Method for producing rice flour paste

Abstract

To provide a method for producing rice flour paste easily soluble in hot water suitable for production of rice flour pastes with rice flour as a raw material, in particular, suitable for production of sweet soup with rice flour of "Akita Komachi" as a raw material.SOLUTION: A method for producing rice flour paste using rice flour as a raw material, including the following processes (1) and (2). (1) Mix rice flour with a particle size of 110-140 μm in volume average: sucrose: salt: water=15-25:35-45:0.5-1.5:28.5-49.5 by a weight ratio. (2) Raise the temperature of the mixture of (1) to 55-85°C within 4 minutes of starting heating, and to 65-85°C within 8 minutes of starting heating, once reaching 65-85°C, maintain that temperature and heat for a total of 12-22 minutes from the start of heating. According to this invention, using rice flour, particularly rice flour from Akita Komachi, a rice flour paste with texture, hardness, mouthfeel, and taste that closely resembles that of red bean paste can be produced. Furthermore, if this is used to make sweet soup, it can provide an unprecedented white sweet soup.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a method for producing rice flour filling using rice flour as a raw material. More specifically, it relates to a method for producing rice flour filling that has a taste similar to that of red bean paste filling and is more suitable for the production of soup dumplings.

Background Art

[0002] Yokote City is promoting the utilization of regional resources and the development of the sixth industry in the fields of agriculture and food. Therefore, in Yokote City, which is a rice-producing area, the utilization of rice flour has become a major theme. Currently, the utilization of rice flour has expanded to various fields such as the production of bread and noodles. As one of these utilization methods, rice flour filling, which uses rice flour instead of red beans when making dumplings, is known (Patent Document 1, Non-Patent Document 1, Non-Patent Document 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Non-Patent Documents

[0004]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Using the rice flour of "Akita Komachi", which is the main variety in Akita Prefecture, as a raw material, and aiming to produce a rice flour filling that is easily soluble in the soup suitable for making thick soup, it could not be achieved by the production method of the existing Non-Patent Document 1. An object of the present invention is to provide a method for producing a rice flour filling using rice flour as a raw material, particularly a rice flour filling that uses the rice flour of "Akita Komachi" as a raw material and is easily soluble in the soup suitable for making thick soup.

Means for Solving the Problems

[0006] As a result of various studies to achieve the above object, the inventor of the present invention limited the particle size of the rice flour to be used and reduced both the heating temperature and time after mixing raw materials such as sucrose, thereby arriving at the present invention. That is, the present invention is as follows.

[0007] 1. A method for producing a rice flour filling using rice flour as a raw material, comprising the following steps (1) and (2). (1) Mix so that the weight ratio is rice flour with a volume average particle diameter of 110 - 140 μm:sucrose:salt:water = 15 - 25:35 - 45:0.5 - 1.5:28.5 - 49.5. (2) Raise the temperature of the mixture in step (1) to 55 - 85°C within 4 minutes from the start of heating and to 65 - 85°C within 8 minutes from the start of heating. After reaching 65 - 85°C, maintain 65 - 85°C and heat for a total of 12 - 22 minutes from the start of heating. 2. A method for producing thick soup using rice flour as a raw material, comprising the following steps (1) to (3). (1) Mix so that the weight ratio is rice flour with a volume average particle diameter of 110 - 140 μm:sucrose:salt:water = 15 - 25:35 - 45:0.5 - 1.5:28.5 - 49.5. (2) Raise the temperature of the mixture in step (1) to 55 - 85°C within 4 minutes from the start of heating and to 65 - 85°C within 8 minutes from the start of heating. After reaching 65 - 85°C, maintain 65 - 85°C and heat for a total of 12 - 22 minutes from the start of heating. Mix the heated mixture of (3) and (2) with water or hot water. 3. The method for producing the rice flour paste according to item 1, wherein the rice flour is the rice flour of Akita Komachi. 4. The method for producing the soup jelly according to item 2, wherein the rice flour is the rice flour of Akita Komachi.

