Fermented milk and its manufacturing method

Abstract

To provide fermented milk which contains milk protein decomposition products and a gelling agent and to which an appropriate hardness is imparted after a fermentation process.SOLUTION: In a method for producing gelling agent-containing fermented milk including a sterilization process for raw material mixture solution containing milk protein decomposition products, the raw material mixture solution has a pH of 6.7 to 7.4 in the sterilization process.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing fermented milk containing a gelling agent, and to fermented milk containing a gelling agent.The present invention also relates to a method for imparting hardness to fermented milk. [Background technology]

[0002] When microorganisms such as lactic acid bacteria and yeast are added to the raw milk and kept at a certain temperature, the microorganisms multiply. This results in fermented milk, such as yogurt. If fermented milk does not have sufficient hardness, its structure may collapse during transportation. For this reason, additives such as stabilizers containing polymeric compounds such as agar, starch, and gelatin have generally been used to impart hardness to fermented milk. Furthermore, a manufacturing method has been reported for obtaining fermented milk that has a hardness that can withstand vibration during distribution and that suppresses whey separation and increases in acidity (Patent Document 1).

[0003] Milk protein hydrolysates (milk peptides) are produced by enzymatically reducing the molecular weight of milk proteins. They are widely used to prevent food allergies caused by milk or dairy products, and as peptide raw materials. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-99019 Summary of the Invention [Problem to be solved by the invention]

[0005] The present inventors attempted to produce fermented milk containing a milk protein hydrolysate and a gelling agent. They found that the hardness of the fermented milk containing the milk protein hydrolysate and the gelling agent did not increase even after the fermentation process, despite the addition of the gelling agent. If the hardness after the fermentation process is low, the structure may collapse during transportation, which may significantly reduce the value of the fermented milk as a product. [Means for solving the problem]

[0006] The present inventors have conducted extensive research to solve the above problems, and have found that hardness can be imparted to gelling agent-containing fermented milk by adjusting the pH of a raw material mixture solution containing a milk protein hydrolysate to 6.7 to 7.4 during sterilization, thereby completing the present invention.

[0007] That is, the present invention has the following configuration. <1> A method for producing gelling agent-containing fermented milk, comprising a sterilization step of a raw material mixture solution containing a milk protein hydrolysate. A method for producing gelling agent-containing fermented milk, wherein the pH of the raw material mixture solution in the sterilization step is 6.7 to 7.4. <2> The gelling agent is agar. <1> A method for producing fermented milk containing the gelling agent described in claim 1. <3> The milk protein hydrolysate is a whey protein hydrolysate. <1> or <2> A method for producing fermented milk containing the gelling agent described in claim 1. <4> The content of the milk protein hydrolysate is 0.1% by weight to 3.0% by weight based on the fermented milk, and the content of the gelling agent is 0.01% by weight to 0.3% by weight based on the fermented milk. <1> ~ <3> A method for producing fermented milk containing a gelling agent according to any one of the preceding claims. <5> The hardness of the fermented milk at 10°C after refrigerated storage for one day after production is 18g f ~70g f That is, <1> ~ <4> A method for producing fermented milk containing a gelling agent according to any one of the preceding claims. <6> Fermented milk containing a milk protein hydrolysate and a gelling agent, the hardness of which at 10°C after refrigerated storage for one day after production is 18g f ~70g f Fermented milk. <7> Fermented milk containing a milk protein hydrolysate and a gelling agent, which has a hardness of 18g at 10°C at any time up to 18 days after production and refrigerated storage. f ~70g f Fermented milk. <8> A method for imparting hardness to fermented milk in the production of fermented milk containing a milk protein hydrolysate and a gelling agent, comprising: A method for imparting hardness to fermented milk, comprising the step of adjusting the pH of a raw material mixture solution containing a milk protein hydrolysate to 6.7 to 7.4 before sterilization. [Effects of the Invention]

[0008] According to the present invention, it is possible to impart an appropriate hardness to fermented milk containing a milk protein hydrolysate and a gelling agent after the fermentation process. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present invention will be described in detail below. In this specification, the invention is described in terms of different aspects, but the matters, definitions of terms, and embodiments described in each aspect can also be applied to other aspects.

