Fermented milk and method for producing the same

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. In addition, 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 treating the proteins contained in milk with enzymes to reduce their molecular weight. Milk protein hydrolysates are widely used to prevent food allergies to 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> 13. 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> 13. A method for producing fermented milk containing a gelling agent according to any one of the preceding claims. <6> A 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> A fermented milk containing a milk protein hydrolysate and a gelling agent, the hardness of which at 10°C is 18g or less at any time up to 18 days after refrigerated storage from production. 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 a step of adjusting the pH of a raw material mixture solution containing a milk protein hydrolysate to 6.7 to 7.4 before sterilization. Effect 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 PREFERRED EMBODIMENTS

[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 are also applicable to other aspects.

[0010] 1. How fermented milk is produced (fermented milk) Fermented milk is defined in the "Ministerial Ordinance on Milk, etc." as a product made by fermenting milk or milk, etc. containing an equivalent or greater amount of non-fat milk solids with lactic acid bacteria or yeast, and turning it into a paste or liquid, or by freezing 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) is fermented milk that is filled into a container for consumption and then fermented. That is, it is fermented milk that is filled into a container for consumption and then fermented, and then sold commercially without stirring. Static fermented milk prepared from fermentation raw materials that have been dissolved to give a high protein content or fermented raw materials 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 first fermenting the milk 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 may 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 an optional component to obtain a raw material mixture solution. The 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 can be obtained, but water is preferable, and hot water is more preferable. The temperature of the hot water can be appropriately adjusted. The raw material mixture solution preferably contains 8% by weight to 20% by weight of non-fat milk solids. In the mixing step, in consideration of the action of the present invention described below, it is preferable to dissolve a milk raw material whose protein has not been decomposed, in addition to the milk protein hydrolysate. "Milk raw material whose protein has 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, each raw material may be dissolved in a dissolving solution and then mixed, or each raw material 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, mixer, or 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, or both may be contained in the raw material mixed solution and sterilized together, but it is preferable that both are contained in the raw material mixed solution and sterilized together.

[0013] (Milk protein hydrolysate (milk peptide)) In this specification, "milk protein hydrolysate" means 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. Examples of means for producing milk protein hydrolysates from milk proteins contained in milk or dairy products include 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 characteristics 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 blending amount of the milk protein hydrolysate to the raw material mixture solution or fermented milk is, but is not limited to, 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.

[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 thickening agent. 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. It is preferable to use agar or gelatin. In the present invention, the blending amount of the gelling agent to the raw material mixture solution or fermented milk is not limited to the following, but is, for example, 0.01 wt % to 0.3 wt %, 0.01 wt % to 0.25 wt %, 0.01 wt % to 0.2 wt %, 0.01 wt % to 0.18 wt %, 0.02 wt % to 0.18 wt %, 0.03 wt % to 0.18 wt %, 0.05 wt % to 0.18 wt %, 0.07 wt % to 0.18 wt %, 0.1 wt % to 0.18 wt %, 0.12 wt % to 0.18 wt %, or 0.12 wt % to 0.16 wt % based on the fermented milk. 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 not limited to, 100 g / cm, for example, as measured by the Nihon Kansui 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 It is.

[0015] (The process of heating and homogenizing the raw material mixture solution) The method for producing fermented milk of the present invention may 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 of preheating the raw material mixture solution to increase the homogenization efficiency, and then homogenizing the raw material mixture solution using a homogenizer or the like. Homogenization refers to finely breaking down 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 normal 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. In this specification, 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, the fermented milk will not have hardness even after the fermentation step. 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 other than 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 can be obtained, and the pH may be adjusted during mixing and dissolving of the raw materials, or may be adjusted after the raw material mixture solution is prepared and before the sterilization step. It is preferable to adjust the pH after the raw material mixture solution is prepared 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 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, lemon juice, etc., 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) The sterilization temperature and time are not limited as long as they correspond to the conditions of the methods used in normal fermented milk production, such as the LTLT method of heating at 60° C. to 65° C. for about 30 minutes, the HTLT method of heating at 75° C. to 90° C. for 15 to 60 minutes, the HTST method of heating at 70° C. to 90° C. for 15 to 60 seconds, and the UHT method of heating at 120° C. to 150° C. for 1 to 3 seconds. The sterilization apparatus used may be, for example, a plate-type heat exchanger, a tube-type sterilizer, a direct steam injection, a direct steam infusion, a thermocylinder, a rotatherm, a kettle emulsification pot, a Stephan emulsification pot, a Joule heating device, a batch-type sterilization using a tank, or a combination thereof, and is not limited as long as it can be used for 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 near the fermentation temperature in the fermentation step described below.

