JP2021016317A - Yogurt and manufacturing method of yogurt - Google Patents

Abstract

To provide yogurt having, in addition to thickness, smooth texture, and full feeling without adding food additive, starch, and dextrin that work as a stabilizer, and a manufacturing method of the yogurt.SOLUTION: Yogurt that is a fermentation product of yogurt mix that contains milk having a protein reduction value of 2 to 9, whey protein, and does not contain a stabilizer, in which the yogurt mix contains 93 to 98 mass% of the milk having the protein reduction value of 2 to 9, 3.8 to 4.5 mass% of milk fat content and 4.3 to 5.8 mass% of milk protein content in the total yogurt mix, and a value of ratio of whey protein/casein protein in the milk protein is 23/77 to 30/70 (mass ratio), a median diameter of curd is 25 to 60 μm, the viscosity measured with a BH type viscometer is 20 to 45 Pa s.SELECTED DRAWING: None

Description

The present invention relates to yogurt and a method for producing yogurt.

Conventionally, yogurt has been attracting attention for its health-promoting effect, but with the diversification of foods in recent years, there has been an increasing tendency to emphasize "preference" to enjoy the taste and texture of yogurt itself.

For example, Prior Document 1 describes fermented milk (yogurt) having a viscosity suitable for eating and having a fine and creamy structure. In Prior Document 1, a fermented milk raw material containing a specific amount of high-purity whey protein and not containing a thickener was heat-sterilized at a specific temperature for a specific time, cooled, and a lactic acid bacterium starter was added. A method for producing fermented milk (yogurt) is disclosed, which comprises crushing a fermented milk curd at a specific homogeneous pressure. However, although this fermented milk has a smooth texture, it is considered that the thickness and richness of the fermented milk are unsatisfactory due to the viscosity and the composition of the fermented milk raw material shown in the examples.

Japanese Unexamined Patent Publication No. 7-104

The present invention provides a yogurt that does not contain food additives, starch, dextrin, etc. that act as a stabilizer, has a smooth texture and a thick texture in addition to being rich, and a method for producing the yogurt. Make it an issue.

The first aspect of the present invention is yogurt which is a fermented yogurt mix containing milk having a protein reduction value of 2 to 9 and whey protein and containing no stabilizer, and the yogurt mix is a yogurt mix. In the whole yogurt mix, 93 to 98% by mass of milk having a protein reduction value of 2 to 9 is contained, the milk fat content is 3.8 to 4.5% by mass, and the milk protein content is 4.3 to 4.3 to The value of the whey protein / casein protein ratio in the milk protein is 5.8% by mass, and the value is 23/77 to 30/70 (mass ratio), and the median diameter of the curd is 25 to 60 μm. , BH type viscometer, No. With respect to yogurt, the viscosity measured at 10 ° C. at a rotation speed of 2 rpm using the rotor of 4 is 20 to 45 Pa · s. More preferably, the yogurt mix contains 0.5 to 2% by mass of at least one selected from the group consisting of whey powder, WPC and WPI, and 1.5 to 5 of skim milk powder in the whole yogurt mix. With respect to the yogurt described above, which contains .5% by mass.

A second aspect of the present invention is a yogurt mix containing milk having a protein reduction value of 2 to 9 and whey protein and containing no stabilizer, and the protein reduction value is high in the entire yogurt mix. It contains 93 to 98% by mass of 2 to 9 milks, a milk fat content of 3.8 to 4.5% by mass, a milk protein content of 4.3 to 5.8% by mass, and the above. For yogurt mix in which the ratio value of whey protein / casein protein in milk protein is 23/77 to 30/70 (mass ratio), the horizontal axis is the holding temperature (° C) and the vertical axis is the holding time after reaching the temperature. Point A (80 ° C, 50 minutes), point B (90 ° C, 30 minutes), point C (95 ° C, 30 minutes), point D (95 ° C, 1 minute) shown in the graph of FIG. ), E point (90 ° C., 1 minute), F point (80 ° C., 5 minutes) in order, and the step of heat-treating under the heating conditions in the region surrounded by the broken line, and after the heat treatment The process of primary fermenting the yogurt mix under a temperature condition of 39 to 41 ° C. until the pH reaches 4.65 to 4.85, and the card of the yogurt mix after the primary fermentation, the median diameter of the card is 20 to. Curd's median, including a step of crushing to 58 μm and a step of secondary fermentation of the crushed yogurt mix under temperature conditions of 15 to 25 ° C. until the pH reaches 4.2 to 4.75. The diameter is 25 to 60 μm, and the BH type viscometer shows No. The present invention relates to a method for producing yogurt, wherein the viscosity measured at 10 ° C. at a rotation speed of 2 rpm using the rotor of 4 is 20 to 45 Pa · s. More preferably, in the step of crushing the curd, the yogurt mix after the primary fermentation is passed through a filter of 10 to 25 mesh under a pressure condition of 0.01 to 0.45 MPa to grind the curd. The present invention relates to the above-mentioned method for producing yogurt.