[0010] 1. Fermented milk production method (fermented milk) Fermented milk is defined in the "Ministerial Ordinance on Milk, etc." as a product made by fermenting milk or milk containing an equivalent or greater amount of non-fat milk solids with lactic acid bacteria or yeast into a paste or liquid, or a frozen version of these. In this specification, the definition of "fermented milk" as defined in the Ministerial Ordinance on Milk, etc. applies. The fermented milk produced by the production method of the present invention may be either static fermented milk or stirred fermented milk, but static fermented milk is preferred. In this specification, static fermented milk (also called post-fermented fermented milk, plain yogurt, hard yogurt, or set yogurt) refers to fermented milk that is filled into a drinking container with fermentation ingredients and then post-fermented. That is, it is fermented milk that is filled into a drinking container with fermentation ingredients, fermented, and then sold commercially without stirring. Static fermented milk that is prepared by dissolving the ingredients so that the protein content is high, or by using fermentation ingredients that have been concentrated in advance using a membrane device or the like, is also called concentrated fermented milk (Greek yogurt). Stirred fermented milk (pre-fermented fermented milk) is produced by fermenting milk in advance in a manufacturing facility, crushing the resulting curd, mixing it with auxiliary ingredients such as sugar, flavoring, fruit juice, and fruit pulp, and then filling it into containers.

[0011] (Mixing process) The method for producing fermented milk of the present invention can include a mixing step as an optional step. In this specification, the "mixing step" refers to a step of mixing and dissolving a milk protein hydrolysate, a gelling agent, and / or optional components to obtain a raw material mixture solution. Optional components include dairy products such as raw milk, concentrated skim milk, cream, butter, whole milk powder, skim milk powder, and whey powder, milk proteins, sweeteners, stabilizers, flavorings, etc. The dissolving liquid used for dissolution is not limited as long as the effects of the present invention are obtained, but water is preferred, and warm water is more preferred. The temperature of the warm water can be adjusted as appropriate. The raw material mixture solution preferably contains 8% to 20% by weight of non-fat milk solids. In the mixing step, in consideration of the effects of the present invention described below, it is preferable to dissolve a milk raw material whose proteins have not been decomposed in addition to the milk protein hydrolysate. "Milk raw material whose proteins have not been decomposed" means a material that contains milk protein and the milk protein has not been decomposed by enzymes, etc., such as raw milk, skim milk, whey, and processed products thereof (whole milk powder, whole fat concentrated milk, skim milk powder, desalted skim milk powder, skim concentrated milk, condensed milk, whey powder, whey concentrated powder, cream, butter, cheese, etc.).

[0012] As long as the effects of the present invention can be obtained, the raw materials may be dissolved in a dissolving solution and then mixed, or the raw materials may be mixed and then dissolved in a dissolving solution. If necessary, it is preferable to use an appropriate dissolving machine, such as a power blender, a mixer, or a high-speed stirrer. The milk raw material solution, such as the milk protein hydrolysate and skim milk powder, and the gelling agent solution may be sterilized separately and then mixed together, or both may be contained in the raw material mixed solution and sterilized together, but it is preferred that both be contained in the raw material mixed solution and sterilized together.

[0013] (Milk protein hydrolysate (milk peptide)) As used herein, "milk protein hydrolysate" refers to milk protein whose molecular weight has been reduced by the action of an enzyme. The milk protein hydrolysate used in the present invention is not particularly limited as long as the effects of the present invention can be obtained, and any of casein protein hydrolysate, whey protein hydrolysate, and mixtures thereof can be used, with whey protein hydrolysate being preferred. Methods for producing milk protein hydrolysates from milk proteins contained in milk or dairy products include, for example, acid hydrolysis, alkali hydrolysis, and enzymatic hydrolysis. The milk protein hydrolysate may be commercially available or may be prepared by the user. For example, a whey protein hydrolysate having the following composition and properties can be used. The total amount of BCAA, i.e., valine, leucine, and isoleucine, is 15% by weight or more, preferably 20% by weight or more, and more preferably 21% by weight or more, based on the whey protein hydrolysate. The average molecular weight (MNV) is 200 Da to 500 Da, preferably 300 Da to 500 Da. In the present invention, the amount of milk protein hydrolysate added to the raw material mixture solution or fermented milk is, for example, 0.1% to 3.0% by weight, 0.2% to 2.5% by weight, 0.3% to 2.4% by weight, 0.5% to 2.2% by weight, 0.8% to 2.2% by weight, 1.0% to 2.2% by weight, or 1.5% to 2.2% by weight based on the fermented milk, although not limited to the following.

