Rice flour for donuts

Abstract

To provide doughnut that has a crunchy feeling and food texture with excellent melt in mouth, and has food texture that hardly deteriorates even after a long period of time after frying.SOLUTION: The above problem is solved by using doughnut rice flour having a volume-based median diameter (D50) of 65-600 μm and a value (M / D50) obtained by dividing a volume-based mode diameter (M) by the volume-based median diameter (D50) of 1.5 or less.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to rice flour for donuts.

Background Art

[0002] Donuts are manufactured by using a donut mix obtained by mixing powder raw materials such as flour, starch, and sugars, and optionally an oil raw material, adding liquid raw materials such as water and eggs, mixing to prepare dough, and frying the formed dough in liquid oil or shortening. The donuts thus obtained have a soft or crispy texture with good melt-in-the-mouth properties. With the diversification of foods in recent years, a characteristic texture has also been demanded for donuts. On the other hand, after frying, the texture of donuts is maintained relatively well for a while, but there is a problem that it deteriorates over time. Such deterioration of the texture of donuts is caused by the absorption of moisture in the air and the aging of starch that occur over time when the fried donuts are stored at room temperature. On the other hand, with the promotion of the use of rice, rice flour has also come to be used in donuts. Patent Document 1 discloses a mixed powder for fried bakery foods containing 2 to 28 parts by mass of gelatinized starch with respect to a total of 100 parts by mass of rice flour and wheat flour, and containing wheat flour in an amount of 53% by mass or less with respect to the total mass of rice flour and wheat flour. It is described that high-quality 117 (manufactured by Nippon Flour Mills Co., Ltd.), a roll-milled rice flour with a coarse particle size (particle size: 90 to 120 μm) and a high damaged starch rate (9 to 14%), was used as polished rice flour, and the obtained donuts were soft and chewy. Patent Document 2 discloses a food ingredient made from rice, characterized by soaking rice grains in water to create a rice soaking liquid, allowing the rice grains to absorb water, then putting the entire rice soaking liquid into a grinder and grinding it to obtain rice grains in a state where water has been absorbed, and furthermore, a rice paste in which free water is interposed between the rice grains, wherein the rice grains, which are the ground rice grains contained in the rice paste, have a maximum particle size distribution range of 1 to 10 μm, and it is stated that the texture and taste of donuts made using such rice paste are comparable to those made with the original ingredients. Patent Document 3 discloses a rice flour donut mix characterized by containing 0.1 to 5.0 parts by mass of wheat flour and a leavening agent per 100 parts by mass of rice flour, and states that it can produce donuts that are soft in texture, have no problems with color, and have few shape defects. None of the patent documents describe or suggest that using a specific type of rice flour in the production of donuts can result in donuts that are crispy and melt in the mouth. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-073905 [Patent Document 2] Japanese Patent Publication No. 2010-187663 [Patent Document 3] Japanese Patent Publication No. 2013-081423 [Overview of the project] [Problems that the invention aims to solve]

[0004] The present invention aims to provide a donut that has a crunchy texture and melts easily in the mouth, and whose texture does not deteriorate easily even after time has passed since frying. [Means for solving the problem]

[0005] The inventors of the present invention have found that the above problems can be solved by having a specific median diameter and adjusting the ratio of the mode diameter to the median diameter to a specific range, and have completed the present invention. In other words, the present invention provides the following:

[0006] [1] Rice flour for donuts, wherein the volume-based median diameter (D50) is 65 to 600 μm, and the value obtained by dividing the volume-based mode diameter (M) by the volume-based median diameter (D50) (M / D50) is 1.5 or less. [2] Rice flour for donuts as described in [1], wherein the M / D50 is 1.4 or less. [3] A donut mix containing the donut rice flour described in [1] or [2]. [4] A method for producing rice flour for donuts, comprising the step of grinding rice grains to obtain rice flour such that the volume-based median diameter (D50) is 65 to 600 μm and the value obtained by dividing the volume-based mode diameter (M) by the volume-based median diameter (D50) (M / D50) is 1.5 or less. [5] The method for producing rice flour for donuts according to [4], further comprising the step of sizing the rice flour such that |YZ|≧0.1 when the M / D50 before sizing is Y and the M / D50 after sizing is Z. A method for producing donuts, comprising producing donuts using the donut rice flour described in [6] [1] or [2]. [Effects of the Invention]

