JP2023032567A - Novel yogurt - Google Patents

Abstract

To provide a yogurt keeping flavor inherent in yoghurt even though a lactic acid bacterium where fermentation metabolite presents foreign taste is added; and to provide a production method thereof.SOLUTION: A yogurt contains 1.0×107 to 1.0×1011 cfu/g of at least one lactic acid bacterium other than a lactic acid bacteria group A. The yogurt is a fermented raw material mix containing raw material milk whose protein reduction value is 2 to 9, and whey protein. The yogurt contains 3.5-4.5 wt.% of milk fat and 4.3-5.4 wt.% of milk protein in the whole raw material mix, and a ratio of whey protein/casein protein in the milk protein is 23/77 to 30/70 (weight ratio). Furthermore, the yogurt contains 1.2×105 to 7.0×109 cfu/g pf of at least one lactic acid bacterium included in the lactic acid bacteria group A where fermentation metabolite presents foreign taste, and in the yogurt, a curd median diameter of the yogurt is 20-60 μm, and a viscosity of the yogurt at 10°C is 20-60 Pa s.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to yogurt containing lactic acid bacteria whose fermented metabolites have an off-taste.

In recent years, research has been conducted on various physiologically active actions of lactic acid bacteria, and interest in foods using lactic acid bacteria is increasing, and sales of lactic acid bacteria-containing foods such as yogurt are increasing. However, depending on the lactic acid bacterium, the fermented metabolites have an unpleasant taste, and in that case, even if the lactic acid bacterium is functional, it is not acceptable as a food.

Patent Literature 1 discloses a method for improving the bitter taste and astringent taste of yogurt to moderate taste by adding aspartame, which is a high-intensity sweetener, to yogurt. However, this method is not sufficiently effective in reducing the off-taste caused by fermented metabolites of lactic acid bacteria, and the peculiar peculiarity of high-intensity sweeteners is felt, and the original flavor of fermented dairy products is lost.

JP-A-59-224650

While investigating the improvement of the flavor of yogurt with the addition of specific lactic acid bacteria whose fermented metabolites exhibit off-flavours, we found that it can be suppressed by adjusting the raw material mix of yogurt to a specific composition and adjusting to specific physical properties. Found it. Therefore, the object of the present invention is to provide a yogurt that has the original flavor of yogurt produced without adding lactic acid bacteria whose fermentation metabolites give off-taste even if lactic acid bacteria whose fermentation metabolites give off-taste are added, and a method for producing the same. It is to be.

The present inventors have made intensive studies to solve the above problems, and found that the raw material milk and whey protein are contained, and milk fat milk and protein are contained in a specific amount, and the whey protein in the milk protein / By adjusting the casein protein ratio at the time of production so as to have a specific viscosity and a specific curd diameter, even if a specific amount of specific lactic acid bacteria exhibiting a bad taste is added to the fermentation metabolites, the fermentation metabolites can be produced. The inventors have found that it is possible to obtain a yogurt that has the original flavor of the yogurt produced without adding lactic acid bacteria that exhibit an off-taste, and have completed the present invention.

That is, the first aspect of the present invention is a yogurt containing 1.0 × 107 to 1.0 × 1011 cfu/g of at least one lactic acid bacterium other than lactic acid bacteria group A in the whole yogurt, wherein the yogurt is protein-reduced A fermented product of a raw mix containing raw milk with a value of 2 to 9 and whey protein, wherein 3.5 to 4.5% by weight of milk fat and 4.3 to 5% by weight of milk protein in the whole raw mix .4% by weight, the whey protein/casein protein ratio in the milk protein is 23/77 to 30/70 (weight ratio), and at least one lactic acid bacterium contained in lactic acid bacteria group A is added to 1. 2 × 10 cfu / g to 7.0 × 10 cfu / g, the median diameter of the yogurt curd is 20 to 60 μm, and the viscosity of the yogurt at 10 ° C. is 20 to 60 Pa s Yogurt (lactic acid bacteria group A: Lactobacillus plantarum CECT7527, Lactobacillus plantarum CECT7528, Lactobacillus plantarum CECT7529, Lactobacillus plantarum CECT7484, Lactobacillus plantarum CECT7485, and Pediococcus acidilactici CECT7483). A preferred embodiment relates to the yogurt described above, wherein the lactic acid bacterium other than the lactic acid bacterium group A is at least one selected from the group consisting of Streptococcus thermophilus, Lactobacillus delbrueckii subsp. Bulgaricus, Lactobacillus acidophilus, and Bifidobacterium lactis. More preferably, 0.2 to 2% by weight of at least one selected from the group consisting of whey powder, whey protein concentrate (WPC), and whey protein isolate (WPI) in the entire raw material mix, and It relates to the yogurt described above containing 1 to 5.7% by weight of skim milk powder. The second aspect of the present invention is a raw material mix containing raw milk having a protein reduction value of 2 to 9 and whey protein, wherein 3.5 to 4.5% by weight of milk fat in the whole raw material mix, A raw mix containing 4.3 to 5.4% by weight of milk protein and having a whey protein/casein protein ratio of 23/77 to 30/70 (weight ratio) in the milk protein, with the horizontal axis being the holding temperature ( ° C.), and the vertical axis is the retention time (minutes) after reaching the temperature. 30 minutes), point D (95° C., 1 minute), point E (90° C., 1 minute), point F (80° C., 5 minutes), respectively. and at least one lactic acid bacterium selected from lactic acid bacteria group A and at least one lactic acid bacterium other than lactic acid bacteria group A is added to the raw material mix after the heat treatment, and under a temperature condition of 39 to 41 ° C., Ferment until the pH reaches 4.5 to 4.7, and the curd of the raw material mix after the fermentation has a median diameter of 20 to 60 μm and a viscosity of 20 to 60 Pa s at 10 ° C. It relates to a method for producing yogurt, which is characterized by pulverizing so that it becomes

According to the present invention, there is provided a yogurt in which the original flavor of yogurt produced without adding lactic acid bacteria whose fermentation metabolites give offensive taste can be felt even when lactic acid bacteria whose fermentation metabolites give offensive taste are added, and to provide a method for producing the yogurt. be able to.

