Method for reducing sourness

Abstract

The present invention addresses the problem of providing a method for reducing the sourness of a lactic-acid-fermented food or a food / beverage that contains the lactic-acid-fermented food.　Provided is a method for reducing the sourness of a lactic-acid-fermented food or a food / beverage that contains the lactic-acid-fermented food, wherein the pH of the lactic-acid-fermented food is 6.1 or lower, the method including a step for carrying out stirring and / or shaking in lactic acid fermentation for obtaining the lactic-acid-fermented food.

Description

Method for reducing sour taste

[0001] Related application This application claims the benefit of priority of application No. 2024-170273, filed with the Japan Patent Office on September 30, 2024. The priority basis application is incorporated herein by reference in its entirety.

[0002] The present invention relates to a method for reducing sour taste.

[0003] Sour taste, which is one of the five basic tastes (sweet, sour, salty, bitter, umami) of food and beverages, is an important element that constitutes the flavor of food and beverages. On the other hand, excessive sour taste can cause discomfort, so there may be a need for a method to reduce it. In particular, lactic acid-fermented foods have a unique sour taste because they have a fermentation process during the manufacturing process, and some people may dislike this sour taste depending on their personal preferences.

[0004] In the related art, for example, as Patent Document 1, a method of masking the sour taste of food by adding 0.0001 to 20%, preferably 0.0005 to 10%, of sodium 5'-uridylate and / or sodium 5'-cytidylate to food has been proposed.

[0005] JP 2005-348748 A

[0006] An object of the present invention is to provide a method for reducing the sour taste of lactic acid-fermented foods or food and beverages containing the lactic acid-fermented foods.

[0007] Although Patent Document 1 is useful in that it can reduce the sour taste by adding a specific component, depending on the type and use of the lactic acid-fermented food used, there may be cases where the addition of a specific component is to be avoided. Assuming such a situation, it is also considered desirable to have a technique that can reduce the sour taste without adding a specific component.

[0008] The present inventors, after diligently studying the problem, have found that the acidity of a lactic acid fermented food or a food or beverage containing the lactic acid fermented food can be reduced by a method in which the pH of the lactic acid fermented food is 6.1 or less, and the lactic acid fermentation to obtain the lactic acid fermented food includes a step of stirring and / or shaking, thereby completing the present invention.

[0009] In other words, the present invention encompasses the following: [1] A method for reducing the acidity of a lactic acid fermented food or a food or beverage containing the lactic acid fermented food, wherein the pH of the lactic acid fermented food is 6.1 or less, and the lactic acid fermentation for obtaining the lactic acid fermented food includes a step of stirring and / or shaking. [2] The method according to [1], wherein the total time spent stirring and / or shaking accounts for 50% or more of the total time required for lactic acid fermentation. [3] The method according to [1] or [2], wherein the lactic acid fermentation is carried out under aerobic conditions. [4] The method according to [1] or [2], wherein the lactic acid content in the lactic acid fermented food is 0.0003% by mass or more. [5] The method according to [3], wherein the lactic acid content in the lactic acid fermented food is 0.0003% by mass or more. [6] The method according to [1] or [2], wherein the milk protein and / or plant protein content in the substrate for lactic acid fermentation to obtain the lactic acid fermented food is 0.002% by mass or more. [7] The method according to [3], wherein the content of milk protein and / or plant protein in the substrate for lactic acid fermentation to obtain a lactic acid fermented food is 0.002% by mass or more. [8] The method according to [4], wherein the content of milk protein and / or plant protein in the substrate for lactic acid fermentation to obtain a lactic acid fermented food is 0.002% by mass or more. [9] The method according to [5], wherein the content of milk protein and / or plant protein in the substrate for lactic acid fermentation to obtain a lactic acid fermented food is 0.002% by mass or more.

[10] A method for producing a lactic acid fermented food with reduced acidity, or a food or beverage containing the lactic acid fermented food, characterized in that the pH of the lactic acid fermented food is 6.1 or less, and the lactic acid fermentation step for obtaining the lactic acid fermented food includes a step of stirring and / or shaking.

[11] The method according to

[10] , wherein the total time spent stirring and / or shaking accounts for 50% or more of the total time required for lactic acid fermentation.

[12] The method according to

[10] or

[11] , wherein lactic acid fermentation is carried out under aerobic conditions.

[13] The method according to

[10] or

[11] , wherein the lactic acid content in the lactic acid fermented food is 0.0003% by mass or more.

[14] The method according to

[12] , wherein the lactic acid content in the lactic acid fermented food is 0.0003% by mass or more.

[15] The method according to

[10] or

[11] , wherein the content of milk protein and / or plant protein in the substrate for lactic acid fermentation to obtain a lactic acid fermented food is 0.002% by mass or more.

[16] The method according to

[12] , wherein the content of milk protein and / or plant protein in the substrate for lactic acid fermentation to obtain a lactic acid fermented food is 0.002% by mass or more.

[17] The method according to

[13] , wherein the content of milk protein and / or plant protein in the substrate for lactic acid fermentation to obtain a lactic acid fermented food is 0.002% by mass or more.

