Composition for modifying protein solution

Abstract

The present invention provides a composition for modifying a milk protein or plant protein solution, and the like, comprising a protease that has dipeptidyl aminopeptidase activity and leucine aminopeptidase activity without having endo-type activity.

Description

Composition for modifying protein solution 【0001】 The present invention relates to a composition for modifying a protein solution and the like. 【0002】 Against the backdrop of the growing health consciousness, the demand for high-protein foods has been increasing, and among them, beverage forms that can be easily consumed have been supported by a wide range of consumers. For example, dairy manufacturers are considering products such as high-protein yogurt containing more protein, but when the amount of protein is increased, there is a problem that the viscosity of the milk protein solution before sterilization increases, and the production suitability decreases due to adhesion to pipes and the like. For example, the milk protein solution is often placed in a state for about two days at most before sterilization, and in this case, the viscosity increase becomes particularly significant after the next day of mixing. Also, in the final product after sterilization, aggregation, viscosity increase, etc. are problems. 【0003】 Regarding the production of low-viscosity and high-protein foods including yogurt, methods such as exposing milk protein concentrates, milk protein isolates, etc. to the action of endopeptidases such as metalloprotein endopeptidase and serine endopeptidase have been proposed (Patent Document 1). 【0004】 Japanese Patent Publication No. 2024-519230 【0005】 An object of the present invention is to provide a composition for suppressing the viscosity of a milk protein or plant protein solution and the like. 【0006】 As a result of intensive studies on the above problems, the present inventors have found that the viscosity of a milk protein solution can be suppressed by adding a protease having dipeptidyl aminopeptidase activity and leucine aminopeptidase activity without having endo-type activity in the milk protein solution production process, and based on such findings, further research has been carried out to complete the present invention. That is, the present invention is as follows. 【0007】[1] A composition for modifying milk protein or plant protein solutions, comprising a protease that does not have endo-type activity but has dipeptidylaminopeptidase activity and leucineaminopeptidase activity. [2] The composition according to [1], wherein the milk protein or plant protein solution material is added such that the number of units of total protease activity measured by the casein-forin method is 15 U (units) or less per gram of protein in the entire milk protein or plant protein solution material. [3] The composition according to [1] or [2], further comprising glucose oxidase. [4] The composition according to any one of [1] to [3], wherein the modification is viscosity suppression. [5] The composition according to any one of [1] to [4], wherein the milk protein or plant protein solution is a milk protein solution. [6] The composition according to [5], wherein the milk protein solution is for yogurt production. [7] The composition according to any one of [1] to [6] above, wherein in the process of manufacturing a milk protein or plant protein solution, a protease having dipeptidylaminopeptidase activity and leucineaminopeptidase activity but lacking endo-type activity is added to the material of the milk protein or plant protein solution such that the number of units of dipeptidylaminopeptidase activity and the number of units of leucineaminopeptidase activity per 100 g of the total material of the milk protein or plant protein solution are each in the range of 0.0001 U to 100,000 U. [8] A method for manufacturing a milk protein or plant protein solution, comprising the step of adding a protease having dipeptidylaminopeptidase activity and leucineaminopeptidase activity but lacking endo-type activity to the material of the milk protein or plant protein solution. [9] The method for producing the product according to [8], wherein a protease that does not have endo-type activity but has dipeptidylaminopeptidase activity and leucineaminopeptidase activity is added to the milk protein or plant protein solution in an amount such that the number of units of total protease activity measured by the casein-forin method per gram of protein in the entire material is 15 U or less.

[10] The method for producing the product according to [8] or [9], further comprising the step of adding glucose oxidase.

[11] The manufacturing method according to any one of [8] to

[10] above, wherein the milk protein or plant protein solution is a milk protein solution.

[12] The manufacturing method according to

[11] above, wherein the milk protein solution is for yogurt production.

[13] The manufacturing method according to any one of [8] to

[12] above, wherein a protease having dipeptidylaminopeptidase activity and leucine aminopeptidase activity but lacking endo-type activity is added such that the number of units of dipeptidylaminopeptidase activity and the number of units of leucine aminopeptidase activity per 100 g of the total material of the milk protein or plant protein solution are each in the range of 0.0001 U to 100,000 U.

[14] A method for suppressing the viscosity of a milk protein or plant protein solution, comprising the step of adding a protease having dipeptidylaminopeptidase activity and leucine aminopeptidase activity but lacking endo-type activity to the material of the milk protein or plant protein solution.

[15] The method according to

[14] , wherein a protease that does not have endo-type activity but has dipeptidylaminopeptidase activity and leucineaminopeptidase activity is added in an amount such that the number of units of total protease activity measured by the casein-forin method per gram of protein in the entire material of the milk protein or plant protein solution is 15 U or less.

[16] The method according to

[14] or

[15] , further comprising the step of adding glucose oxidase.

[17] The method according to any one of

[14] to

[16] , wherein the milk protein or plant protein solution is a milk protein solution.

[18] The method according to

[17] , wherein the milk protein solution is for yogurt production.

