Oats milk and method for producing the same

Abstract

To provide oats milk that abundantly contains oats-derived protein and dietary fiber, has less rough texture and excellent flavor, and a method for producing the milk.SOLUTION: In producing oats milk by performing: an enzyme treatment step S1 of adding enzyme to raw material liquid including a ground product of oats to perform enzyme treatment; a blending step S2 of adding an auxiliary raw material to the liquid after enzyme treatment; a sterilization step S3 of heating the liquid after adding an auxiliary raw material under a temperature condition of 121 to 150°C for 5 to 300 seconds; and a homogenization step S4 of homogenizing the liquid after sterilization and / or before sterilization, at least protease is used as enzyme in the enzyme treatment step S1, and oats milk in which the content of oats-derived protein is 0.7 mass% or more, the content of oats-derived dietary fiber is 0.3 mass% or more, the content of exogenous calcium is less than 0.1445 mass% (including 0 mass%), and pH is 6.0 to 6.8 is obtained.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] Oat milk is a plant-based beverage made from oats and, like other plant-based milks such as soy milk and almond milk, has attracted attention as an alternative to animal milks such as cow's milk. Generally, oat milk is produced by dispersing a pulverized product of oats, which is a raw material, in water to obtain a raw material liquid, subjecting the raw material liquid to enzymatic treatment under specific temperature conditions, and then diluting with water or adding various components as necessary (see, for example, Patent Document 1).

[0003] On the other hand, since oats contain a large amount of insoluble components such as dietary fiber, roughness is likely to occur in the undiluted solution after enzymatic treatment or in oat milk after component adjustment. Therefore, conventionally, 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 saccharification liquid with little roughness and excellent liquid permeability without performing filtration treatment or homogenizer treatment by setting the particle size distribution of the cereal powder used as a raw material within a specific range.

[0004] Further, Patent Document 3 describes a method for producing a liquid grain-based product with improved viscosity and roughness by treating a suspension of a pulverized product of whole cereal grains with α-amylase and an enzyme composition containing exocellulase and endoxylanase. Furthermore, in the method for producing a whole grain oat liquid food product described in Patent Document 4, a texture improvement is achieved by performing an enzymatic treatment step of treating a liquid composition containing a pulverized product of whole grain oats with α-amylase, glucoamylase, cellulase, and pectinase.

[0005] On the other hand, a method has also been proposed in which roasted oats are used as a raw material to reduce the increase in free sugars that cause sweetness while reducing the viscosity of the liquefied product (see Patent Document 5). In the method for producing a cereal liquefied product described in Patent Document 5, a raw material liquid containing roasted cereals is enzymatically treated with (1) 4-α-glucanotransferase and / or maltotriohydrolase, (2) cellulase, and (3) protease to obtain a cereal saccharide having a viscosity of 500 mPa·s or less and a value obtained by dividing the total free sugar content of the cereal liquefied product by the sugar degree of 0.30 or less.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, when producing oat milk by the conventional method described above, there are problems such as protein aggregation and roughness during sterilization treatment, and charring in the apparatus. Among these problems, the generation of roughness due to protein aggregation can be prevented, for example, by reducing the amount of oats used as a raw material or by performing centrifugation treatment after enzymatic treatment to separate and remove proteins. In that case, however, the amount of protein and dietary fiber in the produced oat milk will decrease.

[0008] In addition, since burning inside the apparatus is particularly likely to occur when applying the direct sterilization method of treating the liquid at a high temperature, it is conceivable to adopt the indirect sterilization method of heating at a low temperature for a long time. In that case, however, the off-flavor derived from the cereal as the raw material may become stronger, and the flavor of the oatmeal may deteriorate.

[0009] Therefore, an object of the present invention is to provide oatmeal milk rich in proteins and dietary fibers derived from oats, having little roughness, and having a good flavor, and a method for producing the same.

Means for Solving the Problems

[0010] The oatmeal milk according to the present invention contains 0.7% by mass or more of proteins derived from oats, 0.3% by mass or more of dietary fibers derived from oats, and less than 0.1445% by mass (including 0% by mass) of added calcium, and has a pH of 6.0 to 6.8. The oatmeal milk of the present invention may contain 0.01 to 0.1% by mass of protease, and may also be configured to substantially contain no added calcium.

