Oat milk and its manufacturing method

Abstract

To provide oat milk which is rich in oat-derived protein and dietary fiber, has little roughness and a good flavor, and a method for producing the same. [Solution] Oat milk is produced by carrying out an enzyme treatment step S1 in which an enzyme is added to a raw material liquid containing ground oats for enzyme treatment, a blending step S2 in which auxiliary materials are added to the liquid after the enzyme treatment, a sterilization step S3 in which the liquid after the auxiliary materials have been added is heated at a temperature condition of 121 to 150°C for 5 to 300 seconds, and a homogenization step S4 in which the liquid after and / or before sterilization is homogenized, and at least a protease is used as the enzyme in the enzyme treatment step S1 to obtain oat milk having an oat-derived protein content of 0.7% by mass or more, an oat-derived dietary fiber content of 0.3% by mass or more, an externally added calcium content of less than 0.1445% by mass (including 0% by mass) and a pH of 6.0 to 6.8.

Description

[Technical field]

[0001] The present invention relates to oat milk produced from oats and a method for producing the same. [Background technology]

[0002] Oat milk is a plant-based beverage made from oats, and like other plant-based milks such as soy milk and almond milk, it has been attracting attention as a substitute for animal-based milks such as cow's milk. In general, oat milk is produced by enzymatically treating a raw material liquid in which ground oats, the raw material, are dispersed in water under specific temperature conditions, and then diluting the liquid with water or adding various ingredients as necessary (see, for example, Patent Document 1).

[0003] On the other hand, oats contain a large amount of insoluble components such as dietary fiber, so that the raw solution after enzyme treatment and the oat milk after the component adjustment tend to become rough. Therefore, methods for reducing the roughness of oat milk and improving the texture have been proposed (see Patent Documents 2 to 4). For example, Patent Document 2 describes a method for producing a grain saccharified liquid with less roughness and excellent liquid permeability without performing filtration or homogenization treatment by setting the particle size distribution of the raw grain flour within a specific range.

[0004] Patent Document 3 describes a method for producing a liquid cereal-based food product in which a suspension of ground whole cereal grains is treated with α-amylase and an enzyme composition containing exocellulase and endoxylanase to improve viscosity and roughness. Furthermore, Patent Document 4 describes a method for producing a liquid whole oat food or drink product in which a liquid composition containing ground whole oats is treated with α-amylase, glucoamylase, cellulase, and pectinase in an enzyme treatment step to improve the texture.

[0005] Meanwhile, a method has been proposed in which roasted oats are used as a raw material to reduce the viscosity of a liquefied product while suppressing an increase in free sugars that cause sweetness (see Patent Document 5). In the method for producing a liquefied grain product described in Patent Document 5, a raw material liquid containing roasted wheat or wheat is enzymatically treated with (1) 4-α-glucanotransferase and / or maltotriohydrolase, (2) cellulase, and (3) protease to obtain a saccharified grain product having a viscosity of 500 mPa s or less and a value of the total free sugar content of the liquefied grain product divided by the sugar content of 0.30 or less. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2009-207359 A [Patent Document 2] JP 2023-74308 A [Patent Document 3] JP 2023-91789 A [Patent Document 4] JP 2023-146935 A [Patent Document 5] Patent Publication No. 2021-40553 Summary of the Invention [Problem to be solved by the invention]

[0007] However, when oat milk is produced using the above-mentioned conventional method, there are problems such as the aggregation of proteins during sterilization, which causes roughness, and the occurrence of burning inside the equipment. Of these problems, the occurrence of roughness due to protein aggregation can be prevented, for example, by reducing the amount of oats used as a raw material, or by separating and removing proteins by centrifugal separation after enzyme treatment, but in that case, the amount of protein and dietary fiber in the produced oat milk will be reduced.