4 is a graph showing a suitable range of holding temperature and holding time after reaching the temperature in the heat treatment of the raw material mix according to one embodiment of the present invention.

The present invention will be described in more detail below. The yogurt of the present invention contains at least one lactic acid bacterium selected from lactic acid bacteria group A and at least one lactic acid bacterium other than lactic acid bacteria group A in specific amounts, and raw milk with a specific protein reduction value, It is a fermented raw material mix containing whey protein and specific amounts of milk fat and milk protein, and the curd median diameter and viscosity are within specific ranges.

The lactic acid bacteria group A is a group consisting of Lactobacillus plantarum CECT7527, Lactobacillus plantarum CECT7528, Lactobacillus plantarum CECT7529, Lactobacillus plantarum CECT7484, Lactobacillus plantarum CECT7485, and Pediococcus acidilactici CECT7483. Commercial products of the lactic acid bacteria group A include, for example, the product name "AB-LIFE" (manufactured by AB-Biotics: three types of mixture of Lactobacillus plantarum CECT7527, Lactobacillus plantarum CECT7528, and Lactobacillus plantarum CECT7529) and the product name "i3" ( AB-Biotics: Lactobacillus plantarum CECT7484, Lactobacillus plantarum CECT7485, and Pediococcus acidilactici CECT7483 mixed product) and the like.

The yogurt preferably contains 1.2×10 ⁵ to 7.0×10 ⁹ cfu/g of at least one lactic acid bacterium contained in the lactic acid bacteria group A, and 1.2×10 ⁵ to 5.0 cfu/g. ^X108 cfu/g is more preferred, and ^1.2x105 to ^5.0x107 cfu/g is even more preferred. If ^the content of the lactic acid bacteria contained in the lactic acid bacteria group A is less than 1.2×10 ⁵ cfu/g, the physiologically active action of the lactic acid bacteria group A may not be enjoyed. If the amount is large, the fermented metabolites of lactic acid bacteria group A may give off an unpleasant taste.

The yogurt preferably contains 1.0×10 ⁷ to 1.0×10 ¹¹ cfu/g of at least one lactic acid bacterium other than the lactic acid bacteria group A, and 1.0×10 ⁸ to 1.0×10 cfu/g. 10 ¹¹ cfu/g is more preferred, and 1.0×10 ⁹ to 1.0×10 ¹⁰ cfu/g is even more preferred. If the content of lactic acid bacteria other than lactic acid bacteria group A is less than 1.0×10 ⁷ cfu/g, an off-taste due to the fermentation metabolites of lactic acid bacteria group A may be felt, and the content is less than 1.0×10 ¹¹ cfu/g. If it is too much, the acidity may be felt too strong.

The lactic acid bacteria other than the lactic acid bacteria group A are not particularly limited as long as they are lactic acid bacteria other than the lactic acid bacteria group A. Among them, from the viewpoint of flavor, Streptococcus thermophilus, Lactobacillus delbrueckii subsp. Bulgaricus, Lactobacillus acidophilus, and Bifidobacterium lactis. It is preferably at least one selected from the group.

The number of lactic acid bacteria in the yogurt can be determined by culturing the lactic acid bacteria in a lactic acid bacteria culture medium such as BCP agar medium or MRS agar medium, and measuring the number of colonies.

The raw material milk is not particularly limited, but is preferably raw milk or cow's milk. The raw material milk may be a single type of milk or a mixture of multiple types of milk. For example, it may be a mixture of two types of raw milk with different protein reduction values, or a mixture of two types of milk with different protein reduction values. It may also be a mixture of raw milk and cow's milk. When using a mixture of multiple types of milk as raw material milk, the mixing ratio is not particularly limited. However, if the proportion of unpasteurized raw milk is increased, the milk protein is denatured by the heat sterilization treatment and the viscosity increases, which has the advantage of making it easier to adjust the target physical properties of yogurt.

The protein reduction value of the raw material milk is preferably 2-9. If the protein reduction value of the raw material milk is outside the above range, an off-taste due to fermentation metabolites of the lactic acid bacteria of the lactic acid bacteria group A may be felt. The protein reduction value of the raw material milk is more preferably 2-7, more preferably 2-5. When a mixture of multiple types of milk is used as the raw material milk, the protein reduction value of the mixture as a whole should be within the above range, and the protein reduction value of each milk contained in the mixture is not within the above range. good too.

The protein reduction value can be measured by a known method. and the like.

The whey protein is one type of milk protein contained in whey. The whey protein in the raw material mix is preferably derived from a whey protein source that is blended separately from the raw milk, from the viewpoint of ease of adjustment of the whey protein/casein protein ratio in the milk protein, which will be described later. The whey protein source is preferably at least one selected from the group consisting of whey powder, whey protein concentrate (WPC) and whey protein isolate (WPI).

The content of the whey protein source is preferably 0.2 to 2% by weight in the entire raw material mix. When the content of the whey protein source is within the above range, it becomes easy to adjust the whey protein/casein protein ratio in the milk protein, which will be described later. The content of the whey protein source is more preferably 0.5 to 1.5% by weight, still more preferably 0.7 to 1.2% by weight.

The whey powder is obtained by, for example, spray-drying a liquid (cheese whey) produced as a by-product when cheese is produced by coagulating raw milk. The main components of whey powder are 60-80% by weight of lactose, 7-30% by weight of whey protein, and 3-12% by weight of inorganic salts. Desalted whey powder may be used as whey powder.