[0019] (filling process) When producing stationary fermented milk (post-fermented fermented milk), the milk can be filled into a suitable container after the sterilization step. The container can be a paper or plastic cup-shaped container with a paper, aluminum, or plastic top lid.

[0020] (Fermentation process) In this specification, the "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 selected from lactobacillus bacteria such as Lactobacillus bulgaricus, Lactobacillus lactis, Lactobacillus casei, Lactobacillus paracasei, lactobacillus bacteria such as Streptococcus thermophilus, and other lactobacilli 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 not particularly limited, and any method commonly used in the production of fermented milk can be appropriately used. When there are multiple types of microorganisms used for fermentation, the order in which these microorganisms are inoculated into the raw material mixture solution does not matter, and all of them may be added at the same time. Any of these microorganisms may be inoculated multiple times. Fermentation conditions can be appropriately set taking into consideration the type of fermented milk, the desired flavor, the type of starter used, etc. For example, the temperature inside the fermentation chamber (fermentation temperature) can be maintained in the range of 30°C to 50°C, and fermentation can be carried out while the mixture is left stationary in the fermentation chamber. Such temperature conditions generally facilitate the activity of lactic acid bacteria, allowing fermentation to proceed effectively. The fermentation temperature is usually about 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 based on the lactic acidity of the fermented milk reaching a predetermined ratio, and 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, and specifically, the fermentation can be stopped after the pH of the fermented milk reaches 4.0 to 5.0. After fermentation, it is preferable to cool to a temperature of 10°C or less. It is desirable to rapidly cool from the culture temperature to 10°C 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 steps necessary for producing these types of fermented milk after the fermentation step, such as a crushing step for crushing the curd by stirring after the fermentation step, a step for adding solids or other raw materials such as fruit pulp or fruit preserves, a step for stirring the solids or other raw materials and the fermented milk to homogenize them, etc.

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

[0023] (action) The reason why the manufacturing method of the present invention has an effect is not completely understood, but can be presumed as follows. However, the present invention is not limited to the following explanation. In fermented milk, proteins bond together during fermentation to impart hardness. However, if heat-denatured milk protein hydrolysates are present during fermentation, it is believed that the bond between proteins is inhibited. In addition, it is believed that if the pH of the solution during sterilization is closer to acidic, the heat denaturation of the milk protein hydrolysates contained in the solution is more likely to occur. 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 concentrated milk, condensed milk, whey powder, whey concentrated powder, cream, butter, cheese, and the like). In addition to milk components, the fermented milk of the present invention can contain foods or food components 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, starches, modified starches, dextrins, and the like, as necessary.

[0025] (hardness) The hardness of the fermented milk of the present invention is set to 18 g / kg or less after refrigerated storage for one day after production, taking into consideration the flavor, smoothness of the texture, and durability of the product during transportation. 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 set to 20 g or less at any time point 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) in consideration of flavor such as texture and smoothness of mouthfeel. 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 and 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] (Method of measuring hardness) In the present invention, the hardness is measured by the following method. 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 referred to as D+1. That is, The raw material mixture solution is filled into the container, and the day when 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% by weight to 30% by weight, 12% by weight to 27% by weight, 15% by weight to 25% by weight, or 18% by weight 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, "hardening" or "hardening" means imparting sufficient hardness to the fermented milk after fermentation so that the structure does not collapse even after transportation. Specifically, "hardening" or "hardening" means imparting hardness to the fermented milk after 1 day of refrigeration after production. f This means that a hardness of at least 100 mm 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. The jelly strength is a value measured by the Nissan-sui method.

