Dried buckwheat

Abstract

To provide dried buckwheat noodles that can be stably mass-produced while containing a lot of buckwheat flour without using wheat flour, the buckwheat noodles excellent in original flavor of buckwheat.SOLUTION: Dried buckwheat noodles include only buckwheat flour as a flour raw material, and have a content of protein of 10 to 15 mass%. A ratio of soluble protein is 35 mass% or more in the protein. The dried buckwheat noodles preferably each have a noodle line shape. An orthogonal cross-sectional shape of the noodle line has thickness 0.9 to 1.1 mm and width 1.2 to 1.5 mm.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to dried buckwheat that does not use wheat flour as a raw material, and more particularly to dried buckwheat with a very high flavor derived from buckwheat.

Background Art

[0002] Buckwheat is a food product made by adding kneading water to buckwheat flour obtained by grinding buckwheat seeds, kneading them to form dough, and shaping the dough into noodle strings or the like. It has a unique flavor and is popular. Similarly, as noodle string-shaped food products using cereal flour as a raw material, those using wheat flour such as udon and soba are widely eaten. Wheat flour has the property that dough with viscoelasticity can be obtained simply by adding water and kneading, and it is extremely versatile from the viewpoints of moldability and binding property. On the other hand, since buckwheat flour lacks the properties of wheat flour, it is difficult to obtain dough even if buckwheat flour is used and simply added with water and kneaded in the same manner as wheat flour. Therefore, general buckwheat is manufactured using a mixture of buckwheat flour and wheat flour as a binder as a raw material powder. For example, buckwheat manufactured from a mixture of buckwheat flour: wheat flour = 8:2 is called 20% buckwheat. However, naturally, as the proportion of the binder in the raw material powder increases, the proportion of buckwheat flour relatively decreases, resulting in difficulty in obtaining the flavor of buckwheat.

[0003] On the other hand, people who are allergic to wheat cannot eat buckwheat containing wheat flour. Therefore, if they want to eat buckwheat, they need to eat buckwheat using only buckwheat flour as the cereal flour and using sweet potato or the like as a binder, or 100% buckwheat using only buckwheat flour as a raw material. In the production of 100% buckwheat, usually, in order to enable the production of dough, hot water instead of water is used as the kneading water added to buckwheat flour to gelatinize the starch contained in buckwheat flour, and the stickiness of the gelatinized starch is utilized. Also, noodle making may be performed using pre-gelatinized buckwheat flour. However, in 100% buckwheat obtained by such a production method, the components contained in buckwheat are often denatured, and in many cases, the original flavor of buckwheat flour cannot be obtained.

[0004] For example, even in the case of 100% buckwheat noodles, if a highly skilled craftsman quickly manufactures them using hot water and consumes them on the spot, the flavor of buckwheat can be enjoyed to a certain extent. However, when industrially manufacturing 100% buckwheat noodles, since the production volume is large, compared to the case of handmade production, the manufacturing process takes more time, and during that time, the flavor of buckwheat gradually decreases. Therefore, among commercially available 100% buckwheat noodles, especially those produced in large quantities, there are many with poor buckwheat flavor, and this tendency is particularly prominent in dried buckwheat noodles where the manufactured buckwheat is dried to enhance its preservability and facilitate distribution. Therefore, whether it is buckwheat noodles using a binder or 100% buckwheat noodles, there is a problem that the commercially available buckwheat noodles lack flavor.

[0005] Regarding such problems, technologies for improving the flavor of buckwheat have been proposed. In the technology described in Patent Document 1, while improving the flavor of buckwheat by using buckwheat flour in an amount equal to or greater than the weight of wheat flour, the problem of difficulty in manufacturing the dough that is a concern due to using a large amount of buckwheat flour is solved by using powdered wheat flour protein (powdered gluten) as a binder for the buckwheat flour and adjusting the temperature of the dough within a specific range when passing the dough through a rolling machine to obtain a noodle sheet. Patent Document 2 describes that when buckwheat is ground to obtain a fraction with a protein content of 16% by mass or more and the fraction is further finely ground to 10 - 60 μm and used as buckwheat flour, the flavor of buckwheat is enhanced.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] An object of the present invention is to provide dried buckwheat that can be stably mass-produced while containing a large amount of buckwheat flour without using wheat flour and has an excellent original flavor of buckwheat.