[18] The method according to

[14] , wherein the content of milk protein and / or plant protein in the substrate for lactic acid fermentation to obtain a lactic acid fermented food is 0.002% by mass or more.

[0010] The present invention provides a method for reducing the sourness of a lactic acid fermented food, or a food or beverage containing a lactic acid fermented food, by using a method that includes stirring and / or shaking during lactic acid fermentation to obtain the lactic acid fermented food, provided that the pH of the lactic acid fermented food is 6.1 or less.

[0011] The present invention will be described in more detail below.

[0012] As used herein, the singular forms, "a," "an," and "the" are intended to include the plural form, including "at least one," unless the context explicitly indicates otherwise. As used herein, the terms "and / or," "at least one," and "one or more" include any and all combinations of the relevant enumerated items.

[0013] In this specification, "or" is used when "at least one" of the items listed in the text can be adopted. The same applies to "or else". In this specification, when it is specified as "within the range of two values", that range includes the two values ​​themselves.

[0014] Furthermore, any combination of at least two components disclosed in the claims and / or the specification and / or drawings is included in the present invention. In particular, any combination of two or more claims described in the claims is included in the present invention.

[0015] In this specification and in the claims, "~" means a value greater than or equal to a predetermined number (lower limit of the numerical range) and less than or equal to a predetermined number (upper limit of the numerical range). When upper and lower limits of a numerical range are indicated, the upper and lower limits may be combined as appropriate, and the numerical range obtained by such combination is also disclosed.

[0016] In this specification and in the claims of this patent, "sourness" refers to the sourness perceived when eating or drinking. In this specification and in the claims of this patent, "reduction of sourness" refers to the effect of using a lactic acid fermented food described in this specification and in the claims of this patent, or a food or beverage containing the lactic acid fermented food, resulting in a perceived less sourness compared to when the lactic acid fermented food or food or beverage containing the lactic acid fermented food is not used.

[0017] In this specification and in the claims, lactic acid fermented food refers to any food or beverage obtained by lactic acid fermentation of a substrate by microorganisms such as lactic acid bacteria, and is not particularly limited. In this specification and in the claims, food or beverages containing lactic acid fermented food refers to food or beverages in which lactic acid fermented food is used as part of the raw materials for manufacturing various food or beverages. Even when lactic acid fermented food is used as part of the raw materials for manufacturing various food or beverages, the effects of the present invention can be achieved. The proportion of lactic acid fermented food in the food or beverage containing lactic acid fermented food is preferably 5% by mass or more, more preferably 10% by mass or more, 15% by mass or more, 20% by mass or more, or 25% by mass or more. When this range is appropriate, the effects of the present invention can be achieved more effectively.

[0018] The types of lactic acid fermented foods and food and beverages containing lactic acid fermented foods are not particularly limited. Examples include beverages such as soy milk beverages, dairy beverages and soft drinks; desserts such as puddings, bavarian creams, jellies, frozen desserts and soft serve mixes; creams such as whipped cream, pre-whipped cream and cooking cream; fillings; whiteners; fermented foods such as yogurt, cheese and fermented beverages; high-calorie liquid foods; bakery products such as biscuits, cookies, bread and cakes; chocolate products such as hydrated chocolate; spreads such as margarine and butter; condiment products such as mayonnaise, dressings, sauces, broths and seasoned soups; soup products such as corn soup and clam chowder; and prepared foods such as fried foods, processed seafood products and poultry and fish meat products.

[0019] The pH of the lactic acid fermented food used in the method of the present invention is 6.1 or less. The upper limit of the pH is preferably 6.0, and more preferably 5.9, 5.8, 5.7, 5.6, 5.5, 5.4, 5.3, 5.2, 5.1, and 5.0. On the other hand, the lower limit of the pH is preferably 3.0, and more preferably 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, and 4.0. If this range is appropriate, the effects of the present invention can be achieved. One embodiment of the lactic acid fermented food is oat milk ferment. In the case of oat milk ferment, the upper limit of its pH is preferably 6.1, and more preferably 6.0, 5.9, 5.8, 5.7, and 5.6. On the other hand, the lower limit of the pH is preferably 3.5, and more preferably 3.6, 3.7, 3.8, 3.9, and 4.0. Another embodiment of the lactic acid fermented food is a fermented soy milk product. In the case of the fermented soy milk product, the upper limit of its pH is preferably 5.9, more preferably 5.8, 5.7, 5.6, or 5.5. On the other hand, the lower limit of its pH is preferably 3.5, more preferably 3.6, 3.7, 3.8, 3.9, or 4.0. One embodiment of the fermented soy milk product is soy milk yogurt. Another embodiment of the lactic acid fermented food is a cheese filling. In the case of the cheese filling, the upper limit of its pH is preferably 6.1, more preferably 6.0, 5.9, 5.8, 5.7, or 5.6. On the other hand, the lower limit of its pH is preferably 4.0, more preferably 4.1, 4.2, 4.3, 4.4, or 4.5. Another embodiment of the lactic acid fermented food is pasteurized fermented milk. In the case of the pasteurized fermented milk described above, the upper limit of the pH is preferably 5.8, and more preferably 5.7, 5.6, 5.5, 5.4, 5.3, 5.2, 5.1, and 5.0. On the other hand, the lower limit of the pH is preferably 3.0, and more preferably 3.1, 3.2, 3.3, 3.4, and 3.5. In any embodiment, even if the pH is adjusted using an organic acid or alkaline salt after lactic acid fermentation, it can still be used as a lactic acid fermented food for the acidity reduction method of the present invention.