[0011] The method for producing oatmeal milk according to the present invention includes a step of adding an enzyme to a raw material liquid containing a pulverized product of oats and performing an enzyme treatment, a step of adding a secondary raw material to the liquid after the enzyme treatment, and a step of heating and sterilizing the liquid after adding the secondary raw material at a temperature condition of 121 to 150°C for 5 to 300 seconds. In the step of performing the enzyme treatment, at least protease is used as the enzyme, and an oatmeal milk having a protein content derived from oats of 0.7% by mass or more, a dietary fiber content derived from oats of 0.3% by mass or more, an added calcium content of less than 0.1445% by mass (including 0% by mass), and a pH of 6.0 to 6.8 is obtained. In the step of performing the enzyme treatment, amylase, glucoamylase, cellulase, and protease can be used as the enzyme. In the method for producing oatmeal milk of the present invention, a step of homogenizing the liquid after sterilization and / or before sterilization can also be performed. In that case, in the step of homogenizing the liquid, a high-pressure type or rotary homogenizer may be used. In the method for producing oat milk of the present invention, centrifugation may not be performed after the enzymatic treatment, and a component containing calcium may not be added as the auxiliary raw material.

Effects of the Invention

[0012] According to the present invention, since the aggregation and scorching of proteins during the sterilization treatment can be suppressed, oat milk rich in proteins and dietary fibers derived from oats, having less roughness and good flavor can be obtained.

Brief Description of the Drawings

[0013]

Figure 1

Modes for Carrying Out the Invention

[0014] Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the embodiments described below.

[0015] The oat milk according to the embodiment of the present invention contains a protein derived from oats at 0.7% by mass or more and a dietary fiber derived from oats at 0.3% by mass or more at a high concentration, 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 in the range of 6.0 to 6.8. Further, the oat milk of the present embodiment may contain protease in the range of, for example, 0.01 to 0.1% by mass in addition to the above-described components.

[0016] [Externally added calcium: 0% by mass or more and less than 0.1445% by mass] Exogenous calcium refers to calcium not derived from oats, and is added to oat milk as calcium chloride, calcium citrate, calcium hydroxide, calcium carbonate, calcium lactate, and calcium sulfate. The components containing the aforementioned calcium (hereinafter referred to as "calcium components") are added as necessary for purposes such as pH adjustment, food stabilization, and food fortification. Therefore, the oat milk of this embodiment may substantially contain no exogenous calcium, that is, the exogenous calcium content may be 0% by mass.

[0017] On the other hand, when the amount of exogenous calcium in oat milk increases, protein aggregation and scorching are likely to occur during sterilization. Therefore, in the oat milk of this embodiment, the exogenous calcium content is regulated to be less than 0.1445% by mass. The exogenous calcium content of the oat milk of this embodiment is preferably 700 ppm by mass or less, more preferably 70 ppm by mass or less. The "exogenous calcium content" referred to here is a value (converted value) obtained from the total content of calcium chloride, calcium citrate, calcium hydroxide, calcium carbonate, calcium lactate, and calcium sulfate.

[0018] [pH: 6 - 6.8] When the pH of oat milk is less than 6, the storage stability and flavor are likely to deteriorate. Also, when the pH exceeds 6.8, proteins are likely to aggregate upon heating. Therefore, in the oat milk of this embodiment, the pH is set to 6 - 6.8. This can suppress protein aggregation and reduce the occurrence of scorching without deteriorating the storage stability and flavor.

[0019] [Protease: 0.01 - 0.1% by mass] The oat milk of this embodiment preferably contains protease derived from the enzyme treatment performed in the manufacturing process in the range of 0.01 - 0.1% by mass. This can suppress protein aggregation, reduce the occurrence of scorching, and also suppress bitterness.

[0020] [Manufacturing method] Next, the method for producing oats milk according to the present embodiment will be described. FIG. 1 is a flowchart showing the manufacturing process of the present embodiment. As shown in FIG. 1, the oats milk of the present embodiment includes an enzyme treatment step S1 of treating the raw material liquid with an enzyme, a formulation step S2 of adding auxiliary raw materials to the liquid after the enzyme treatment, a sterilization treatment step S3 of sterilizing the liquid after the addition of the auxiliary raw materials, and a homogenization treatment step S4 of homogenizing the liquid after sterilization and / or before sterilization as necessary, to obtain oats milk having a protein content derived from oats of 0.7% by mass or more, a dietary fiber content derived from oats of 0.3% by mass or more, an 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 the ground product of oats as the raw material is treated with an enzyme to liquefy and / or saccharify the oats. Here, as the raw material liquid, for example, a dispersion of oat powder in water is used. The size of the ground product of oats blended in the raw material liquid is not particularly limited, but from the viewpoints of texture and smoothness, it is preferable to use one having an average particle diameter of about 10 to 100 μm on a volume basis. Also, the content of the ground product of oats in the raw material liquid is not particularly limited, but from the viewpoints of taste and flavor, it is preferably 5.0 to 15.0% by mass.