Means for Solving the Problems

[0008] The present invention is dried buckwheat that contains only buckwheat flour as a flour raw material, has a protein content of 10 to 15% by mass, and the proportion of soluble protein in the protein is 35% by mass or more. Moreover, the present invention is a cooking method for buckwheat in which the dried buckwheat is boiled within 6 minutes so that the boiled buckwheat becomes 210 to 275 g per 100 g of dried buckwheat.

Effects of the Invention

[0009] According to the present invention, it is possible to stably mass-produce buckwheat that contains only buckwheat flour as a flour raw material and has an excellent original flavor of buckwheat. Further, the buckwheat of the present invention contains only buckwheat flour as a flour raw material and does not contain wheat flour that may cause allergies, so people with wheat allergies can safely eat buckwheat.

Modes for Carrying Out the Invention

[0010] The dried buckwheat of the present invention is obtained by forming buckwheat dough into a predetermined shape such as noodle strands and drying it. Generally, the moisture content of dried buckwheat is preferably 14% by mass or less, more preferably 12.5 to 13.5% by mass. The moisture content is determined by drying the sample at 105 ° C. until it reaches a constant mass according to the absolute drying method, regarding the mass difference before and after drying as the moisture mass in the sample before drying, and expressing the moisture mass in the mass of the sample before drying as a percentage.

[0011] For the dried buckwheat of the present invention, solid raw materials and liquid raw materials are used as raw materials. For the dried buckwheat of the present invention, buckwheat flour is used as the main component of the solid raw materials. As the buckwheat flour, those obtained by grinding buckwheat seeds can be used, and examples include commercially available first-grade flour, second-grade flour, third-grade flour, whole-layer flour, and mixtures thereof. In the solid raw materials of the dried buckwheat of the present invention, the content of buckwheat flour is preferably 90% by mass or more, more preferably 95% by mass or more, based on the total mass of the solid raw materials. More preferably, the dried buckwheat of the present invention is produced using only 100% by mass of buckwheat flour as the solid raw material, that is, more preferably, the dried buckwheat of the present invention is 100% buckwheat.

[0012] The solid raw materials used for the dried buckwheat of the present invention do not contain cereal flour raw materials other than the above-mentioned buckwheat flour. In other words, the dried buckwheat of the present invention contains only buckwheat flour as the cereal flour raw material. Generally, cereal flour raw materials other than buckwheat flour that can be used in foods include wheat flour, rice flour, corn flour, etc. Among them, wheat flour is often used for buckwheat, but the dried buckwheat of the present invention does not contain these cereal flour raw materials except for unavoidable impurities, in addition to buckwheat flour. That is, it is allowed that the dried buckwheat of the present invention unavoidably contains cereal flour raw materials other than buckwheat flour during production.

[0013] Also, the solid raw materials used for the dried buckwheat of the present invention may contain other components other than buckwheat flour as long as the effects of the present invention are not inhibited. Examples of other components include starches, sugars, egg powder, yam powder, matcha, nori, buckwheat leaf powder, emulsifiers, pigments, flavors, seasonings, etc., and one of these can be used alone or in combination of two or more. Starches include unprocessed starches such as potato starch, wheat starch, tapioca starch, corn starch, etc., and processed starches obtained by subjecting these unprocessed starches to one or more treatments such as oil processing, gelatinization, etherification, esterification, cross-linking, oxidation, etc. The content of other components in the solid raw materials is preferably 10% by mass or less, more preferably 5% by mass or less, based on the total mass of the solid raw materials, and more preferably, no other components are used.