[0020] The method for reducing acidity of the present invention includes a stirring and / or shaking step in lactic acid fermentation to obtain the target lactic acid fermented food, thereby achieving the effects of the present invention. Generally, lactic acid fermentation can be carried out by standing, but if the stirring and / or shaking step is not included at all, the effects of the present invention cannot be achieved. Stirring in this specification and the claims of this patent means the operation in which the target is mixed with a predetermined device. The device is not limited to, but includes stirrers, mixers, food processors, stirring blades, spatulas, spoons, chopsticks, etc. The stirring blade may also be attached to a stirrer, etc. The shape of the stirring blade is not limited to, but includes, for example, a propeller, a paddle, etc. Power for operating the device can be an electric power method or a manual power method, etc., but is not limited to, but an electric power method is preferred. Shaking in this specification and the claims of this patent means the operation in which the target is shaken by a predetermined vibration motion. As an example of the aforementioned vibration motion, a commercially available shaking device is used to support the object, and then, according to a program, the object is shaken linearly or rotationally. Examples of commercially available shaking devices include shakers, shaking incubators, ultrasonic generators, etc. Furthermore, various conditions in the stirring and / or shaking process, such as the material of the container, the scale of the container, the stirring intensity, the shaking speed, and the temperature, can be appropriately determined by a person skilled in the art based on known technology.

[0021] In the method of the present invention, it is preferable that the total time spent stirring and / or shaking accounts for 50% or more of the total time required for lactic acid fermentation. More preferably, this percentage is 60% or more, even more preferably 70% or more, 75% or more, 80% or more, 85% or more, 90% or more, 95% or more, and most preferably 100%. When this range is appropriate, the effects of the present invention can be achieved. In this specification and in the claims of this patent, "total time required for lactic acid fermentation" means from the time when lactic acid bacteria are added to the substrate until the pH first reaches the target value. In this specification and in the claims of this patent, "total time spent stirring and / or shaking" means the total time spent stirring the substrate and lactic acid bacteria, and the total time spent shaking the substrate and lactic acid bacteria during the fermentation process. Therefore, the step of stirring and / or shaking after adding lactic acid bacteria to the substrate at the start of lactic acid fermentation, with the aim of uniformly dispersing the lactic acid bacteria in the substrate, shall be included in the “time for stirring and / or shaking” in this specification and the claims of this patent. As an example, the case in which the entire fermentation process is subdivided shall be explained. In a case in which lactic acid bacteria are added to the substrate, the first step is stirring and / or shaking, the second step is not stirring and / or shaking, and the third step is stirring and / or shaking, and the pH first reaches the target value, the “total time required for lactic acid fermentation” refers to the sum of the time required for all three steps, and the “total time for stirring and / or shaking” refers to the sum of the time required for the first and third steps. The total time required for lactic acid fermentation is not particularly limited, but is preferably, for example, 1 to 120 hours. The upper limits of the above time are more preferably 96 hours, 72 hours, 48 ​​hours, and 24 hours. The lower limit of the time is more preferably 2 hours, 3 hours, 4 hours, or 5 hours. One embodiment of the lactic acid fermented food is a fermented oat milk product. In the case of the fermented oat milk product, the upper limit of the time is preferably 72 hours, and more preferably 66 hours, 60 hours, 54 hours, 48 ​​hours, 42 hours, 36 hours, 30 hours, or 24 hours. The lower limit of the time is preferably 1 hour, and more preferably 2 hours, 3 hours, 4 hours, or 5 hours.Another embodiment of the lactic acid fermented food is a fermented soy milk product. In the case of the fermented soy milk product, the upper limit of the time is preferably 120 hours, and more preferably 96 hours, 72 hours, 48 ​​hours, 24 hours, and 12 hours. The lower limit of the time is preferably 1 hour, and more preferably 2 hours, 3 hours, 4 hours, and 5 hours. Another embodiment of the lactic acid fermented food is a cheese filling. In the case of the cheese filling, the upper limit of the time is preferably 96 hours, and more preferably 90 hours, 84 hours, 78 hours, 72 hours, 66 hours, 60 hours, 54 hours, 48 ​​hours, 42 hours, 36 hours, 30 hours, and 24 hours. The lower limit of the time is preferably 1 hour, and more preferably 2 hours, 3 hours, 4 hours, and 5 hours. Another embodiment of the lactic acid fermented food is pasteurized fermented milk. In the case of pasteurized fermented milk, the upper limit of the time is preferably 120 hours, and more preferably 96 hours, 72 hours, 48 ​​hours, and 24 hours. The lower limit of the aforementioned time is preferably 1 hour, and more preferably 2, 3, 4, or 5 hours. In the method of the present invention, either stirring or shaking can be used in the process during lactic acid fermentation, but stirring is preferred from the viewpoint of achieving the effects of the present invention.