A third aspect of the present invention is a yogurt mix containing milk having a protein reduction value of 2 to 9 and whey protein and containing no stabilizer, and the protein reduction value is high in the entire yogurt mix. It contains 93 to 98% by mass of 2 to 9 milks, a milk fat content of 3.8 to 4.5% by mass, a milk protein content of 4.3 to 5.8% by mass, and the above. For yogurt mix in which the ratio value of whey protein / casein protein in milk protein is 23/77 to 30/70 (mass ratio), the horizontal axis is the holding temperature (° C) and the vertical axis is the holding time after reaching the temperature. Point A (80 ° C, 50 minutes), point B (90 ° C, 30 minutes), point C (95 ° C, 30 minutes), point D (95 ° C, 1 minute) shown in the graph of FIG. ), E point (90 ° C., 1 minute), F point (80 ° C., 5 minutes) in order, and the step of heat-treating under the temperature condition in the region surrounded by the broken line, and after the heat treatment The step of fermenting the yogurt mix under a temperature condition of 39 to 41 ° C. until the pH reaches 4.5 to 4.7, and the card of the yogurt mix after fermentation have a median diameter of 25 to 60 μm. The median diameter of the curd, which includes the step of pulverizing the protein so as to be 25 to 60 μm, was determined by a BH type viscometer. The present invention relates to a method for producing yogurt, wherein the viscosity measured at 10 ° C. at a rotation speed of 2 rpm using the rotor of 4 is 20 to 45 Pa · s. More preferably, the method for producing yogurt according to the above method, wherein the curd is pulverized by passing the fermented yogurt mix through a filter of 10 to 25 mesh under a pressure condition of 0.005 to 0.4 MPa.

According to the present invention, yogurt having a smooth texture and a thick texture in addition to being rich, and a method for producing the yogurt, without adding food additives, starch, dextrin, etc. that act as stabilizers. Can be provided.

It is a figure which shows the heat treatment condition at the time of fermentation in the manufacturing method of yogurt which concerns on one Embodiment of this invention.

[Definition]
Unless otherwise specified, the terms related to milk and dairy products in this specification are used in Japan on December 27, 1952, Ministry of Health and Welfare Ordinance No. 52, "Ministerial Ordinance on Ingredient Standards for Milk and Dairy Products, etc." Follow the definition specified in. The definitions of the main terms are described below.
"Milk" refers to raw milk, milk, special milk, raw goat milk, sterilized goat milk, raw noodle milk, ingredient-adjusted milk, low-fat milk, non-fat milk and processed milk.
"Raw milk" refers to the milk of cows that have been exploited.
"Milk" refers to cow's milk sold for the purpose of direct drinking or for the production or processing of foods made from it.
"Special milk" refers to milk that is sold as special milk. "Raw goat milk" refers to goat milk as it is exploited. "Sterilized goat milk" refers to goat milk sold for the purpose of direct drinking. "Raw sheep milk" refers to as-exploited sheep milk. "Ingredient-adjusted milk" refers to raw milk from which milk fat and other components have been partially removed. "Low-fat milk" refers to component-adjusted milk from which milk fat has been removed, other than non-fat milk. "Fat-free milk" refers to ingredient-adjusted milk from which almost all milk fat has been removed.
"Skim milk powder" refers to milk powder obtained by removing almost all water from raw milk, milk or special milk from which the milk fat content has been removed.
"Whey powder" refers to powdered whey obtained by fermenting milk with lactic acid bacteria or adding enzymes or acids to the milk to remove almost all water.

The yogurt of the present invention is a fermented yogurt mix containing milk having a specific protein-reducing value and whey protein and containing no stabilizer. The yogurt mix contains a specific amount of milk, milk fat, and milk protein having the specific protein reducing value, and the weight ratio of whey protein / casein protein in the milk protein is a specific value. In addition, the median diameter of the yogurt card is within a specific range, and the BH type viscometer shows that the yogurt card has a No. The viscosities measured at 10 ° C. at a rotation speed of 2 rpm using the rotor of 4 are in a specific range.

The protein reduction value of milk used in the fermented product of the yogurt mix is preferably 2 to 9, and is not particularly limited, but is preferably raw milk or milk. The protein reduction value of the milk is more preferably 2 to 7, and even more preferably 2 to 5. The milk may be a mixture of a plurality of types of milk, for example, a mixture of raw milk and milk. When the milk is a mixture of a plurality of types of milk, the protein reduction value of the milk mixture may be 2 to 9, and milk having a protein reduction value of not 2 to 9 may be contained. When a mixture of milk is used, the mixing ratio is not particularly limited, but if the ratio of unsterilized raw milk is increased, the milk protein is denatured by the heat sterilization treatment and the viscosity is increased, so that the thickening feeling of yogurt tends to be improved.
The protein reduction value can be measured by a known method. Examples of the method for measuring the protein reduction value include the methods described in "Dairy Product Testing Method / Commentary edited by the Pharmaceutical Society of Japan" (Kanehara Publishing Co., Ltd., p.131, published on March 20, 1984). Be done.
The content of the milk having a protein reduction value of 2 to 9 is preferably 93 to 98% by mass, and more preferably 93 to 96% by mass in the whole yogurt mix. If the milk content is less than 93% by mass, the smooth texture may be insufficient, and if it is more than 98% by mass, it may be difficult to adjust the composition of the yogurt mix to a preferable range.