[0007] According to the present invention, it is possible to obtain donuts that are crunchy, melt in the mouth, and whose texture does not deteriorate easily even when stored after frying. Furthermore, even when frozen and then thawed at room temperature, it is possible to obtain donuts that retain their crunchy texture and melt-in-your-mouth quality. [Modes for carrying out the invention]

[0008] The following describes embodiments for carrying out the present invention. <Rice flour> Rice flour is obtained by threshing and polishing rice grains, which are the seeds (carpels) of plants belonging to the genus Oryza in the grass family, and then grinding them. Brown rice flour, obtained by grinding brown rice before polishing, is also considered rice flour in a broad sense. While various subspecies of plants in the genus Oryza, such as Japonica, Indica, and Javanica, as well as their waxy varieties and cultivars, are known, any type of rice grain can be used for the donut rice flour of this invention. Preferably, the rice varieties include non-glutinous rice such as "Akitakomachi" and "Koshihikari" with an amylose content of 17% to 23% by mass, high-amylose non-glutinous rice such as "Koshi no Kaori" and "Momi Roman" with an amylose content of 23% or more by mass, low-amylose non-glutinous rice such as "Yumepikari" and "Milky Queen" with an amylose content of 5% to 15% by mass, and glutinous rice such as "Kinunohada" and "Kogane Mochi," with non-glutinous rice being more preferable.

[0009] Generally, in rice flour obtained by grinding polished rice grains using various grinding methods, the particle size frequency distribution curve often resembles a normal distribution with one maximum value. However, depending on the grinding method and conditions, two or more maximum values ​​or shoulders may be observed. Furthermore, the cumulative particle size distribution curve is a sigmoid growth curve. The "median diameter" (also known as D50) is the particle diameter at the 50% cumulative point in a cumulative distribution curve, starting from the smallest particle size. The "mode diameter" refers to the particle diameter channel with the highest frequency of occurrence in the measuring device. Note that if a particle population has only one maximum value, that maximum particle diameter coincides with the mode diameter. Furthermore, if the particle population follows a normal distribution, the mode diameter and median diameter coincide. While measurement of powders and granules can be performed using volume-based, number-based, etc., in this invention, unless otherwise specified, volume-based measurement is used. Volume-based particle diameter measurement can be performed using known laser diffraction / scattering methods, and a device such as Microtrac can be used for this purpose. Unless otherwise specified, DXX in this specification refers to the cumulative XX% particle diameter accumulated from the smallest particles in the cumulative distribution curve.

[0010] The rice flour for donuts of the present invention has a volume-based median diameter (D50) of 65 to 600 μm, and the value obtained by dividing the volume-based mode diameter (M) by the volume-based median diameter (M / D50) is 1.5 or less. Using rice flour that satisfies the above range, it is possible to obtain donuts that are crispy, melt in the mouth, and whose texture does not deteriorate easily even when stored after frying. Furthermore, even when frozen and then thawed at room temperature, it is possible to obtain donuts that retain their crispy texture and melt-in-your-mouth quality without deterioration.

[0011] The volume-based median diameter D50 of rice flour for donuts is preferably 75 μm or more, more preferably 90 μm or more, even more preferably 100 μm or more, even more preferably 110 μm or more, still more preferably 120 μm or more, even more preferably 125 μm or more, even more preferably 130 μm or more, and also preferably 550 μm or less, more preferably 500 μm or less, even more preferably 450 μm or less, even more preferably 400 μm or less, even more preferably 300 μm or less, and even more preferably 180 μm or less. By using rice flour with a median diameter exceeding 100 μm, it is possible to obtain donuts that have a better crispness, a better melt-in-the-mouth texture, and whose texture does not deteriorate easily even when stored, and the effect is further improved by using rice flour with a median diameter of 110 μm or more. Furthermore, by using rice flour with a median diameter of 450 μm or less, it is possible to obtain donuts with a better crispness, a more melt-in-your-mouth texture, and a texture that does not deteriorate easily even when stored. The effect is even better if rice flour with a median diameter of less than 180 μm is used.

[0012] The value obtained by dividing the volume-based mode diameter of the rice flour for donuts by the volume-based median diameter is preferably 1.45 or less, more preferably 1.4 or less, even more preferably 1.3 or less, and even more preferably 1.2 or less. By using rice flour within this range, it is possible to obtain donuts that have a crunchy texture and melt in the mouth, and whose texture does not deteriorate easily even when stored. The lower limit of the above M / D50 is not particularly limited, but is preferably 1.0 or more, more preferably 1.05 or more, even more preferably 1.1 or more, even more preferably 1.2 or more, and especially preferably 1.3 or more. The mode diameter (M) of the volume-based rice flour for donuts can be any value as long as it satisfies the above requirements, but for example, it may be around 55-600 μm, or even 100-500 μm or 100-300 μm. Furthermore, the relationship between the numerical ranges for volume-based median diameter D50, volume-based mode diameter M, and M / D50, etc., as specified herein and experimentally obtained numerical values ​​is determined by rounding the third digit of the experimentally measured value with an accuracy of three or more significant figures to two digits, and then determining whether it falls within the numerical range of the present invention.