[19] The method according to any one of

[14] to

[18] above, wherein a protease having dipeptidylaminopeptidase activity and leucineaminopeptidase activity but lacking endo-type activity is added such that the number of units of dipeptidylaminopeptidase activity and the number of units of leucineaminopeptidase activity per 100 g of the total material of the milk protein or plant protein solution are each in the range of 0.0001 U to 100,000 U. 【0008】The present invention provides a composition for modifying milk protein or plant protein solutions, etc., for producing milk protein or plant protein solutions with suppressed viscosity. 【0009】 1. Composition for modifying protein solutions The present invention provides a composition for modifying milk protein or plant protein solutions (hereinafter also referred to as "the composition of the present invention") that contains a protease that does not have endo-type activity but has dipeptidylaminopeptidase activity and leucineaminopeptidase activity. 【0010】 In this specification, dipeptidylaminopeptidase (hereinafter also referred to as "DPP") is an enzyme that has the activity of releasing a dipeptide from the N-terminus of a protein or peptide, and is classified into DPP I, II, III, IV, etc. Furthermore, dipeptidylaminopeptidase activity (hereinafter also referred to as "DPP activity") refers to the activity of releasing a dipeptide from the N-terminus of the protein or peptide. In this specification, a protease that does not have endo-type activity but has dipeptidylaminopeptidase activity and leucine aminopeptidase activity (hereinafter also referred to as "this protease") is preferred if it has dipeptidylaminopeptidase IV activity (hereinafter also referred to as "DPP IV activity"). 【0011】 DPP activity in this specification can be determined by known measurement methods. For example, in this specification, DPP IV activity is measured and defined as follows: DPP activity is determined by reacting an enzyme with L-glycyl-L-prolyl-p-nitroanilide p-toluene sulfate as a substrate and colorimetrically quantifying the produced p-nitroaniline (pNA). More specifically, 0.4 mL of enzyme solution is mixed with 0.4 mL of substrate solution containing L-glycyl-L-prolyl-p-nitroanilide p-toluene sulfate and reacted at 40°C for 10 minutes. After the reaction is stopped, the absorbance at a wavelength of 405 nm is measured to determine the amount of pNA produced. The amount of enzyme that produces 1 μmol of pNA per minute with L-glycyl-L-prolyl-p-nitroanilide p-toluene sulfate as a substrate is defined as 1 U (unit). 【0012】In this specification, leucine aminopeptidase (hereinafter also referred to as "LAP") is an enzyme that has the activity to act on the N-terminal amino acid of a protein or peptide and release the amino acid one by one, and leucine aminopeptidase activity (hereinafter also referred to as "LAP activity") refers to the activity of acting on the N-terminal amino acid of the protein or peptide and releasing the amino acid one by one. 【0013】 In this specification, LAP activity is measured and defined as follows: LAP activity is determined by reacting an enzyme with L-leucyl-p-nitroanilide hydrochloride as a substrate and colorimetrically quantifying the resulting p-nitroaniline (pNA). More specifically, 0.1 mL of enzyme solution is mixed with 4 mL of substrate solution containing L-leucyl-p-nitroanilide hydrochloride and reacted at 40°C for 5 minutes. After the reaction is stopped, the absorbance at a wavelength of 405 nm is measured to determine the amount of pNA produced. The amount of enzyme that produces 1 μmol of pNA per minute with L-leucyl-p-nitroanilide hydrochloride as a substrate is defined as 1 U. 【0014】 In this specification, endo-type activity is measured and defined as total protease activity (overall protease activity) by the casein-forin (CFA) method as follows: Using casein as a substrate, 1 mL of enzyme solution is mixed with 5 mL of a pH 6.0 substrate solution containing casein, and the mixture is reacted at 30°C for 10 minutes. After stopping the reaction, the precipitate is filtered off, and phenol is added to a solution adjusted to basicity to produce a color. The absorbance of the colored solution at a wavelength of 660 nm is measured to determine the amount of tyrosine produced. The amount of enzyme that produces 1 μg of tyrosine per minute using casein as a substrate is defined as 1 U. Note that the tyrosine targeted for quantification by the CFA method is produced when the endo-type activity and exo-type activity of the protease work in concert to decompose the protein down to amino acid units. Decomposition by endo-type activity is essential for the production of tyrosine. Therefore, in this specification, the amount of endo-type activity possessed by this protease and the total number of protease active units are substantially synonymous. 【0015】The protease used in this invention is not particularly limited as long as it is a protease that can be used in food. As the protease, plant-derived protease, microorganism-derived protease, animal-derived protease, etc., may be used, as may protease prepared by genetic modification. The protease used in this invention may also be a commercially available product. A specific example is Sumizyme TDR (available from Shin Nippon Chemical Industries, Ltd.). 【0016】 The content of the protease in the composition of the present invention is not particularly limited, but it is preferably in the range of 0.0001 U to 5,000 U, more preferably in the range of 0.0005 U to 3,000 U, and even more preferably in the range of 0.001 U to 1,000 U, for each of the DPP activity units and LAP activity units per gram of the composition of the present invention. 【0017】 In this specification, a milk protein or plant protein solution (hereinafter also simply referred to as "protein solution") refers to a solution in which milk protein or plant protein is dissolved in all or part of an edible liquid such as water. 【0018】 In this specification, milk protein refers to protein derived from milk, and is a concept that includes, for example, milk protein concentrate (MPC), whey protein, whey protein isolate (WPI), whey protein concentrate (WPC), casein, lactoferrin, etc., as well as milk proteins contained in milk, skim milk powder, whole milk powder, etc. 【0019】In this specification, plant protein refers to a protein derived from a plant or a composition containing the same, and also includes plants that have been processed to increase their protein content. Specific examples of plant protein include, for example, soy protein, wheat protein, pea protein, mung bean protein, broad bean protein, edamame protein, rapeseed protein, chia seed protein, corn protein, rice protein, buckwheat protein, sweet potato protein, asparagus protein, broccoli protein, avocado protein, oat protein, almond protein, etc., with soy protein being more preferred. 