[0022] The conditions for lactic acid fermentation used in the method of the present invention include aerobic conditions in which lactic acid fermentation is carried out in the presence of oxygen, and anaerobic conditions in which lactic acid fermentation is carried out in the absence of oxygen, and are not particularly limited. However, from the viewpoint of more effectively demonstrating the effects of the present invention, aerobic conditions in which lactic acid fermentation is carried out in the presence of oxygen are preferred. Among the aerobic conditions, it is more preferable that the dissolved oxygen concentration during lactic acid fermentation is 1 ppm or higher, and even more preferable that it is 2 ppm or higher, 3 ppm or higher, 4 ppm or higher, or 5 ppm or higher.

[0023] The lactic acid fermentation used in the method of the present invention shall be carried out using microorganisms such as lactic acid bacteria. The microorganisms such as lactic acid bacteria are not particularly limited, but lactic acid bacteria (including bifidobacteria) are preferred. Examples of types of lactic acid bacteria include Lactobacillus species such as Lactobacillus casei, Lactobacillus plantarum, Lactobacillus helveticus, and Lactobacillus bulgaricus, Streptococcus species such as Streptococcus thermophilus, Streptococcus lactis, and Streptococcus diacetylactis, and Lactococcus lactis subspecies lactis. Examples include the Lactococcus genus, such as Biover diacetylactis and Lactococcus lactis subspecies cremoris; the Leuconostoc genus, such as Leuconostoc mesenteroides subspecies cremoris and Leuconostoc lactis; and the Bifidobacterium genus, such as Bifidobacterium bifidum, Bifidobacterium longum, Bifidobacterium infantis and Bifidobacterium breve. Preferably, one or more lactic acid bacteria selected from the group consisting of Lactobacillus plantarum, Lactobacillus bulgaricus, Streptococcus thermophilus, Lactococcus lactis subspecies lactis, Lactococcus lactis subspecies lactis biover diacetylactis, Lactococcus lactis subspecies cremoris, Leuconostoc mesenteroides subspecies cremoris, and Bifidobacterium bifidum can be used as the lactic acid bacteria. More preferably, one or more species selected from the group consisting of Lactobacillus bulgaricus, Streptococcus thermophilus, Lactococcus lactis subspecies lactis, Lactococcus lactis subspecies cremoris, Leuconostoc mesenteroides subspecies cremoris, and Bifidobacterium bifidum can be used.In addition, certain strains of bacteria used in commercially available yogurt and lactic acid bacteria beverages, or known to the public, such as Lactobacillus casei (YIT9029 strain (Shirota strain), YIT10003 strain, NY1301 strain, SBR1202 strain), Lactobacillus mari YIT0243 strain, Lactobacillus acidophilus (SBT-2062 strain, CK92 strain), Lactobacillus helveticus CK60 strain, Lactobacillus gasseri (SP strain (SBT2055SR), LG21 strain, LC1 strain, OLL2716 strain, FERM P-17399, etc.), Lactobacillus delbrueckii subspecies bulgaricus (OLL1023 (Stocks, OLL1029 stocks, OLL1030 stocks, OLL1043 stocks, OLL1057 stocks, OLL1073R-1 stock, OLL1075 stocks, OLL1083 stocks, OLL1097 stocks, OLL1104 stocks, OLL1162 stocks, 2038 stocks), Lactobacillus johnsonii La1 stock (LC1 stock), Lactobacillus GG stock, Streptococcus thermophilus (1131 stocks, OLS3059 stocks), Bifidobacterium breve (Yakult stock, YIT4065 stock), Bifidobacterium bifidum (Yakult stock), Bifidobacterium longum (SP stock (SBT2928), BB536 stock, BE80 stock, FERM) Strains such as BP-7787, Bifidobacterium lactis (FK120, LKM512, Bb-12) can also be suitably used. The temperature of lactic acid fermentation used in the method of the present invention is not particularly limited, but is preferably 4 to 48°C. The upper limit of the temperature is more preferably 47°C, 46°C, 45°C, 44°C, and 43°C. The lower limit of the temperature is more preferably 6°C, 8°C, 10°C, 12°C, and 14°C.

[0024] The lactic acid fermented food obtained by lactic acid fermentation used in the method of the present invention preferably has a lactic acid content of 0.0003% by mass or more. The upper limit of the content is more preferably 5% by mass, 4% by mass, 3% by mass, 2.5% by mass, 2% by mass, 1.8% by mass, 1.6% by mass, and 1.5% by mass. The lower limit of the above-mentioned content is more preferably 0.0004% by mass, 0.0005% by mass, 0.0006% by mass, 0.0007% by mass, 0.0008% by mass, 0.0009% by mass, 0.001% by mass, 0.0011% by mass, 0.0012% by mass, 0.0013% by mass, 0.0015% by mass, 0.002% by mass, 0.005% by mass, 0.01% by mass, 0.02% by mass, 0.05% by mass, 0.1% by mass, 0.2% by mass, 0.3% by mass, 0.4% by mass, 0.5% by mass, 0.6% by mass, 0.7% by mass, 0.8% by mass, 0.9% by mass, and 1% by mass. When this range is appropriate, the effects of the present invention can be more fully realized. In one embodiment (a), the lactic acid contained in the lactic acid fermented food is that which is produced by lactic acid fermentation. Another embodiment (b) is one in which the substance is added during lactic acid fermentation. Another embodiment (c) is one in which the substance is added to a lactic acid fermented food obtained by lactic acid fermentation. Furthermore, an embodiment may be one in which the above three embodiments are arbitrarily combined. Any of the embodiments is not particularly limited, but embodiment (a) is preferred. The lactic acid content in the lactic acid fermented food can be quantified, for example, using a Merck RQflex 20 reflectometer and a ReflectoQuant lactic acid test strip.