[0013] <Donuts> Generally, donuts are classified into two types based on their texture: cake donuts, which have a cake-like texture and are made using a cake-like dough, and yeast donuts, which have a bread-like texture and are made using a bread-like dough. In this invention, it is possible to obtain donuts, whether cake donuts or yeast donuts, that are crunchy, melt in the mouth, and do not easily deteriorate in texture even when stored after frying. This effect is particularly pronounced and preferable in cake donuts. The donut dough is preferably produced from a starchy raw material (flour and starch), an additive described later, and a liquid material described later. The amount of the rice flour for donuts of the present invention used in the starchy raw material (flour and starch) used for producing the donut dough is not particularly limited, but it is preferably about 10 to 90% by mass, more preferably 20 to 80% by mass, still more preferably 25 to 75% by mass, even more preferably 35 to 65% by mass, and still more preferably 40 to 60% by mass with respect to the total amount of the starchy raw material contained in the dough. Note that the total amount may be rice flour, but it is preferably 90% by mass or less from the viewpoint of cost effectiveness.

[0014] Cake donuts are roughly classified into those using a soft and fluid "batter dough", those using a relatively hard and plastic "paste dough", and those using a fluid "gelatinized dough" in which part or all of the starch derived from the starchy raw material contained in the raw material is gelatinized. Such a dough for cake donuts is obtained by using a powder raw material containing auxiliary raw materials such as flour and sugars and a liquid raw material containing moisture and liquid eggs, etc., and mixing them until they become homogeneous so that gluten is not formed as much as possible. The liquid raw material varies depending on the type and amount of the powder raw material other than the starchy raw material such as flour, but it is generally 50 to 90 parts by mass with respect to 100 parts by mass of the starchy raw material (flour and starch) for the batter dough and the paste dough, and generally 180 to 250 parts by mass for the gelatinized dough. Note that gluten may be intentionally formed in order to obtain the intended cake donut. For example, in the case of old-fashioned donuts, gluten is formed in order to bring out a characteristic appearance with cracks.

[0015] For the heating expansion of cake donuts, the gas generated by the reaction of chemical leavening agents is utilized. Although yeast fermentation may be combined for purposes such as flavoring, since the batter dough and gelatinized dough for cake donuts have high fluidity, the gas generated during yeast fermentation is released from the dough during fermentation, and its contribution to heating expansion is low or non - existent. Also, in order to avoid the release of the gas generated by the reaction of chemical leavening agents from the dough as much as possible, after manufacturing the dough for cake donuts, it is fried without much delay. Before frying, the dough for cake donuts is shaped, but it is difficult to shape the highly fluid batter dough and gelatinized dough without using tools or equipment. For paste - like dough, it is common to shape it using tools or equipment because of its plasticity.

[0016] Yeast donuts, like bread, are manufactured using "dough" that has extensibility and elasticity. Such dough for yeast donuts is obtained by kneading a powder raw material containing auxiliary raw materials such as flour and sugars and a liquid raw material containing water and liquid eggs so that gluten is formed. The liquid raw material varies depending on the type and amount of the powder raw material other than the starchy raw material such as flour, but is generally 50 - 80 mass with respect to 100 mass parts of the starchy raw material. For the heating expansion of yeast donuts, the gas generated by yeast fermentation is utilized. Therefore, similar to the production of bread, the final dough is obtained through processes such as primary fermentation, punching, dividing, bench work, and secondary fermentation (proofing). Although chemical leavening agents may be used in combination, they generally play the role of an auxiliary for yeast fermentation. Since the dough has extensibility and elasticity, it can be easily shaped through operations such as dividing and rounding without using tools or equipment.

[0017] In such dough for donuts, the gas generated by the reaction of chemical leavening agents or yeast fermentation forms fine bubbles, and these bubbles are heated and expanded by frying or the like, resulting in a donut with a porous structure.