[0014] The liquid raw material used for the dried buckwheat of the present invention serves as kneading water when producing buckwheat dough using buckwheat flour and has water as the main component. Further, the liquid raw material may contain, together with water, one kind of liquid such as a liquid flavor, a liquid seasoning, or an oil and fat alone or in combination of two or more kinds as desired. The content of water in the liquid raw material is preferably 95% by mass or more, more preferably 98% by mass or more, based on the total mass of the liquid raw material. Even more preferably, the dried buckwheat of the present invention is produced using only 100% by mass of water as the liquid raw material.

[0015] The usage ratio of the solid raw material and the liquid raw material used for the dried buckwheat of the present invention can be the same as that in the case of ordinary dried buckwheat. For example, both can be used at a ratio of 0.2 to 0.5 L of the liquid raw material per 1 kg of the solid raw material.

[0016] In addition to being produced using a large amount of buckwheat flour as the solid raw material in this way, the dried buckwheat of the present invention is characterized in that the content of protein in the dried buckwheat and the proportion of soluble protein in the protein are each within a specific range. In addition, the "protein content", the "proportion of soluble protein in the protein", and the "content of soluble protein" to be described in detail later mentioned here are values based on the mass of the dried buckwheat in the dry state as described above. More specifically, they are preferably values based on the mass of the dried buckwheat with a water content of 14% by mass or less, more preferably 12.5 to 13.5% by mass.

[0017] The dried buckwheat of the present invention has a protein content of 10 to 15% by mass, preferably 11 to 14% by mass. When the protein content in buckwheat is 10 to 15% by mass, combined with the proportion of soluble protein described later, the flavor of the dried buckwheat of the present invention can be enhanced.

[0018] The protein content referred to here is determined by the combustion method (modified Dumas method). Specifically, a dried buckwheat sample with a known mass is prepared, and the nitrogen content in this dried buckwheat sample is measured by the standard method of the combustion method (modified Dumas method), and the nitrogen content is converted into the protein mass using a predetermined coefficient. {(Protein mass) / (Mass of the dried buckwheat sample) × 100 (%)} is the protein content of the dried buckwheat.

[0019] The dried buckwheat of the present invention has a proportion of soluble protein in the protein of 35% by mass or more, preferably 40% by mass or more. When the proportion of this soluble protein is less than 35% by mass, a burnt odor flavor is generated in the buckwheat. The upper limit of the proportion of soluble protein in the protein is not particularly limited, but considering the component composition of buckwheat flour, it is usually at most about 50% by mass.

[0020] The proportion of soluble protein referred to here is the ratio of the content of soluble protein determined by the combustion method (modified Dumas method) to the content of the above-mentioned protein. Specifically, first, soluble protein is extracted from a dried buckwheat sample with a known mass using a 0.08 M phosphate buffer solution to obtain a soluble protein fraction. Next, the nitrogen content in this soluble protein fraction is measured by the standard method of the combustion method (modified Dumas method), and the nitrogen content is converted into the soluble protein mass using a predetermined coefficient. The soluble protein content of the dried buckwheat is determined from {(Soluble protein mass) / (Mass of the dried buckwheat sample used for extraction) × 100 (%)}. And {(Soluble protein content) / (Protein content) × 100 (%)} is the "proportion of the amount of soluble protein in the protein".