[0022] In the enzyme treatment step S1, at least protease is used for treatment. As a result, since proteins are broken down into small molecules, it is possible to prevent the aggregation and charring of proteins. The protease used for the enzyme treatment is not particularly limited, and for example, serine protease, cysteine protease, threonine protease, aspartic protease, glutamic protease, metalloprotease, aspartic peptidase, etc. can be used. Also, 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 of multiple types. Among the proteases described above, from the viewpoint of the optimum pH, neutral protease or alkaline protease is preferred.

[0023] The usage amount of protease can be appropriately set within the range where the above-described effects can be obtained, but it is preferable that the amount of protease remaining in the produced oat milk is in the range of 0.01 to 0.1% by mass. Thereby, it is possible to produce oat milk with suppressed bitterness and astringency.

[0024] Also, 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 as long as they do not inhibit the effects of the protease described above. In particular, when treating with four enzymes, namely protease, amylase, glucoamylase, and cellulase, the starch is broken down into small molecules by amylase, glucose is produced by glucoamylase, and the dietary fiber contained in oats is decomposed by cellulase. Therefore, no roughness due to dietary fiber occurs, and oat milk with excellent mouthfeel and flavor can be obtained.

[0025] Note that for the "liquefaction" and "saccharification" of oats, either both can be performed simultaneously or continuously, or only one of them can be performed. For example, when only "liquefaction" is performed, enzymatic treatment can be carried out using protease and α-amylase. When only "saccharification" is performed, enzymatic treatment can be carried out using protease together with β-amylase, glucoamylase, pullulanase or maltotriohydrolase. When "liquefaction" and "saccharification" are performed simultaneously or continuously, these enzymes can be added and processed at once or sequentially.

[0026] The conditions for enzymatic treatment can be appropriately set according to the temperature and time at which each enzyme acts. For example, it can be carried out at 40 to 70 °C for 10 minutes to 8 hours. When ending the enzymatic treatment, each enzyme can be inactivated, for example, by rapidly raising the temperature of the liquid. In that case, the liquid temperature is preferably set to a temperature at which each enzyme is inactivated within at least 1 minute, and more preferably within 15 seconds.

[0027] <Mixing step S2> In the mixing step S2, auxiliary raw materials are added to the enzyme-treated liquid obtained in the enzyme treatment step S1. At this time, the addition amount of the auxiliary raw materials is adjusted so that the pH of the oat milk obtained through the sterilization treatment step S3 and the homogenization treatment step S4 described later 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 proteins, sugars, fruit juices, salts, dietary fibers, pH adjusters, sweeteners, colorants, thickening and stabilizing agents, antioxidants, emulsifiers, nutritional fortifiers, flavors, etc.

[0028] Also, to make the externally added calcium content of the obtained oat milk within the above-mentioned range, the addition amount of calcium components such as calcium chloride, calcium citrate, calcium hydroxide, calcium carbonate, calcium lactate and calcium sulfate added as auxiliary raw materials can be adjusted, and it is preferable not to add these calcium components. On the other hand, to make the pH of the obtained oat milk within the above-mentioned range, a pH adjuster can be added as an auxiliary raw material.

[0029] <Sterilization treatment step S3> In the sterilization treatment step S3, the liquid after the addition of the auxiliary raw material is heated at a temperature of 121 to 150 °C for 5 to 300 seconds, so as to maintain a state where commercial sterility can be maintained. The method of sterilization treatment is not particularly limited, and either an indirect heating method of heating the liquid without contacting the liquid with steam or a direct heating method of heating the liquid by contacting the liquid with steam may be used, but a direct sterilization method of directly heating the liquid by contacting it with steam is preferred. Thereby, the off-flavor derived from oats can be reduced, and oat milk with a good flavor can be produced.