[0014] (gelling agent) In this specification, the term "gelling agent" refers to a substance added to make a liquid solid or semi-solid, and is also called a thickener. The gelling agent used in the present invention is not particularly limited as long as the effects of the present invention can be obtained, and for example, at least one selected from agar, pectin, carrageenan, gellan gum, gelatin, xanthan gum, locust bean gum, guar gum, guar gum hydrolyzate, tara gum, alginic acid, and sodium alginate can be used. The use of agar or gelatin is preferred. In the present invention, the amount of gelling agent added to the raw material mixture solution or fermented milk is, for example, 0.01% by weight to 0.3% by weight, 0.01% by weight to 0.25% by weight, 0.01% by weight to 0.2% by weight, 0.01% by weight to 0.18% by weight, 0.02% by weight to 0.18% by weight, 0.03% by weight to 0.18% by weight, 0.05% by weight to 0.18% by weight, 0.07% by weight to 0.18% by weight, 0.1% by weight to 0.18% by weight, 0.12% by weight to 0.18% by weight, or 0.12% by weight to 0.16% by weight, based on the fermented milk, but is not limited to the following. The type and concentration of the gelling agent can be appropriately selected depending on the type and concentration of the milk protein hydrolysate, the type of fermented milk, etc. When the gelling agent is agar, the jelly strength of the agar is, but is not limited to, 100 g / cm, for example, as measured by the Nikkansui method. 2 ~2000g / cm 2 , 200g / cm 2 ~1500g / cm 2 , 300g / cm 2 ~1200g / cm 2 , 400g / cm 2 ~1000g / cm 2 , or 500g / cm 2 ~900g / cm 2 is.

[0015] (Process for heating and homogenizing the raw material mixture solution) The method for producing fermented milk of the present invention can include, as an optional step, a step of heating and homogenizing the raw material mixture solution. The step of heating and homogenizing the raw material mixture solution is a step in which the raw material mixture solution is preheated to increase the homogenization efficiency, and then homogenized using a homogenizer or the like. Homogenization means finely breaking down the fat globules in the milk fat and other raw materials to make them stable. Before homogenization, the raw material mixture solution is preferably heated to 50°C to 85°C. The raw material mixture solution preferably contains a milk protein hydrolysate and a gelling agent, and these are homogenized together. The homogenization pressure may be the same as that used for ordinary fermented milk, and is, for example, 10 MPa to 20 MPa, preferably 12 MPa to 18 MPa.

[0016] (sterilization process) The method for producing fermented milk of the present invention includes a sterilization step of a raw material mixture solution containing a milk protein hydrolysate. As used herein, the term "sterilization step" refers to treating the raw material mixture solution at a high temperature to reduce the number of microorganisms in the raw material mixture solution. In the method for producing fermented milk of the present invention, the pH of the raw material mixture solution in the sterilization step is 6.7 to 7.4. If the pH is below 6.7, hardness will not be imparted to the fermented milk even after the fermentation step. On the other hand, if the pH is above 7.4, aggregation or separation may occur in the raw material mixture solution after sterilization. When a milk protein hydrolysate is added to a raw material mixture solution, the pH of the raw material mixture solution tends to decrease. When producing fermented milk containing a milk protein hydrolysate, the pH of the raw material in the sterilization step is, for example, pH 6.6. On the other hand, in the present invention, the pH of the raw material mixture solution in the sterilization step is 6.7 to 7.4, more preferably 6.7 to 7.2, and even more preferably 6.8 to 7.1.