[0025] The lactic acid fermented food obtained by lactic acid fermentation used in the method of the present invention preferably has a milk protein and / or plant protein content of 0.002% by mass or more. The upper limit of the content is more preferably 15% by mass, 14% by mass, 13% by mass, 12% by mass, 11% by mass, 10% by mass, 9% by mass, 8% by mass, 7% by mass, and 6% by mass. The lower limit of the content is more preferably 0.003% by mass, 0.004% by mass, 0.005% by mass, 0.006% by mass, 0.007% by mass, 0.008% by mass, 0.009% by mass, and 0.01% by mass. When this range is appropriate, the effects of the present invention can be more fully realized.

[0026] In some embodiments, the substrate for lactic acid fermentation used in the method of the present invention may include animal-derived raw materials. The type of animal-derived raw material is not particularly limited, but examples include natural fresh cream or milk, processed milk, or skim milk, skim milk powder, whole milk powder, casein such as acid casein, rennet casein, or sodium caseinate, or milk proteins derived from whey protein, and cream mixes containing various animal-derived proteins. In some embodiments, the substrate may include plant proteins obtained from plant-derived raw materials as basic raw materials. The type of plant raw material for the plant protein is not particularly limited, but examples include legumes such as soybeans, peas, and broad beans, seeds such as almonds, hazelnuts, cashews, walnuts, peanuts, and pistachios, and grains such as rice and oats, and these may be mixed in appropriate proportions. In some embodiments, the substrate may include oil-in-water emulsions. The type of oil-in-water emulsion is not particularly limited, but examples include an oil-in-water emulsion containing milk raw materials, protein, oil and fat, and water. Furthermore, in one embodiment, the substrate may be a combination of the three embodiments described above.

[0027] It is preferable that the content of milk protein and / or plant protein in the substrate for lactic acid fermentation used to obtain the lactic acid fermented food in the method of the present invention is 0.002% by mass or more. The upper limit of the content is more preferably 15% by mass, 14% by mass, 13% by mass, 12% by mass, 11% by mass, 10% by mass, 9% by mass, 8% by mass, 7% by mass, and 6% by mass. The lower limit of the content is more preferably 0.003% by mass, 0.004% by mass, 0.005% by mass, 0.006% by mass, 0.007% by mass, 0.008% by mass, 0.009% by mass, and 0.01% by mass. When this range is appropriate, the effects of the present invention can be more fully realized.

[0028] In addition to the lactic acid fermentation substrate used in the method of the present invention, sugars, starch, thickening polysaccharides, gelling agents, emulsifiers, flavorings, acidulants, antioxidants, chelating agents, etc., may be added as needed.

[0029] The lactic acid fermented food used in the method of the present invention may undergo filtration, homogenization, and sterilization steps as necessary after the fermentation process, such as lactic acid fermentation. The order and conditions of these steps are not particularly limited and can be set as appropriate by those skilled in the art. For example, homogenization can be carried out at 0 to 20 MPa, and sterilization can be carried out at 60 to 160°C.

[0030] The present invention is also a method for producing a food or beverage containing a lactic acid fermented food or a pre-lactic acid fermented food with reduced acidity, characterized in that the pH of the lactic acid fermented food is 6.1 or less, and the lactic acid fermentation step for obtaining the lactic acid fermented food includes a step of stirring and / or shaking.

[0031] The present invention will be described in more detail below with reference to examples of the present invention, but the spirit of the present invention is not limited to these examples. In the examples, %, parts, and ratios all refer to mass.

[0032] ■Test 1: Oat Milk Fermented Product <Test Section 1> To a mixture obtained by mixing 1 part by mass of oat milk and 99 parts by mass of water, the mixture was heat-sterilized at 80°C for 1 minute and cooled to 24°C. This mixture was used as a substrate (the content of milk protein and / or plant protein in the substrate is 0.004% by mass). 0.01 parts by mass of a freeze-dried lactic acid bacteria starter containing Lactococcus lactis subspecies lactis, Lactococcus lactis subspecies lactis biover diacetylactis, Leuconostoc mesenteroides subspecies cremoris, Lactococcus lactis subspecies cremoris, and Streptococcus thermophilus was added, and lactic acid fermentation was carried out at 24°C. The lactic acid fermentation was carried out using a Primix Homodisper 2.5 model under aerobic conditions (dissolved oxygen concentration of 4-7 ppm) without nitrogen aeration during fermentation, until the pH reached 6.1. The total time required for the lactic acid fermentation was 15 hours, of which 9 hours were spent stirring (performed at 3000 rpm using the apparatus). Through the above process, the fermented oat milk product of Example 1 was obtained. <Example 1 Control> 1 part by mass of oat milk and 99 parts by mass of water were mixed, heated and sterilized at 80°C for 1 minute, cooled to 24°C, and then lactic acid was added without lactic acid fermentation to adjust the pH to 6.1. Through the above process, the control of Example 1 was obtained. The results are shown in Table 1.