[0021] The dried buckwheat of the present invention is produced using the above-mentioned solid raw material and liquid raw material so that the protein content is 10 to 15% by mass and the proportion of soluble protein in the protein is 35% by mass or more. As a result of investigations by the present inventors, it was found that the amount of soluble protein decreases due to the heat during kneading and the heat when using hot water as the liquid raw material (kneading water) in the buckwheat dough manufacturing process. Based on this finding, the dried buckwheat of the present invention has a protein content of the solid raw material of the dried buckwheat exceeding 10 to 15% by mass (preferably, the solid raw material is 100% by mass of buckwheat flour and the protein content of the buckwheat flour exceeds 10 to 15% by mass), and further, by paying attention to the temperature of the dough during the dough manufacturing process so that the amount of soluble protein does not decrease, it can be produced. In other words, by setting the protein content of the solid raw material of the dried buckwheat to exceed 10 to 15% by mass and further paying attention to the temperature of the dough during the dough manufacturing process so that the amount of soluble protein does not decrease, the proportion of soluble protein in the protein in the obtained dried buckwheat can be made 35% by mass or more. Here, the reason for setting the "protein content of the solid raw material to exceed 10 to 15% by mass" is that in the manufacturing process of dried buckwheat, the amount of protein may slightly decrease due to various factors (for example, hydration by adding water, heating during drying, etc.), and it is intended to prepare the solid raw material in anticipation of such an inevitable slight decrease in manufacturing. Also, the above-mentioned dough temperature refers to the temperature of the solid raw material, the liquid raw material, and the dough during kneading (a mixture of the solid raw material and the liquid raw material).

[0022] As specific methods for producing buckwheat dough while preventing the amount of soluble protein from decreasing, the following (1) and (2) can be exemplified, but are not limited thereto. (1) As a result of the inventors' studies, it became clear that the soluble protein decreases at 70°C or higher. On the other hand, the starch contained in buckwheat gelatinizes at about 60°C. Therefore, when the temperature of the buckwheat dough during preparation is set to 60 - 66°C, the starch gelatinizes and the dough becomes more likely to stick together, and the soluble protein is less likely to decrease. Accordingly, an example of a preferred method for producing buckwheat dough while preventing the amount of soluble protein from decreasing is to set the temperature of the dough to 60 - 66°C when mixing the solid raw material and the liquid raw material to prepare the dough. The adjustment of the temperature of the dough can be achieved, for example, by adjusting the temperature of the mixer used for kneading and by adjusting the temperature of the liquid raw material when adding it to the solid raw material.

[0023] (2) There are buckwheat flours with different protein contents. According to the Japanese Food Standard Composition Table 2015 Edition (Seventh Revised Edition), the protein contents of first-grade flour (inner-layer flour), second-grade flour (middle-layer flour), third-grade flour (surface-layer flour), and whole-layer flour are 6.0%, 10.2%, 15.0%, and 12.0% respectively. Also, the amount of protein varies depending on the harvest year and harvest location of buckwheat. Among these, by heating buckwheat flour with a relatively low amount of protein (low-protein buckwheat flour) to gelatinize the starch and adding buckwheat flour with a relatively high amount of protein without heating to form a mixture, and using this mixture as the solid raw material (raw flour), it becomes possible to produce buckwheat dough with good cohesion by solidifying the starch while ensuring the ratio of protein to soluble protein. Accordingly, another example of a preferred method for producing buckwheat dough without reducing the amount of soluble protein is to prepare buckwheat dough using, as the solid raw material, a mixture of heat-treated buckwheat flour obtained by heating buckwheat flour with a relatively low amount of protein and unheated buckwheat flour with a relatively high amount of protein.

[0024] In the method of (2), as the low-protein buckwheat flour that is the raw material for the heated buckwheat flour, for example, buckwheat flour with a protein content of 7.0% by mass or less may be used, but even a higher protein content may be acceptable. The lower limit of the protein content in the low-protein buckwheat flour is not particularly limited either, but usually, even when the protein content of the buckwheat flour is low, it is about 5.0% by mass. By adding water to such low-protein buckwheat flour and heating it to gelatinize the starch, heated buckwheat flour can be obtained. The amount of water added is preferably 20 to 120 parts by mass with respect to 100 parts by mass of the low-protein buckwheat flour. To promote gelatinization, it is preferable to add water so that the water reaches uniformly throughout the low-protein buckwheat flour. For example, the low-protein buckwheat flour may be thinly spread in a vat or the like, and water may be sprayed using an atomizer or the like. The heating after adding water may be carried out under conditions where the starch is gelatinized. The heating temperature is preferably 60 to 120°C, and the heating time is preferably 5 to 120 minutes.