[0017] (pH adjustment) If the pH of the raw material mixture solution before sterilization is outside the range of 6.7 to 7.4, the pH is adjusted. In this case, the timing of adjusting the pH is not limited as long as the effects of the present invention are obtained, and the adjustment may be performed during mixing and dissolution of the raw materials, or after preparation of the raw material mixture solution and before the sterilization step. It is preferable to adjust the pH after preparation of the raw material mixture solution and before the sterilization step. Specifically, it is preferable to continuously mix the pH adjuster with the raw material mixture in the piping before sterilization using a static mixer, or to add the pH adjuster to a tank containing the raw material mixture before sterilization and stir and dissolve it. Alternatively, a combination of these methods may be used. The pH may be adjusted using pH adjusters, food additives, foods, etc., which are generally used to adjust the pH of foods, such as potassium carbonate, sodium carbonate, sodium bicarbonate, trisodium citrate, sodium hydroxide, lactic acid, hydrochloric acid, glucono-delta-lactone, and lemon juice, or combinations thereof. Alternatively, a fermented product obtained by fermenting a raw material mix in advance with one or more types of lactic acid bacteria and / or yeast may be added.

[0018] (sterilization conditions) There are no limitations on the sterilization temperature and time as long as they correspond to the conditions used in ordinary fermented milk production, such as the LTLT method, which involves heating at 60°C to 65°C for about 30 minutes, the HTLT method, which involves heating at 75°C to 90°C for 15 to 60 minutes, the HTST method, which involves heating at 70°C to 90°C for 15 to 60 seconds, or the UHT method, which involves heating at 120°C to 150°C for 1 to 3 seconds. The sterilization apparatus used may be, for example, a plate heat exchanger, a tube sterilizer, direct steam injection, direct steam infusion, a thermocylinder, a rotatherm, a kettle emulsifying apparatus, a Stephan emulsifying apparatus, a Joule heating apparatus, a batch sterilization apparatus using a tank, or a combination thereof, and there are no limitations as long as it can be used in fermented milk production. In the present invention, after sterilization, the raw material mixture solution may be cooled to a predetermined temperature. Specifically, for example, it may be cooled to a temperature close to the fermentation temperature in the fermentation step described below.

[0019] (filling process) When producing static fermented milk (post-fermented fermented milk), after the sterilization step, it can be filled into an appropriate container. The container can be a cup-shaped container made of paper or plastic with a paper, aluminum, or plastic lid.

[0020] (Fermentation process) As used herein, the term "fermentation process" refers to a process of fermenting a raw material mixture solution using a starter. Examples of starters to be added to and mixed (inoculated) with the raw material mixture solution include one or more species selected from lactobacilli such as Lactobacillus bulgaricus, Lactobacillus lactis, Lactobacillus casei, and Lactobacillus paracasei, lactococci such as Streptococcus thermophilus, and other lactic acid bacteria and yeasts commonly used in the production of fermented milk. The amount of starter added can be appropriately set according to the amount used in known methods for producing fermented milk. The method for inoculating the starter is also not particularly limited, and any method commonly used in the production of fermented milk can be used as appropriate. When multiple types of microorganisms are used for fermentation, the order in which these microorganisms are inoculated into the raw material mixture solution is not particularly important, and all of them may be added simultaneously. Any of these microorganisms may be inoculated multiple times. Fermentation conditions can be set appropriately taking into consideration the type of fermented milk, the desired flavor, the type of starter used, etc. For example, a method can be used in which the temperature inside the fermentation chamber (fermentation temperature) is maintained in the range of 30°C to 50°C, and the fermentation is carried out while the milk is left standing in the fermentation chamber. Lactic acid bacteria are generally active under such temperature conditions, allowing fermentation to proceed effectively. The fermentation temperature is usually around 30°C to 50°C, preferably in the range of 35°C to 45°C, and more preferably in the range of 37°C to 43°C. The fermentation time can be adjusted appropriately, with the aim of the lactic acid acidity of the fermented milk reaching a predetermined ratio, but is usually about 3 to 24 hours, or usually about 4 to 18 hours. The fermentation time can also be determined based on the final acidity or final pH. Specifically, fermentation can be stopped after the pH of the fermented milk reaches 4.0 to 5.0. After fermentation, it is preferable to cool the fermented milk to a temperature of 10°C or less. Rapid cooling from the culture temperature to 10°C is preferably carried out within 10 hours, more preferably within 5 hours, even more preferably within 3 hours, and particularly preferably within 1 hour.