[0033] <Comparative Example 1 Test Section> Comparative Example 1 was prepared in the same manner as in Example 1, except that the total time spent stirring was set to 0 hours as part of the total time required for lactic acid fermentation. <Comparative Example 1 Control Section> The control section from Example 1 was used. The results are shown in Table 2.

[0034] <Example 2 Test Section> A substrate was obtained using a mixture of 3 parts by mass of oat milk and 97 parts by mass of water (the content of milk protein and / or plant protein in the substrate is 0.012% by mass). Except that lactic acid fermentation was carried out until the pH reached 5.8, Example 2 Test Section was obtained in the same manner as Example 1 Test Section. <Example 2 Control Section> A control section was obtained using a mixture of 3 parts by mass of oat milk and 97 parts by mass of water, except that the pH was adjusted to 5.8. The results are shown in Table 3.

[0035] <Comparative Example 2 Test Section> Comparative Example 2 was prepared in the same manner as in Example 2, except that lactic acid fermentation was carried out until the pH reached 6.6, the total time required for lactic acid fermentation was 4 hours, and the total time spent stirring within the total time required for lactic acid fermentation was 2.4 hours. <Comparative Example 2 Control Section> Comparative Example 2 control section was prepared in the same manner as in Example 2 control section, except that the pH was adjusted to 6.6. The results are shown in Table 4.

[0036] <Example 3 Test Section> The substrate obtained was prepared by mixing 10 parts by mass of oat milk and 90 parts by mass of water (the content of milk protein and / or plant protein in the substrate was 0.04% by mass). Except that lactic acid fermentation was carried out until the pH reached 6.0, Example 3 Test Section was prepared in the same manner as Example 1 Test Section. <Example 3 Control Section> The control section of Example 3 was prepared by mixing 10 parts by mass of oat milk and 90 parts by mass of water, and adjusting the pH to 6.0, except that the pH was adjusted. The results are shown in Table 5.

[0037] <Example 4 Test Section> Example 4 was prepared in the same manner as Example 3 Test Section, except that lactic acid fermentation was carried out under anaerobic conditions with nitrogen aeration (dissolved oxygen concentration less than 1 ppm). <Example 4 Control Section> The control section from Example 3 was used. The results are shown in Table 6.

[0038] <Comparative Example 3> Comparative Example 3 was prepared in the same manner as in Example 3, except that the total time spent stirring was 4.5 hours as a percentage of the total time required for lactic acid fermentation. <Comparative Example 3 Control> The control group from Example 3 was used. The results are shown in Table 7.

[0039] Five preference panelists who are proficient in the field of lactic acid fermented foods were asked to conduct a sensory evaluation of the effect of reducing sourness in the test group compared to the control group. The sensory evaluation was carried out according to the following evaluation method. The results are shown in Tables 1 to 7. The evaluation was determined by the consensus of the five panelists, and a score of 3 or more was considered passing. <Evaluation criteria> 1 point: The sourness has not been reduced at all compared to the control group. 2 points: There is a slight difference compared to the control group, but the sourness has not been significantly reduced. 3 points: A difference can be recognized compared to the control group, and the sourness has been reduced. 4 points: The difference is greater than 3 points compared to the control group, and the sourness has been considerably reduced. 5 points: The difference is greater than 4 points compared to the control group, and the sourness has been significantly reduced.

[0040] The content of lactic acid in the lactic acid fermented food was measured using an RQ flex 20 reflectometer manufactured by Merck and test strips for the reflectoquant lactic acid test.

[0041] ■Table 1 * In the table, the "protein content [%]" refers to the total amount of milk protein and / or vegetable protein. The same applies to all the following tables.

[0042] ■Table 2

[0043] ■Table 3

[0044] ■Table 4

[0045] ■Table 5

[0046] ■Table 6

[0047] ■Table 7

[0048] ■Discussion of Test 1 As seen in the results above, a reduction in acidity was observed in lactic acid fermented foods with a pH of 6.1 or lower obtained by performing lactic acid fermentation on a mixture of oat milk and water and stirring during the lactic acid fermentation, compared to the control group. In particular, a further reduction in acidity was observed when the proportion of the total stirring time to the total time required for lactic acid fermentation was 60% or more, when the lactic acid fermentation was aerobic fermentation, when the lactic acid content in the lactic acid fermented food was 0.0005% by mass or more, and when the substrate for lactic acid fermentation contained 0.004% by mass or more of plant protein.