[0030] <Homogenization treatment step S4> In the method for producing oat milk of the present embodiment, the liquid after sterilization treatment and / or the liquid before sterilization treatment may be homogenized using a homogenizer or the like. The homogenizer used for the homogenization treatment may be either a high-pressure type or a rotary type, and can be appropriately selected according to the viscosity and amount of the liquid to be treated. Also, the timing of performing the homogenization treatment step S4 may be either before or after the sterilization treatment step S3, but from the viewpoint of improving the mouthfeel and flavor, it is preferably performed after the sterilization treatment step S3, and more preferably performed before and after the sterilization treatment step S3.

[0031] <Other steps> In the method for producing oat milk of the present embodiment, a step of removing insoluble components such as dietary fiber and protein by centrifugation treatment or the like is not carried out. Thereby, oat milk with a high component concentration can be obtained.

[0032] As described in detail above, since the oat milk of the present embodiment adjusts the pH of the liquid and the amount of externally added calcium in the blending step, even when heated at a high temperature in the subsequent sterilization treatment step, protein aggregation and charring in the apparatus are unlikely to occur. As a result, it is possible to perform the sterilization treatment under conditions capable of reducing off-flavors without lowering the concentration of the raw material liquid or removing insoluble components after the enzyme treatment. Therefore, an oat milk rich in proteins and dietary fibers derived from oats, having less roughness, and having a good flavor can be obtained.

[0033] In addition, the method for producing oat milk of the present embodiment uses at least protease and combines it with amylase, glucoamylase, and cellulase for enzyme treatment, so that the roughness can be further reduced. Therefore, it is possible to produce oat milk having a higher component concentration, better mouthfeel, and better flavor than conventional products. Furthermore, since the occurrence of precipitation during the storage period of the oat milk of the present embodiment is suppressed, good quality can be maintained for a long time.

Example

[0034] Hereinafter, the effects of the present invention will be specifically described with reference to examples and comparative examples. In this example, oat milk of examples and comparative examples was produced by changing the pH and the content of externally added calcium, and the roughness and flavor were subjected to sensory evaluation.

[0035] 〔Preparation of Samples〕 First, 400 g of oat powder (a pulverized product of whole grain oats, with an average particle diameter based on volume of 10 to 100 μm) was dispersed in 600 g of hot water at about 80°C to prepare a raw material liquid. Alkaline protease was added to this raw material liquid at the concentrations shown in Tables 1 and 2 below, and α-amylase derived from the genus Bacilus 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, followed by enzyme treatment at 55°C for 1 hour.

[0036] Next, calcium carbonate as an externally added calcium, sodium hydrogen carbonate as an alkaline agent, and disodium hydrogen phosphate were added in predetermined amounts as auxiliary raw materials to the enzyme treatment solution to obtain a solution having the pH and externally added calcium content shown in Tables 1 to 3 below. Subsequently, the solution after adding the auxiliary raw materials was diluted with water so that the total protein concentration was 1.2% by mass and the dietary fiber concentration was 0.4% by mass, and then heated at 121 ° C for 5 minutes for sterilization to obtain the evaluation oat milk.

[0037] 〔Evaluation method〕 (1) Aggregation Regarding the evaluation oat milk prepared by the method described above, sensory evaluation was performed by four trained panelists (training period: 8 to 27 years). The aggregability was visually evaluated in the following four grades, and the evaluation of each sample was determined based on the overall consensus. ◎ (Excellent): Those with very fine aggregates ○ (Good): Those with fine aggregates △ (Fair): Those with slightly fine aggregates × (Poor): Those with coarse aggregates

[0038] (2) Gritty feeling and flavor The gritty feeling and flavor were sensory evaluated by four trained panelists (training period: 8 to 27 years) who tasted the evaluation oat milk sample in the following four grades. At that time, the evaluation of each sample was determined based on the overall consensus.

[0039] <Gritty feeling> ◎ (Excellent): Those without a gritty feeling ○ (Good): Those with hardly any gritty feeling △ (Fair): Those with a slightly gritty feeling × (Poor): Those with a gritty feeling

[0040] <Flavor> ◎ (Excellent): Those without a bitter taste ○ (Good): Those with a very slight bitter taste △ (Fair): Those with a bitter taste × (Poor): Those with a strong bitter taste

[0041] The above results are shown in Tables 1 and 2 below. The pH values of the respective liquids in the examples and comparative examples shown in Tables 1 and 2 below are the values measured by a desktop water quality meter LAQUA F-2000 manufactured by Horiba, Ltd., and the externally added calcium amount is the value converted from the added amount of calcium carbonate.