[0021] When the fermented milk produced by the production method of the present invention is a stirred fermented milk, the production method of the present invention may include, after the fermentation step, steps necessary for producing such types of fermented milk. Examples of the necessary steps include a crushing step of crushing curds by stirring after the fermentation step, a step of adding solids or other ingredients such as fruit pulp or fruit preserve, and a step of stirring the solids or other ingredients and the fermented milk to homogenize them.

[0022] The production method of the present invention may include a concentration step before or after the fermentation step. Concentration methods include membrane concentration and centrifugation.

[0023] (action) The reason why the manufacturing method of the present invention is effective is not completely understood, but can be inferred as follows: However, the present invention is not limited to the following explanation. In fermented milk, proteins bond together during fermentation, imparting hardness. However, if heat-denatured milk protein hydrolysates are present during fermentation, it is believed that the bond between proteins is inhibited. Furthermore, it is believed that if the pH of the solution during sterilization is made closer to acidic, the heat-denatured milk protein hydrolysates contained in the solution are more likely to be denatured. Therefore, by making the pH of the solution during sterilization closer to neutral, it is possible to prevent the heat-denatured milk protein hydrolysates from inhibiting the bond between proteins during fermentation. Furthermore, if the pH is too high, aggregation and / or separation may occur in the raw material mixture solution containing the milk protein hydrolysate.

[0024] 2. Fermented milk (raw materials) The fermented milk of the present invention can contain raw milk, skim milk, whey, and the like, as well as processed products thereof (e.g., whole milk powder, whole fat concentrated milk, skim milk powder, desalted skim milk powder, skim milk concentrated milk, condensed milk, whey powder, whey concentrated powder, cream, butter, cheese, etc.). In addition to milk components, the fermented milk of the present invention can also contain foods or food ingredients and food additives such as sugar, sugars, sweeteners, flavorings, fruit juice, fruit pulp, vitamins, minerals, vegetable oils and fats, and emulsifiers. Furthermore, the raw materials for the fermented milk can contain stabilizers, starch, modified starch, dextrin, etc., as necessary.

[0025] (hardness) The hardness of the fermented milk of the present invention is set to 18g after refrigerated storage for one day after production, taking into consideration the flavor and smoothness of the texture, such as the feel on the tongue, and durability in transporting the product. f ~70g f , 20g f ~60g f , 20g f ~50g f , 20g f ~45g f , 22g f ~40g f , 25g f ~40g f , or 25g f ~35g f It can be. The hardness of the fermented milk of the present invention is determined by taking into consideration the flavor and smoothness of the texture, such as the feel on the tongue, at any time up to 18 days after refrigerated storage after production (i.e., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18 days after refrigerated storage after production). f ~70g f , 20g f ~60g f , 20g f ~50g f , 20g f ~45g f, 22g f ~40g f , 25g f ~40g f , or 25g f ~35g f Preferably, after 7 days of refrigerated storage after production, f ~70g f , 20g f ~60g f , 20g f ~50g f , 20g f ~45g f , 22g f ~40g f , 25g f ~40g f , or 25g f ~35g f It can be.

[0026] (Hardness measurement method) The method for measuring hardness in the present invention is as follows. The hardness is measured using a creep meter (manufactured by Yamaden Co., Ltd.). That is, a plunger with a diameter of 15 mm is inserted into each sample (10°C) filled in a 100 ml container at a speed of 1 mm / sec, and the stress (g f ) is measured and this value is taken as the hardness.

[0027] In this specification, "one day after refrigerated storage after production" means the day after the raw material mixed solution is filled into a container. "One day after refrigerated storage after production" may be expressed as D+1. That is, The raw material mixture solution is filled into a container, and the day on which fermentation begins is counted as day 0.