Advantages of the Invention

[0008] According to the present invention, using rice flour, particularly the rice flour of Akita Komachi as a raw material, it is possible to produce a rice flour paste that is similar to a red bean paste (hereinafter referred to as red bean paste) in terms of texture, firmness, touch, taste, and flavor. Furthermore, it is possible to produce a rice flour paste suitable for the production of soup jelly that easily dissolves in hot water, and by using this to produce soup jelly, it is possible to provide a white soup jelly that evokes the image of the purity of snow, which has never existed before.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0010] The present invention will be described in detail below.

[0011] 1. Regarding rice flour In the present invention, rice flour, more preferably rice flour of Akitakomachi, is used as a raw material. Akitakomachi includes Akitakomachi R with low cadmium absorbency. Furthermore, it also includes varieties obtained by crossing Akitakomachi with other varieties and backcrossing. It is preferable that the volume average particle diameter of the rice flour is 110 to 140 μm, and more preferably 110 to 130 μm. The measurement of the volume average particle diameter is the value measured by the laser diffraction / scattering particle size distribution measurement method. If the particle diameter is small, it will form lumps when mixed with water, making it difficult to dissolve. Conversely, if the particle diameter is large, compared with ordinary red bean paste, the texture will become rough and powdery, and the taste of rice will also come out, reducing the flavor of the paste. This appropriate particle diameter range of the rice flour is considered to be different from the existing manufacturing methods (hereinafter referred to as existing manufacturing methods) described in the prior art documents (Non-Patent Document 1 mentions a median diameter of 75 - 100 μm. Non-Patent Document 2 mentions "separating the sample with a 60-mesh sieve". Patent Document 3 does not specify the particle size of the sample. However, [Figure 1]

[0022] describes the major axis of the expanded grains). For the rice flour, rice that has been pulverized with a set particle size is used. There are wet pulverization and dry pulverization methods for pulverizing rice, but wet pulverization, which involves soaking in water and then pulverizing, is more preferable. When wet pulverization is performed, rice flour with less starch damage can be produced. The pulverization method can be any of barrel pulverization, pulverization by a mill, jet milling, etc., but more preferably barrel pulverization, jet milling, or a combination of these two. Furthermore, it is more preferable to sieve the pulverized rice flour. The sieve can be used to make the particle sizes uniform or to remove particles that deviate significantly from the target particle size range. Also, rice flour paste refers to a paste made from rice flour. Usually, paste is produced by mixing red beans, sugar, salt, and water and boiling them, but in the case of rice flour paste, rice flour is used instead of red beans. Rice flour paste has a texture, feel, firmness, and taste similar to those when using red beans.

[0012] 2. Regarding raw materials other than rice flour and mixing of raw materials To produce the rice flour filling, mix rice flour, sucrose, salt, and water. The mixing ratio is preferably by weight, rice flour:sucrose:salt:water = 15 - 25:35 - 45:0.5 - 1.5:28.5 - 49.5, and more preferably 18 - 22:38 - 43:0.8 - 1.2:33.8 - 43.2. There is no restriction on the type of sucrose to be used. For example, raw sugar, medium raw sugar, granulated sugar, superior white sugar, or soft sugar can be used. There is also no particular restriction on the salt to be used. For example, it can be produced with an ion exchange membrane, by evaporating seawater, or it can be rock salt. When mixing the raw materials, it is more preferable to stir with a spatula so that no lumps are formed.