[0025] On the other hand, as the unheated buckwheat flour, buckwheat flour with a protein content of 12% by mass or more may be used. The upper limit of the protein content in the unheated buckwheat flour is not limited, but usually, even when the protein content of the buckwheat flour is high, it is about 16% by mass.

[0026] When such heated buckwheat flour and unheated buckwheat flour are mixed, the mixing ratio of the two is not particularly limited as long as the final protein content of the dried buckwheat is 10 to 15% by mass and the proportion of soluble protein in the protein is 35% by mass or more. As a guideline, the heated buckwheat flour: unheated buckwheat flour = 15:85 to 40:60 (mass ratio) can be used.

[0027] Also, in the method of (2), since the starch in the heated buckwheat flour has already been gelatinized, the liquid raw material used for producing buckwheat dough does not need to be at a high temperature like hot water and may be, for example, at room temperature. Rather, when using a liquid raw material at a relatively high temperature, the amount of soluble protein contained in the unheated buckwheat flour will decrease. Therefore, the temperature of the liquid raw material is preferably 70°C or lower.

[0028] The dried buckwheat of the present invention can be produced according to the production method of conventional dried buckwheat while incorporating the above-described methods. The production method of conventional dried buckwheat typically includes a dough production step of adding a liquid raw material to a solid raw material, kneading to produce buckwheat dough, a shaping step of shaping the dough into a predetermined shape (typically noodle string shape) to obtain buckwheat, and a drying step of drying the shaped buckwheat. Therefore, in order to produce the dried buckwheat of the present invention, it is preferable to incorporate the above-described method (1) or (2) into the dough production step. Also, in the shaping step and the drying step, it is preferable to apply as little heat as possible to the dough and the buckwheat. Specifically, it is preferable to perform the shaping step and the drying step at 40°C or lower. Examples of the method for shaping the dough include a method of cutting out a noodle band obtained by rolling the dough into noodle strings, and a method of extruding the dough into noodle strings using an extruder or the like. Examples of the method for drying the buckwheat include ventilation drying and vacuum drying.

[0029] When the shape of the dried buckwheat of the present invention is noodle string shape, if the orthogonal cross-sectional shape of the noodle string as dried buckwheat is a thickness of 0.9 to 1.1 mm and a width of 1.2 to 1.5 mm, it is preferable because the flavor of buckwheat can be felt more strongly. In order to obtain such an orthogonal cross-sectional shape, for example, considering the shrinkage due to drying in the drying step, in the above shaping step, the noodle band is adjusted to a thickness of 1.0 to 1.2 mm and cut out to a width of 1.3 to 1.7 mm using rolling rolls, and at that time, it is preferable to use a square blade of No. 18 to 24.

[0030] Also, when cooking the dried buckwheat of the present invention by boiling, from the viewpoint of minimizing the decrease in the amount of soluble protein, it is preferable to boil it within 6 minutes, preferably within 5 minutes. At that time, it is preferable to boil it so that the amount of boiled buckwheat per 100 g of dried buckwheat is 210 to 275 g. If the amount of boiled buckwheat per 100 g of dried buckwheat is less than 210 g, a powdery texture with a strong core may remain in the central part, and if it exceeds 275 g per 100 g of dried buckwheat, it will be soft and the noodles will be easily torn during boiling.

[0031] Normally, for fully dried buckwheat noodles, it is necessary to perform a steaming process for several minutes after boiling. This steaming process is carried out to shorten the boiling time of the easily breakable fully dried buckwheat noodles and to allow the hot water to penetrate well during steaming. However, if a steaming process is provided, a dry and unappetizing texture often occurs. The dried buckwheat noodles of the present invention can produce fully dried buckwheat noodles with a good texture, where the hot water penetrates to the center of the buckwheat noodles only by boiling without providing such a steaming process.