[0018] Any known method can be used to incorporate fine air bubbles into donut dough, but chemical leavening agents are preferable for cake donuts, and yeast is preferable for yeast donuts. Chemical leavening agents are food additives that generate gases such as carbon dioxide and ammonia when they come into contact with moisture, and gas generation is accelerated by heating when in contact with moisture. Examples of such chemical leavening agents include compound leavening agents such as baking powder and Ispata, and individual leavening agents such as baking soda and ammonium bicarbonate. Compound leavening agents use individual leavening agents as a base and contain auxiliary agents such as sodium bitartrate, calcium dihydrogen phosphate, fumaric acid, alum, and ammonium chloride, as well as blocking agents such as starch. The reactivity of the base can be adjusted according to the proportion of these, and fast-acting and slow-acting compound leavening agents are commercially available. When using individual leavening agents, an appropriate amount of auxiliary agents is added according to the amount used.

[0019] <Donut mix powder> The donut mix of the present invention contains the donut rice flour. Generally, a donut mix refers to a mixture of donut rice flour with powdered ingredients such as wheat flour, sugars, starch, leavening agents, seasonings, flavorings, colorings, and oils and fats, depending on its intended use. The donut mix of the present invention, in addition to the donut rice flour, contains grain flour derived from grains such as common wheat, durum wheat, rye, barley, rice, corn, buckwheat, soybeans, barnyard millet, foxtail millet, and amaranth (except when the grain flour is rice flour, the donut rice flour is excluded); tuber flour or root flour of staple crops similar to grains, such as potatoes, taro, cassava, sweet potatoes, and yams; grains, tubers, and roots. Starches isolated and purified from tree trunks, etc., and their waxy or high-amylose varieties (wheat starch, rice starch, corn starch, tapioca starch, potato starch, sweet potato starch, mung bean starch, sago starch, etc., and their waxy and high-amylose starches); modified starches obtained by gelatinization, etherification, esterification, acetylation, crosslinking, oxidation treatment, heat treatment, enzymatic treatment, etc., or combinations thereof; grapes The mix may contain: sugars such as sucrose, fructose, lactose, sugar, and isomaltose; egg components such as egg yolk, egg white, whole egg and their powdered forms, and other egg-derived ingredients; milk components such as powdered milk, skim milk powder, and soy milk powder; fats and oils such as shortening, lard, margarine, butter, palm oil, soybean oil, corn oil, rapeseed oil, olive oil, and linseed oil; emulsifiers such as sucrose fatty acid esters, glycerin fatty acid esters, lecithin, and saponins; leavening agents such as baking powder and baking soda; thickening polysaccharides such as xanthan gum, locust bean gum, gellan gum, pectin, carrageenan, guar gum, tamarind gum, and gum arabic; cellulose derivatives such as methylcellulose; inorganic salts such as sodium chloride; preservatives; flavorings; spices; vitamins; and fortifiers such as calcium, etc., which are commonly used ingredients in the manufacture of donut mixes.

[0020] The amount of rice flour for donuts in the donut mix of the present invention is not particularly limited. Preferably, the amount of rice flour for donuts is 10% by mass or more, preferably 20% by mass or more, more preferably 25% by mass or more, even more preferably 35% by mass or more, and even more preferably 40% by mass or more, relative to the total amount of starchy raw materials contained in the donut mix. Alternatively, the entire amount may be rice flour, but from the viewpoint of cost-effectiveness, it is 90% by mass or less, preferably 80% by mass or less, more preferably 75% by mass or less, even more preferably 65% ​​by mass or less, and even more preferably 60% by mass or less. If rice flour for donuts is included in the donut mix, it is possible to obtain donuts that have a crunchy texture and melt in the mouth, and whose texture does not deteriorate easily even when stored. The term "starchy raw material" refers to a concept encompassing powders of agricultural products whose main component is starch, such as grains or staple foods similar to grains; starch separated and refined from these agricultural products; and modified starch obtained by chemically and / or physically treating these starches. This concept also includes the rice flour for donuts of the present invention.

[0021] <Method for producing rice flour for donuts> The present invention relates to a method for producing rice flour for donuts, which includes a step of grinding rice grains such that the volume-based median diameter (D50) is 65 to 600 μm and the value obtained by dividing the volume-based mode diameter (M) by the volume-based median diameter (M / D50) is 1.5 or less. The grinding method for obtaining rice flour from rice grains is not particularly limited, and known milling methods such as roll type, airflow type, pin type (impact type), hammer type, cyclone type, ultracentrifugal type, turbo mill type, grinding mill type, and drum pounding type can be used. In particular, in the case of a roll type grinder, the D50 and M / D50 of the rice flour can be easily adjusted to the above range by adjusting the gap between the rolls, and in the case of an airflow type grinder, the airflow velocity and flow rate can be adjusted, so it is preferable to adopt these grinding methods.