The milk protein is a milk-derived protein and comprises the whey protein and casein protein. As the source of the milk protein, the following substances having a high milk protein content are preferably used, for example, whey, unsalted whey, whey powder (including desalted whey powder), whey protein concentrate. (WPC), Whey Protein Isolate (WPI), Whole Fat Powder, Non-Fat Powder, Whole Fat Concentrate, Non-Fat Concentrate, High Purity Milk Protein (TMP), Milk Protein Concentrate (MPC), Milk Protein Isolate (MPI) ), Sugar-free milk, sugar-free fat-free milk, sugar-free milk, sugar-free fat-free milk, and the like.
Among the milk proteins, from the viewpoint of flavor, it is preferable to include skim milk powder and skim milk powder, and more preferably skim milk powder is contained. When skim milk powder is used, the content thereof is preferably 1.5 to 5.5% by mass, more preferably 2 to 5.5% by mass, and even more preferably 3 to 5% by mass in the entire yogurt mix. .. If the content of skim milk powder is less than 1.5% by mass, the thickening feeling may be insufficient, and if it is more than 5.5% by mass, the smooth texture may be impaired.
The content of the milk protein is preferably 4.3 to 5.8% by mass, more preferably 4.3 to 5.4% by mass, and even more preferably 4.5 to 5.2% by mass in the entire yogurt mix. When the content of milk protein in the whole yogurt mix is within the above range, the richness and thickening of yogurt are improved. The content of milk protein in the yogurt mix can be measured by a known method, and examples thereof include a combustion method.

Whey protein is one of the milk proteins contained in whey, and the whey protein contained in the yogurt mix is preferably derived from a whey protein source which is blended separately from milk. Examples of the whey protein source include the above-mentioned whey protein source, but whey powder, whey protein concentrate, and whey protein isolate are preferable. Since whey protein is easily heat-denatured, by heat-denaturing the yogurt mix under specific conditions, the whey protein is heat-denatured to increase its viscosity, and the yogurt is given a thick feeling.
As the whey protein source, at least one selected from the group consisting of whey powder, WPC and WPI is preferably contained in the total yogurt mix in an amount of 0.5 to 2% by mass, preferably 0.5 to 1.5% by mass. It is more preferably contained, and even more preferably 0.7 to 1.2% by mass. If the content of the whey protein source is less than 0.5% by mass, the thickening feeling may be insufficient or the flavor may not be improved, and if it is more than 2% by mass, the smooth texture may be impaired.

The whey powder is, for example, spray-dried of a liquid (cheese whey) produced as a by-product when raw milk is coagulated to produce cheese. The main components of whey powder are lactose (60-80%), whey protein (7-30%), and inorganic salts (3-12%). As the whey powder, desalted whey powder may be used.
The whey protein concentrate (WPC) is a powder obtained by removing lactose from cheese whey by membrane treatment and concentrating the protein to 30 to 95%.
The whey protein isolate (WPI) has a higher whey protein content than the whey protein concentrate.

In the yogurt mix of the present invention, the whey protein / casein protein in the milk protein is preferably 23/77 to 30/70 (mass ratio), more preferably 25/75 to 30/70, and 25/75. ~ 28/72 is more preferable. If the ratio is smaller than 23/77, the thickening feeling may be insufficient, and if it is larger than 30/70, the rich flavor may be insufficient or the smooth texture may be poor.
Here, the content of the whey protein and the content of the casein protein can be measured by separating the milk protein by electrophoresis and then quantifying the band of each protein by dye binding.

The milk fat is a fat content derived from milk. The milk fat contained in the yogurt mix is preferably derived from milk, whey protein sources, and dairy products. Examples of the dairy product include cream, fermented cream, butter, fermented butter, buttermilk, buttermilk powder, butter oil, full-fat powdered milk, and full-fat concentrated milk. Among them, cream, fermented cream, butter, fermented butter, and butter oil, which are dairy products having a high milk fat content, are preferable. The milk fat content is preferably 3.8 to 4.5% by mass, more preferably 4.1 to 4.5% by mass in the entire yogurt mix. If the milk fat content is less than 3.8% by mass, the rich flavor may be insufficient, and if it is more than 4.5% by mass, the thickening feeling may be insufficient. The content of milk fat in the yogurt mix can be measured by a known method. Examples of the method for measuring milk fat include the Reese Gottlieb method.

The yogurt mix may contain other ingredients in addition to milk, milk protein sources and milk fat sources. However, in this embodiment, the yogurt mix is characterized by not containing a stabilizer. As used herein, the term "stabilizer" refers to food additives, starches, and dextrins used to increase the viscosity of yogurt and stabilize the viscosity of yogurt during storage and distribution. Examples of the food additive include thickeners for foods, such as pectin, gelatin, carrageenan, agar, arabic gum, sodium alginate, xanthan gum, locust bean gum, carboxymethyl cellulose, and processed starch.
The yogurt of the present invention uses a yogurt mix having a specific composition and adjusts the median diameter to a specific range to obtain a rich flavor like Greek yogurt or Belgian yogurt without using a stabilizer. In addition, yogurt with a smooth texture and a thick texture can be obtained.

Examples of the other components include fructose, glucose, sucrose, and flavors.

In the present specification, the fermented product of yogurt mix refers to a yogurt mix inoculated with a lactic acid bacterium starter and fermented. Specifically, the fermented yogurt mix can be prepared by the method for producing yogurt described later.

<Median diameter and viscosity of card>
The yogurt according to this embodiment preferably has a median diameter of 25 to 60 μm, more preferably 30 to 55 μm, further preferably 35 to 50 μm, and particularly preferably 40 to 50 μm. If the median diameter is smaller than 25 μm, the rich flavor and thick texture may be insufficient, and if it is larger than 60 μm, the rich flavor and smooth texture may be insufficient.
The median diameter of the card can be measured by a known method. Examples of the method for measuring the median diameter of the card include a method of measuring using a laser diffraction / scattering type particle size distribution measuring device. Examples of the laser diffraction / scattering type particle size distribution measuring device include LA-960V2 (manufactured by HORIBA, Ltd.) and the like.