Examples

[0032] Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

[0033] In the following examples, the protein content and soluble protein content were measured by the following methods. (Method for measuring protein content) A dried buckwheat noodle sample was prepared and its mass was measured. Using a protein measuring device by combustion method (Dumas Thermo N Pro; Gerhardt Japan Co., Ltd.), the nitrogen content in this dried buckwheat noodle sample was measured by the standard method, and the nitrogen content was converted to the protein mass using a predetermined coefficient. The protein content of the dried buckwheat noodle sample was determined by dividing the protein mass by the mass of the dried buckwheat noodle sample.

[0034] (Method for measuring soluble protein content) A soluble protein fraction was obtained by extracting soluble protein from the dried buckwheat noodle sample according to the following procedure. The mass of the dried buckwheat noodle sample was measured, 10 mL of 0.08 M phosphate buffer solution was added per 1 g of the dried buckwheat noodle sample and dispersed, and shaken for 2 hours to extract soluble protein from the dried buckwheat noodle sample. Then, it was centrifuged at 10000 rpm to remove the precipitate, and the supernatant was freeze-dried by a conventional method to obtain a soluble protein fraction. Using a protein measuring device by combustion method (Dumas Thermo N Pro; Gerhardt Japan Co., Ltd.), the nitrogen content in the obtained soluble protein fraction was measured by the standard method, and the nitrogen content was converted to the soluble protein mass using a predetermined coefficient. The soluble protein content of the dried buckwheat noodle sample was determined by dividing the soluble protein mass by the mass of the dried buckwheat noodle sample used for extraction.

[0035] The raw materials used in the following examples and comparative examples are as follows. Buckwheat flour A with a high protein content (high-protein buckwheat flour A): Tokumei: manufactured by Ishimori Flour Milling Co., Ltd. (protein content 15.2%) Buckwheat flour B with a high protein content (high-protein buckwheat flour B): Gin Ebisu: manufactured by Ishimori Flour Milling Co., Ltd. (protein content 12.2%) Buckwheat flour with a low protein content (low-protein buckwheat flour): (Special) Kinsyu: manufactured by Nikko Flour Milling Co., Ltd. (protein content 6.0%)

[0036] (Example 1) 5 kg of high-protein buckwheat flour B was put into the mixer of a noodle-making machine (Taro Bando; manufactured by Yamato Seisakusho Co., Ltd.). While maintaining the temperature around the mixer at 65 °C with a jacket, 2 L of water at 65 °C was put into the mixer and mixed for 3 minutes to produce dough. The dough was pressed, rolled, and stretched to a dough with a thickness of 1.1 mm. This dough was folded and cut at a width of 1.45 mm to obtain raw buckwheat. This forming process was carried out at room temperature. The raw buckwheat was hung on a pole and dried in a constant-temperature room at 30 °C for 12 hours to obtain dried buckwheat. Using the obtained dried buckwheat as a sample, the protein content and soluble protein content were measured, and the ratio of soluble protein to protein was determined. Also, the thickness and width of the orthogonal cross-sectional shape of the obtained dried buckwheat were measured. The results are shown in Table 1.

[0037] (Comparative Example 1) Dried buckwheat was produced in the same manner as in Example 1, except that water at 75 °C was added and mixed while maintaining the mixer at 75 °C. Using the obtained dried buckwheat as a sample, the protein content and soluble protein content were measured, and the ratio of soluble protein to protein was determined. Also, the thickness and width of the orthogonal cross-sectional shape of the obtained dried buckwheat were measured. The results are shown in Table 1.