The whey protein concentrate (WPC) refers to a powder obtained by removing lactose from cheese whey by membrane treatment and concentrating the protein to 30 to 95% by weight.

The whey protein isolate (WPI) refers to a whey protein concentrate with a higher whey protein content.

The milk fat is fat derived from milk. The milk fat contained in the raw mix is preferably derived from raw milk, whey protein sources, and other dairy products. Examples of the other dairy products include cream, fermented cream, butter, fermented butter, buttermilk, buttermilk powder, butter oil, whole milk powder, full-fat concentrated milk, and the like. Among them, cream, fermented cream, butter, fermented butter, and butter oil are preferred because of their high milk fat content.

The milk fat content is preferably 3.5 to 4.5% by weight, more preferably 3.7 to 4.3% by weight, based on the entire raw material mix. If the content of milk fat is out of the above range, an off-taste due to fermentation metabolites of lactic acid bacteria belonging to lactic acid bacteria group A may be felt. The milk fat content can be measured by a known method, such as the Roese-Gottlieb method.

The milk protein is a protein derived from milk and consists of the whey protein and casein protein, and the whey protein/casein protein ratio is approximately 20/80 (weight ratio). The milk protein content is preferably 4.3 to 5.4% by weight, more preferably 4.8 to 5.2% by weight, based on the entire raw material mix. If the content of milk protein is out of the above range, an off-taste due to fermentation metabolites of lactic acid bacteria belonging to group A of lactic acid bacteria may be felt. The milk protein content can be measured by a known method, such as a combustion method.

The milk protein is preferably derived from raw milk and dairy products. The dairy product is not limited as long as it uses milk as a raw material, but from the viewpoint of easiness of adjusting the milk protein content in the raw material mix, a dairy product with a high milk protein content is preferable. Specifically, whey, desalted whey, whey powder (including desalted whey powder), whey protein concentrate (WPC), whey protein isolate (WPI), whole milk powder, skim milk powder, whole milk concentrate, Concentrated skim milk, high-purity milk protein (TMP), milk protein concentrate (MPC), milk protein isolate (MPI), sweetened condensed milk, sweetened condensed skim milk, sugar-free condensed milk, sugar-free condensed skim milk, and the like.

From the viewpoint of flavor, it is preferable to use whole milk powder or skim milk powder, more preferably skim milk powder, as the source of the milk protein. When powdered skim milk is used, its content is preferably 1 to 5.7% by weight, more preferably 3 to 5% by weight, based on the whole raw material mix. When the skim milk powder content is within the above range, it becomes easy to adjust the milk protein content in the raw material mix.

In the raw material mix, the whey protein/casein protein ratio (weight ratio) in the milk protein is preferably 23/77 to 30/70, more preferably 25/75 to 30/70, and 25/75 to 28/72 is more preferred. If the ratio is out of the range, an off-taste due to fermentation metabolites of lactic acid bacteria of group A may be felt.

The whey protein content and the casein protein content can be measured by separating milk proteins by electrophoresis and then quantifying individual protein bands by dye binding.

The casein protein refers to a protein that precipitates when skim milk is adjusted to pH 4.6 at 20°C. The casein protein in the raw material mix is preferably derived from bovine, sheep or goat. That is, the casein protein source is the same raw milk and dairy products as the source of the milk protein, and specifically, the dairy raw material itself containing casein protein such as raw milk, milk, skim milk, whole milk powder, and skim milk powder. Alternatively, it may be acid casein purified by an isoelectric precipitation method in which a milk raw material containing casein protein is precipitated at pH 4.5 to 4.7 by fermentation or addition of acid, sodium caseinate, calcium caseinate, casein. It is preferably at least one selected from the group consisting of salts such as potassium and magnesium caseinate.

In addition to the raw material milk, the dairy product, and the whey protein source, the raw material mix may contain sugars, stabilizers, fragrances, flavors, and the like as appropriate within a range that does not impair the effects of the invention.

The sugars are not particularly limited, and include refined sugar, granulated sugar, powdered sugar, glucose, fructose, sucrose, maltose, enzymatically saccharified starch syrup, reduced starch saccharified product, reduced starch syrup, isomerized liquid sugar, sucrose bond Starch syrup, reducing sugar, reduced palatinose, sorbitol, lactose, reduced lactose, L-arabinose, trehalose, xylose, xylitol, maltitol, erythritol, mannitol, fructooligosaccharide, soybean oligosaccharide, galactooligosaccharide, milk oligosaccharide, xylooligosaccharide, Sugars and sugar alcohols such as raffinose, lactulose, palatinose, palatinose oligosaccharides, etc. can be mentioned, and at least one selected from these groups can be used.

From the viewpoint of not impairing the original flavor of yogurt derived from dairy ingredients as much as possible, the lower the content of the saccharides, the better. Specifically, the content of the saccharides is preferably 7% by weight or less, more preferably 5% by weight or less, still more preferably 2% by weight or less, and particularly preferably not contained in the entire raw material mix.

The stabilizers include food additives, starch, and dextrin used to increase the viscosity of yogurt and stabilize the viscosity of yogurt during storage and distribution. Examples of the food additives include food thickeners, pectin, gelatin, carrageenan, agar, gum arabic, sodium alginate, xanthan gum, locust bean gum, carboxymethylcellulose, modified starch, etc., and these groups. At least one selected from can be used.

The content of the stabilizer is preferably as low as possible from the viewpoint of not impairing the original flavor of yogurt derived from dairy ingredients as much as possible. Specifically, the content of the stabilizer is preferably 1% by weight or less, more preferably 0.5% by weight or less, still more preferably 0.2% by weight or less, in the entire raw material mix, and especially not containing preferable.

