1-1-1 Sakuragaoka, Setagaya-ku, Tokyo) etc. More specifically, for example, the JCM strain is from the RIKEN BioResource Center Microbial Material Development Office (http://jcm.brc.riken.jp/ja/), and the NBRC strain is from the Independent Administrative Agency Product Evaluation From the National Institute of Technology Biotechnology Center (http://www.nbrc.nite.go.jp), the NRIC strain is from the Tokyo University of Agriculture Strain Storage Room (http://nodaiweb.university.jp/nric/), Each can be obtained.
A commercially available starter culture may be used as the lactic acid bacteria and the like used in the present invention.

In the present invention, the dead cell strains listed in the present specification include strains equivalent to the strains as long as they have the effect of improving the shape retention of the fermented composition. Here, equivalent strains refer to strains derived from the aforementioned strains, strains derived from the aforementioned strains, or progeny strains thereof. Equivalent strains may be preserved in other strain collection institutions. FIG. 1 shows strains derived from Lactococcus lactis subspecies lactis JCM5805 and strains derived from Lactococcus lactis subspecies lactis JCM5805. Equivalent strains of Lactococcus lactis subspecies lactis JCM5805 shown in FIG. 1 can also be used as the killed cells of the present invention as long as they have the effect of improving the shape retention of the fermented composition. As used herein, references to Lactococcus lactis subsp. lactis JCM5805 (Lactococcus lactis JCM5805) also include these equivalent strains.

(Fermented composition with improved shape retention)
The fermented composition of the present invention is a fermented composition with improved shape retention. In the present specification, the fermented composition with "improved shape retention" means a fermented composition produced by the same production method using the same kind of milk raw material except that dead lactic acid bacteria are not added (hereinafter , also indicated as “the control fermentation composition in the present invention”).

The degree of shape retention in a fermented composition and how such degree of shape retention is compared to a control fermented composition of the present invention (eg, whether it is improved) can be determined by trained Panels can be easily and unambiguously determined. General methods can be used for evaluation criteria and how to summarize evaluations between panels. The number of panel members who evaluate the degree of shape retention in the fermented composition may be one person, but from the viewpoint of obtaining a more objective evaluation, the lower limit of the number of panel members is, for example, 3 or more, preferably The number of panelists can be 5 or more, and the upper limit of the number of panel members can be, for example, 7 or less from the viewpoint of conducting the evaluation test more easily. For the evaluation of the degree of shape retention in the fermented composition when there are two or more panelists, the average of the evaluations of all members of the panel regarding the degree of shape retention in the fermented composition may be adopted. When evaluation points are given to each evaluation criterion, the average value of the evaluation points of all members of the panel may be used as the evaluation of the degree of shape retention in the fermented composition. As described above, when the average value of evaluation points is used, the average value may be rounded off to the first decimal place. In addition, when there are two or more panels, in order to reduce the variation in the evaluation of each panel, the evaluation criteria are standardized so that the evaluation criteria of each panel are as uniform as possible before conducting the actual sensory evaluation test. It is preferable to do the work to As such a standardization work, each fermented composition sample is evaluated after preliminarily sharing the recognition of the degree of shape retention corresponding to the evaluation point when the strength of shape retention is the highest among the panels. Things are mentioned. In addition, due to the prior standardization work on such evaluation criteria, for example, when the evaluation score is 1 point; 2 points; 3 points; 4 points; 5 points; It is preferable to keep the standard deviation of the degree evaluation within 0.5.

The degree of shape retention in a certain fermented composition can be evaluated, for example, by the same method, preferably the same method, as the sensory evaluation method described in Test 1 of Examples below. More specifically, the degree of shape retention in the fermented composition is "1: no shape retention", "2: shape retention but weak", "3: shape retention", " 4: Slightly strong shape retention”, “5: Strong shape retention”, and compared with the degree of shape retention of the control fermentation composition in the present invention. A fermented composition with improved properties is preferably mentioned as a fermented composition that can be evaluated as a fermented composition with improved shape retention.