[0022] As means of adjusting the above D50 and M / D50, in addition to the grinding method and its conditions, known grain sizing methods such as sieving and air classification can also be employed. In this invention, "grain sizing" means separating and removing the fine and / or coarse fractions of rice flour to adjust the particle size distribution of the rice flour. For example, when sieving is performed, fine rice flour can be removed by sieving. When air classification is performed, the rice flour can be separated by particle size by balancing the centrifugal force and air resistance caused by the vortex forcibly generated using a rotor, and fine rice flour can be removed more effectively by using a mesh filter. When fine rice flour is removed, the difference between M and D50 becomes smaller, and M / D50 can be reduced (approaching 1). Also, by using a coarse sieve and a fine sieve in combination, both coarse and fine rice flour can be removed, so M / D50 can be reduced even further. From another perspective, grain sizing reduces the difference between DXX and D50.

[0023] The present invention further preferably includes a step of sizing the rice flour so that, when the M / D50 of the rice flour before sizing is Y and the M / D50 of the rice flour after sizing is Z, |YZ|≧0.1, preferably |YZ|≧0.2, more preferably |YZ|≧0.25, even more preferably |YZ|≧0.3, and even more preferably |YZ|≧0.35. This makes it easier to maintain a crispy and melt-in-your-mouth texture. In this invention, |YZ| represents the absolute value of YZ. Before grinding the rice grains, pretreatment such as soaking the rice grains in water or enzymatic treatment may be performed. [Examples]

[0024] <Production Example 1: Production of Rice Flour> Polished non-glutinous rice was subjected to either an air-jet pulverizer (Yakushin Machinery Manufacturing Co., Ltd., KV-15-5S) or a roll-type pulverizer (Meiji Machinery Co., Ltd., MQ type), and pulverized under adjusted operating conditions to obtain rice flour. The particle size distribution of the obtained rice flour was measured by volume using the microtrac method (Microtrac Bell Co., Ltd., MT3000) (Table 1). For rice flours A to C, the particle size frequency distribution curve was a normal distribution-like curve with one maximum value (mode diameter). For rice flours D and E, a shoulder was observed on the finer particle side (around 200 μm) than the mode diameter. Rice flour F had a distribution curve that could be interpreted as either a maximum or a shoulder on the finer particle side (around 200 μm).

[0025] [Table 1] *M stands for mode diameter. *DXX refers to the cumulative particle size of XX% of the rice flour particles, starting with the smallest ones. *The unit of particle size is μm.

[0026] <Production Example 2: Production of Whole Grain Rice Flour> Polished non-glutinous rice was subjected to an air-jet pulverizer (Nishimura Machinery Works Co., Ltd., SPM-R200) ​​to obtain rice flour G. A portion of the obtained rice flour G was sieved for 30, 60, and 90 seconds using a small test sifter (Tokyo Flour Milling Machinery Co., Ltd., TS-245) equipped with a 53-mesh sieve, yielding rice flours H, J, and K, respectively. The particle size distribution was measured by volume using the microtrac method, as in Production Example 1 (Table 2). In all rice flour samples, the particle size frequency distribution curve was a normal distribution-like curve with one maximum value (mode diameter). The D50 (median diameter) of unsieved rice flour G was 79.88 μm, and the D50 of rice flours H to K increased depending on the sieving time. In addition, for rice flours J and K, the mode diameter of the original rice flour G was 114.1 μm, but after sieving for 60 seconds or more, it increased to 124.5 μm. The difference between the mode diameter and D50 decreased with sieving, and the ratio of mode diameter to D50 decreased from 1.428 to 1.075 for rice flour K (approaching 1). From this, it was found that the fine rice flour contained in the rice flour that made up rice flour G was removed.

[0027] [Table 2] *M stands for mode diameter. *DXX refers to the cumulative particle size of XX% of the rice flour particles, starting with the smallest ones. *The unit of particle size is μm.