[0042]

Table 1

[0043]

Table 2

[0044] As shown in Tables 1 and 2 above, for Samples No. 5 to 8, 10 to 12, and 14 to 16, which were subjected to enzymatic treatment using protease, had a pH of 6.0 to 6.8, and an externally added calcium content of 0% by mass, the aggregation and charring of proteins during sterilization treatment were suppressed, there was little roughness, and the flavor was also good. In contrast, for Samples No. 1 to 3, which had a pH exceeding 6.8 and an externally added calcium content of 0.1445% by mass, protein aggregation and charring occurred during sterilization treatment, and the obtained oat milk also felt rough. Also, for Samples No. 4, 9, and 13, in which protease was not used during enzymatic treatment, the obtained oat milk felt rough.

[0045] From the above results, according to the present invention, it was confirmed that an oat milk rich in proteins and dietary fibers derived from oats, having little roughness, and having a good flavor can be obtained.

[0046] In addition, the present invention can also adopt the following configurations. 〔1〕 Containing 0.7% by mass or more of proteins derived from oats, 0.3% by mass or more of dietary fibers derived from oats, less than 0.1445% by mass (including 0% by mass) of externally added calcium and Oat milk with a pH of 6.0 to 6.8. [2] The oat milk according to [1], containing 0.01 to 0.1% by mass of protease. [3] The oat milk according to [1] or [2], substantially free of added calcium. [4] A step of adding an enzyme to a raw material liquid containing a ground product of oats and subjecting it to an enzyme treatment, A step of adding auxiliary raw materials to the liquid after the enzyme treatment, A step of heating and sterilizing the liquid after the addition of auxiliary raw materials at a temperature of 121 to 150 °C for 5 to 300 seconds, having In the step of enzyme treatment, at least protease is used as the enzyme, A method for producing oat milk, wherein the content of protein derived from oats is 0.7% by mass or more, the content of dietary fiber derived from oats is 0.3% by mass or more, the content of added calcium is less than 0.1445% by mass (including 0% by mass), and the pH is 6.0 to 6.8. [5] The method for producing oat milk according to [4], wherein in the step of enzyme treatment, amylase, glucoamylase, cellulase and protease are used as the enzyme. [6] The method for producing oat milk according to [4] or [5], which comprises a step of homogenizing the liquid after sterilization and / or before sterilization. [7] The method for producing oat milk according to [6], wherein a high-pressure type or rotary homogenizer is used in the step of homogenizing the liquid. [8] The method for producing oat milk according to any one of [4] to [7], wherein centrifugation is not performed after enzyme treatment. [9] The method for producing oat milk according to any one of [4] to [8], wherein a component containing calcium is not added as the auxiliary raw material.

Claims

1. Containing 0.7% by mass or more of protein derived from oats, 0.3% by mass or more of dietary fiber derived from oats, less than 0.1445% by mass (including 0% by mass) of added calcium and oat milk having a pH of 6.0 to 6.

8.

2. The oat milk according to claim 1, containing 0.01 to 0.1% by mass of protease.

3. The oat milk according to claim 1, substantially free of added calcium.

4. A step of adding an enzyme to a raw material liquid containing a pulverized product of oats and performing an enzyme treatment; A step of adding auxiliary raw materials to the liquid after the enzyme treatment; A step of heating and sterilizing the liquid after adding the auxiliary raw materials at a temperature of 121 to 150°C for 5 to 300 seconds; and in the step of performing the enzyme treatment, at least protease is used as the enzyme, A method for producing oat milk, in which the content of protein derived from oats is 0.7% by mass or more, the content of dietary fiber derived from oats is 0.3% by mass or more, the content of added calcium is less than 0.1445% by mass (including 0% by mass), and the pH is 6.0 to 6.

8.

5. The method for producing oat milk according to claim 4, wherein in the step of performing the enzyme treatment, amylase, glucoamylase, cellulase and protease are used as the enzyme.

6. The method for producing oat milk according to claim 4, wherein a step of homogenizing the liquid is performed after sterilization and / or before sterilization.

7. The method for producing oat milk according to claim 6, wherein a high-pressure type or rotary homogenizer is used in the step of homogenizing the liquid.

8. The method for producing oat milk according to claim 4, wherein no centrifugation treatment is performed after the enzyme treatment.

9. The method for producing oat milk according to claim 4, wherein a component containing calcium is not added as the auxiliary raw material.

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