【0020】 More specifically, plant protein is not particularly limited as long as it contains protein derived from plants. For example, soy protein is not particularly limited as long as it contains protein derived from soybeans, and refers to proteins that can be obtained by processing soybeans, such as concentrated soy protein, isolated soy protein, fibrous soy protein, and extracted soy protein. Furthermore, plant protein may be a single type of plant protein, or a mixture of two or more types of plant proteins. 【0021】 Furthermore, in this specification, the term "protein solution" also includes a solution containing one or more of the milk proteins and one or more of the plant proteins described above. 【0022】 In this specification, water is preferred as the solvent in protein solutions. Examples of water include distilled water, purified water such as ion-exchanged water, tap water, and alkaline electrolyzed water, but the water is not limited to these, and any water suitable for food production can be used. 【0023】 The protein content in the protein solution as used herein is not particularly limited, but is preferably 1% to 25% by weight, more preferably 5% to 25% by weight, even more preferably 8% to 20% by weight, even more preferably 10% to 18% by weight or 12% to 17% by weight, and particularly preferably 13% to 16% by weight. 【0024】The protein solution produced using the composition of the present invention can be safely ingested by humans and non-human animals (e.g., mammals and birds such as livestock, poultry, and laboratory animals) either as is or added to food (feed). Furthermore, the protein solution produced using the composition of the present invention can also be used as a raw material for food (feed) (e.g., dairy products such as yogurt and cheese). For example, yogurt can be produced by adding lactic acid bacteria to a protein solution produced using the composition of the present invention and allowing it to ferment. 【0025】 In this specification, "food" is a broad concept encompassing anything that can be taken orally (excluding pharmaceuticals), and includes not only so-called "foods" but also beverages, health supplements, functional foods (e.g., foods for specified health uses, foods with functional claims, foods with nutritional function claims), supplements, etc. 【0026】 In this specification, "modification of milk protein or plant protein solution" means suppression of viscosity of the protein solution, etc. In this specification, "modification of milk protein or plant protein solution" may also include, for example, improving the texture (smoothness, etc.) of the final product yogurt when milk protein solution is used as a raw material, or improving the texture of the final product using the protein solution as a raw material. 【0027】 In this specification, "inhibition of viscosity of milk protein or plant protein solution" means, for example, that in a protein solution prepared using the composition of the present invention, the viscosity immediately after preparation, 5 minutes to 2 hours after preparation, 1 day to 1 week after preparation, preferably 1 to 5 days after preparation, and more preferably 1 to 2 days after preparation, is inhibited (for example, by 10% or more, preferably 20% or more, more preferably 30% or more, even more preferably 40% or more, and even more preferably 50% or more) compared to the viscosity of a protein solution prepared without using the composition of the present invention at the same time. This inhibitory effect is particularly effective when preparing a high-protein-content protein solution. 【0028】In this specification, "high protein-containing protein solution" refers to a protein solution that has a protein content that is 5% or more higher than a standard milk protein solution or the like, preferably 5% to 50% higher, more preferably 8% to 40% higher, even more preferably 10% to 30% higher, and even more preferably 12% to 25% higher. 【0029】 In one embodiment, "viscosity suppression of milk protein or plant protein solution" as used herein means that, for example, in a protein solution prepared using the composition of the present invention, the viscosity under acidic to neutral conditions, for example, in the range of pH 4.0 to 9.0, preferably in the range of pH 5.5 to 8.5, more preferably in the range of pH 6.0 to 8.0, is suppressed (for example, by 10% or more, preferably 20% or more, more preferably 30% or more, even more preferably 40% or more, and even more preferably 50% or more) compared to a protein solution prepared without using the composition of the present invention. 【0030】 Viscosity can be evaluated by measuring it using a viscometer (for example, DV1MLVTJ0 (Brookfield)) under conditions such as 8°C, 30 rpm, and after 60 seconds, as shown in the test examples described later. 【0031】 The composition of the present invention may further contain glucose oxidase. 【0032】 The glucose oxidase (hereinafter also referred to as "GO") used in the present invention is an oxidase that catalyzes the reaction that produces gluconic acid and hydrogen peroxide using glucose, oxygen, and water as substrates. The GO used in the present invention is not particularly limited as long as it is suitable for use in food. Examples of GO include plant-derived GO, microbial-derived GO, animal-derived GO, and genetically modified GO can also be used. The GO used in the present invention may be a commercially available product, and a specific example is Sumizyme PGO (Shin Nippon Chemical Industries, Ltd.). 【0033】In this specification, the active unit of GO is measured and defined as follows: Hydrogen peroxide is produced by reacting GO with glucose as a substrate in the presence of oxygen, and the quinone imine dye produced by reacting the generated hydrogen peroxide with peroxidase in the presence of aminoantipyrine and phenol is measured at a wavelength of 500 nm, and the amount of enzyme required to oxidize 1 μmol of glucose per minute is defined as 1 U. 【0034】 When the composition of the present invention contains GO, the amount of GO in the composition of the present invention is not particularly limited, but it is preferably an amount such that the number of units of glucose oxidase activity (hereinafter also referred to as "GO activity") per gram of the composition of the present invention is 0.001 U to 5,000 U, more preferably 0.003 U to 3,000 U, and even more preferably 0.01 U to 2,000 U. 【0035】 The composition of the present invention may contain other components besides the protease and GO, as long as they do not impair the effects of the present invention. 【0036】 Other ingredients that are commonly used in food products can be used as appropriate, and there are no particular restrictions on their content, but it is preferable that the total amount be 90% by weight or less, more preferably 70% by weight or less, and even more preferably 50% by weight or less. 