The yogurt according to this embodiment was subjected to No. 1 by a BH type viscometer. The viscosity measured at 10 ° C. at a rotation speed of 2 rpm using the rotor of 4 is preferably 20 to 45 Pa · s, more preferably 25 to 45 Pa · s, still more preferably 25 to 40 Pa · s. If the viscosity is lower than 20 Pa · s, the rich flavor and thick texture may be insufficient, and if it is higher than 45 Pa · s, the rich flavor and smooth texture may be insufficient.
The yogurt of the present invention is a fermented yogurt mix having a specific composition as described above, and the median diameter and viscosity of the curd are within a specific range, so that the yogurt has a rich flavor and a smooth texture. And all of the thickening feeling can be satisfied.

The yogurt of the present invention can be produced by the method for producing a yogurt mix described later.

<In the case of two-stage fermentation>
In the present invention, the step a1 of heat-treating the yogurt mix at a specific heating temperature, the step a2 of primary fermenting the yogurt mix after the heat treatment under specific conditions and indexes, and the yogurt mix after the primary fermentation. The card has a median diameter of 25 to 60 μm by a manufacturing method including a step a3 of crushing the card according to a specific index and a step a4 of secondary fermentation of the crushed yogurt mix under specific conditions and an index. Yes, according to the BH type viscometer, No. Using the rotor of No. 4, a yogurt having a viscosity measured at 10 ° C. of 20 to 45 Pa · s can be produced at a rotation speed of 2 rpm. Specifically, it is as follows.

(Step a1)
Point A (80 ° C., 50 minutes) and point B (90 ° C.) shown in the graph of FIG. 1 in which the horizontal axis represents the holding temperature (° C.) and the vertical axis represents the holding time (minutes) after reaching the temperature. , 30 minutes), C point (95 ° C, 30 minutes), D point (95 ° C, 1 minute), E point (90 ° C, 1 minute), F point (80 ° C, 5 minutes) in order. It is preferable to perform heat treatment under the heating conditions in the region surrounded by the connecting broken line. If heat treatment is performed under conditions outside the above range, the rich flavor and thick texture may be insufficient, or the smooth texture may be inferior. The yogurt mix can be prepared by mixing milk, a whey protein source, and optionally other components. The yogurt mix is preferably homogenized using an apparatus such as a homogenizer, a microfludizer, or a colloid mill after mixing and dissolving the raw materials.
Further, the heat treatment is performed, for example, by raising the temperature of the yogurt mix using an apparatus used for heat sterilization, placing it in an apparatus capable of holding it by heating, reaching the sterilization temperature, and then holding it for a predetermined time. This sterilizes the yogurt mix. The heating device for performing heat sterilization of milk is not particularly limited as the heat sterilization device, and can be appropriately selected, but a flow path type sterilization device is preferable in consideration of productivity. Examples of such a sterilizer include, but are not limited to, a plate type sterilizer, a tube type sterilizer, a spin injection type sterilizer, and a Joule type sterilizer. Further, examples of the device for holding the heating reach include, but are not limited to, a container with a jacket capable of retaining heat, a tank, and the like. In FIG. 1, the holding temperature on the horizontal axis is the sterilization temperature, and the holding time after reaching the temperature on the vertical axis is the time for holding at the temperature after reaching the sterilization temperature. For example, point A (80 ° C., 50 minutes) in FIG. 1 is a heating condition in which the sterilization temperature is 80 ° C. and the temperature is maintained for 50 minutes.
By setting the heating conditions as described above, the whey protein that is easily heat-denatured can be gelled and the viscosity of the yogurt mix can be increased. In addition, the whey protein denatured by heat treatment is adsorbed on the surface of undenatured casein micelles (casein protein exists as colloidal particles with a diameter of 30 to 600 nm called casein micelles in milk), and the hydrophobicity of the micelle surface. Increased properties and facilitates acid aggregation of micelles. As a result, in the step a1 described later, the curd becomes larger as the fermentation progresses. Further, by using a yogurt mix having whey protein / casein protein = 23/77 to 30/70 (mass ratio), micelles are more likely to aggregate.

(Step a2)
It is preferable that the heat-treated yogurt mix obtained in step a1 is primarily fermented under a temperature condition of 39 to 41 ° C. until the pH reaches 4.65 to 4.85. More preferably, the primary fermentation is carried out until the pH reaches 4.65 to 4.8. If the primary fermentation is performed under conditions outside the above range, the rich flavor and thickening may be insufficient.
The lactic acid bacterium starter is not particularly limited, and a known lactic acid bacterium starter can be used. Examples of the lactic acid bacterium starter include lactic acid bacteria belonging to Lactococcus, Streptococcus, Pediococcus, Leuconostoc, and Lactobacillus lactobacillus (Lactobacillus). ) Etc. can be mentioned. Specific examples include Streptococcus thermophilus, Lactobacillus delbruecchii subsp. Examples include Bulgaricus, Lactobacillus acidophilus, Bifidobacterium lactis and the like.

(Step a3)
The curd of the yogurt mix after the primary fermentation obtained in step a2 is preferably pulverized so that the median diameter of the curd is 20 to 58 μm, more preferably 25 to 53 μm, further preferably 30 to 48 μm, and 35 to 48 μm. Is particularly preferable. If the median diameter of the card is smaller than 20 μm, the thickening feeling may be insufficient, and if it is larger than 58 μm, the rich flavor may be insufficient or the smooth texture may be poor.
The curd can be pulverized by a known method. Examples of the card crushing method include a method using a stirring blade, a pump, a homomixer, a homogenizer, a mesh filter, and the like. From the viewpoint of convenience and card size uniformity, a method using a mesh filter is used. Is preferable. Examples of the mesh filter include a filter of 10 to 25 mesh, a filter of 10 to 20 mesh is preferable, and a filter of 12 to 18 mesh is more preferable. Examples of the pressure condition for passing through the mesh filter include 0.01 to 0.45 MPa, preferably 0.1 to 0.4 MPa, more preferably 0.15 to 0.3 MPa, and 0.2 to 0.25 MPa. Is even more preferable.