Examples of the flavors include milk flavor, yogurt flavor, vanilla flavor and the like. From the viewpoint of not impairing the original flavor of yogurt derived from dairy ingredients as much as possible, the smaller the content of the flavoring agent, the better. Specifically, the content of the perfume is preferably 0.5% by weight or less, more preferably 0.1% by weight or less, still more preferably 0.05% by weight or less, in the entire raw material mix, and may not be contained. Especially preferred.

The flavoring agent is not particularly limited as long as it is edible, but is strawberry, peach, mango, papaya, watermelon, melon, apple, persimmon, pear (including pear), banana, loquat, pomegranate, litchi, and plum. , apricots, pineapples, grapes, kiwis, plums, plums, cherries, passion fruits, black currants, red currants; berries such as cranberries, blackberries, blueberries, and raspberries; citrus fruits such as oranges and grapefruits; Mesophyll, seeds, and pericarp are cut, pureed, or grated, and cut products such as jelly, agar gel, nata de coco, and apricot tofu imitating these fruits are included. At least one selected can be used.

The content of the flavoring material is preferably 10 to 25% by weight, more preferably 12 to 25% by weight, and even more preferably 12 to 22% by weight in the entire raw material mix, from the viewpoint of the original flavor of yogurt derived from dairy ingredients. , 14 to 20% by weight are particularly preferred.

The median size of the yogurt curd of the present invention is preferably 20 to 60 μm, more preferably 25 to 55 μm, still more preferably 30 to 50 μm, and particularly preferably 35 to 50 μm. If the median diameter is out of the above range, an off-taste due to fermentation metabolites of lactic acid bacteria of lactic acid bacteria group A may be felt.

The median diameter of the card can be measured by a known method, for example, a method of measuring using a laser diffraction/scattering particle size distribution analyzer. Examples of the measuring device include LA-960V2 (manufactured by Horiba, Ltd.). Specifically, after diluting the sample with deionized water and adjusting the transmittance within the appropriate range, the intensity distribution pattern of the diffracted/scattered light is analyzed using the dedicated software "LA-960 for Windows". , the median diameter can be obtained.

The yogurt according to the present embodiment is rated No. 1 by a BH type viscometer. 4 rotor at a rotation speed of 2 rpm at 10° C., the viscosity is preferably 20 to 60 Pa·s, more preferably 20 to 50 Pa·s, and even more preferably 25 to 45 Pa·s. If the viscosity is out of the above range, an off-taste due to fermentation metabolites of lactic acid bacteria of group A may be felt.

The yogurt of the present invention is a fermented product of a raw material mix having a specific composition as described above, and the median diameter and viscosity of the curd are within the above ranges, so that the fermentation metabolites have a bad taste. Also, it is possible to obtain a yogurt that has the original flavor of yogurt produced without adding lactic acid bacteria whose fermentation metabolites have an unpleasant taste.

[Manufacturing method of yogurt]
(Process of mixing and dissolving raw materials)
The raw materials for yogurt described above (raw milk having a protein reduction value of 2 to 9, whey protein source, and other optional ingredients) are mixed and dissolved to obtain a raw material mix.

Even if lactic acid bacteria whose fermented metabolites exhibit an offensive taste are added, the raw material mix is heat-treated from the viewpoint of obtaining yogurt that has the original flavor of yogurt produced without adding lactic acid bacteria whose fermented metabolites exhibit an offensive taste. It is preferable to

It is preferable that the heating temperature and the heating time in the heat treatment are within the region surrounded by the dashed line shown in the graph of FIG. In the graph of FIG. 1, the horizontal axis is the holding temperature (° C.) of heating, and the vertical axis is the holding time (minutes) after reaching the temperature. The regions shown in FIG. This is an area formed by connecting points (90° C., 1 minute) and point F (80° C., 5 minutes) with straight lines in this order.

Prior to the heat treatment, a known homogenization treatment may be performed for the purpose of aligning the diameters of the fat globules contained in the raw material milk and stabilizing the quality. In that case, apparatuses such as a homogenizer, a microfluidizer, and a colloid mill can be used. Such homogenization treatment can also be performed after the heat treatment.

(Primary fermentation process)
After adjusting the temperature of the raw material mix obtained in the mixing and dissolving step of the raw materials to 39 to 41 ° C., adding at least one lactic acid bacterium selected from the lactic acid bacteria group A and at least one lactic acid bacterium other than the lactic acid bacteria group A, It is preferable to ferment under the same temperature conditions until the pH reaches 4.5 to 4.7 to obtain a raw material mix after the fermentation process. More preferably, the pH is 4.5 to 4.65. If the pH is out of the above range, an off-taste due to fermentation metabolites of lactic acid bacteria belonging to group A of lactic acid bacteria may be felt.

The amount of the lactic acid bacteria group A and the lactic acid bacteria other than the lactic acid bacteria group A to be added is not particularly limited, but may be an amount normally used for making yogurt. For example, 0.00001 to 5 parts by weight may be added to 100 parts by weight of the raw material mix, 0.00001 to 0.05 parts by weight for the freeze-dried type, and 0.01 to 5 parts by weight for the fermentation liquid type. Then, each lactic acid bacterium in yogurt can be easily adjusted to a predetermined number, which is desirable.

(Cooling and secondary fermentation process)
Furthermore, from the viewpoint of further suppressing offensive taste due to fermentation metabolites of lactic acid bacteria of lactic acid bacteria group A, it is preferable to cool down to 15 to 25° C. after completion of the fermentation step and perform secondary fermentation under the same temperature conditions. The temperature conditions for secondary fermentation are more preferably 15 to 19°C.

The secondary fermentation is preferably performed until the raw material mix has a pH of 4.2 to 4.65, from the viewpoint of further suppressing the off-taste caused by the fermentation metabolites of lactic acid bacteria of lactic acid bacteria group A. .6 is more preferred, and 4.3 to 4.6 are even more preferred.