[0038] (Comparative Example 2) Buckwheat noodles were produced in the same manner as in Example 1, except that water at 85°C was added and mixed while maintaining the mixer at 85°C. Using the obtained buckwheat noodles as samples, the protein content and soluble protein content were measured, and the ratio of soluble protein in the protein was determined. In addition, the thickness and width of the orthogonal cross-sectional shape of the obtained buckwheat noodles were measured. The results are shown in Table 1.

[0039] (Comparative Example 3) Buckwheat noodles were produced in the same manner as in Example 1, except that water at 55°C was added and mixed while maintaining the mixer at 55°C. However, the dough did not stick together, and buckwheat could not be produced.

[0040] (Example 2) Low-protein buckwheat flour was thinly spread on a tray, and water was uniformly sprayed in an amount of 30 parts by mass with respect to 100 parts by mass of the low-protein buckwheat flour by spraying. Then, the tray was placed in an oven at 90°C, and the low-protein buckwheat flour was heat-treated for 60 minutes to obtain heat-treated low-protein buckwheat flour. After the heat treatment, the tray was taken out of the oven, and the heat-treated low-protein buckwheat flour was cooled to room temperature. 20 parts by mass of this heat-treated low-protein buckwheat flour and 80 parts by mass of high-protein buckwheat flour A were mixed uniformly with a mixer. 5 kg of this mixed flour was put into the mixer of a noodle-making machine (Taro Bando; Yamato Seisakusho Co., Ltd.), 2 L of water was put into the mixer, and the mixture was mixed for 3 minutes to produce dough. The dough was pressed, rolled, and stretched to obtain a dough with a thickness of 1.1 mm. This dough was folded and cut at a width of 1.45 mm to obtain raw buckwheat noodles. Note that all steps from the mixing of the heat-treated low-protein buckwheat flour and the high-protein buckwheat flour to the obtaining of the raw buckwheat noodles were carried out at room temperature. The obtained raw buckwheat noodles were hung on a pole and dried in a constant-temperature room at 30°C for 12 hours to obtain buckwheat noodles. Using the obtained buckwheat noodles as samples, the protein content and soluble protein content were measured, and the ratio of soluble protein in the protein was determined. In addition, the thickness and width of the orthogonal cross-sectional shape of the obtained buckwheat noodles were measured. The results are shown in Table 1.

[0041] (Comparative Example 4) Buckwheat noodles were produced in the same manner as in Example 2, except that only heat-treated low-protein buckwheat flour was used. The obtained buckwheat noodles were used as samples, and the protein content and soluble protein content were measured. In addition, the thickness and width of the cross-sectional shape of the obtained buckwheat noodles were measured. The results are shown in Table 1.

[0042] (Comparative Example 5) High-protein buckwheat flour B was thinly spread on a tray, and water was uniformly sprayed thereon in an amount of 30 parts by mass with respect to 100 parts by mass of high-protein buckwheat flour B by spraying. Then, the tray was placed in an oven at 90 °C, and high-protein buckwheat flour B was heat-treated for 60 minutes to obtain heat-treated high-protein buckwheat flour B. After the heat treatment, the tray was taken out of the oven, and the heat-treated high-protein buckwheat flour B was cooled to room temperature. Buckwheat noodles were produced in the same manner as in Example 2, except that a mixed flour obtained by uniformly mixing 20 parts by mass of this heat-treated high-protein buckwheat flour B and 80 parts by mass of low-protein buckwheat flour with a mixer was used. The obtained buckwheat noodles were used as samples, and the protein content and soluble protein content were measured, and the ratio of soluble protein in the protein was determined. In addition, the thickness and width of the cross-sectional shape of the obtained buckwheat noodles were measured. The results are shown in Table 1.

[0043] Incidentally, the buckwheat noodles obtained in Examples 1 to 2 and Comparative Examples 1 to 5 all had a moisture content in the range of 13.2 to 13.6% by mass.