(Step a4)
It is preferable that the pulverized yogurt mix obtained in step a3 is secondarily fermented under temperature conditions of 15 to 25 ° C. until the pH reaches 4.2 to 4.75. The temperature condition is more preferably 15 to 19 ° C. Further, in the secondary fermentation, the secondary fermentation is more preferable until the pH of the yogurt mix reaches 4.2 to 4.6, and 4.3 to 4.6 is further preferable. By performing the secondary fermentation, a large curd can be regenerated, and the richness and thickness of the yogurt can be improved. If secondary fermentation is performed under conditions outside the above range, the rich flavor and thickening may be insufficient.

The yogurt obtained by the production method of the present invention has a median diameter of 25 to 60 μm, and is No. 1 by a BH type viscometer. The viscosity measured at 10 ° C. at a rotation speed of 2 rpm using the rotor of 4 is 20 to 45 Pa · s.

According to the above-mentioned method for producing yogurt, it is possible to produce yogurt having a rich flavor, a smooth texture, and a thick texture. In the method for producing yogurt, by sterilizing a yogurt mix having a specific composition containing whey protein in a specific ratio under specific heating conditions, the whey protein that is easily heat-denatured is denatured and gelled, and the viscosity is increased. .. In addition, the denatured whey protein is adsorbed on the surface of the undenatured casein micelle, the hydrophobicity of the micelle surface is increased, and the micelle is easily acid-aggregated. Therefore, as the fermentation progresses, the card becomes larger. Further, a smooth texture is imparted by crushing the curd so as to have a specific median diameter, and then a secondary fermentation is performed to regenerate the curd to impart a thick texture. Further, by using a yogurt mix having a specific composition, a rich flavor is imparted.

<In the case of one-stage fermentation>
In the present invention, a step b1 of heat-treating the yogurt mix under a specific temperature condition, a step b2 of fermenting the heat-treated yogurt mix obtained in the step b1 under a specific temperature condition and an index, and a step b2. According to the production method including the step b3 of crushing the curd of the yogurt mix after fermentation obtained in the above with a specific index, the median diameter of the curd was 25 to 60 μm, and the BH type viscometer showed No. Using the rotor of No. 4, a yogurt having a viscosity measured at 10 ° C. of 20 to 45 Pa · s can be produced at a rotation speed of 2 rpm. Specifically, it is as follows.

(Step b1)
Point A (80 ° C., 50 minutes) and point B (90 ° C.) shown in the graph of FIG. 1 in which the horizontal axis represents the holding temperature (° C.) and the vertical axis represents the holding time (minutes) after reaching the temperature. , 30 minutes), C point (95 ° C, 30 minutes), D point (95 ° C, 1 minute), E point (90 ° C, 1 minute), F point (80 ° C, 5 minutes) in order. It is preferable to perform heat treatment under the heating conditions in the region surrounded by the connecting broken line. If heat treatment is performed under conditions outside the above range, a rich flavor and a thick feeling may be insufficient.

(Step b2)
The heat-treated yogurt mix obtained in step b1 is preferably fermented under temperature conditions of 39 to 41 ° C. until the pH reaches 4.5 to 4.7, with 4.5 to 4.65 further. preferable. In step b2, fermentation is carried out longer than in step a2, so that the formation of cards progresses and the median diameter of the cards becomes larger than in step a2. Fermentation under conditions and indicators outside the above range may result in a lack of rich flavor and thickening.

(Step b3)
It is preferable that the curd of the fermented yogurt mix obtained in step b2 is pulverized so that the median diameter of the curd is 25 to 60 μm. Examples of the card crushing method include the same method as in step a3, but a method using a mesh filter is preferable from the viewpoint of simplicity and uniformity of card size. Examples of the mesh filter include a filter of 10 to 25 mesh, a filter of 10 to 20 mesh is preferable, and a filter of 12 to 18 mesh is more preferable. Examples of the pressure condition for passing through the mesh filter include 0.005 to 0.4 MPa, preferably 0.01 to 0.35 MPa, and more preferably 0.05 to 0.2 MPa.

In step b3, it is preferable that the yogurt mix fermented in step b2 is passed through a filter of 10 to 25 mesh under a pressure condition of 0.005 to 0.4 MPa to pulverize the curd.
In this step, the texture of yogurt can be smoothed by crushing the curd so that the median diameter of the curd is within a specific range.

According to the method for producing yogurt by one-stage fermentation as described above, yogurt having a rich flavor, a smooth texture, and a thick texture can be produced. In the method for producing yogurt by one-stage fermentation, the fermentation after the heat treatment is performed longer than the production method by two-stage fermentation to form a large curd. Further, by crushing the card so as to have a specific median diameter, a smooth texture is imparted and a thickening feeling is imparted. Further, by using a yogurt mix having a specific composition, a rich flavor is imparted. In the method for producing yogurt by one-stage fermentation, the fermentation in step b2 is carried out for a long time, and the crushing treatment is carried out so that the median diameter of the curd is 25 to 60 μm, so that a rich flavor can be obtained without performing secondary fermentation. A smooth texture and a thick feeling can be imparted.