【0037】 Specific forms of the composition of the present invention include solid form (tablets, granules, powders, etc.), paste form, liquid form, suspension form, emulsion form, etc., but a solid form is preferred. 【0038】 Next, a method for producing the composition of the present invention will be described. 【0039】 The composition of the present invention can be produced by adding GO and / or the other components described above to the protease as needed and mixing them together, or by other production methods common in the food industry. The order in which these components are added is not particularly limited and can be set as appropriate depending on the intended use. 【0040】By adding the composition of the present invention to the raw material of a protein solution during the manufacturing process of the protein solution, the viscosity of the protein solution can be suppressed. 【0041】 In this specification, the material of a protein solution refers to the raw materials of the protein solution (for example, the milk protein or plant protein mentioned above, edible liquids such as water, etc.), and intermediate compositions used before reaching the final protein solution. 【0042】 When adding the composition of the present invention to the protein solution material described above, the amount of composition of the present invention added is not particularly limited as long as the desired effect of the present invention is obtained. Typically, the amount is such that the number of DPP activity units and LAP activity units per 100 g of the total protein solution material are in the range of 0.0001 U to 10,000 U, preferably in the range of 0.001 U to 1,000 U, more preferably in the range of 0.005 U to 100 U, even more preferably in the range of 0.01 U to 50 U, even more preferably in the range of 0.05 U to 10 U, and particularly preferably in the range of 0.1 U to 5 U. 【0043】 In one embodiment, when adding the composition of the present invention to the protein solution material described above, the amount of the composition of the present invention added is usually such that the number of DPP activity units per gram of protein in the entire protein solution material is in the range of 0.0001 U to 1,000 U, preferably in the range of 0.0005 U to 10 U, more preferably in the range of 0.001 U to 1 U, and even more preferably in the range of 0.005 U to 0.35 U. Also, when adding the composition of the present invention to the protein solution material described above, the amount of the composition of the present invention added is usually such that the number of LAP activity units per gram of protein in the entire protein solution material is in the range of 0.0001 U to 1,000 U, preferably in the range of 0.0005 U to 500 U, and more preferably in the range of 0.001 U to 100 U. Conventional methods such as the combustion method and the Kjeldahl method can be used to measure the amount of protein in the protein solution. 【0044】 In one aspect, when adding the composition of the present invention to the material of the protein solution described above, the addition amount of the composition of the present invention is usually such that the number of units of the total protease activity measured by the CFA method per 1 g of protein in the entire material of the protein solution is 15 U or less, preferably 10 U or less, and more preferably 5 U or less. 【0045】 Further, when the composition of the present invention contains GO, when adding the composition of the present invention to the material of the protein solution described above, the addition amount of the composition of the present invention is usually such that the number of units of GO activity per 1 g of protein in the entire material of the protein solution is within the range of 0.001 U to 10,000 U, preferably within the range of 0.003 U to 3,000 U, more preferably within the range of 0.01 U to 1,000 U, still more preferably within the range of 0.03 U to 500 U, still more preferably within the range of 0.1 U to 300 U, and particularly preferably within the range of 0.3 U to 100 U. 【0046】 2. Method for producing a milk protein or plant protein solution and method for suppressing the viscosity of a milk protein or plant protein solution The present invention also provides a method for producing the milk protein or plant protein solution (hereinafter, also referred to as "the production method of the present invention") and a method for suppressing the viscosity of the milk protein or plant protein solution (hereinafter, also referred to as "the method of the present invention"), which include the step of adding a protease having dipeptidyl aminopeptidase activity and leucine aminopeptidase activity without end-type activity to the material of the milk protein or plant protein solution. 【0047】 Regarding "end-type activity", "dipeptidyl aminopeptidase activity", "leucine aminopeptidase activity", "protease having dipeptidyl aminopeptidase activity and leucine aminopeptidase activity without end-type activity", "milk protein or plant protein solution", "material of the milk protein or plant protein solution", and "suppression of the viscosity of the milk protein or plant protein solution", they are as described above for the composition of the present invention. 【0048】 The amount of the protease added to the material of the protein solution is not particularly limited as long as the desired effect of the present invention can be obtained. Usually, the number of units of DPP activity and the number of units of LAP activity per 100 g of the entire material of the protein solution after the addition of the protease are each in the range of 0.0001 U to 10,000 U, preferably in the range of 0.001 U to 1,000 U, more preferably in the range of 0.005 U to 100 U, even more preferably in the range of 0.01 U to 50 U, and even more preferably in the range of 0.05 U to 10 U, and particularly preferably in the range of 0.1 U to 5 U. 【0049】 In one aspect, the amount of the protease added to the material of the protein solution is usually such that the number of units of DPP activity per 1 g of protein in the entire material of the protein solution is in the range of 0.0001 U to 1,000 U, preferably in the range of 0.0005 U to 10 U, more preferably in the range of 0.001 U to 1 U, and even more preferably in the range of 0.005 U to 0.35 U. Also, the amount of the protease added to the material of the protein solution is usually such that the number of units of LAP activity per 1 g of protein in the entire material of the protein solution is in the range of 0.0001 U to 1,000 U, preferably in the range of 0.0005 U to 500 U, and more preferably in the range of 0.001 U to 100 U. 【0050】 In one aspect, the amount of the protease added to the material of the protein solution is usually such that the number of units of the total protease activity measured by the CFA method per 1 g of protein in the entire material of the protein solution is 15 U or less, preferably 10 U or less, and more preferably 5 U or less. 