[0013] 3. Regarding heating Heat the mixture of raw materials. The heating should increase the temperature to 55 - 85°C within 4 minutes from the start of heating and to 65 - 85°C within 8 minutes from the start of heating. After reaching 65 - 85°C, maintain 65 - 85°C and heat for a total of 12 - 22 minutes from the start of heating. More preferably, the temperature change is the same, and heat for a total of 15 - 20 minutes from the start of heating. The following temperature change is more preferable. Increase the temperature to 60 - 80°C within 4 minutes from the start of heating and to 70 - 80°C within 8 minutes from the start of heating. After reaching 70 - 80°C, maintain 70 - 80°C and heat for a total of 12 - 22 minutes from the start of heating. More preferably, the temperature change is the same, and heat for a total of 15 - 20 minutes from the start of heating. Surprisingly, the appropriate heating time is much shorter than existing production methods. Regarding the heating method, if the reaching temperature is low, the firmness is soft, the texture is powdery, and the taste has no flavor like that of red bean paste. This is the same even if the heating time is lengthened. In fact, experiments were conducted at a reaching temperature of 50°C and heating times of 30, 60, and 90 minutes, but the result was not close to that of red bean paste. The above heating conditions can be realized, for example, by simmering with hot water maintained at a temperature slightly higher than the target temperature to be reached. When the mixture is between 100 g and 1000 g, simmering with hot water maintained at about 90°C results in the above temperature change, and the firmness, texture, and taste become similar to those of red bean paste. In fact, it was confirmed that with 250 g, 500 g, and 1000 g of the mixture, without covering the lid, and simmering at 90°C for 15 minutes, the firmness, texture, and taste became similar to those of red bean paste.

[0014] 4. Regarding the theory of the manufacturing method In the present invention, the optimal rice flour paste is produced mainly by defining the average particle size and the heating method. When water is added and the rice flour is heated, the swelling and alpha - conversion of starch proceed. However, if overheated, the starch particles collapse, resulting in a firmer texture than red bean paste, a nettly texture, and the loss of the taste similar to red bean paste. The conditions under which the starch particles do not collapse while undergoing alpha - conversion are considered the manufacturing conditions of the present invention.

[0015] 5. Regarding the production of the juice paste By mixing the rice flour paste of the present invention with water or hot water, a white juice paste can be obtained. If the temperature of the hot water is 60 - 100°C, more preferably 80°C - 100°C, it can be directly used as the juice paste, which is more preferable. Also, even if the temperature of the water or hot water is low, the rice flour paste will dissolve upon stirring, but heating to dissolve is not excluded. When heating, in order to prevent the gelatinization of the rice flour, the temperature should not rise locally. For example, when heating by simmering or heating over an open flame, stir while heating. Also, since gelatinization starts when the product temperature exceeds 90°C, it is more preferable to keep the product temperature not exceeding 90°C. Note that this heating method is the same when reheating the cooled juice paste. The mixing ratio with hot water or water is more preferably a weight ratio of rice flour paste: hot water or water = 1:1.5 - 3. The Brix sugar degree after mixing is more preferably 13 - 18% (measured at a product temperature of 60°C). The rice flour paste of the present invention is easily soluble in hot water and is optimal as a material for the juice paste.

Examples

[0016] The present invention will be described below with reference to examples.

[0017] Example 1 [Production of rice flour filling] (1) Raw materials As the rice, Akita Komachi produced in Akita Prefecture was used, and rice flour (manufactured by Ozawa Flour Milling Co., Ltd.) produced by wet hulling and milling (soaked in water → hulled and ground → passed through a sieve with an opening of about 1400 μm → dried) was used. The volume average particle size was 124.2 μm (★ in FIG. 1). At the same time, the median diameter measured was also 127.7 μm (★ in the lower part of FIG. 1), which was almost the same value. The measurement was performed using a Micrtotrac MT3300EXII / laser diffraction / scattering particle size distribution measuring device. Sucrose was white granulated sugar (Okatsune Sugar Manufacturing Co., Ltd., product name "Oni-zarazato", model number SZ20kg), and table salt (Salt Industry Center, a public interest incorporated foundation, 5 kg of table salt) was used. (2) Manufacturing method (I) 100 g of rice flour of "Akita Komachi", 200 g of white granulated sugar, and 5 g of table salt were all put into a small pot (inner diameter 18 cm, depth 11 cm, made of stainless steel, hereinafter referred to as a small pot) and mixed together. Then 195 mL of water was added thereto. Thereafter, it was mixed with a rubber spatula for 1 minute so that no lumps were formed, resulting in a mixture. At this time, the white granulated sugar was not completely dissolved and particles remained. Note that no heating was performed in the process up to this point. (II) Approximately 16 L of hot water was put into a large pot (inner diameter 39 cm, depth 19 cm, made of stainless steel, hereinafter referred to as a large pot), and it was kept at 90 °C while applying a low heat. The small pot containing the mixture was immersed in the large pot to about half of its depth, that is, so that the water surface of the liquid mixture with undissolved sugar remaining in the small pot was lower than the water surface of the hot water in the outer large pot, and it was simmered without a lid. The simmering was continued for 15 minutes while paying attention to making the temperature uniform by stirring the mixture. The state of the temperature change of the mixture at this time is shown in FIG. 2. It reached 60 °C in 2 minutes from the start of simmering, 70 °C in 6 minutes, 76 °C in 9 minutes, and then remained at the same temperature until 15 minutes. About 3 minutes after starting to heat the water, all the undissolved white granulated sugar had dissolved. After heating the water, when measuring the sugar content of multiple products produced, rice flour paste with a Brix sugar content of 60.3 to 62.2% (product temperature at the time of measurement: 60 °C) was obtained. The sugar content was measured with a Brix refractometer (Atago Co., Ltd., model P: AL-1, Cat. No. 3810). (III) The produced rice flour paste and hot water were mixed at a ratio of 1:2 to produce the soup powder. The Brix sugar content was 16.9 to 17.7% (product temperature at the time of measurement: 60 °C). Different from the usual red bean-colored soup powder, the soup powder was a white one close to pure white.