[0028] The non-fat milk solids content of the fermented milk of the present invention is, for example, 8.0% to 20% by weight, 8.0% to 15% by weight, 8.0% to 12% by weight, 8.0% to 10% by weight, or 8.0% to 9.5% by weight. The milk fat content of the fermented milk of the present invention is, for example, 0.5 to 3.0% by weight, 0.5 to 2.5% by weight, 1.0 to 2.2% by weight, or 1.5 to 2.0% by weight. The total solid content of the fermented milk of the present invention is, for example, 10% to 30% by weight, 12% to 27% by weight, 15% to 25% by weight, or 18% to 22% by weight. The pH of the fermented milk of the present invention is, for example, 4.0 to 5.0, 4.1 to 4.9, 4.2 to 4.8, or 4.3 to 4.7.

[0029] 3. Method for imparting hardness to fermented milk The method of the present invention for imparting hardness to fermented milk includes a step of adjusting the pH of a raw material mixture solution containing a milk protein hydrolysate and a gelling agent to 6.7 to 7.4 before sterilization. In this specification, "imparting hardness" or "imparting hardness" means imparting sufficient hardness to the fermented milk after fermentation so that the structure does not collapse even after transportation. Specifically, "imparting hardness" or "imparting hardness" means imparting hardness to 18g of fermented milk stored in a refrigerator for one day after production. f This means that a hardness of at least 100 mm or more is imparted to the surface.

[0030] The present invention will be described in more detail below with reference to examples, but the present invention is not limited thereto. Unless otherwise specified, % indicates % by weight. Jelly strength is a value measured by the Nikkansui method.

[0031] Example 1 9% skim milk powder, jelly strength 700g / cm 2 The resulting solution was adjusted to pH 6.9 using a pH adjuster. It was then heated to 80°C in a plate sterilizer, homogenized in a homogenizer at a homogenizing pressure of 15 MPa, sterilized in a plate sterilizer at 120°C for 3 seconds, and cooled to 45°C. The solution was then mixed with DVS lactic acid bacteria starter (Lactobacillus bulgaricus and Streptococcus faecium) for yogurt production (Lactobacillus bulgaricus and Streptococcus faecium) for 3 seconds. The resulting solution was then mixed with water to obtain a final concentration of 0.15% agar, 8% sugar, 3.5% 50% milk fat cream, and 1.7% milk protein enzyme hydrolysate HW-3 (Megmilk Snow Brand Co., Ltd.: BCAA total 22.3%, number average molecular weight (MNV) approximately 400 Da). The resulting solution was then heated to 80°C in a plate sterilizer, homogenized in a homogenizer at a homogenizing pressure of 15 MPa, sterilized in a plate sterilizer at 120°C for 3 seconds, and cooled to 45°C. The resulting mixture was then mixed with DVS lactic acid bacteria starter (Lactobacillus bulgaricus and Streptococcus faecium) for yogurt production (Lactobacillus bulgaricus and Streptococcus faecium). Add and mix the thermophilic starter (mixture of 200U / 1000kg) The mixture was mixed. 90 g of the mixture was filled into paper cup-shaped containers, and aluminum lids were sealed with an iron. The mixture was then fermented in an incubator at 41°C, and when the pH reached 4.6, it was transferred to a 5°C incubator to stop the fermentation. The next day, it was transferred to a 10°C incubator to obtain Example Product 1. Example Product 1 had a non-fat milk solids content of 8.7%, a milk fat content of 1.8%, and a total solids content of 20.0%. The milk protein enzymatic hydrolysate HW-3 used is a whey protein hydrolysate and has the following properties: The total amount of BCAA, i.e., valine, leucine, and isoleucine, is 15% by weight or more, preferably 20% by weight or more, and more preferably 21% by weight or more, based on the whey protein hydrolysate. The average molecular weight (MNV) is 200 Da to 500 Da, preferably 300 Da to 500 Da.