[0008] In addition, since burning inside the equipment is particularly likely to occur when applying direct sterilization, in which the liquid is treated at high temperatures, it is possible to adopt indirect sterilization, in which heating is performed at low temperatures for a long period of time. However, in that case, the off-flavors derived from the grains used as raw materials may become stronger, which may deteriorate the flavor of the oat milk.

[0009] Therefore, an object of the present invention is to provide oat milk that is rich in oat-derived protein and dietary fiber, has little graininess, and has a good flavor, and a method for producing the same. [Means for solving the problem]

[0010] The oat milk according to the present invention contains 0.7% by mass or more of oat-derived protein, 0.3% by mass or more of oat-derived dietary fiber, and less than 0.1445% by mass (including 0% by mass) of externally added calcium. Amylase, glucoamylase, cellulase and protease derived from the enzyme treatment Contains The content of the protease is 0.01 to 0.1% by mass, The pH is 6.0 to 6.8. The oat milk of the present invention may also be substantially free of exogenous calcium.

[0011] The method for producing oat milk according to the present invention includes a step of adding an enzyme to a raw material liquid containing ground oats to perform an enzyme treatment, a step of adding a secondary raw material to the liquid after the enzyme treatment, and a step of sterilizing the liquid after the secondary raw material addition by heating it at a temperature condition of 121 to 150°C for 5 to 300 seconds. Amylase, glucoamylase, cellulase and Using protease, No centrifugation is performed after the enzyme treatment, The content of oat-derived protein is 0.7% by mass or more, the content of oat-derived dietary fiber is 0.3% by mass or more, and the content of externally added calcium is less than 0.1445% by mass (including 0% by mass). The enzyme treatment Obtaining oat milk having a protease content of 0.01 to 0.1% by mass and a pH of 6.0 to 6.8 。 Books The method of producing oat milk of the invention may also include a step of homogenizing the liquid after and / or before sterilization, in which case the step of homogenizing the liquid may use a high pressure or rotary homogenizer. In the method for producing oat milk of the present invention, ,before It is also possible to obtain oat milk that is substantially free of externally added calcium by not adding any calcium-containing component as the secondary ingredient. Effect of the Invention

[0012] According to the present invention, the occurrence of protein aggregation and burning during sterilization can be suppressed, so that oat milk is obtained that is rich in oat-derived protein and dietary fiber, has little graininess, and has a good flavor. [Brief description of the drawings]

[0013] [Figure 1] 1 is a flowchart showing a process for producing oat milk according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the following preferred embodiments.

[0015] The oat milk according to the embodiment of the present invention contains high concentrations of oat-derived protein at 0.7% by mass or more and oat-derived dietary fiber at 0.3% by mass or more, while the content of externally added calcium is suppressed to less than 0.1445% by mass (including 0% by mass) and the pH is adjusted to the range of 6.0 to 6.8. In addition to the above-mentioned components, the oat milk according to the present embodiment may contain protease in the range of, for example, 0.01 to 0.1% by mass.

[0016] [External calcium: 0% by mass or more, but less than 0.1445% by mass] The externally added calcium is calcium that is not derived from oats, and is added to the oat milk as calcium chloride, calcium citrate, calcium hydroxide, calcium carbonate, calcium lactate, and calcium sulfate. The above-mentioned calcium-containing components (hereinafter referred to as "calcium components") are added as necessary for the purpose of adjusting pH, stabilizing food, and enhancing the nutritional value of food, and therefore the oat milk of this embodiment does not substantially contain externally added calcium, i.e., the content of externally added calcium may be 0% by mass.

[0017] On the other hand, if the amount of externally added calcium in the oat milk is large, protein aggregation and burning are likely to occur during sterilization, so the content of externally added calcium in the oat milk of this embodiment is regulated to less than 0.1445 mass%. The content of externally added calcium in the oat milk of this embodiment is preferably 700 mass ppm or less, more preferably 70 mass ppm or less. The "content of externally added calcium" here is the value (converted value) calculated from the total content of calcium chloride, calcium citrate, calcium hydroxide, calcium carbonate, calcium lactate, and calcium sulfate.