(Fermented composition with improved flavor)
The fermented composition in the present invention is preferably a fermented composition with improved shape retention and further improved flavor. As used herein, the fermented composition with "improved flavor" means that the original flavor of the milk component (preferably milk) is improved and / or miscellaneous taste ( That is, it means a fermented composition with reduced harshness, bitterness, medium odor, etc., preferably the original flavor of milk components (preferably milk) is improved, and miscellaneous tastes (that is, harshness, bitterness, Fermented compositions with reduced medium odor, etc. are included.

The extent of the original flavor and off-taste of the milk component in a certain fermented composition, how the original flavor and off-taste of the milk component are compared to the control fermented composition in the present invention (for example, whether it is improved , whether it is reduced) can be easily and unambiguously determined by a trained panel. General methods can be used for evaluation criteria and how to summarize evaluations between panels. The number of panel members who evaluate the degree of the original flavor and miscellaneous taste of the milk component in the fermented composition may be one person, but from the viewpoint of obtaining a more objective evaluation, the lower limit of the number of panel members is, for example, 3. The number can be at least 5, preferably at least 5, and the upper limit of the number of panel members can be, for example, 7 or less from the viewpoint of conducting the evaluation test more easily. In the case of two or more panels, the evaluation of the original flavor and unfavorable taste of the milk component in the fermented composition is the average of the evaluations of all the panel members regarding the original flavor and unfavorable taste of the milk component in the fermented composition. may be adopted. When evaluation points are assigned to each evaluation criterion, the average value of the evaluation points of all members of the panel may be used as the evaluation of the degree of flavor and off-taste inherent in the milk component in the fermented composition. As described above, when the average value of evaluation points is used, the average value may be rounded off to the first decimal place. In addition, when there are two or more panels, in order to reduce the variation in the evaluation of each panel, the evaluation criteria are standardized so that the evaluation criteria of each panel are as uniform as possible before conducting the actual sensory evaluation test. It is preferable to do the work to As such a standardization work, after sharing the recognition of the degree of the original flavor and taste of the milk component, which corresponds to the evaluation point when the intensity of the original flavor and taste of the milk component is the highest, among the panels, Conducting an evaluation of each fermentation composition sample is included. In addition, due to the prior standardization work on such evaluation criteria, for example, when the evaluation score is 1 point; 2 points; 3 points; 4 points; 5 points; It is preferable that the standard deviation of the evaluation of the degree of flavor and off-flavour is within 0.5.

The degree of flavor and off-taste inherent in milk components in a certain fermented composition can be evaluated, for example, by the same method, preferably the same method, as the sensory evaluation method described in Test 4 of Examples below. More specifically, the degree of the original flavor and miscellaneous taste of the milk component in the fermented composition was determined as follows: "1: strong miscellaneous taste, no milk original flavor", "2: miscellaneous taste, milk original flavor is hardly felt”, “3: There is a little miscellaneous taste and the original flavor of milk is weak”, “4: There is almost no miscellaneous taste and the original flavor of milk”, “5: Milk with no miscellaneous taste The fermented composition in which the original flavor of the milk component of the control fermented composition in the present invention is improved and / or the miscellaneous taste is reduced has the original flavor of the milk component. It is preferably mentioned as a fermented composition with improved and/or reduced unpleasant taste.

(Fermented composition with improved smooth texture)
The fermented composition in the present invention is preferably a fermented composition having improved shape retention, or improved shape retention and flavor, and further improved smooth texture. As used herein, the fermented composition with "improved smooth texture" means a fermented composition with improved smooth texture compared to the control fermented composition in the present invention.