[0032] Example 2 9% skim milk powder, jelly strength 700g / cm 2 Example Product 2 was obtained in the same manner as Example 1, except that an aqueous solution was prepared by dissolving 0.15% agar, 8% sugar, 3.5% cream with a 50% milk fat content, and 1.7% milk protein enzymatic hydrolysate HW-3 (manufactured by Megmilk Snow Brand Co., Ltd.) in water, and the pH was adjusted to 6.7 using a pH adjuster.

[0033] Example 3 9% skim milk powder, jelly strength 700g / cm 2 Example Product 3 was obtained in the same manner as Example 1, except that an aqueous solution was prepared by dissolving 0.15% agar, 8% sugar, 3.5% cream with a 50% milk fat content, and 1.7% milk protein enzymatic hydrolysate HW-3 (manufactured by Megmilk Snow Brand Co., Ltd.) in water, and the pH was adjusted to 7.2 using a pH adjuster.

[0034] Example 4 9% skim milk powder, jelly strength 700g / cm 2Example Product 4 was obtained in the same manner as Example 1, except that the agar was dissolved in water to a concentration of 0.15%, sugar to 8%, cream with a 50% milk fat content to 3.5%, and milk protein enzymatic hydrolysate HW-3 (manufactured by Megmilk Snow Brand Co., Ltd.) to a concentration of 0.5%.

[0035] Example 5 9% skim milk powder, jelly strength 700g / cm 2 Example Product 5 was obtained in the same manner as Example 1, except that the agar was dissolved in water to a concentration of 0.15%, sugar to 8%, cream with a 50% milk fat content to 3.5%, and milk protein enzymatic hydrolysate HW-3 (manufactured by Megmilk Snow Brand Co., Ltd.) to a concentration of 2.2%.

[0036] Example 6 9% skim milk powder, jelly strength 700g / cm 2 Example Product 6 was obtained in the same manner as Example 1, except that the agar was dissolved in water to a concentration of 0.05%, sugar to 8%, cream with a 50% milk fat content to 3.5%, and milk protein enzymatic hydrolysate HW-3 (manufactured by Megmilk Snow Brand Co., Ltd.) to a concentration of 1.7%.

[0037] Example 7 9% skim milk powder, jelly strength 700g / cm 2 Example Product 7 was obtained in the same manner as Example 1, except that the agar was dissolved in water to a concentration of 0.18%, sugar to 8%, cream with a 50% milk fat content to 3.5%, and milk protein enzymatic hydrolysate HW-3 (manufactured by Megmilk Snow Brand Co., Ltd.) to a concentration of 1.7%.

[0038] Example 8 16% skim milk powder, jelly strength 700g / cm 2 Example Product 8 was obtained in the same manner as Example 1, except that the agar was dissolved in water to a concentration of 0.05%, sugar to 8%, cream with a 50% milk fat content to 3.5%, and milk protein enzymatic hydrolysate HW-3 (manufactured by Megmilk Snow Brand Co., Ltd.) to a concentration of 1.7%. Example Product 8 had a non-fat milk solids content of 15.4%, a milk fat content of 1.8%, and a total solids content of 27.0%.

[0039] (Comparative Example 1) 9% skim milk powder, jelly strength 700g / cm 2 Comparative Example 1 was obtained in the same manner as in Example 1, except that an aqueous solution of 0.15% agar, 8% sugar, 3.5% cream with a 50% milk fat content, and 0% milk protein enzymatic hydrolysate HW-3 (manufactured by Megmilk Snow Brand Co., Ltd.) was dissolved in water and the pH was adjusted to 6.6 without using a pH adjuster.

[0040] (Comparative Example 2) 9% skim milk powder, jelly strength 700g / cm 2 Comparative Example 2 was obtained in the same manner as in Example 1, except that an aqueous solution of 0.15% agar, 8% sugar, 3.5% cream with a 50% milk fat content, and 1.7% milk protein enzymatic hydrolysate HW-3 (manufactured by Megmilk Snow Brand Co., Ltd.) was dissolved in water and the pH was adjusted to 6.6 without using a pH adjuster.