【0051】 In the production method and method of the present invention, glucose oxidase may also be further added. "Glucose oxidase" is as described above for the composition of the present invention. 【0052】 When the manufacturing method and method of the present invention include a step of adding GO, there are no particular restrictions on the amount of GO added to the protein solution material, but it is usually an amount such that the number of GO activity units per gram of protein in the entire protein solution material is in the range of 0.001 U to 10,000 U, preferably in the range of 0.003 U to 3,000 U, more preferably in the range of 0.01 U to 1,000 U, even more preferably in the range of 0.03 U to 500 U, even more preferably in the range of 0.1 U to 300 U, and particularly preferably in the range of 0.3 U to 100 U. 【0053】 Furthermore, the manufacturing method and method of the present invention may further include a step of adding other components other than the protease and GO to the protein solution material, to the extent that the effects of the present invention are not impaired. Other components that are commonly used in protein solutions can be used as appropriate. One or more of these other components may be added as needed. 【0054】 The method of adding the protease to the protein solution material in the manufacturing method or method of the present invention is not particularly limited. For example, the protease, and optionally GO and / or the other components mentioned above, can be appropriately added to the protein solution material and mixed as is, or it can be manufactured by other manufacturing methods common in the field of protein solutions. The order in which these components are added is not particularly limited and can be appropriately set according to the intended use. 【0055】 The manufacturing method and method of the present invention can suppress the viscosity of the resulting protein solution. The viscosity can be evaluated by measuring it using a viscometer (for example, DV1MLVTJ0 (Brookfield Corporation)) under conditions such as 8°C, 30 rpm, and after 60 seconds, as shown in the test examples described later. 【0056】When adding the protease, and optionally GO and / or the other components mentioned above, to the protein solution material and mixing them, the temperature range is usually 10°C to 80°C, preferably 20°C to 70°C, more preferably 30°C to 65°C, and even more preferably 50°C to 60°C. Furthermore, when adding the protease, and optionally GO and / or the other components mentioned above, and mixing them, the mixing time is usually 1 minute to 12 hours, preferably 5 minutes to 3 hours, more preferably 10 minutes to 1 hour, and even more preferably 10 minutes to 30 minutes. 【0057】 Next, the present invention will be specifically described with reference to examples, but the present invention is not limited in any way by these examples. 【0058】In the examples, unless otherwise specified in each example, the following raw materials and enzymes were used: • Skim milk powder: "Skim Milk 175g" (Morinaga Milk Industry Co., Ltd.) • Concentrated milk protein: "MPC480 (20kg x 1) FONTERRA" (FONTERRA Corporation) • Protease 1: "Sumizyme TDR" (obtained from Shin Nippon Chemical Industries, Ltd.) (Exotype: LAP activity + DPP IV activity) (DPP IV activity 100 U / g, LAP activity 15 U / g, total protease activity 880 U / g measured by CFA method) • Protease 2: "Sumizyme FLAP-G" (Shin Nippon Chemical Industries, Ltd.) (Exotype: LAP activity) (LAP activity 1,000 U / g, total protease activity 10 U / g or less measured by CFA method)・Protease 3: "Sumizyme FP" (Shin Nippon Chemical Industries, Ltd.) (exotype + endotype) (Total protease activity measured by CFA method: 86,000 U / g, LAP activity: 1,500 U / g to 2,000 U / g) ・Protease 4: "Sumizyme ACP-G" (Shin Nippon Chemical Industries, Ltd.) (exotype + endotype) (Total protease activity measured by CFA method: 78,000 U / g) ・Protease 5: "Sumizyme DPP-G" (Shin Nippon Chemical Industries, Ltd.) (exotype + endotype) (Total protease activity measured by CFA method: 20,000 U / g, DPP IV activity: 100 U / g) ・Protease 6: "Sumizyme AP" (Shin Nippon Chemical Industries, Ltd.) (endotype) (endotype activity: 50,000 U / g) - Glucose oxidase: "Sumizyme PGO" (Shin Nippon Chemical Industries, Ltd.) (GO activity 2,000 U / g) - Phospholipase D: "Denazyme PMD-P1" (Nagase & Co., Ltd.) (Phospholipase D activity 50,000 U / g or more) - Thermophilus strain cultured lactic acid bacteria: "FD-DVS YC-380-Yo-Flex" (Christian Hansen GmbH) - Powdered soy protein: "New Fuji Pro IJN" (Fuji Oil Co., Ltd.) 【0059】(Example 1, Comparative Examples 1-4, Reference Example 1 and Control Examples 1-2)-1 (Preparation of Milk Protein Solution) Skim milk powder, concentrated milk protein, and ion-exchanged water were mixed and stirred using a hand blender (Bamix Co., Ltd.) in the proportions shown in Table 1 (mixed immediately before stirring). Each protease was then added in the proportions shown in Table 1 and filled into a container (aluminum jug). The mixture was then heated in a water bath (AS ONE Corporation) at 55°C for 30 minutes to obtain each milk protein solution. The milk protein solution of Control Example 1 is a milk protein solution containing a normal amount of protein, and the milk protein solution of Control Example 2 is a milk protein solution with a high protein content. 【0060】 【0061】 Test Example 1 (Viscosity Evaluation) For each milk protein solution obtained in (Example 1, Comparative Examples 1-4, Reference Example 1, and Control Examples 1-2)-1, viscosity and torque were measured using a viscometer (DV1MLVTJ0 (Brookfield Corporation)) after standing at 4°C for 24 hours, under the conditions of 8°C, 30 rpm, and 60 seconds. The results are shown in Table 1. 【0062】 As shown in Table 1, the high viscosity observed in the high-protein-content milk protein solution of Control Example 2 was significantly suppressed by adding the protease Sumizyme TDR (Example 1). On the other hand, when a protease with endo-type activity was added (Comparative Examples 1-4), the viscosity of the resulting milk protein solution increased further. 【0063】 (Example 1, Comparative Examples 1-4, Reference Example 1 and Control Examples 1-2)-2 (Preparation of Yogurt) Each milk protein solution obtained in (Example 1, Comparative Examples 1-4, Reference Example 1 and Control Examples 1-2)-1 was left to stand at 4°C for 24 hours, then heated in a water bath at 95°C for 5 minutes, cooled to 50°C, and then cultured lactic acid bacteria of the Thermophilus strain were added and filled into standing pouches. Next, it was fermented at 44°C until the pH reached 4.6 (approximately 5.5 hours), filtered through a mesh (500 μm), and each yogurt was obtained. Note that the yogurt of Control Example 1 is a yogurt containing a normal amount of protein, and the yogurt of Control Example 2 is a yogurt with a high protein content. 