The degree of smooth texture in a fermented composition, and how such smooth texture is compared to a control fermented composition in the present invention (e.g., whether it is improved) can be determined by a trained panel. If so, it can be determined easily and unambiguously. General methods can be used for evaluation criteria and how to summarize evaluations between panels. The number of panel members who evaluate the degree of smooth texture in the fermented composition may be 1 person, but from the viewpoint of obtaining a more objective evaluation, the lower limit of the number of panel members is, for example, 3 or more, preferably. can be 5 or more, and from the viewpoint of making the evaluation test easier, the upper limit of the number of panel members can be, for example, 7 or less. For the evaluation of the degree of smooth texture of the fermented composition when there are two or more panelists, the average of the evaluations of all the panelists regarding the degree of smooth texture of the fermented composition may be adopted. When evaluation points are given to each evaluation criterion, the average value of the evaluation points of all members of the panel may be used as the evaluation of the degree of smooth texture in the fermented composition. As described above, when the average value of evaluation points is used, the average value may be rounded off to the first decimal place. In addition, when there are two or more panels, in order to reduce the variation in the evaluation of each panel, the evaluation criteria are standardized so that the evaluation criteria of each panel are as uniform as possible before conducting the actual sensory evaluation test. It is preferable to do the work to As such a standardization work, after sharing the recognition of the degree of smooth texture corresponding to the evaluation point when the strength of the smooth texture is the highest among the panels in advance, evaluate each fermented composition sample. to do. In addition, due to the prior standardization work on such evaluation criteria, for example, when the evaluation score is 1 point; 2 points; 3 points; 4 points; 5 points; smooth texture by each panel It is preferable that the standard deviation of the degree of evaluation is within 0.5.

(Method for improving shape retention of the present invention)
As a method for improving the shape retention of the present invention, in the production of the fermented composition, one or more live bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria are used to make milk raw materials. It is not particularly limited as long as it includes a fermenting step and as long as dead lactic acid bacteria are added.
The method for improving shape retention of the present invention is preferably also a method for improving flavor and/or smoothness of mouthfeel. That is, the method for improving shape retention of the present invention is preferably a method for improving shape retention and flavor in a fermented composition, or a method for improving shape retention and texture in a fermented composition. It is a method for improving smoothness, more preferably a method for improving shape retention and flavor, and improving smoothness of texture in a fermented composition.

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

[Test 1]
(Evaluation of improvement in shape retention of fermented composition by dead cells of Lactococcus bacteria)
The following test was conducted to examine how the addition of dead Lactococcus bacteria affects the shape retention of the fermented composition in the production of the fermented composition.

1) milk (milk fat content of 3% by weight or more, non-fat milk solids content of 8% by weight or more), a predetermined amount of dry killed cell powder of Lactococcus lactis JCM5805 (3 × 10 ¹² cells / g), and 2% by weight of a fermented culture of viable Streptococcus thermophilus was added, fermented at 40° C. until the milk was coagulated, and then cooled to 10° C. to prepare each fermented composition sample. The fermented composition samples prepared by adding 0.01% by weight, 0.05% by weight, 0.1% by weight, and 0.2% by weight of dried dead cell powder were designated as samples A to D, respectively. (Table 1).
In addition, a fermented composition sample prepared in the same manner without the addition of dried dead cell powder was used as a control sample (Table 1).
These samples in Test 1-1) correspond to "fermented milk" defined in the "Ministerial Ordinance Concerning Ingredient Standards for Milk and Dairy Products".

2) In the above 1) of Test 1, milk was used as a substrate for lactic acid fermentation. Therefore, in 2), a fermented composition sample was prepared using another substrate (substrate prepared by mixing skimmed milk powder with milk and adjusting the non-fat milk solid content to 10% by weight). Specifically, it was prepared by the following method.
Powdered dry dead cells of Lactococcus lactis JCM5805 (3×10 ¹² cells/ g), and 2% by weight of a fermentation culture of live bacteria of Streptococcus thermophilus are added, fermented at 40 ° C. until the substrate solidifies, and then cooled to 10 ° C. Each fermented composition A sample was prepared. In addition, 0.05% by weight, 0.1% by weight, and 0.2% by weight of the dry killed cell powder of Lactococcus lactis JCM5805 (3 × 10 ¹² cells / g) used in 1) above were added. Each fermented composition sample prepared was designated as samples B2, C2, and D2 (Table 2).
A fermented composition sample prepared in the same manner without the addition of dried dead cell powder was used as control 2 samples (Table 2).
These samples in Test 1-2) correspond to "fermented milk" defined in the "Ministerial Ordinance Concerning Ingredient Standards for Milk and Dairy Products".