[0041] (Comparative Example 3) 9% skim milk powder, jelly strength 700g / cm 2 Comparative Example 3 was obtained in the same manner as in Example 1, except that an aqueous solution was prepared by dissolving 0.15% agar, 8% sugar, 3.5% cream with a 50% milk fat content, and 1.7% milk protein enzymatic hydrolysate HW-3 (manufactured by Megmilk Snow Brand Co., Ltd.) in water, and the pH was adjusted to 7.5 using a pH adjuster.

[0042] Comparative Example 4 9% skim milk powder, jelly strength 700g / cm 2 Comparative Example 4 was obtained in the same manner as in Example 1, except that the agar was dissolved in water to a concentration of 0%, sugar to a concentration of 8%, cream with a 50% milk fat content to a concentration of 3.5%, and milk protein enzymatic hydrolysate HW-3 (manufactured by Megmilk Snow Brand Co., Ltd.) to a concentration of 1.7%.

[0043] (Evaluation of mix properties after sterilization process) The properties of the mix after the sterilization step were visually inspected and evaluated as either "○: the mix after sterilization is uniform" or "×: the mix after sterilization is in an aggregated or separated state."

[0044] (Transportation test evaluation method) The evaluation method for the transportation test was as follows: 20 samples filled in 100 ml containers were packed in plastic containers and loaded into a refrigerated truck at 5°C for transportation of 1000 km. After transportation, samples whose structure was not broken down were rated as ◯, and samples whose structure was broken down or water separation occurred were rated as ×.

[0045] The evaluation results of Example Products 1 to 8 and Comparative Examples 1 to 4 are shown in Tables 1, 2 and 3. For Example Products 1 to 8, the hardness was 18g at the time points D+1 to D+18. f ~70g f The transport test results were good.

[0046] Comparative Example 1, which does not contain milk protein hydrolysate, has a hardness of 32g at D+1. f The transport test was rated as good. Comparative Example 2, which contains a milk protein hydrolysate and has a raw material mixture solution pH of 6.6 at the time of sterilization, has a hardness of 6g at D+1. f The transport test was evaluated as "×". Comparative Example 3, which contains a milk protein hydrolysate and has a raw material mixture solution pH of 7.5 at the time of sterilization, had an uneven mix after sterilization. Comparative Example 4, which does not contain agar, had a hardness of 16g ​​at D+1. f This resulted in a lack of hardness.

[0047] Therefore, by adjusting the pH of the raw material containing the milk protein hydrolysate to 6.7 to 7.4 and then sterilizing it, hardness was imparted to the fermented milk after fermentation, and a static fermented milk with good transport resistance was obtained.

[0048] [Table 1]

[0049] [Table 2]

[0050] [Table 3] [Industrial Applicability]

[0051] According to the present invention, it is possible to provide fermented milk containing a milk protein hydrolysate, which has a hardness that can withstand vibration during distribution.

Claims

1. A method for producing agar-containing fermented milk, comprising a sterilization step of a raw material mixture solution containing a whey protein hydrolysate, The pH of the raw material mixture solution in the sterilization step is 6.7 to 7.4; The whey protein hydrolysate content is 1.0% by weight to 2.2% by weight based on the fermented milk, and the agar content is 0.05% by weight to 0.3% by weight based on the fermented milk, The method for producing agar-containing fermented milk, wherein the fermented milk has a hardness of 18 gf to 70 gf at 10°C after refrigerated storage for one day after production.

2. The fermented milk contains a whey protein hydrolysate and agar, wherein the whey protein hydrolysate content is 1.0% by weight to 2.2% by weight based on the fermented milk, and the agar content is 0.05% by weight to 0.3% by weight based on the fermented milk, and the fermented milk has a hardness of 18 gf to 70 gf at 10°C after refrigerated storage for one day after production.

3. A fermented milk containing a whey protein hydrolysate and agar, wherein the whey protein hydrolysate content is 1.0% by weight to 2.2% by weight based on the fermented milk, and the agar content is 0.05% by weight to 0.3% by weight based on the fermented milk, and the fermented milk has a hardness of 18 gf to 70 gf at 10°C at any time up to 18 days after refrigerated storage after production.

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