[0018] [pH: 6~6.8] If the pH of oat milk is less than 6, the storage stability and flavor are likely to deteriorate, and if the pH exceeds 6.8, the proteins are likely to aggregate when heated. Therefore, the pH of the oat milk of this embodiment is set to 6 to 6.8. This makes it possible to suppress protein aggregation and reduce burning without deteriorating the storage stability and flavor.

[0019] [Protease: 0.01 to 0.1% by mass] The oat milk of the present embodiment preferably contains protease derived from the enzyme treatment carried out in the manufacturing process in the range of 0.01 to 0.1% by mass, which suppresses protein aggregation, makes the oat milk less likely to burn, and also suppresses bitterness.

[0020] [Manufacturing method] Next, a method for producing oat milk according to the present embodiment will be described. Fig. 1 is a flow chart showing the production steps according to the present embodiment. As shown in Fig. 1, the oat milk according to the present embodiment is produced by carrying out an enzyme treatment step S1 in which a raw material liquid is treated with an enzyme, a blending step S2 in which an auxiliary material is added to the liquid after the enzyme treatment, a sterilization treatment step S3 in which the liquid after the auxiliary material is added is sterilized, and a homogenization treatment step S4 in which the liquid after sterilization and / or before sterilization is homogenized as necessary, to obtain oat milk having an oat-derived protein content of 0.7% by mass or more, an oat-derived dietary fiber content of 0.3% by mass or more, an externally added calcium content of less than 0.1445% by mass (including 0% by mass), and a pH of 6.0 to 6.8.

[0021] <Enzyme treatment step S1> In the enzyme treatment step S1, the raw material liquid containing ground oats as a raw material is treated with an enzyme to liquefy and / or saccharify the oats. Here, the raw material liquid may be, for example, a dispersion of oat powder in water. The size of the ground oats to be mixed into the raw material liquid is not particularly limited, but it is preferable to use oats with a volume-based average particle size of about 10 to 100 μm from the viewpoint of texture and smoothness. The content of ground oats in the raw material liquid is also not particularly limited, but it is preferable to set it to 5.0 to 15.0 mass % from the viewpoint of taste and flavor.

[0022] In the enzyme treatment step S1, at least a protease is used for the treatment. This breaks down the protein into smaller molecules, thereby preventing the occurrence of protein aggregation and burning. The protease used in the enzyme treatment is not particularly limited, and examples thereof include serine protease, cysteine ​​protease, threonine protease, aspartic acid protease, glutamic acid protease, metalloprotease, and asparagine peptide lyase. In addition, in the classification based on the optimum pH (the optimum pH at which the enzyme exerts its action), acidic protease, neutral protease, and alkaline protease can be used. These may be used alone or in combination. Among the above-mentioned proteases, neutral protease or alkaline protease is preferred from the viewpoint of the optimum pH.

[0023] The amount of protease used can be appropriately set within a range that provides the above-mentioned effects, but it is preferable that the amount of protease remaining in the produced oat milk is set to be within a range of 0.01 to 0.1% by mass, which allows the production of oat milk with reduced bitterness and harshness.

[0024] In the enzyme treatment step S1, other enzymes such as α-amylase, β-amylase, glucoamylase, pullulanase, maltotriohydrolase, transglucosidase, hemicellulase, nuclease, β-glucosidase, tannase, cellulase and pectinase can be used in combination, provided that they do not inhibit the effects of the protease. In particular, when the treatment is performed using four enzymes, namely, amylase, glucoamylase and cellulase, the amylase breaks down starch into smaller molecules, the glucoamylase produces glucose, and the cellulase breaks down the dietary fiber contained in the oats, resulting in oat milk that is free of the roughness caused by dietary fiber and has excellent mouthfeel and flavor.