In addition, the lactic acid bacteria group A may be added to the raw material mix after all the fermentation steps are completed without being added in any of the fermentation steps.

(Pulverization process)
By pulverizing the curd of the raw material mix obtained in the primary and / or secondary fermentation process after all the fermentation processes are completed so that the median diameter of the curd is 20 to 60 μm, the present embodiment can be obtained. Such yogurt can be obtained. The median diameter is more preferably 25 to 55 μm, still more preferably 30 to 50 μm, and particularly preferably 35 to 50 μm.

The pulverization of the curd can be performed by a known method, and specific examples include stirring in a tank, a method using a mesh filter, and the like. From the viewpoint of convenience and uniformity of card size, the method using a mesh filter is preferred.

Examples of the mesh filter include filters of 10 to 100 mesh, preferably filters of 10 to 90 mesh, and more preferably filters of 12 to 80 mesh. The pressure condition for passing through the mesh filter is, for example, preferably 0.005 to 0.4 MPa, more preferably 0.01 to 0.35 MPa, and even more preferably 0.05 to 0.2 MPa.

By the production method described above, a yogurt having a curd median diameter of 20 to 60 μm and a viscosity measured at 10° C. of 20 to 60 Pa·s can be obtained.

Even if the yogurt of the present invention contains lactic acid bacteria whose fermentation metabolites have an offensive taste, it is possible to provide a yogurt that does not contain lactic acid bacteria whose fermentation metabolites have an offensive taste and has the original flavor of yogurt.

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples. In addition, "parts" and "%" in the examples are based on weight.

Raw materials used in Examples and Comparative Examples are as follows.
1) Raw milk is treated with primary heating (75 ° C., 30 seconds) and secondary heating (115 ° C., 7 seconds) (milk fat content: 3.7%, milk protein content: 3.2%)
2) Meiji Co., Ltd. “Meiji Tokachi Fresh Cream 47” (milk fat content: 47.0%, milk protein content: 1.0%)
3) Kaneka Co., Ltd. "Kaneka skimmed milk powder" (milk fat content: 1.0%, milk protein content: 34.0%)
4) "WPC80" manufactured by Warrnambool Cheese and Butter (milk fat content: 4.8%, milk protein content: 76.5%)
5) “Yotsuba Whey Powder” manufactured by Yotsuba Milk Industry Co., Ltd. (milk fat content: 1.1%, milk protein content: 12.1%)
6) "AB-LIFE" manufactured by AB-Biotics (L.plantarum CECT7527, L.plantarum CECT7528, L.plantarum CECT7529)
7) Raw milk (milk fat content: 3.7%, milk protein content: 3.2%)

<Measurement of protein reduction value>
The measurement of the protein reduction value was carried out according to the method described in "Dairy Product Test Method and Commentary, edited by the Pharmaceutical Society of Japan" (Kinbara Publishing Co., Ltd., p. 131, published on March 20, 1984).

<Raw material mix component analysis>
Milk protein and milk fat were analyzed in accordance with the general method for analyzing nutritional components of dairy products, as described below.
Milk protein: Combustion method Milk fat: Roese-Gottlieb method The whey protein ratio in the milk protein in the yogurt mix was calculated as a theoretical value calculated from the protein content of each material and the whey protein ratio in the protein. Specifically, the whey protein ratio in the total protein in milk, raw milk, skim milk powder, and cream is 20%, and the whey protein ratio in the total protein in whey powder and WPC is 100%, and the milk protein in the yogurt mix The whey protein ratio of was calculated.

<Measurement of median diameter of yogurt curd>
The median diameter of the yogurt curd was measured by collecting the yogurt curd without breaking it and using water as a dispersion medium with a laser diffraction/scattering particle size distribution analyzer LA-960V2 (manufactured by Horiba, Ltd.). .

<Measurement of yogurt viscosity>
The viscosity of the yogurt curd was measured as No. 1 by a BH type viscometer. 4 rotor with a rotation speed of 2 rpm and a temperature of 10°C.

<Measurement of pH of yogurt>
The pH of yogurt was measured with a pH meter ("F-52" manufactured by Horiba, Ltd.).

<Measurement of the number of lactic acid bacteria in yogurt>
The number of lactic acid bacteria (X) in yogurt was measured by dissolving 24.7 g of BCP-added plate count agar "Nissui" (Nissui Pharmaceutical Co., Ltd.) in 1 L of purified water and sterilizing with high pressure steam at 121 ° C. for 15 minutes. After adjusting the temperature at 55°C, diluted yogurt was added to the plate, mixed with the medium, left to cool and solidified, cultured in a constant temperature bath at 35°C for 3 days, and colonies were counted.

The number of lactic acid bacteria (Y) of lactic acid bacteria group A in yogurt was measured by counting only colonies with a shape specific to lactic acid bacteria group A among the colonies expressed on the plate cultured by the above method.

The number of lactic acid bacteria other than lactic acid bacteria group A in yogurt was calculated by (X)-(Y).

<Sensory evaluation>
Ten skilled panelists were asked to eat and drink the yogurts obtained in Examples and Comparative Examples that had been temperature-controlled to 10 ° C., and the off-taste due to fermentation metabolites and the original flavor of yogurt derived from milk raw materials. Each sensory evaluation was performed from the point of view, and the average value of the evaluation points was described in each table as the evaluation value of the sensory evaluation. The evaluation criteria at that time were as follows.