[0018] Example 2 [Examination of the particle size of rice flour using the results of the sensory test as an indicator] (1) Production of rice flour paste with shaken particle size Four types of rice flour with volume average particle diameters of A. 70.62, B. 124.2, C. 159.4, and D. 283.6 μm were used. For A, the rice flour formed lumps in the mixture and it was not possible to produce rice flour paste, but for B, C, and D, rice flour paste could be produced. Among them, the one with the smallest particle diameter of A was further subjected to airflow pulverization after Example 1, the one with a small particle diameter of B was produced by wet barrel milling similar to Example 1, and the ones with large particle diameters of C and D used rice flour produced by a dry impact pulverization method equipped with a screen type classifier. Except for the raw material rice flour, rice flour paste was produced in the same manner as in Example 1 and subjected to a sensory test. (2) Sensory test (I) Method For the rice flour paste produced with each of the rice flours of B, C, and D, a sensory test was conducted by 5 evaluators for texture and taste. For the texture, the one similar to red bean paste was rated 5, and the rating was lowered as it became different from the texture of red bean paste, such as "hard and sticky" or "coarse and powdery". For the taste, the one with a flavor similar to red bean paste was rated 5, and the rating was lowered as it deviated from this. In both cases, the higher the rating, the closer it was to red bean paste. The average of the average scores of each item was used as the comprehensive evaluation. (II) Results Among B, C, and D, the score of B was the highest in both texture and taste (Table 1). As the volume average particle diameter increased, the coarseness of the rice flour filling became stronger, and it became more powdery, resulting in a lower texture score. Moreover, the taste of rice emerged, leading to a lower taste score. It was found that a volume average particle diameter around 120 μm of the rice flour used was appropriate.

[0019]