The yogurt of the present invention can be eaten as it is, or mixed with confiture or jam to enhance the smoothness, and the richness of yogurt and the flavor of confiture or jam can be felt in a well-balanced manner.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these examples.

[Measuring method]
<Measurement of protein reduction value>
The protein reduction value was measured according to the method described in "Dairy Product Test Method / Commentary edited by The Pharmaceutical Society of Japan" (Kanehara Publishing Co., Ltd., p.131, published on March 20, 1984).

<Yogurt mix component analysis>
Milk protein and milk fat were analyzed according to a general nutritional component analysis method for dairy products as follows.
Milk protein: Burning method Milk fat: Reese 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 ratio of whey protein in total protein in milk, defatted milk powder, and cream is 20%, the ratio of whey protein in total protein in whey powder is 100%, and the ratio of whey protein in milk protein in yogurt mix. Was calculated.

<Measurement of viscosity>
The viscosity of yogurt was determined by a BH type viscometer (manufactured by Tokyo Keiki Co., Ltd.). Using the rotor of 4, the measurement was performed at a rotation speed of 2 rpm at 10 ° C.

<Median diameter of card>
The median diameter of the yogurt card was measured by a laser diffraction / scattering type particle size distribution measuring device LA-960V2 (manufactured by Horiba Seisakusho Co., Ltd.) using water as a dispersion medium.

<Sensory evaluation>
We asked 10 skilled panelists to eat and drink each yogurt obtained in Examples and Comparative Examples at a temperature of 10 ° C, and each from the viewpoint of rich flavor, smooth texture, and thickening. The sensory evaluation was performed, and the average value of the evaluation points was shown in each table as the evaluation value of the sensory evaluation. The evaluation criteria at that time were as follows.

(Rich flavor)
5 points: Better than the yogurt of Example 7 and a strong flavor is felt 4 points: Equivalent to the yogurt of Example 7 and a rich flavor is felt 3 points: A little worse than the yogurt of Example 7 It is hard to feel the rich flavor 2 points: It is worse than the yogurt of Example 7 and it is hard to feel the rich flavor 1 point: It is much worse than the yogurt of Example 7 and the rich flavor is not felt

(Smooth texture)
5 points: Better than the yogurt of Example 7 and a strong smooth texture 4 points: Equivalent to the yogurt of Example 7 and a smooth texture 3 points: A little more than the yogurt of Example 7 Poor and slightly difficult to feel a smooth texture 2 points: Worse than the yogurt of Example 7 and difficult to feel a smooth texture 1 point: Very worse than the yogurt of Example 7 and a smooth texture Can't feel

(Thickness)
5 points: Very better than the yogurt of Example 7 and a very strong feeling of thickening 4 points: Better than the yogurt of Example 7 and a strong feeling of thickening 3 points: Equivalent to the yogurt of Example 7 So, you can feel the thickening feeling 2 points: It is worse than the yogurt of Example 7 and it is hard to feel the thickening feeling 1 point: It is much worse than the yogurt of Example 7 and you can not feel the thickening feeling

(Comprehensive evaluation)
A comprehensive evaluation was performed based on the evaluation results of rich flavor, smooth texture, and thick texture. The evaluation criteria at that time are as follows.
A: Rich flavor, smooth texture, and thick texture all satisfy 4.0 points or more and 5.0 points or less.
B: Rich flavor, smooth texture, and thick texture are all 3.5 points or more and 5.0 points or less, and at least one of 3.5 points or more and less than 4.0 points.
C: A product having a rich flavor, a smooth texture, and a thick texture of 3.0 points or more and 5.0 points or less, and at least one of 3.0 points or more and less than 3.5 points.
D: A product having a rich flavor, a smooth texture, and a thick texture of 2.0 points or more and 5.0 points or less, and at least one of 2.0 or more and less than 3.0 points.
E: At least one score of less than 2.0 in the evaluation of rich flavor, smooth texture, and thick texture.

(Raw materials used in Examples and Comparative Examples)
1) Raw milk (milk fat content: 3.7%, milk protein content: 3.2%)
2) Milk treated with raw milk by primary heating (75 ° C, 30 seconds) and secondary heating (115 ° C, 7 seconds) (milk fat content: 3.7%, milk protein content: 3.2%)
3) Milk treated with raw milk by primary heating (60 ° C, 30 seconds) and secondary heating (135 ° C, 2 seconds) (milk fat content: 3.7%, milk protein content: 3.2%)
4) "Meiji Tokachi Fresh Cream 47" manufactured by Meiji Co., Ltd. (milk fat content: 47.0%, milk protein content: 1.0%)
5) "Kaneka skim milk powder" manufactured by Kaneka Corporation (milk fat content: 1.0%, milk protein content: 34.0%)
6) "WPC80" manufactured by Warrnambool Cheese and Butter (milk fat content: 4.8%, milk protein content: 76.5%)
7) Yotsuba Whey Powder manufactured by Yotsuba Dairy Co., Ltd. (milk fat content: 1.1%, milk protein content: 12.1%)