【0064】Test Example 2 (Sensory Evaluation) For each yogurt obtained in (Example 1, Comparative Examples 1-4, Reference Example 1, and Control Examples 1-2)-2, a panel of five experts experienced in evaluation tasted the yogurts and evaluated their smoothness and firmness in 1-point increments using the following evaluation scale through deliberation. The results are shown in Table 1. 【0065】 [Smoothness Rating Scale] 1 point: Stronger graininess compared to the yogurt obtained in control example 1-2 3 points: Graininess is felt compared to the yogurt obtained in control example 1-2 5 points: Graininess is at the same level as the yogurt obtained in control example 1-2 8 points: No graininess is felt compared to the yogurt obtained in control example 1-2 10 points: No graininess is felt at all compared to the yogurt obtained in control example 1-2 【0066】 [Hardness Rating Scale] 1 point: Significantly softer than the yogurt obtained in control example 1-2 3 points: Softer than the yogurt obtained in control example 1-2 5 points: Hardness equivalent to the yogurt obtained in control example 1-2 8 points: Harder than the yogurt obtained in control example 1-2 10 points: Significantly harder than the yogurt obtained in control example 1-2 【0067】 As shown in Table 1, the yogurt produced using a high-protein milk protein solution manufactured by adding the protease sumizyme TDR (Example 1) had a smoothness and firmness when consumed that was comparable to that of yogurt produced using a milk protein solution containing a normal amount of protein (Control Example 1). 【0068】(Examples 2-5, Reference Examples 2-5, and Control Examples 3-4)-1 (Preparation of Milk Protein Solution) Skim milk powder, concentrated milk protein, and deionized water were mixed and stirred using a hand blender (Bamix) in the proportions shown in Table 2 (mixed immediately before stirring). Each protease was then added in the proportions shown in Table 2 and filled into a container (aluminum jug). The mixture was then heated in a water bath (AS ONE Corporation) at 55°C for 30 minutes to obtain each milk protein solution. The milk protein solution in Control Example 3 contains a normal amount of protein, while the milk protein solution in Control Example 4 is a high-protein milk protein solution. 【0069】 【0070】 Test Example 3 (Viscosity Evaluation) For each milk protein solution obtained in (Examples 2-5, Reference Examples 2-5, and Control Examples 3-4)-1, viscosity and torque were measured using a viscometer (DV1MLVTJ0, Brookfield) under the conditions of 8°C, 30 rpm, and 60 seconds after standing for 1 hour after preparation, 24 hours at 4°C, and 48 hours at 4°C. The results are shown in Table 2. 【0071】 As shown in Table 2, the high viscosity observed in the high-protein milk protein solution of Control Example 4 was suppressed by adding the protease, Sumizyme TDR (Examples 2-5), regardless of the concentration of Sumizyme TDR. In particular, the viscosity after 48 hours of standing was significantly suppressed by adding 0.05% by weight of Sumizyme TDR (Example 2). 【0072】 (Examples 2-5, Reference Examples 2-5, and Control Examples 3-4)-2 (Preparation of Yogurt) Using the milk protein solutions obtained in (Examples 2-5, Reference Examples 2-5, and Control Examples 3-4)-1, each yogurt was prepared in the same manner as in (Example 1, Comparative Examples 1-4, Reference Example 1, and Control Examples 1-2)-2. Note that the yogurt in Control Example 3 is a yogurt containing a normal amount of protein, and the yogurt in Control Example 4 is a high-protein yogurt. 【0073】Test Example 4 (Sensory Evaluation) Each yogurt obtained in Examples 2-5, Reference Examples 2-5, and Control Examples 3-4-2 was evaluated in the same manner as in Test Example 2. The results are shown in Table 2. 【0074】 (Examples 6-9 and Control Examples 5-6)-1 (Preparation of Milk Protein Solution) Skim milk powder, concentrated milk protein, and deionized water were mixed and stirred using a hand blender (Bamix) in the proportions shown in Table 3 (mixed immediately before stirring). Each enzyme was then added in the proportions shown in Table 3, and the mixture was filled into a container (aluminum jug). The mixture was then heated in a water bath (AS ONE Corporation) at 55°C for 30 minutes to obtain each milk protein solution. The milk protein solution in Control Example 5 contains a normal amount of protein, while the milk protein solution in Control Example 6 is a high-protein milk protein solution. 【0075】 【0076】 Test Example 5 (Viscosity Evaluation) The viscosity of each milk protein solution obtained in (Examples 6-9 and Control Examples 5-6)-1 was measured in the same manner as in Test Example 3. The results are shown in Table 3. 【0077】 As shown in Table 3, by adding the protease Sumizyme TDR (Examples 6-9), the high viscosity observed in the high-protein-containing milk protein solution of Control Example 6 was suppressed, regardless of the type of enzyme added. 【0078】 (Examples 6-9 and Control Examples 5-6)-2 (Preparation of Yogurt) Using the milk protein solutions obtained in (Examples 6-9 and Control Examples 5-6)-1, each yogurt was prepared in the same manner as in (Example 1, Comparative Examples 1-4, Reference Example 1 and Control Examples 1-2)-2. Note that the yogurt in Control Example 5 is a yogurt containing a normal amount of protein, and the yogurt in Control Example 6 is a high-protein yogurt. 【0079】 Test Example 6 (Sensory Evaluation) Each yogurt obtained in Examples 6-9 and Control Examples 5-6-2 was evaluated in the same manner as in Test Example 2. The results are shown in Table 3. 【0080】As shown in Table 3, in the yogurts produced using a high-protein milk protein solution made by adding sumizyme PGO (a GO) in addition to the protease sumizyme TDR (Examples 8 and 9), the smoothness when eaten was improved compared to the yogurt produced using a high-protein milk protein solution as a raw material (Control Example 6). Furthermore, the smoothness and firmness when eaten were also improved compared to the yogurt produced using a milk protein solution containing a normal amount of protein as a raw material (Control Example 5). 【0081】 (Examples 10-11, Reference Examples 6-7, and Control Examples 7-8)-1 (Preparation of Milk Protein Solution) Skim milk powder, concentrated milk protein, and deionized water were mixed and stirred using a hand blender (Bamix) in the proportions shown in Table 4 (mixed immediately before stirring). Each enzyme was then added in the proportions shown in Table 4 and filled into a container (aluminum jug). The mixture was then heated in a water bath (AS ONE Corporation) at 55°C for 30 minutes to obtain each milk protein solution. The milk protein solution of Control Example 7 contains a normal amount of protein, while the milk protein solution of Control Example 8 is a high-protein milk protein solution. 【0082】 【0083】 Test Example 7 (Viscosity Evaluation) The viscosity of each milk protein solution obtained in (Examples 10-11, Reference Examples 6-7, and Control Examples 7-8)-1 was measured in the same manner as in Test Example 3. The results are shown in Table 4. 