(Unpleasant taste due to fermentation metabolites)
5 points: Better than the yogurt of Example 1, and no offensive taste due to the fermented metabolites of lactic acid bacteria group A 4 points: Equivalent to the yogurt of Example 1, due to the fermented metabolites of lactic acid bacteria group A No offensive taste 3 points: A little worse than the yogurt of Example 1, and an offensive taste due to fermentation metabolites of lactic acid bacteria of lactic acid bacteria group A is felt, but it is a level that is not a problem as a product 2 points: Yogurt of Example 1 1 point: much worse than the yogurt of Example 1, and an off-taste due to the fermentation metabolites of lactic acid bacteria group A is clearly felt

(Original flavor of yogurt derived from dairy ingredients)
Comparison with yogurt with no addition of lactic acid bacteria group A (Reference Examples 1 to 8) 5 points: Equivalent to Reference Example, and the original flavor of yogurt derived from dairy ingredients can be felt firmly 4 points: Slightly inferior to Reference Example However, the original flavor of yogurt derived from dairy ingredients can be felt 3 points: It is inferior to the reference example, and the original flavor of yogurt derived from dairy ingredients is felt slightly weak, but there is no problem in terms of product quality 2 points: Reference Worse than the example, the original flavor of yogurt derived from dairy ingredients is not felt much 1 point: Much worse than the reference example, the original flavor of yogurt derived from dairy ingredients is not felt at all

(comprehensive evaluation)
Comprehensive evaluation was performed based on the evaluation results of the off-taste due to fermentation metabolites and the original flavor of yogurt derived from dairy ingredients. The evaluation criteria in that case are as follows.
A: Bad taste due to fermentation metabolites and original flavor of yogurt derived from dairy ingredients satisfying 4.0 or more and 5.0 points or less B: Bad taste due to fermentation metabolites and original flavor of yogurt derived from dairy ingredients is 3.5 or more and 5.0 or less, and there is at least one of 3.5 or more and less than 4.0. .0 points or more and 5.0 points or less and at least one of 3.0 or more and less than 3.5 D: Offensive taste due to fermentation metabolites and the original flavor of yogurt derived from dairy ingredients is 2.0 A score of 2.0 or more and 5.0 or less and at least one score of 2.0 or more and less than 3.0 At least one score below 0

(Example 1)
According to the formulation in Table 1, 93.5 parts by weight of milk (protein reduction value: 9.0), 0.8 parts by weight of fresh cream, 4.7 parts by weight of skim milk powder, 0.5 parts by weight of WPC, and 0.5 parts by weight of whey powder. A raw material mix was prepared by adding and dissolving parts by weight. This was preheated to 60°C, homogenized using a high pressure homogenizer at a pressure of 3.5/17 MPa, heated to 90°C using a plate heat exchanger, and heated to 90°C for 30 minutes using a jacketed tank. After being heat-treated for 1 minute, it is cooled to 40°C, and 0.006 parts by weight of lactic acid bacteria X and 0.0009 parts by weight of lactic acid bacteria other than lactic acid bacteria group A (Streptococcus thermophilus, Lactobacillus delbrueckii subsp. Bulgaricus, Lactobacillus acidophilus, Bifidobacterium lactis) are added. The primary fermentation was carried out until the pH reached 4.7. After that, the mixture was cooled to 19°C by stirring and cooling in a tank, maintained at that temperature until the pH reached 4.5, and subjected to secondary fermentation, and then passed through a 60-mesh filter to obtain plain yogurt. After storing the obtained yogurt at 5 ° C. for 14 days, the number of lactic acid bacteria group A and lactic acid bacteria other than lactic acid bacteria group A, the median size of curd, viscosity, off-taste due to fermentation metabolites, and the original flavor of yogurt derived from dairy ingredients. The results are shown in Table 1.

(Examples 2 and 3)
Same as Example 1 except that the amount of lactic acid bacteria X added was changed from 0.006 parts by weight to 0.001 parts by weight (Example 2) or 0.12 parts by weight (Example 3) according to the formulation in Table 1. and got yogurt. After storing the obtained yogurt at 5 ° C. for 14 days, the number of lactic acid bacteria group A and lactic acid bacteria other than lactic acid bacteria group A, the median size of curd, viscosity, off-taste due to fermentation metabolites, and the original flavor of yogurt derived from dairy ingredients. The results are shown in Table 1.

(Comparative example 1)
Yogurt was obtained in the same manner as in Example 1 according to the formulation in Table 1, except that no lactic acid bacteria other than lactic acid bacteria group A were added. After storing the obtained yogurt at 5 ° C. for 14 days, the number of lactic acid bacteria group A and lactic acid bacteria other than lactic acid bacteria group A, the median size of curd, viscosity, off-taste due to fermentation metabolites, and the original flavor of yogurt derived from dairy ingredients. The results are shown in Table 1.

(Reference example 1)
Yogurt was obtained in the same manner as in Example 1 according to the formulation in Table 1, except that lactic acid bacteria X was not added in Example 1. The obtained yogurt was stored at 5° C. for 14 days and then evaluated. The results were compared with Examples 1 to 3 and Comparative Example 1 as shown in Table 1 as Reference Example 1.

As is clear from Table 1, in the whole yogurt, the number of lactic acid bacteria other than lactic acid bacteria group A is in the range of 1.0 × 10 ⁷ to 1.0 × 10 ¹¹ cfu / g (Examples 1 to 3) Also, the bad taste due to fermentation metabolites and the original flavor of yogurt derived from milk raw materials were evaluated as good results.

On the other hand, the yogurt to which no lactic acid bacteria other than lactic acid bacteria group A were added (Comparative Example 1) clearly felt an off-taste due to fermentation metabolites, and did not feel the original flavor of yogurt derived from dairy ingredients, and the overall evaluation was E. Met.