[0031] Example 1 Skim milk powder 9%, jelly strength 700g / cm 2 The aqueous solution was adjusted to pH 6.9 using a pH adjuster, heated to 80°C in a plate-type sterilizer, homogenized at a homogenizing pressure of 15 MPa in a homogenizer, sterilized at 120°C for 3 seconds in a plate-type sterilizer, and cooled to 45°C. The aqueous solution was then mixed with DVS lactic acid bacteria starter (Lactobacillus bulgaricus and Streptococcus cerevisiae) for yogurt production ... Add 200U of mixed starter (thermophilus) per 1000kg. The mixture was mixed. 90 g of the mixture was filled into paper cup-shaped containers, and the aluminum lids were sealed with an iron. Then, the mixture was fermented in a 41°C incubator, 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 solid content of 8.7%, a milk fat content of 1.8%, and a total solid content of 20.0%. The milk protein enzymatic hydrolysate HW-3 used is a whey protein hydrolysate and has the following characteristics. 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 Skim milk powder 9%, 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 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 Skim milk powder 9%, jelly strength 700g / cm 2 Example Product 3 was obtained in the same manner as Example 1, except that an aqueous solution was obtained by dissolving 0.15% agar, 8% sugar, 3.5% cream with 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 Skim milk powder 9%, jelly strength 700g / cm 2Example product 4 was obtained in the same manner as in Example 1, except that agar was dissolved in water to a concentration of 0.15%, sugar to a concentration of 8%, cream with a milk fat content of 50% to a concentration of 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 Skim milk powder 9%, jelly strength 700g / cm 2 Example product 5 was obtained in the same manner as in Example 1, except that agar was dissolved in water to a concentration of 0.15%, sugar to a concentration of 8%, cream with a milk fat content of 50% to a concentration of 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 Skim milk powder 9%, 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 a concentration of 8%, cream with a milk fat content of 50% 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%.

[0037] Example 7 Skim milk powder 9%, jelly strength 700g / cm 2 Example Product 7 was obtained in the same manner as Example 1, except that agar was dissolved in water to a concentration of 0.18%, sugar to a concentration of 8%, cream with a milk fat content of 50% 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%.

[0038] Example 8 Skim milk powder 16%, jelly strength 700g / cm 2 Example Product 8 was obtained in the same manner as Example 1, except that agar was dissolved in water to a concentration of 0.05%, sugar to a concentration of 8%, cream with a milk fat content of 50% 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%. 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 Skim milk powder 9%, 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 50% milk fat, and 0% milk protein enzymatic hydrolysate HW-3 (manufactured by Megmilk Snow Brand Co., Ltd.) was dissolved in water and the pH was set to 6.6 without adjusting the pH using a pH adjuster.

[0040] Comparative Example 2 Skim milk powder 9%, 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 50% milk fat, and 1.7% milk protein enzymatic hydrolysate HW-3 (manufactured by Megmilk Snow Brand Co., Ltd.) was dissolved in water and the pH was set to 6.6 without adjusting the pH using a pH adjuster.

[0041] Comparative Example 3 Skim milk powder 9%, 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 50% milk fat, 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 Skim milk powder 9%, jelly strength 700g / cm 2 Comparative Example 4 was obtained in the same manner as in Example 1, except that 0% agar, 8% sugar, 3.5% cream with 50% milk fat, and 1.7% milk protein enzymatic hydrolysate HW-3 (manufactured by Megmilk Snow Brand Co., Ltd.) were dissolved in water.

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

[0044] (Transportation test evaluation method) The evaluation method for the transportation test is 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 that, samples whose structure was not broken down were rated as ◯, and samples whose structure was broken down or water was released 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 18 g at the time points D+1 to D+18. f ~70g f The transportation 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 pH of 6.6 when sterilized, has a hardness of 6 g at D+1. f The transport test was rated as ×. Comparative Example 3, which contains a milk protein hydrolysate and has a pH of 7.5 during sterilization, had a non-uniform mix after sterilization. Comparative Example 4, which does not contain agar, had a hardness of 16 g 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 sufficient to withstand vibration during distribution.

Claims

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 method for producing gelling agent-containing fermented milk according to claim 1 , wherein the gelling agent is agar.

3. The method for producing gelling agent-containing fermented milk according to claim 1 or 2, wherein the milk protein hydrolysate is a whey protein hydrolysate.

4. The method for producing gelling agent-containing fermented milk according to any one of claims 1 to 3, wherein 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.

5. The method for producing gelling agent-containing fermented milk according to any one of claims 1 to 4, wherein the fermented milk has a hardness of 18 gf to 70 gf at 10°C one day after refrigerated storage after production.

6. The fermented milk contains a milk protein hydrolysate and a gelling agent, and has a hardness of 18 gf to 70 gf at 10° C. after refrigerated storage for one day after production.

7. The fermented milk contains a milk protein hydrolysate and a gelling agent, and has a hardness of 18 gf to 70 gf at 10° C. at any time up to 18 days after refrigerated storage after production.

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 a step of adjusting the pH of a raw material mixture solution containing a milk protein hydrolysate to 6.7 to 7.4 before sterilization.

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