[Yogurt production example]
(Examples 1 to 6, Comparative Examples 1 to 8)
Each material was mixed at the blending ratio shown in Table 1 to prepare a yogurt mix of each example. These are preheated to 60 ° C., homogenized at a pressure of 3.5 / 17 MPa using a high-pressure homogenizer, heated to 90 ° C. using a plate heat exchanger, and 10 at 90 ° C. in a tank with a jacket. It was held for a minute and heat-treated.
Then, the mixture was cooled to 40 ° C., 0.0009 parts by weight of lactic acid bacterium starters (Streptococcus thermophilus, Lactobacillus delbrueckii subsp. Bulgaricus, Lactobacillus acidophilus, Bifidobacterium lactis) were added, and primary fermentation was carried out until the pH reached 4.7.
The yogurt mix after the primary fermentation was passed through a 15 mesh filter at the pressure shown in Table 1 to grind the curds.
Then, it was cooled to 19 ° C. using a plate-type cooler, and kept at that temperature until the pH reached 4.5 for secondary fermentation.
Then, it was filled in a retail container and cooled to 8 ° C. in a refrigerated warehouse to obtain yogurt. The obtained yogurt was measured for viscosity and median diameter of curd, and sensory evaluation was performed. The results are shown in Table 1.

In Examples 1 to 6, the rich flavor, smooth texture, and thick texture were all good evaluation results, and the overall evaluation was A to C. On the other hand, in Comparative Examples 1 to 8, one or more of the rich flavor, the smooth texture, and the thick texture were inferior, and the overall evaluation was D or E. From this result, 93 to 98% by mass of milk having a protein reduction value of 2 to 9 was contained, the milk fat content was 3.8 to 4.5% by mass, and the milk protein content was 4.3 to 5.8. By using a yogurt mix, which is by mass% and the value of the whey protein / casein protein ratio in the milk protein is whey protein / casein protein = 23/77 to 30/70 (mass ratio), it is concentrated. It was confirmed that a yogurt having a good flavor, a smooth texture, and a thick feeling can be obtained.

(Examples 7 to 10, Comparative Examples 9 to 12)
Each material was mixed in the same blending ratio as in Example 1 to prepare a yogurt mix of each example. These are preheated to 60 ° C., homogenized at a pressure of 3.5 / 17 MPa using a high-pressure homogenizer, heated to the temperature of the sterilization conditions shown in Table 2 using a plate heat exchanger, and a tank with a jacket. Then, heat treatment was performed under the sterilization conditions shown in Table 2.
Then, the mixture was cooled to 40 ° C., 0.0009 parts by weight of lactic acid bacterium starters (Streptococcus thermophilus, Lactobacillus delbrueckii subsp. Bulgaricus, Lactobacillus acidophilus, Bifidobacterium lactis) were added, and primary fermentation was carried out until the pH reached 4.7.
The yogurt mix after the primary fermentation was passed through a 15 mesh filter at the pressure shown in Table 2 to grind the curds.
Then, it was cooled to 19 ° C. using a plate-type cooler, and maintained at that temperature until the pH reached 4.5 for secondary fermentation.
Then, it was filled in a retail container and cooled to 8 ° C. in a refrigerated warehouse to obtain yogurt. The obtained yogurt was measured for viscosity and median diameter of curd, and sensory evaluation was performed. The results are shown in Table 2 together with the results of Example 1.

In Examples 1 and 7 to 10, the rich flavor, smooth texture, and thick texture were all good evaluation results, and the overall evaluation was A or C. On the other hand, in Comparative Examples 9 to 12, one or more of the rich flavor, the smooth texture, and the thick texture were inferior, and the overall evaluation was D. From this result, the heat treatment for sterilization was performed at points A (80 ° C., 50 minutes), B point (90 ° C., 30 minutes), C point (95 ° C., 30 minutes), and D point (95 minutes) shown in FIG. By heating under the heating conditions in the area surrounded by the broken line connected by 6 points, point E (90 ° C, 1 minute), point F (80 ° C, 5 minutes), a rich flavor, It was confirmed that yogurt with a smooth texture and a good thickening feeling could be obtained.

(Examples 11 to 13, Comparative Examples 13 to 20)
Each material was mixed in the same blending ratio as in Example 1 to prepare a yogurt mix of each example. These are preheated to 60 ° C., homogenized at a pressure of 3.5 / 17 MPa using a high-pressure homogenizer, heated to 90 ° C. using a plate heat exchanger, and 10 at 90 ° C. in a tank with a jacket. It was held for a minute and heat-treated.
Then, the mixture was cooled to the primary fermentation temperature shown in Table 3, and 0.0009 parts by weight of lactic acid bacterium starters (Streptococcus thermophilus, Lactobacillus delbrueckii subsp. Bulgaricus, Lactobacillus acidophilus, Bifidobacterium lactis) were added, and the primary fermentation temperature was reached. Fermentation was performed.
The yogurt mix after the primary fermentation was passed through a 15 mesh filter at the pressure shown in Table 3 to grind the curds.
Then, it was cooled to the temperature shown in Table 3 using a plate-type cooler, and kept at that temperature until the pH shown in Table 3 was reached, and secondary fermentation was carried out. No secondary fermentation was carried out in Example 12 and Comparative Example 20.
Then, it was filled in a retail container and cooled to 8 ° C. in a refrigerated warehouse to obtain yogurt. The obtained yogurt was measured for viscosity and median diameter of curd, and sensory evaluation was performed. The results are shown in Table 3 together with the results of Example 1.