[0025] The "liquefaction" and "saccharification" of oats may be carried out simultaneously or consecutively, or only one of them may be carried out. For example, when only "liquefaction" is carried out, enzyme treatment may be carried out using protease and α-amylase, and when only "saccharification" is carried out, enzyme treatment may be carried out using protease together with β-amylase, glucoamylase, pullulanase or maltotriohydrolase. When "liquefaction" and "saccharification" are carried out simultaneously or consecutively, these enzymes may be added at once or sequentially.

[0026] The conditions of the enzyme treatment can be appropriately set depending on the temperature and time at which each enzyme acts, and can be, for example, 40 to 70°C and 10 minutes to 8 hours. When the enzyme treatment is terminated, each enzyme can be inactivated, for example, by rapidly increasing the temperature of the liquid. In this case, the liquid temperature is preferably set to a temperature at which each enzyme is inactivated within at least 1 minute, and more preferably set to a temperature at which each enzyme is inactivated within 15 seconds.

[0027] <Blending process S2> In the blending step S2, the auxiliary raw materials are added to the enzyme-treated liquid obtained in the enzyme treatment step S1. At that time, the amount of the auxiliary raw materials added is adjusted so that the pH of the oat milk obtained through the sterilization treatment step S3 and the homogenization treatment step S4 described below is 6.0 to 6.8 and the externally added calcium content is less than 0.1445% by mass (including 0% by mass). Here, examples of the auxiliary raw materials added to the enzyme-treated liquid include vegetable oils and fats, powdered protein, sugar, fruit juice, salt, dietary fiber, pH adjusters, sweeteners, colorants, thickening stabilizers, antioxidants, emulsifiers, nutritional enhancers, and flavors.

[0028] In order to adjust the external calcium content of the obtained oat milk to the above-mentioned range, it is sufficient to adjust the amount of calcium components added as auxiliary ingredients such as calcium chloride, calcium citrate, calcium hydroxide, calcium carbonate, calcium lactate, and calcium sulfate, and it is preferable not to add these calcium components. On the other hand, in order to adjust the pH of the obtained oat milk to the above-mentioned range, it is sufficient to add a pH adjuster as an auxiliary ingredient.

[0029] <Sterilization process S3> In the sterilization step S3, the liquid after the addition of the auxiliary raw materials is heated at a temperature of 121 to 150°C for 5 to 300 seconds to maintain commercial sterility. The sterilization method is not particularly limited, and may be either an indirect heating method in which the liquid is heated without contacting with steam, or a direct heating method in which the liquid is heated by contacting with steam, although a direct sterilization method in which the liquid is directly heated by contacting with steam is preferred. This reduces off-flavors derived from oats, making it possible to produce oat milk with a good flavor.

[0030] <Homogenization process S4> In the method for producing oat milk of this embodiment, a homogenizer or the like may be used to homogenize the liquid after sterilization and / or the liquid before sterilization. The homogenizer used for the homogenization may be either a high-pressure type or a rotary type, and may be appropriately selected depending on the viscosity and amount of the liquid to be treated. The homogenization step S4 may be performed either before or after the sterilization step S3, but from the viewpoint of improving the mouthfeel and flavor, it is preferable to perform it after the sterilization step S3, and more preferably before or after the sterilization step S3.

[0031] <Other processes> In the method for producing oat milk according to the present embodiment, a step of removing insoluble components such as dietary fiber and protein by centrifugation or the like is not performed, thereby obtaining oat milk with a high concentration of components.

[0032] As described above in detail, the oat milk of this embodiment has the pH of the liquid and the amount of externally added calcium adjusted in the preparation process, so that protein aggregation and burning in the device are unlikely to occur even when heated at high temperatures in the subsequent sterilization process. As a result, it is possible to perform sterilization under conditions that can reduce off-flavors without lowering the concentration of the raw material liquid or removing insoluble components after enzyme treatment, and therefore oat milk that is rich in oat-derived protein and dietary fiber, has little roughness, and has a good flavor can be obtained.