Table 1

[0020] Example 3 [Examination of Heating Time Using the Results of Sensory Tests as an Index] (1) Production of Heated Rice Flour Filling Using the rice flour with a volume average particle diameter of B.124.2 μm, which had a high score in Example 2, as the raw material. The heating times were set to 10, 15, 20, 30, 45, and 60 minutes, and the rice flour filling was produced in the same manner as in Example 1 for the rest. (2) Sensory Test (I) Method For the rice flour fillings with heating times of 10, 15, 20, 30, 45, and 60 minutes, sensory tests were conducted by 5 evaluators on hardness, texture, and taste. Regarding hardness, a filling similar to adzuki bean paste was rated 5, and as it became "softer" or "harder" than this, the score was lowered as it deviated from the hardness of adzuki bean paste. Regarding texture, a filling similar to adzuki bean paste was rated 5, and as it became "more powdery" or "more sticky" than this, the score was lowered as it deviated from the texture of adzuki bean paste. The taste was evaluated in the same manner as in Example 2. The average of the average scores of each item was used as the comprehensive evaluation. (II) Results The results are shown in Table 2. Regarding hardness, as the heating time increased, it changed from "soft" (low score) → "hardness similar to adzuki bean paste" (high score) → "hard" (low score). The fillings heated for 15 and 20 minutes had high scores and were close to the hardness of adzuki bean paste. Regarding the texture, as the temperature increased, the texture changed from "powdery" (low score) → "texture similar to red bean paste" (high score) → "gooey" (low score). With a heating time of 10 minutes, it was slightly powdery. As the heating time increased to 15 and 20 minutes, the score gradually increased, and the texture became closer to that of red bean paste. When the heating time exceeded 30 minutes, the texture became gooey and the score decreased. Regarding the taste, there was no significant difference in the samples heated for 10, 15, and 20 minutes. However, when the heating time exceeded 20 minutes, the taste deviated from that of red bean paste. Based on the above, as a comprehensive evaluation, it was found that the samples heated for 15 and 20 minutes were excellent as the rice flour material for the rice flour paste. Note that the sensory test is a relative evaluation within the test system, and it is not appropriate to simply and directly compare the scores in Table 1 and Table 2.

[0021] [Table 2]

[0022] Example 4 [Examination of heating time using ease of dissolution in hot water as an index] (1) Production of rice flour paste with varying heating times The rice flour paste produced in Example 3 with heating times of 10, 15, 20, 30, 45, and 60 minutes was used as samples. (2) Test for ease of dissolution (I) Method To 10 g of the sample rice flour paste, 20 mL of hot water at 90 - 100 °C was added, and it was stirred 15 times with a spoon. The degree of dissolution of the rice flour paste was visually judged. The degree of dissolution was evaluated in three levels: ○: easily dissolved, △: slightly dissolved, ×: difficult to dissolve. (II) Results The results are shown in Table 3. Samples heated for 10, 15, and 20 minutes dissolved easily. (3) From the results of the sensory test (Example 3) and the results of ease of dissolution (Example 4), it was found that the optimal heating time was 15 and 20 minutes.

[0023] [Table 3]

Industrial Applicability

[0024] According to the method for producing rice flour paste of the present invention, rice flour, particularly rice flour of Akitakomachi, can be used as a raw material to provide rice flour paste. Therefore, the consumption of rice and rice flour can be expanded, which is useful for rice farmers and rice flour manufacturers. Furthermore, this rice flour paste can provide a white rice gruel that has never been available before, expanding the demand for rice gruel and being useful for the confectionery industry as well.

Claims

1. A method for manufacturing rice flour filling, using rice flour as a raw material and including the following steps (1) and (2). (1) Mix so that the weight ratio is rice flour with a volume average particle diameter of 110 to 140 μm: sucrose: salt: water = 15 to 25: 35 to 45: 0.5 to 1.5: 28.5 to 49.

5. (2) Raise the temperature of the mixture in (1) to 55 to 85 °C within 4 minutes from the start of heating and to 65 to 85 °C within 8 minutes from the start of heating. After reaching 65 to 85 °C, maintain 65 to 85 °C and heat for a total of 12 to 22 minutes from the start of heating.

2. A method for manufacturing soup powder, using rice flour as a raw material and including the following steps (1) to (3). (1) Mix so that the weight ratio is rice flour with a volume average particle diameter of 110 to 140 μm: sucrose: salt: water = 15 to 25: 35 to 45: 0.5 to 1.5: 28.5 to 49.

5. (2) Raise the temperature of the mixture in (1) to 55 to 85 °C within 4 minutes from the start of heating and to 65 to 85 °C within 8 minutes from the start of heating. After reaching 65 to 85 °C, maintain 65 to 85 °C and heat for a total of 12 to 22 minutes from the start of heating. (3) Mix the heated mixture in (2) with water or hot water.

3. The method for manufacturing rice flour filling according to Claim 1, wherein the rice flour is Akita Komachi rice flour.

4. The method for manufacturing soup powder according to Claim 2, wherein the rice flour is Akita Komachi rice flour.

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