In Examples 1 and 11 to 13, the rich flavor, smooth texture, and thick texture were all good evaluation results, and the overall evaluation was A or C. On the other hand, in Comparative Examples 13 to 20, any one or more of the rich flavor, the smooth texture, and the thick texture was inferior, and the overall evaluation was D or E. From this result, it was confirmed that yogurt having a rich flavor, a smooth texture, and a good thickening feeling can be obtained by adjusting the primary fermentation conditions and the curd crushing conditions and performing the secondary fermentation. In addition, it was confirmed that yogurt with a rich flavor, smooth texture, and good thickening can be obtained by performing the primary fermentation for a long time and adjusting the curd crushing conditions even when the secondary fermentation is not performed. It was.

(Example 14)
A retail container was filled with 18 g of blueberry confiture, and then 82 g of the yogurt mix after the completion of the secondary fermentation of Example 1 was filled therein to prepare a two-layer type yogurt. When the obtained yogurt was ate at a temperature of 10 ° C, 8 out of 10 panelists answered that the smoothness was more pronounced than eating the yogurt itself, and among the 10 panelists. Seven respondents said that the richness of yogurt and the flavor of blueberry confiture were well-balanced.

According to the present invention, yogurt having a smooth texture and a thick texture in addition to being rich, and a method for producing the yogurt, without adding food additives, starch, dextrin, etc. that act as stabilizers. Can be provided.

Claims (6)

A yogurt that is a fermented yogurt mix that contains milk with a protein reduction value of 2 to 9 and whey protein and does not contain stabilizers.
The yogurt mix contains 93 to 98% by mass of milk having a protein reduction value of 2 to 9, a milk fat content of 3.8 to 4.5% by mass, and a milk protein content in the whole yogurt mix. Is 4.3 to 5.8% by mass, and the value of the ratio of whey protein / casein protein in the milk protein is 23/77 to 30/70 (mass ratio).
The median diameter of the card is 25-60 μm
According to the BH type viscometer, No. The viscosity measured at 10 ° C. at a rotation speed of 2 rpm using the rotor of 4 is 20 to 45 Pa · s.
Yogurt. The yogurt mix contains 0.5 to 2% by mass of at least one selected from the group consisting of whey powder, WPC and WPI, and 1.5 to 5.5% by mass of skim milk powder in the whole yogurt mix. The yogurt according to claim 1. A yogurt mix containing milk having a protein reduction value of 2 to 9 and whey protein and containing no stabilizer.
In the whole yogurt mix, 93 to 98% by mass of milk having a protein reduction value of 2 to 9 is contained, the milk fat content is 3.8 to 4.5% by mass, and the milk protein content is 4.3 to 4.3 to A yogurt mix containing 5.8% by mass and having a whey protein / casein protein ratio of 23/77 to 30/70 (mass ratio) in the milk protein.
Point A (80 ° C., 50 minutes), point B (90 ° C., 30 minutes), shown in the graph of FIG. 1 where the horizontal axis is the holding temperature (° C.) and the vertical axis is the holding time (minutes) after reaching the temperature. It is surrounded by a broken line connecting points C (95 ° C, 30 minutes), D (95 ° C, 1 minute), E point (90 ° C, 1 minute), and F point (80 ° C, 5 minutes) in order. The process of heat treatment under the heating conditions in the area
A step of primary fermentation of the yogurt mix after the heat treatment under a temperature condition of 39 to 41 ° C. until the pH reaches 4.65 to 4.85.
A step of crushing the yogurt mix curd after the primary fermentation so that the median diameter of the curd is 20 to 58 μm, and
A step of secondary fermentation of the pulverized yogurt mix under a temperature condition of 15 to 25 ° C. until the pH reaches 4.2 to 4.75 is included.
The median diameter of the card is 25-60 μm
According to the BH type viscometer, No. The viscosity measured at 10 ° C. at a rotation speed of 2 rpm using the rotor of 4 is 20 to 45 Pa · s.
How to make yogurt. In the step of crushing the curd, the yogurt mix after the primary fermentation is passed through a filter of 10 to 25 mesh under a pressure condition of 0.01 to 0.45 MPa to crush the curd, according to claim 3. The method for producing yogurt described. A yogurt mix containing milk having a protein reduction value of 2 to 9 and whey protein and containing no stabilizer.
In the whole yogurt mix, 93 to 98% by mass of milk having a protein reduction value of 2 to 9 is contained, the milk fat content is 3.8 to 4.5% by mass, and the milk protein content is 4.3 to 4.3 to A yogurt mix containing 5.8% by mass and having a whey protein / casein protein ratio of 23/77 to 30/70 (mass ratio) in the milk protein.
Point A (80 ° C., 50 minutes), point B (90 ° C., 30 minutes), shown in the graph of FIG. 1, where the horizontal axis is the holding temperature (° C.) and the vertical axis is the holding time (minutes) after reaching the temperature. It is surrounded by a broken line connecting points C (95 ° C, 30 minutes), D (95 ° C, 1 minute), E point (90 ° C, 1 minute), and F point (80 ° C, 5 minutes) in order. The process of heat treatment under the temperature conditions in the region
A step of fermenting the yogurt mix after the heat treatment under a temperature condition of 39 to 41 ° C. until the pH reaches 4.5 to 4.7.
A step of pulverizing the fermented yogurt mix curd so that the median diameter of the curd is 25 to 60 μm is included.
The median diameter of the card is 25-60 μm
According to the BH type viscometer, No. The viscosity measured at 10 ° C. at a rotation speed of 2 rpm using the rotor of 4 is 20 to 45 Pa · s.
How to make yogurt. The fifth aspect of the present invention, wherein in the step of crushing the curd, the yogurt mix after fermentation is passed through a filter of 10 to 25 mesh under a pressure condition of 0.005 to 0.4 MPa to grind the curd. How to make yogurt.

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