(Example 4)
According to the composition of Table 2, yogurt was obtained in the same manner as in Example 1, except that 0.8 parts by weight of fresh cream was changed to 0.8 parts by weight of water. After storing the obtained yogurt at 5 ° C. for 14 days, the number of lactic acid bacteria group A and lactic acid bacteria other than lactic acid bacteria group A, the median size of curd, viscosity, off-taste due to fermentation metabolites, and the original flavor of yogurt derived from dairy ingredients. The results are shown in Table 2.

(Reference example 2)
Yogurt was obtained in the same manner as in Example 4 according to the formulation in Table 2, except that lactic acid bacteria X was not added in Example 4. The obtained yogurt was stored at 5° C. for 14 days and then evaluated.

(Example 5)
Yogurt was obtained in the same manner as in Example 1, except that 93.5 parts by weight of milk was changed to 92.2 parts by weight and 0.8 parts by weight of fresh cream was changed to 2.1 parts by weight according to the formulation in Table 2. . After storing the obtained yogurt at 5 ° C. for 14 days, the number of lactic acid bacteria group A and lactic acid bacteria other than lactic acid bacteria group A, the median size of curd, viscosity, off-taste due to fermentation metabolites, and the original flavor of yogurt derived from dairy ingredients. The results are shown in Table 2.

(Reference example 3)
Yoghurt was obtained in the same manner as in Example 5 according to the formulation in Table 2, except that lactic acid bacteria X was not added in Example 5. The obtained yogurt was stored at 5° C. for 14 days and then evaluated.

(Comparative example 2)
According to the formulation in Table 2, 93.5 parts by weight of milk was changed to 80.0 parts by weight, 4.7 parts by weight of powdered skim milk was changed to 6.0 parts by weight, and 0.5 parts by weight of whey powder was changed to 0.4 parts by weight. A yogurt was obtained in the same manner as in Example 1, except that 0.8 parts by weight of fresh cream was not added and 13.1 parts by weight of water was added. After storing the obtained yogurt at 5 ° C. for 14 days, the number of lactic acid bacteria group A and lactic acid bacteria other than lactic acid bacteria group A, the median size of curd, viscosity, off-taste due to fermentation metabolites, and the original flavor of yogurt derived from dairy ingredients. The results are shown in Table 2.

(Reference example 4)
Yogurt was obtained in the same manner as in Comparative Example 2 according to the formulation in Table 2, except that lactic acid bacteria X was not added in Comparative Example 2. The obtained yogurt was stored at 5° C. for 14 days, and then evaluated.

As is clear from Table 2, all the yogurts (Examples 1, 4 and 5) with milk fat in the range of 3.5 to 4.5% by weight in the whole yogurt raw material mix have an offensive taste due to fermentation metabolites. , and the original flavor of yoghurt derived from milk raw materials were evaluated as good results.

On the other hand, the yogurt (Comparative Example 2), which has a low milk fat content of 3.0% by weight in the whole yogurt raw material mix, has an off-taste due to fermentation metabolites, and does not have the original flavor of yogurt derived from dairy ingredients. Comprehensive evaluation was D.

(Example 6)
According to the formulation in Table 3, 4.7 parts by weight of skim milk powder was changed to 2.6 parts by weight, 0.5 parts by weight of WPC was changed to 0.4 parts by weight, and 2.2 parts by weight of water was added. A yogurt was obtained in the same manner as in 1. After storing the obtained yogurt at 5 ° C. for 14 days, the number of lactic acid bacteria group A and lactic acid bacteria other than lactic acid bacteria group A, the median size of curd, viscosity, off-taste due to fermentation metabolites, and the original flavor of yogurt derived from dairy ingredients. The results are shown in Table 3.

(Reference example 5)
Yogurt was obtained in the same manner as in Example 6 according to the formulation in Table 3, except that lactic acid bacteria X was not added in Example 6. The obtained yogurt was stored at 5° C. for 14 days, and then evaluated.

(Example 7)
According to the formulation in Table 3, 93.5 parts by weight of milk to 92.3 parts by weight, 4.7 parts by weight of skim milk powder to 5.0 parts by weight, 0.5 parts by weight of WPC to 0.7 parts by weight, whey powder A yogurt was obtained in the same manner as in Example 1, except that 0.5 parts by weight was changed to 0.7 parts by weight and 0.5 parts by weight of water was added. After storing the obtained yogurt at 5 ° C. for 14 days, the number of lactic acid bacteria group A and lactic acid bacteria other than lactic acid bacteria group A, the median size of curd, viscosity, off-taste due to fermentation metabolites, and the original flavor of yogurt derived from dairy ingredients. The results are shown in Table 3.

(Reference example 6)
Yogurt was obtained in the same manner as in Example 7 according to the formulation in Table 3, except that lactic acid bacteria X was not added in Example 7. The obtained yogurt was stored at 5° C. for 14 days and then evaluated.

(Comparative Example 3)
According to the formulation in Table 3, 4.7 parts by weight of powdered skim milk was changed to 0.5 parts by weight, 0.5 parts by weight of WPC was changed to 0.4 parts by weight, and 0.5 parts by weight of whey powder was changed to 0.1 parts by weight. A yogurt was obtained in the same manner as in Example 1, except that 4.7 parts by weight of water was added. After storing the obtained yogurt at 5 ° C. for 14 days, the number of lactic acid bacteria group A and lactic acid bacteria other than lactic acid bacteria group A, the median size of curd, viscosity, off-taste due to fermentation metabolites, and the original flavor of yogurt derived from dairy ingredients. The results are shown in Table 3.

(Reference example 7)
Yogurt was obtained in the same manner as in Comparative Example 3 according to the formulation in Table 3, except that lactic acid bacteria X was not added in Comparative Example 3. The obtained yogurt was stored at 5° C. for 14 days and then evaluated.

As is clear from Table 3, milk protein is 4.3 to 5.4% by weight in the entire yogurt raw material mix, and the whey protein/casein protein ratio in the milk protein is 23/77 to 30/70 (weight ratio ), all the yogurts (Examples 1, 6 and 7) had good evaluation results for the off-taste due to fermentation metabolites and the original flavor of yogurt derived from dairy ingredients.