[0033] In addition, the method for producing oat milk of the present embodiment uses at least protease, and performs enzymatic treatment using amylase, glucoamylase, and cellulase in combination to further reduce roughness, making it possible to produce oat milk with a higher ingredient concentration and better mouthfeel and flavor than conventional products. Furthermore, the oat milk of the present embodiment is able to maintain good quality for a long period of time because precipitation during storage is suppressed. EXAMPLES

[0034] The effects of the present invention will be specifically described below with reference to Examples and Comparative Examples. In these Examples, oat milks of Examples and Comparative Examples were produced with different pH values ​​and different amounts of externally added calcium, and the roughness and flavor were evaluated by a sensory test.

[0035] [Sample preparation] First, 400 g of oat powder (ground whole oats, with an average particle size of 10 to 100 μm on a volume basis) was dispersed in 600 g of hot water at about 80° C. to prepare a raw material solution. Alkaline protease was added to this raw material solution at the concentrations shown in Tables 1 and 2 below, and α-amylase derived from the genus Bacillus was added at a final concentration of 0.01% by mass, cellulase derived from the genus Trichoderma was added at a final concentration of 0.1% by mass, and glucoamylase derived from the genus Rhizopus was added at a final concentration of 0.1% by mass, and the mixture was treated with enzymes at 55° C. for 1 hour.

[0036] Next, predetermined amounts of externally added calcium carbonate, and alkaline agents, sodium hydrogen carbonate and disodium hydrogen phosphate, were added as auxiliary materials to the enzyme-treated liquid to obtain liquids with the pH and externally added calcium content shown in the following Tables 1 to 3. Subsequently, the liquid after the addition of the auxiliary materials was diluted with water to a total protein concentration of 1.2% by mass and a dietary fiber concentration of 0.4% by mass, and then sterilized by heating at a temperature condition of 121°C for 5 minutes to obtain oat milk for evaluation.

[0037] [Evaluation method] (1)Agglutination The oat milk samples prepared by the above method were subjected to a sensory evaluation by four trained panelists (training period: 8 to 27 years). The cohesiveness was visually evaluated on the following four-point scale, and the evaluation of each sample was determined based on the overall consensus. ◎ (Excellent): The aggregates were very fine. ○ (Good): The aggregates were fine. △ (Acceptable): The aggregates were somewhat fine. × (Not acceptable): Coarse aggregates

[0038] (2) Roughness and flavor The roughness and flavor were evaluated by four trained panelists (training period: 8 to 27 years) who tasted the oat milk samples and performed a sensory evaluation using the following four-point scale. The evaluation of each sample was determined based on the overall consensus.

[0039] <Roughness> ◎ (Excellent): No roughness felt ○ (Good): Almost no roughness felt △(Acceptable): Slightly rough feeling × (Not acceptable): Items that feel rough

[0040] <flavor> ◎ (Excellent): No bitterness was felt ○(Good): Very little bitterness was felt △(OK): Bitter taste was felt × (Not acceptable): Strong bitterness

[0041] The results are shown in Tables 1 and 2. The pH of each liquid in the Examples and Comparative Examples shown in Tables 1 and 2 was measured using a LAQUA F-2000 benchtop water quality meter manufactured by HORIBA, Ltd., and the amount of externally added calcium was calculated from the amount of calcium carbonate added.

[0042] [Table 1]

[0043] [Table 2]

[0044] As shown in Tables 1 and 2 above, samples Nos. 5 to 8, 10 to 12, and 14 to 16, which were treated with protease, had a pH of 6.0 to 6.8, and contained 0% external calcium by mass, suppressed protein aggregation and burning during sterilization, had little graininess, and had a good flavor. In contrast, samples Nos. 1 to 3, which had a pH of over 6.8 and contained 0.1445% external calcium by mass, caused protein aggregation and burning during sterilization, and the resulting oat milk had a grainy texture. Samples Nos. 4, 9, and 13, which did not use protease during enzyme treatment, had a grainy texture in the resulting oat milk.