[0049] ■Test 2: Soy Milk Yogurt (Soy Milk Fermented Product) <Example 5 Test Section> A mixture obtained by mixing 76 parts by mass of soy milk, 10 parts by mass of dextrin, and 14 parts by mass of water was heated and sterilized at 80°C for 1 minute, cooled to 40°C, and used as a substrate (the content of milk protein and / or plant protein in the substrate is 4% by mass). 0.01 parts by mass of a freeze-dried lactic acid bacteria starter containing Lactobacillus bulgaricus and Streptococcus thermophilus was added, and lactic acid fermentation was carried out at 40°C. The lactic acid fermentation was carried out using a Primix Homodisper 2.5 type, under aerobic conditions (dissolved oxygen concentration of 4-7 ppm) without nitrogen aeration during fermentation, until the pH reached 4.6. The total time required for the lactic acid fermentation was 15 hours, and the total time spent stirring (at 3000 rpm using the above apparatus) was 8.25 hours. Through the above process, soy milk yogurt, Test Group 5, was obtained. <Control Group 5> A mixture obtained by mixing 76 parts by mass of soy milk, 10 parts by mass of dextrin, and 14 parts by mass of water was heated and sterilized at 80°C for 1 minute, cooled to 40°C, and lactic acid was added without lactic acid fermentation to adjust the pH to 4.6. Through the above process, Control Group 5, Test Group 5, was obtained. The results are shown in Table 8.

[0050] ■Table 8

[0051] ■Discussion of Test 2 As seen in the results above, in the lactic acid fermented food obtained by performing lactic acid fermentation on a mixture of soy milk, dextrin, and water, and stirring during the lactic acid fermentation, a sourness reduction effect was observed in the pH 6.1 or lower food product, similar to Test 1, with the control group as the baseline.

[0052] ■Test 3: Cheese Filling <Example 6 Test Section> A mixture was obtained by mixing 26 parts by mass of vegetable oil, 7.5 parts by mass of skim milk powder, 5 parts by mass of Gouda cheese, 2 parts by mass of milk protein, 0.7 parts by mass of salt, 55.3 parts by mass of water, and 3.5 parts by mass of modified starch. This mixture was then heat-sterilized at 80°C for 1 minute and cooled to 24°C. This mixture was used as a substrate (the content of milk protein and / or vegetable protein in the substrate is 5.3% by mass). 0.01 parts by mass of a freeze-dried lactic acid bacteria starter containing Lactobacillus helveticus, Streptococcus thermophilus, Lactococcus lactis subspecies lactis biover diacetylactis, and Leuconostoc mesenteroides subspecies cremoris was added, and lactic acid fermentation was carried out at 40°C. The lactic acid fermentation was carried out using a Primix Homodisper 2.5 model under aerobic conditions (dissolved oxygen concentration of 4-7 ppm) without nitrogen aeration during fermentation, until the pH reached 5.2. The total time required for the lactic acid fermentation was 18 hours, of which 18 hours were spent stirring (performed at 3000 rpm using the apparatus). Through the above process, Example 6 test section, which is a cheese filling, was obtained. <Example 6 control section> A mixture was obtained by mixing 26 parts by mass of vegetable oil, 7.5 parts by mass of skim milk powder, 5 parts by mass of Gouda cheese, 2 parts by mass of milk protein, 0.7 parts by mass of salt, 55.3 parts by mass of water, and 3.5 parts by mass of modified starch. The mixture was heat-sterilized at 80°C for 1 minute, cooled to 24°C, and then lactic acid was added without lactic acid fermentation to adjust the pH to 5.2. Through the above process, Example 6 control section was obtained. The results are shown in Table 9.

[0053] ■Table 9

[0054] ■Discussion of Test 3 As seen in the results above, a lactic acid fermentation was performed on a mixture consisting of vegetable oil, skim milk powder, Gouda cheese, milk protein, salt, water, and modified starch, and a lactic acid fermented food with a pH of 6.1 or lower was obtained by stirring during the lactic acid fermentation. Similar to Tests 1 and 2, a reduction in sourness was observed in the control group.

[0055] ■Test 4: Sterilized Fermented Milk (Acidic Beverage) <Example 7 Test Section> A mixture was obtained by mixing 15 parts by mass of vegetable oil, 13 parts by mass of skim milk powder, 2 parts by mass of egg yolk, and 70 parts by mass of water. This mixture was sterilized by heating at 80°C for 1 minute and cooled to 24°C. This mixture was used as a substrate (the content of milk protein and / or vegetable protein in the substrate was 4.6% by mass). 0.01 parts by mass of a freeze-dried lactic acid bacteria starter containing Lactobacillus bulgaricus and Streptococcus thermophilus was added, and fermentation was carried out at 37°C. The lactic acid fermentation was carried out using a Primix Homodisper 2.5 type under aerobic conditions (dissolved oxygen concentration of 4-7 ppm) without nitrogen aeration during fermentation, until the pH reached 5.6. The total time required for the lactic acid fermentation was 15 hours, and the total time spent stirring (at 3000 rpm using the above apparatus) was 12 hours. Through the above process, we obtained Test Group 7, which is a pasteurized fermented milk (acidic beverage). <Control Group 7> A mixture was obtained by mixing 15 parts by mass of vegetable oil, 13 parts by mass of skim milk powder, 2 parts by mass of egg yolk, and 70 parts by mass of water. This mixture was then heat-sterilized at 80°C for 1 minute, cooled to 24°C, and lactic acid was added without lactic acid fermentation to adjust the pH to 5.6. Through the above process, we obtained Control Group 7. The results are shown in Table 10.