On the other hand, the yogurt (Comparative Example 3), which has a low milk protein content of 3.5% by weight in the whole yogurt raw material mix, has an off-taste due to fermentation metabolites, and does not have the original flavor of yogurt derived from dairy ingredients. Comprehensive evaluation was D.

(Example 8)
According to the composition and manufacturing conditions in Table 4, milk was replaced with raw milk, the sterilization conditions of the raw mix were changed from 90 ° C. for 30 minutes to 90 ° C. for 5 minutes, and the end point pH of the primary fermentation was changed from 4.7 to 4.6. obtained yogurt in the same manner as in Example 1. After storing the obtained yogurt at 5 ° C. for 14 days, the number of lactic acid bacteria group A and lactic acid bacteria other than lactic acid bacteria group A, the median size of curd, viscosity, off-taste due to fermentation metabolites, and the original flavor of yogurt derived from dairy ingredients. The results are shown in Table 4.

(Reference example 8)
Yogurt was obtained in the same manner as in Example 8 according to the formulation in Table 4, except that lactic acid bacteria X was not added in Example 8. The obtained yogurt was stored at 5° C. for 14 days and then evaluated.

As is clear from Table 4, both the yogurts (Examples 1 and 8) in which the protein reduction value of the raw material milk used in the raw material mix is in the range of 2 to 9 have an off-taste due to fermentation metabolites, and are derived from milk raw materials. The original flavor of yogurt was evaluated as good. In particular, the yoghurt (Example 8) using raw material milk with a protein reduction value of 4.4 gave better evaluation results.

(Example 9)
Yoghurt was obtained in the same manner as in Example 1, except that the addition timing of lactic acid bacteria X was changed from the raw material mix before fermentation to the raw material mix after secondary fermentation according to the formulation in Table 5. After storing the obtained yogurt at 5 ° C. for 14 days, the number of lactic acid bacteria group A and lactic acid bacteria other than lactic acid bacteria group A, the median size of curd, viscosity, off-taste due to fermentation metabolites, and the original flavor of yogurt derived from dairy ingredients. The results are shown in Table 5.

(Reference example 1)
Yogurt was obtained in the same manner as in Example 9 according to the formulation in Table 5, except that lactic acid bacteria X was not added in Example 9. The obtained yogurt was stored at 5° C. for 14 days and then evaluated.

As is clear from Table 5, in the whole yogurt, the number of lactic acid bacteria other than lactic acid bacteria group A is 1.0×10 ⁷ to 1.0×10 ¹¹ cfu/, and the number of lactic acid bacteria of lactic acid bacteria group A is 1.2×10 ⁵ Both yogurts in the range of ~7.0 × 10 ⁹ cfu / g (Examples 1 and 9) had good evaluation results for the off-taste due to fermentation metabolites and the original flavor of yogurt derived from dairy ingredients. .

Claims (4)

A yogurt containing 1.0×10 ⁷ to 1.0×10 ¹¹ cfu/g of at least one lactic acid bacterium other than lactic acid bacteria group A in the whole yogurt,
The yogurt is a fermented product of raw milk with a protein reduction value of 2 to 9 and a raw mix containing whey protein, wherein 3.5 to 4.5% by weight of milk fat and milk It contains 4.3 to 5.4% by weight of protein, and the whey protein/casein protein ratio in the milk protein is 23/77 to 30/70 (weight ratio),
Furthermore, it contains 1.2×10 ⁵ to 7.0×10 ⁹ cfu/g of at least one lactic acid bacterium contained in lactic acid bacteria group A,
The yogurt curd has a median diameter of 20 to 60 μm,
The yogurt has a viscosity of 20 to 60 Pa s at 10 ° C.
Yogurt.
Lactic acid bacteria group A: Lactobacillus plantarum CECT7527, Lactobacillus plantarum CECT7528, Lactobacillus plantarum CECT7529, Lactobacillus plantarum CECT7484, Lactobacillus plantarum CECT7485, and Pediococcus acidilactici CECT7483 The yogurt according to claim 1, wherein the lactic acid bacterium other than the lactic acid bacterium group A is at least one selected from the group consisting of Streptococcus thermophilus, Lactobacillus delbrueckii subsp. Bulgaricus, Lactobacillus acidophilus, and Bifidobacterium lactis. In the whole raw material mix, 0.2 to 2% by weight of at least one selected from the group consisting of whey powder, whey protein concentrate (WPC), and whey protein isolate (WPI), and 1 skim milk powder Yogurt according to claim 1 or 2, containing ~5.7% by weight. A raw material mix containing raw milk having a protein reduction value of 2 to 9 and whey protein, wherein 3.5 to 4.5% by weight of milk fat and 4.3 to 5% by weight of milk protein in the whole raw material mix A raw mix containing 4% by weight and having a whey protein/casein protein ratio in the milk protein of 23/77 to 30/70 (weight ratio),
Point A (80°C, 50 minutes), point B (90°C, 30 minutes) shown in the graph of FIG. C point (95°C, 30 min), D point (95°C, 1 min), E point (90°C, 1 min), F point (80°C, 5 min) Heat treatment under the heating conditions within the region,
At least one lactic acid bacterium selected from lactic acid bacteria group A and at least one lactic acid bacterium other than lactic acid bacteria group A is added to the raw material mix after the heat treatment, and the pH is 4.5 under a temperature condition of 39 to 41 ° C. Ferment until ~4.7,
The curd of the raw material mix after fermentation is pulverized so that the median diameter of the curd is 20 to 60 μm and the viscosity at 10 ° C. is 20 to 60 Pa s.
Yogurt production method.

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