3) In the above 1) of Test 1, a fermented culture of viable Streptococcus thermophilus was used. Therefore, in 3), fermented composition samples were prepared using fermented compositions of different strains of the same viable strain of Streptococcus thermophilus. Specifically, it was prepared by the following method.
In milk, a predetermined amount of dry dead cell powder (3 × 10 ¹² cells/g) of Lactococcus lactis JCM5805, and a viable strain of Streptococcus thermophilus [above 1) Streptococcus thermophilus, which is a strain different from the viable bacteria 2% by weight of the fermented culture was added, fermented at 40°C until the milk was coagulated, and then cooled to 10°C to prepare each fermented composition sample. The fermented composition samples prepared by adding 0.05% by weight, 0.1% by weight, and 0.2% by weight of dried dead cell powder were designated as samples B3, C3, and D3, respectively (Table 3). .
In addition, fermented composition samples prepared in the same manner without the addition of dried dead cell powder were used as control 3 samples (Table 3).
These samples in Test 1-3) correspond to "fermented milk" defined in the "Ministerial Ordinance Concerning Ingredient Standards for Milk and Dairy Products".
4) For each sample of the control sample and samples A to D, six trained sensory evaluators visually evaluated the appearance shape retention of each sample based on the following appearance shape retention index. . Table 1 shows the evaluation results (average values) of six sensory evaluators. In addition, the results of appearance shape retention evaluated in the same manner for Control 2 samples and samples B2 to D2 are shown in Table 2, and the results of appearance shape retention evaluated in the same manner for Control 3 samples and samples B3 to D3 are shown in Table 3. show.
<Appearance shape retention index>
1: No shape retention 2: Shape retention but weak 3: Shape retention 4: Slightly strong shape retention 5: Strong shape retention 5) Control samples, samples A to D Table 1 shows the results of measuring the content of exopolysaccharide in the medium by the following method, and Table 2 shows the content of exopolysaccharide measured in the same manner for control 2 samples and samples B2 to D2. Table 3 shows the content of exopolysaccharide measured in the same manner for , control 3 samples, and samples B3 to D3.
(Method for measuring content of exopolysaccharide)
The measurement of the content of exopolysaccharide in each sample is based on the Journal of the Japan Society for Food Science and Engineering, Vol. 60, No. 11, 635-643 (2013). It was carried out according to the method described in "EPS amount measurement" in "Influence on production and physical properties of". A specific method is as follows.
5.0 g of a sample homogenized with a stomacher (230 rpm, 3 minutes) was weighed out, 2.5 g of 60% (w/v) trichloroacetic acid was added, stirred well, and allowed to stand in ice water for 1 hour. Centrifugation (4170×g, 30 minutes, 4° C.) was performed, 2.5 g of 20% (w/v) trichloroacetic acid was added to 4.0 g of the resulting supernatant, and the mixture was stirred well and allowed to stand still in ice water for 1 hour. placed. Centrifugation (4170×g, 30 minutes, 4° C.) was performed, 9.4 mL of ethanol was added to 4.0 g of the supernatant, and the mixture was stirred well and allowed to stand overnight at minus 30° C. Centrifugation (4170×g, 30 minutes, 4° C.) was performed, and the supernatant was removed by decantation to obtain a precipitate. 10 mL of 70% (w/v) ethanol was added to the precipitate, stirred well, centrifuged (4170×g, 20 minutes, 4° C.), and the supernatant was removed by decantation. This washing operation of the precipitate was repeated two more times. The resulting precipitate was completely dried with a centrifugal evaporator. 0.5 mL of distilled water and 0.5 mL of 5% (w/v) phenol solution were added to the precipitate. Next, 3 mL of concentrated sulfuric acid was added, the mixture was allowed to stand at room temperature for 20 minutes, and the mixture was stirred. A calibration curve was prepared using glucose, and the exopolysaccharide contained per 1 g of the sample was determined by the glucose equivalent (μg glucose equivalent/g).
6) The pH of each of the control sample and samples A to D was measured with a pH meter. Table 1 shows the results. Table 2 shows the pH values measured in the same manner for the control 2 samples and the samples B2 to D2, and Table 3 shows the pH values measured in the same manner for the control 3 samples and the samples B3 to D3.