【0084】 As shown in Table 4, by adding the protease Sumizyme TDR (Examples 10-11), the high viscosity observed in the high-protein-containing milk protein solution of Control Example 8 was suppressed, regardless of whether the co-added enzyme was present or not. 【0085】(Examples 10-11, Reference Examples 6-7, and Control Examples 7-8)-2 (Preparation of Yogurt) Using the milk protein solutions obtained in (Examples 10-11, Reference Examples 6-7, and Control Examples 7-8)-1, each yogurt was prepared in the same manner as in (Example 1, Comparative Examples 1-4, Reference Example 1, and Control Examples 1-2)-2. Note that the yogurt in Control Example 7 is a yogurt containing a normal amount of protein, and the yogurt in Control Example 8 is a high-protein yogurt. 【0086】 Test Example 8 (Sensory Evaluation) Each yogurt obtained in Examples 10-11, Reference Examples 6-7, and Control Examples 7-8-2 was evaluated in the same manner as in Test Example 2. The results are shown in Table 4. 【0087】 As shown in Table 4, in the yogurt produced using a high-protein milk protein solution as a raw material, which was manufactured by adding sumizyme PGO (a GO) in addition to the protease sumizyme TDR (Example 11), the smoothness when eaten was improved compared to the yogurt produced using a high-protein milk protein solution as a raw material (Control Example 8). Furthermore, the smoothness and firmness when eaten were also improved compared to the yogurt produced using a milk protein solution containing a normal amount of protein as a raw material (Control Example 7). 【0088】 (Examples 12-13, Comparative Example 5, Reference Examples 9-12 and Control Example 9)-1 (Preparation of Soy Protein Solution) Powdered soy protein and ion-exchanged water were mixed and stirred using a hand blender (Bamix Co., Ltd.) in the proportions shown in Table 5 (mixed immediately before stirring). Each enzyme was then added in the proportions shown in Table 5, and the mixture was filled into a container (aluminum jug). The mixture was then heated in a water bath (AS ONE Corporation) at 55°C for 30 minutes to obtain each soy protein solution. The soy protein solution in Control Example 9 is a soy protein solution in which no enzymes were added. 【0089】 【0090】(Examples 12-13, Comparative Example 5, Reference Examples 9-12 and Control Example 9)-2 (Preparation of Sterilized Soybean Protein Solution) Each soybean protein solution obtained in (Examples 12-13, Comparative Example 5, Reference Examples 9-12 and Control Example 9)-1 was heat-sterilized in a water bath (AS ONE Corporation) at 90°C for 10 minutes, and then cooled with ice water to obtain each sterilized soybean protein solution. 【0091】 Test Example 9 (Viscosity Evaluation) For each soy protein solution obtained in (Examples 12-13, Comparative Example 5, Reference Examples 9-12 and Control Example 9)-1, viscosity and torque were measured using a viscometer (DV1MLVTJ0, Brookfield) under the conditions of 8°C, 30 rpm, and 60 seconds after 1 hour after preparation, 24 hours after standing at 4°C, and 48 hours after standing at 4°C. For each sterilized soy protein solution obtained in (Examples 12-13, Comparative Example 5, Reference Examples 9-12 and Control Example 9)-2, viscosity and torque were measured 1 hour after sterilization. The results are shown in Table 5. 【0092】 As shown in Table 5, by adding the protease Sumizyme TDR (Examples 12-13), the high viscosity observed in the soy protein solution without any enzymes in Control Example 9 was significantly suppressed, both after standing without sterilization and after sterilization. On the other hand, in the soy protein solution with an endo-type active protease added (Comparative Example 5), the viscosity was suppressed after standing without sterilization, but conversely, the viscosity increased significantly after sterilization. 【0093】 Test Example 10 (Sensory Evaluation) (Examples 12-13, Comparative Example 5, Reference Examples 9-12, and Control Example 9)-2: For each sterilized soy protein solution obtained, three expert panel members experienced in evaluation tasted them and evaluated the bitterness (especially the bitterness caused by enzymes) and viscosity (thickness) during consumption using the following evaluation scale, in increments of 0.5 points, through deliberation. The total score for bitterness and viscosity during consumption was used as the overall score, with a lower score indicating a more desirable quality for a beverage. The results are shown in Table 5. Table 5 also shows the evaluation comments for each sterilized soy protein solution. 【0094】[Bitterness Rating Scale] 1 point: No bitterness is detected compared to the sterilized soy protein solution obtained in control example 9. 3 points: No bitterness is detected compared to the sterilized soy protein solution obtained in control example 9. 5 points: The bitterness is at the same level as the sterilized soy protein solution obtained in control example 9. 8 points: A strong bitterness is detected compared to the sterilized soy protein solution obtained in control example 9. 10 points: A significantly stronger bitterness is detected compared to the sterilized soy protein solution obtained in control example 9. 【0095】 [Viamitability Evaluation Scale during Consumption] 1 point: Significantly lower viscosity compared to the sterilized soy protein solution obtained in control example 9 3 points: Lower viscosity compared to the sterilized soy protein solution obtained in control example 9 5 points: Viscosity at the same level as the sterilized soy protein solution obtained in control example 9 8 points: Higher viscosity compared to the sterilized soy protein solution obtained in control example 9 10 points: Significantly higher viscosity compared to the sterilized soy protein solution obtained in control example 9 【0096】 As shown in Table 5, the sterilized soy protein solutions obtained by adding the protease Sumizyme TDR (Examples 12-13) had significantly lower viscosity compared to the sterilized soy protein solution obtained in Control Example 9, while the bitterness was similarly low. Furthermore, the sterilized soy protein solutions obtained in Examples 12-13 had a clean and crisp taste. On the other hand, the sterilized soy protein solution obtained by adding a protease with endo-type activity (Comparative Example 5) had a stronger bitter taste, higher viscosity, and a less crisp taste. 【0097】 The present invention provides a composition for modifying milk protein or plant protein solutions, etc., for producing milk protein or plant protein solutions with suppressed viscosity. Therefore, the present invention is useful in the food industry. 【0098】 This application is based on Japanese Patent Application No. 2024-215967 (filing date: December 10, 2024), the contents of which are fully incorporated herein.