[0044] (Test Example 1) During the production of buckwheat in each Example and Comparative Example, the workability of the dough when pressing, rolling, and stretching was evaluated. The evaluation was carried out by 10 professional panelists with experience in the industrial production of buckwheat according to the following evaluation criteria. The evaluation results are shown in Table 1 as the average value of the evaluation scores of 10 panelists. Incidentally, at room temperature, 5 kg of whole-layer flour was put into a mixer of a noodle-making machine (Taro Bando; Yamato Seisakusho Co., Ltd.), 2 L of water was put into the mixer, and the mixture was mixed for 3 minutes to obtain a dough. The workability when pressing, rolling, and stretching this dough and when folding this dough was regarded as 1 point.

[0045] (Evaluation Criteria for Dough Workability) 5 points: The connection of the dough is very good, and it does not break even when the dough is turned back, which is extremely good. 4 points: The connection of the dough is good, and it rarely breaks even when the dough is turned back, which is good. 3 points: The dough does not break during rolling, but it may break when the dough is turned back, which is fairly good. 2 points: The dough may break during rolling and needs to be repaired, and it is also easy to break when the dough is turned back, which is defective. 1 point: The dough is easy to break during rolling, and it is also likely to fall apart when the dough is turned back, so it is difficult to fold, which is extremely defective.

[0046] (Test Example 2) 100 g of dried buckwheat in the examples and comparative examples was boiled in boiling water for 4 minutes, washed with water and cooled, and the water was drained well to obtain cooked buckwheat. The mass of the obtained cooked buckwheat was measured. This cooked buckwheat was eaten by 10 trained professional panelists without dipping it in sauce, and the flavor of the buckwheat at that time was evaluated according to the following evaluation criteria. The evaluation results are shown in Table 1 as the average value of the evaluation scores of 10 panelists.

[0047] <Evaluation Criteria for Buckwheat Flavor> 5 points: The flavor of buckwheat is very felt, like freshly hand-made noodles with only whole-layer flour, which is extremely good. 4 points: Inferior to freshly hand-made noodles with only whole-layer flour, but the flavor of buckwheat is felt, which is good. 3 points: It has the same flavor as commercially available 20% buckwheat noodles, which is fairly good. 2 points: The flavor of buckwheat is not felt much, and there is a slight burnt smell, which is defective. 1 point: The flavor of buckwheat is hardly felt, and a burnt smell is felt, which is extremely defective.

[0048]

Table 1

[0049] (Examples 3 to 10) The buckwheat noodles were produced in the same manner as in Example 2, except that the thickness and cutting width of the fabric were changed in consideration of shrinkage due to drying, and the thickness and width of the dried buckwheat noodles were changed as shown in Table 2. Evaluation was performed in the same manner as in Test Examples 1 and 2. The results are shown in Table 2. Incidentally, the moisture content of all the dried buckwheat noodles obtained in Examples 3 to 10 was in the range of 13.2 to 13.8% by mass.

[0050]

Table 2

Claims

**Claim 1**: It contains only buckwheat flour as the cereal flour raw material, has a protein content of 10 to 15% by mass, and the proportion of soluble protein in the protein is 35% by mass or more. The buckwheat flour includes a heat-treated product of low-protein buckwheat flour with a protein content of 7.0% by mass or less (however, excluding the gelatinized product using an extruder), and non-heat-treated buckwheat flour with a protein content of 12% by mass or more, and is dried buckwheat. **Claim 2** The dried buckwheat according to Claim 1, which is 100% buckwheat. **Claim 3** The dried buckwheat according to Claim 1 or 2, having a noodle-like shape, and the orthogonal cross-sectional shape of the noodle having a thickness of 0.9 to 1.1 mm and a width of 1.2 to 1.5 mm. **Claim 4** A method for cooking buckwheat, which cooks the dried buckwheat according to any one of Claims 1 to 3 by boiling it within 6 minutes so that the cooked buckwheat is 210 to 275 g per 100 g of the dried buckwheat.

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