From the results in Tables 1 to 3, in the production of the fermented composition, the addition of the dry product of dead Lactococcus bacteria improved the appearance shape retention compared to the control sample, and increased the number of extracellular cells. It was shown that the sugar content increased. In addition, it was shown that this is the same even when different substrates and different lactic acid strains are used (Tables 1 to 3).
Furthermore, from the results of Tables 1 to 3, from the viewpoint of further improving the shape retention of the fermented composition, the content of the exopolysaccharide is preferably 5 to 60 μg glucose equivalent / g, more preferably 9 to 55 μg glucose equivalent/g, more preferably 12-52 μg glucose equivalent/g, even more preferably 17-50 μg glucose equivalent/g.
It should be noted that the pH of the sample hardly changed depending on the presence or absence of the addition of dead cells and the amount added, so the improvement in appearance shape retention due to the addition of dead cells was not due to an increase in lactic acid, etc. This is probably due to the increase in exopolysaccharide in the sample due to the addition of the cells.

[Test 2]
(Influence of dead Lactococcus bacteria on viscosity of fermented composition and viable lactic acid bacteria count)
The following tests were carried out in order to investigate how the addition of dead Lactococcus bacteria affects the viscosity of the fermented composition and the number of viable lactic acid bacteria in the production of the fermented composition. .

1) milk (milk fat content of 3% by weight or more, non-fat milk solids content of 8% by weight or more), a predetermined amount of dry killed cell powder of Lactococcus lactis JCM5805 (3 × 10 ¹² cells / g), and Add 2% by weight of a fermented culture of live lactic acid bacteria (Streptococcus thermophilus or Lactobacillus gasseri), ferment at 40 ° C. until milk is coagulated, then cool to 10 ° C. Each fermented composition sample. was prepared. The fermented composition samples prepared using Streptococcus thermophilus were designated as Samples A to C, and the fermented composition sample prepared using Lactobacillus gasseri was designated as Sample D (Table 4).
In addition, a fermented composition sample prepared in the same manner without the addition of dried dead cell powder was used as a control sample (Table 4).
These samples in Test 2-1) correspond to "fermented milk" defined in the "Ministerial Ordinance Concerning Ingredient Standards for Milk and Dairy Products".

2) In the above 1) of Test 2, milk was used as a substrate for lactic acid fermentation. Therefore, in 2), a fermented composition sample was prepared using another substrate (substrate prepared by mixing skimmed milk powder with milk and adjusting the non-fat milk solid content to 10% by weight). Specifically, it was prepared by the following method.
Powdered dry dead cells of Lactococcus lactis JCM5805 (3×10 ¹² cells/ g), and 2% by weight of a fermentation culture of live bacteria of Streptococcus thermophilus are added, fermented at 40 ° C. until the substrate solidifies, and then cooled to 10 ° C. Each fermented composition A sample was prepared. In addition, 0.05% by weight, 0.1% by weight, and 0.2% by weight of the dry killed cell powder of Lactococcus lactis JCM5805 (3 × 10 ¹² cells / g) used in 1) above were added. Each of the prepared fermentation composition samples was designated as samples A2, B2, and C2 (Table 5).
In addition, fermented composition samples prepared in the same manner without the addition of dried dead cell powder were used as control 2 samples (Table 5).
These samples in Test 2-2) correspond to "fermented milk" defined in the "Ministerial Ordinance Concerning Ingredient Standards for Milk and Dairy Products".
3) The viscosity (mPa·s) of each sample, control sample and samples A to D, was mixed with a spatula 10 times so that the entire sample was mixed, transferred to a beaker, and then measured using a vibrating viscometer. . In addition, the viable lactic acid bacteria count (cfu/g) in each sample was measured by a conventional method. Those results are shown in Table 4.
Table 5 shows the viscosity (mPa·s) and viable lactic acid bacteria count (cfu/g) measured in the same manner for control 2 sample and samples A2, B2 and C2.

From the results in Tables 4 and 5, in the production of the fermented composition, when a dry product of killed Lactococcus bacteria is added (preferably, a dry product of killed Lactococcus bacteria is added, Fermentation of dairy raw materials with viable lactic acid bacteria) showed an increase in viscosity compared to the control sample. In addition, it was shown that this is the same even when different substrates and viable lactic acid bacteria of different genera are used (Tables 4 and 5).
Furthermore, from the viewpoint of further improving the shape retention of the fermented composition, the viscosity of the fermented composition is preferably 50 to 600 mPa s, more preferably 50 to 590 mPa s, more preferably 60 to 570 mPa s. , and more preferably 70 to 550 mPa·s.
In addition, the order of the number of viable lactic acid bacteria hardly changed depending on the presence or absence of the addition of dead bacteria and the amount of addition, and considering the results in Tables 1 to 3, it was found that the appearance was preserved by the addition of dead bacteria. It is thought that the improvement in morphology was not due to fluctuations in the number of viable lactic acid bacteria, but due to the addition of dead cells, which increased exopolysaccharide in the sample and increased the viscosity of the sample. be done.