Claims

1. A composition for modifying milk protein or plant protein solutions, comprising a protease that does not have endo-type activity but has dipeptidylaminopeptidase activity and leucineaminopeptidase activity.

2. The composition according to claim 1, wherein the milk protein or plant protein solution material is added such that the number of units of total protease activity, as measured by the casein-forin method, per gram of protein in the entire milk protein or plant protein solution material is 15 U (units) or less.

3. The composition according to claim 1, further comprising glucose oxidase.

4. The composition according to claim 1, wherein the modification is viscosity suppression.

5. The composition according to claim 1, wherein the milk protein or plant protein solution is a milk protein solution.

6. The composition according to claim 5, wherein the milk protein solution is for yogurt production.

7. The composition according to any one of claims 1 to 6, wherein in the process of manufacturing a milk protein or plant protein solution, a protease having dipeptidylaminopeptidase activity and leucineaminopeptidase activity but lacking endo-type activity is added to the milk protein or plant protein solution material such that the number of units of dipeptidylaminopeptidase activity and the number of units of leucineaminopeptidase activity per 100 g of the total material of the milk protein or plant protein solution are each in the range of 0.0001 U to 100,000 U.

8. A method for producing a milk protein or plant protein solution, comprising the step of adding a protease that does not have endo-type activity but has dipeptidylaminopeptidase activity and leucineaminopeptidase activity to the material of the milk protein or plant protein solution.

9. The manufacturing method according to claim 8, wherein a protease that does not have endo-type activity but has dipeptidylaminopeptidase activity and leucineaminopeptidase activity is added to the milk protein or plant protein solution in an amount such that the number of units of total protease activity measured by the casein-forin method per gram of protein in the entire material is 15 U or less.

10. The manufacturing method according to claim 8, further comprising the step of adding glucose oxidase.

11. The manufacturing method according to claim 8, wherein the milk protein or plant protein solution is a milk protein solution.

12. The manufacturing method according to claim 11, wherein the milk protein solution is for yogurt production.

13. The manufacturing method according to any one of claims 8 to 12, wherein a protease having dipeptidylaminopeptidase activity and leucineaminopeptidase activity but lacking endo-type activity is added such that the number of units of dipeptidylaminopeptidase activity and the number of units of leucineaminopeptidase activity per 100 g of the total material of the milk protein or plant protein solution are each in the range of 0.0001 U to 100,000 U.

14. A method for suppressing the viscosity of a milk protein or plant protein solution, comprising the step of adding a protease that does not have endo-type activity but has dipeptidylaminopeptidase activity and leucineaminopeptidase activity to the material of the milk protein or plant protein solution.

15. The method according to claim 14, wherein a protease that does not have endo-type activity but has dipeptidylaminopeptidase activity and leucineaminopeptidase activity is added to the milk protein or plant protein solution in an amount such that the number of units of total protease activity measured by the casein-forin method per gram of protein in the entire material is 15 U or less.

16. The method according to claim 14, further comprising the step of adding glucose oxidase.

17. The method according to claim 14, wherein the milk protein or plant protein solution is a milk protein solution.

18. The method according to claim 17, wherein the milk protein solution is for yogurt production.

19. The method according to any one of claims 14 to 18, wherein a protease having dipeptidylaminopeptidase activity and leucineaminopeptidase activity but lacking endo-type activity is added such that the number of units of dipeptidylaminopeptidase activity and the number of units of leucineaminopeptidase activity per 100 g of the total material of the milk protein or plant protein solution are each in the range of 0.0001 U to 100,000 U.

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