[0056] ■Table 10

[0057] ■Discussion of Test 4 As seen in the results above, when lactic acid fermentation was performed on a mixture of vegetable oil, skim milk powder, egg yolk, and water, and stirring was performed during the lactic acid fermentation, a lactic acid fermented food with a pH of 6.1 or lower was obtained, and a sourness reduction effect was observed, similar to Tests 1 to 3, with the control group as the baseline.

[0058] ■Test 5: Custard cream using pasteurized fermented milk (acidic beverage) <Example 8 Test Section> 30 parts by mass of pasteurized fermented milk (acidic beverage), 16 parts by mass of sugar, 10 parts by mass of vegetable oil, 6 parts by mass of milk, 5 parts by mass of whole egg, 4 parts by mass of skim milk powder, 1 part by mass of milk protein, 25 parts by mass of water, and 4 parts by mass of modified starch were mixed and heat-sterilized at 80°C for 1 minute, resulting in a sterilization rate of 50 kg / cm³. ２ The mixture was homogenized under pressure and cooled to 5°C to obtain custard cream. Through the above steps, the custard cream sample of Example 8 was obtained. <Example 8 Control> The control sample of Example 8 was obtained in the same manner as the test sample of Example 8, except that pasteurized fermented milk (acidic beverage) was used as the control sample of Example 7.

[0059] ■Results and Discussion of Test 5: The acidity reduction effect in Example 8 was evaluated as 4 points. Therefore, a similar acidity reduction effect could be observed in food and beverages containing lactic acid fermented foods that partially incorporate the lactic acid fermented food in which the acidity reduction effect was observed.

[0060] The present invention provides a method for reducing the acidity of a lactic acid fermented food, or a food or beverage containing a lactic acid fermented food, by using a method that includes stirring and / or shaking during lactic acid fermentation to obtain the lactic acid fermented food, where the pH of the lactic acid fermented food is 6.1 or lower. This method has great industrial potential.

Claims

1. A method for reducing the acidity of a lactic acid fermented food or a food or beverage containing the lactic acid fermented food, wherein the pH of the lactic acid fermented food is 6.1 or less, and the method includes a step of stirring and / or shaking during the lactic acid fermentation to obtain the lactic acid fermented food.

2. The method according to claim 1, wherein the total time spent stirring and / or shaking accounts for 50% or more of the total time required for lactic acid fermentation.

3. The method according to claim 1 or claim 2, wherein lactic acid fermentation is carried out under aerobic conditions.

4. The method according to claim 1 or claim 2, wherein the lactic acid content in the lactic acid fermented food is 0.0003% by mass or more.

5. The method according to claim 3, wherein the lactic acid content in the lactic acid fermented food is 0.0003% by mass or more.

6. The method according to claim 1 or claim 2, wherein the content of milk protein and / or plant protein in the substrate for lactic acid fermentation to obtain a lactic acid fermented food is 0.002% by mass or more.

7. The method according to claim 3, wherein the content of milk protein and / or plant protein in the substrate for lactic acid fermentation to obtain a lactic acid fermented food is 0.002% by mass or more.

8. The method according to claim 4, wherein the content of milk protein and / or plant protein in the substrate for lactic acid fermentation to obtain a lactic acid fermented food is 0.002% by mass or more.

9. The method according to claim 5, wherein the content of milk protein and / or plant protein in the substrate for lactic acid fermentation to obtain a lactic acid fermented food is 0.002% by mass or more.

10. A method for producing a lactic acid fermented food with reduced acidity, or a food or beverage containing the lactic acid fermented food, characterized in that the pH of the lactic acid fermented food is 6.1 or less, and the lactic acid fermentation step for obtaining the lactic acid fermented food includes a step of stirring and / or shaking.

11. The method according to claim 10, wherein the total time spent stirring and / or shaking accounts for 50% or more of the total time required for lactic acid fermentation.

12. The method according to claim 10 or claim 11, wherein lactic acid fermentation is carried out under aerobic conditions.

13. The method according to claim 10 or claim 11, wherein the lactic acid content in the lactic acid fermented food is 0.0003% by mass or more.

14. The method according to claim 12, wherein the lactic acid content in the lactic acid fermented food is 0.0003% by mass or more.

15. The method according to claim 10 or claim 11, wherein the content of milk protein and / or plant protein in the substrate for lactic acid fermentation to obtain a lactic acid fermented food is 0.002% by mass or more.

16. The method according to claim 12, wherein the content of milk protein and / or plant protein in the substrate for lactic acid fermentation to obtain a lactic acid fermented food is 0.002% by mass or more.

17. The method according to claim 13, wherein the content of milk protein and / or plant protein in the substrate for lactic acid fermentation to obtain a lactic acid fermented food is 0.002% by mass or more.

18. The method according to claim 14, wherein the content of milk protein and / or plant protein in the substrate for lactic acid fermentation to obtain a lactic acid fermented food is 0.002% by mass or more.

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