[Test 3]
(Influence of dead Lactococcus bacteria on complex elastic modulus of fermented composition)
The following test was conducted to examine how the complex elastic modulus of the fermented composition is affected by the addition of dead Lactococcus bacteria in the production of the fermented composition. The complex elastic modulus is one of the indices of viscoelasticity.

1) milk (milk fat content of 3% by weight or more, non-fat milk solids content of 8% by weight or more), a predetermined amount of dry killed cell powder of Lactococcus lactis JCM5805 (3 × 10 ¹² cells / g), and 2% by weight of a fermented culture of viable Streptococcus thermophilus was added, fermented at 40° C. until the milk was coagulated, and then cooled to 10° C. to prepare each fermented composition sample. In addition, each fermentation composition sample prepared by adding 0.01% by weight, 0.025% by weight, 0.05% by weight, 0.1% by weight, and 0.2% by weight of dried dead cell powder was Samples A to E were used.
In addition, a fermented composition sample prepared in the same manner without the addition of dried dead cell powder was used as a control sample.
These samples in Test 3-1) correspond to "fermented milk" defined in the "Ministerial Ordinance Concerning Ingredient Standards for Milk and Dairy Products".
2) In the above 1) of Test 3, milk was used as a substrate for lactic acid fermentation. Therefore, in 2), a fermented composition sample was prepared using another substrate (substrate prepared by mixing skimmed milk powder with milk and adjusting the non-fat milk solid content to 10% by weight). Specifically, it was prepared by the following method.
Powdered dry dead cells of Lactococcus lactis JCM5805 (3×10 ¹² cells/ g), and 2% by weight of a fermentation culture of live bacteria of Streptococcus thermophilus are added, fermented at 40 ° C. until the substrate solidifies, and then cooled to 10 ° C. Each fermented composition A sample was prepared. Each fermented composition prepared by adding 0.05% by weight and 0.2% by weight of the dried dead cell powder (3×10 ¹² cells/g) of Lactococcus lactis JCM5805 used in 1) above. The samples were designated as samples C2 and E2, respectively (Table 7).
A fermented composition sample prepared in the same manner without the addition of dried dead cell powder was used as control 2 samples (Table 7).
These samples in Test 3-2) correspond to "fermented milk" defined in the "Ministerial Ordinance Concerning Ingredient Standards for Milk and Dairy Products".
3) Table 6 shows the results of measuring the complex elastic modulus (Pa) of each of the control sample and samples A to E by the following method. Table 7 shows the results of the complex elastic modulus (Pa) measured in the same manner for two control samples, samples C2 and E2.
(Method for measuring complex elastic modulus)
Using a commercially available viscoelasticity measuring device (manufactured by Anton Paar), the complex elastic modulus of each sample was measured under the following conditions. That is, at a frequency of 1 Hz and a temperature of 10 ° C., using a PP12 / P2 parallel plate, a strain of 0.1 to 1000% dispersion measurement with a gap of 1 to 2 mm, the measurement result of the maximum complex elastic modulus (Pa) is taken as a representative value. adopted.

The results in Tables 6 and 7 show that, in the production of the fermented composition, the addition of dried dead Lactococcus bacteria increases the maximum complex elastic modulus compared to the control sample. rice field.
This was also shown to be the same when different substrates were used (Tables 6 and 7).
Furthermore, from the viewpoint of further improving the shape retention of the fermented composition, the complex elastic modulus (Pa) of the fermented composition is preferably 5×10 ² to 5×10 ³ Pa, more preferably 6×10 ² to 4.5×10 ³ Pa, more preferably 1×10 ³ to 4×10 ³ Pa, still more preferably 2×10 ³ to 3.6×10 ³ Pa.