[0045] From the above results, it was confirmed that according to the present invention, oat milk can be obtained which is rich in oat-derived protein and dietary fiber, has little granularity, and has a good flavor.

[0046] The present invention can also have the following configuration. [1] Oat-derived protein content of 0.7% or more by mass Contains 0.3% or more by mass of dietary fiber derived from oats, Externally added calcium is less than 0.1445% by mass (including 0% by mass) Contains Oat milk has a pH of 6.0-6.8. [2] The oat milk according to [1] contains 0.01 to 0.1% by mass of protease. [3] The oat milk according to [1] or [2] is substantially free of exogenous calcium. [4] A step of adding an enzyme to a raw material liquid containing oat pulverized material and performing an enzyme treatment; adding a secondary raw material to the liquid after the enzyme treatment; A step of sterilizing the liquid after adding the auxiliary raw materials by heating it under a temperature condition of 121 to 150 ° C for 5 to 300 seconds; having In the enzyme treatment step, at least a protease is used as the enzyme, A method for producing oat milk that produces oat milk having an oat-derived protein content of 0.7% by mass or more, an oat-derived dietary fiber content of 0.3% by mass or more, an exogenous calcium content of less than 0.1445% by mass (including 0% by mass), and a pH of 6.0 to 6.8. [5] The method for producing oat milk according to claim 4, wherein the enzymes used in the enzyme treatment step are amylase, glucoamylase, cellulase and protease. [6] A method for producing oat milk according to [4] or [5], comprising a step of homogenizing the liquid after and / or before sterilization. [7] A method for producing oat milk as described in [6], in which a high-pressure or rotary homogenizer is used in the process of homogenizing the liquid. [8] The method for producing oat milk according to any one of [4] to [7], wherein no centrifugation is performed after the enzyme treatment. [9] The method for producing oat milk according to any one of [4] to [8], wherein no calcium-containing ingredient is added as the secondary ingredient.

Claims

1. The oat milk is obtained by enzymatically treating a raw material solution containing oat pulverized material, adding a secondary raw material to the enzyme-treated solution, and sterilizing the solution. The oat-derived protein is 0.7% by mass or more, The oat-derived dietary fiber is 0.3% by mass or more, Externally added calcium is less than 0.1445% by mass (including 0% by mass), Contains amylase, glucoamylase, cellulase and protease derived from the enzyme treatment, The content of the protease is 0.01 to 0.1% by mass, Oat milk with a pH of 6.0 to 6.

8.

2. 2. The oat milk of claim 1, which is substantially free of exogenous calcium.

3. A step of adding an enzyme to a raw material liquid containing oat pulverized material and performing an enzyme treatment; adding a secondary raw material to the liquid after the enzyme treatment; A step of sterilizing the liquid after adding the auxiliary raw materials by heating it under a temperature condition of 121 to 150° C. for 5 to 300 seconds; having In the enzyme treatment step, amylase, glucoamylase, cellulase and protease are used as the enzymes, No centrifugation is performed after the enzyme treatment, The method for producing oat milk provides oat milk having an oat-derived protein content of 0.7% by mass or more, an oat-derived dietary fiber content of 0.3% by mass or more, an externally added calcium content of less than 0.1445% by mass (including 0% by mass), a protease content derived from the enzyme treatment of 0.01 to 0.1% by mass, and a pH of 6.0 to 6.

8.

4. A method for producing oat milk according to claim 3, further comprising a step of homogenising the liquid after and / or before sterilisation.

5. The method for producing oat milk according to claim 4, wherein a high-pressure or rotary homogenizer is used in the step of homogenizing the liquid.

6. The method for producing oat milk according to claim 3, wherein no calcium-containing component is added as the secondary raw material, and oat milk substantially free of externally added calcium is obtained.

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