[Test 4]
(Influence of dead Lactococcus bacteria on flavor of fermented composition)
The following test was conducted to investigate how the addition of dead Lactococcus bacteria affects the flavor of the fermented composition in the production of the fermented composition.

1) Add a predetermined amount of Lactococcus lactis JCM5805 dry dead cell powder (3×10 ¹² cells/g) or Lactobacillus paracasei dry dead cell powder (4×10 ¹² cells/g) to milk, and 2% by weight of a fermented culture of viable Streptococcus thermophilus was added, fermented at 40° C. until the milk was coagulated, and then cooled to 10° C. to prepare each fermented composition sample. The fermented composition samples prepared by adding 0.1% by weight and 0.2% by weight of dried dead cell powder of Lactococcus lactis JCM5805 were designated as samples A and B, respectively. Fermented composition samples prepared by adding 0.1% by weight and 0.2% by weight of body powder were designated as samples C and D, respectively.
In addition, a fermented composition sample prepared in the same manner without the addition of dried dead cell powder was used as a control sample.
These samples in Test 4 correspond to "fermented milk" defined in the "Ministerial Ordinance Concerning Ingredient Standards for Milk and Dairy Products".
2) For each of the control sample and samples A to D, 6 trained sensory evaluators evaluated the flavor of each sample based on the following flavor index. Table 8 shows the evaluation results (average values) of six sensory evaluators.
<Flavor index>
1: Strong taste, no original milk flavor 2: There is a rough taste, almost no original milk flavor 3: A little rough taste, weak original milk flavor 4: Almost no rough taste , Has the original flavor of milk 5: No miscellaneous taste and the original flavor of milk is strong

From the results of Table 8, in the production of the fermented composition, when the dry product of the killed Lactobacillus bacteria was added, the flavor was not improved compared to the control sample, whereas the Lactococcus spp. In the case of using the dry product of dead bacteria, an improvement in flavor (that is, a reduction in off-flavours and an improvement in the original flavor of milk) was obtained compared to the control sample.
In addition, it was confirmed that the smooth texture was also improved in the case of using the dry product of the killed Lactococcus bacterium compared to the control sample.

Claims (11)

A fermented composition produced by fermenting a dairy raw material with one or more live bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria,
The fermented composition, wherein dead cells of lactic acid bacteria are added. One or more live bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium are selected from the group consisting of Lactobacillus, Streptococcus, and Bifidobacterium 2. The fermented composition according to claim 1, wherein the lactic acid bacterium is one or two or more live bacteria, and the dead lactic acid bacteria are dead bacteria of the genus Lactococcus. 3. The fermented composition according to claim 1 or 2, wherein the dry weight of the dead lactic acid bacteria to be added is 0.2% by weight or less relative to the total amount of the fermented composition. The fermented composition according to any one of claims 1 to 3, wherein the content of dead lactic acid bacteria is 1×10 ⁸ to 1×10 ¹⁰ cells/g. Killed lactic acid bacteria are added to the raw milk material, and the raw milk material is fermented with one or more live bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria. The fermentation composition according to any one of claims 1 to 4. The fermented composition according to any one of claims 1 to 5, wherein the content of exopolysaccharide is 5 to 60 µg glucose equivalent/g. Viscosity measured by a vibrating viscometer is 50 to 600 mPa s, or
The fermented composition according to any one of claims 1 to 6, which has a maximum complex elastic modulus of 5×10 ² to 5×10 ³ Pa measured by a viscoelasticity measuring device. 8. Any one of claims 1 to 7, wherein the dairy raw material is milk, the non-fat milk solid content of the dairy raw material is 8% by weight or more, and the milk fat content of the dairy raw material is 0.1% by weight or more. The fermented composition according to . The fermented composition according to any one of claims 1 to 8, wherein the one or more live bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria is Streptococcus thermophilus. In the method for producing a fermented composition,
It comprises a step of fermenting a raw milk material with live bacteria of one or more kinds of bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria, and adding dead cells of lactic acid bacteria. A method for producing a fermented composition having improved shape retention. In the production of the fermented composition,
It comprises a step of fermenting a raw milk material with live bacteria of one or more kinds of bacteria selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria, and adding dead cells of lactic acid bacteria. do,
A method for improving shape retention in a fermented composition.

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