[0028] <Production Example 3: Production of Cake Doughnut 1 (Paste Dough)> The powder ingredients listed in Table 1 below were put into a mixer (KitchenAid, KSM5) and mixed, then the oil ingredients were added and mixed further to obtain a mixed powder. The liquid ingredients were added to this mixed powder and mixed at low speed for 1 minute and at high speed for 2 minutes to obtain a homogeneous cake donut paste dough. The mixing temperature was 20°C. The kneaded dough was divided into 52g / ring-shaped dough using a donut cutter (Belshaw, F-cutter and plain plunger) and placed in a fryer. Standard cake donuts were obtained by frying in 190°C oil for 50 seconds, flipping, and then frying for 75 seconds.

[0029] Formulation Table 1 TIFF0007853792000003.tif78150 *Wheat flour used is from Nippon Eagle Co., Ltd.

[0030] <Evaluation Example 1: Sensory Evaluation> The texture of the manufactured donuts was sensory evaluated by 10 experienced panelists according to the evaluation criteria table below, both immediately after cooling (1 hour) and after being sealed in a plastic bag and stored until the next day (24 hours). The average score and standard deviation (SD) were calculated. For the donut manufactured according to Manufacturing Example 3, the crispness immediately after cooling (1 hour) was scored as 1 point, and the melt-in-the-mouth quality was scored as 3 points (Reference Example 1).

[0031] Sensory Evaluation Criteria Table TIFF0007853792000004.tif57146

[0032] <Test Example 1: Examination of Rice Flour Particle Size (Paste Dough)> Except for using 50 parts by mass of rice flour and 50 parts by mass of wheat flour as listed in Table 3, donuts were manufactured according to Manufacturing Example 3 and evaluated according to Evaluation Example 1. For ease of handling, the amount of water added was adjusted during donut dough preparation to ensure consistent viscosity. As a result, the donuts made using rice flour A and B were slightly crunchier than the donuts made using only wheat flour in Reference Example 1, but they had a chewy texture and poor melt-in-the-mouth quality. Rice flours C to E had a good texture, both after frying and after storage, with rice flour D being the best. Rice flour F had a good crunchiness both after frying and after storage, but its melt-in-the-mouth quality was the same as in Reference Example 1. Rice flours B and C had the same mode diameter, but their D50 values ​​were different, with the ratio of mode diameter to D50 being 1.984 and 1.330. This difference is said to have led to the difference in donut texture, demonstrating that the particle size distribution of rice flour greatly affects the texture of donuts.

[0033] [Table 3]

[0034] <Test Example 2: Examination of Whole Grain Rice Flour (Paste Dough)> Except for using 50 parts by mass of rice flour and 50 parts by mass of wheat flour as listed in Table 4, donuts were manufactured according to Manufacturing Example 3 and evaluated according to Evaluation Example 1. The amount of water added was adjusted as in Test Example 1. The texture of the donuts made with each type of rice flour was slightly better with rice flour G, and improved as the ratio of mode diameter to D50 decreased (from rice flour H to K). In the donuts made the following day, the evaluation score for rice flour G dropped by 1 point in both crispness and melt-in-the-mouth quality, while the drop was smaller for rice flours H to K, indicating that the deterioration of texture was suppressed.

[0035] [Table 4]

[0036] <Test Example 3: Examination of Mixing Ratio> Except for using the portion sizes of rice flour and wheat flour listed in Table 5, donuts were manufactured according to Manufacturing Example 3 and evaluated according to Evaluation Example 1. The amount of water added was adjusted as in Test Example 1. In tests 3, 4, 9, 11, and 12, which used rice flour, the texture of the donuts was good one hour after frying. In tests 4, 11, and 12, the texture improved as the proportion of rice flour increased. The following day, although some deterioration in texture occurred in all cases, it was still better than when using only wheat flour mix. In particular, in tests 4, 11, and 12, the deterioration in texture became less likely as the proportion of rice flour increased.

[0037] [Table 5]

[0038] <Manufacturing Example 4: Cake Donut Production 2 (Batter)> The powder ingredients listed in Table 2 below were put into a mixer (KitchenAid, KSM5) and mixed. Then the oil ingredients were added and mixed further to obtain a mixed powder. Water and eggs were added to this mixed powder and mixed at low speed for 1 minute and medium speed for 2 minutes to obtain a homogeneous cake donut batter. The kneading temperature was 24°C. The kneaded dough was divided into 45g ring-shaped pieces using a donut cutter (Belshaw, F-cutter and plunger) and placed in a fryer. Standard cake donuts were obtained by frying in 190°C oil for 60 seconds on each side and 60 seconds on each side.

[0039] Formulation Table 2 TIFF0007853792000008.tif78150

[0040] <Test Example 4: Examination of Whole Grain Rice Flour (Batter Dough)> Doughnuts were prepared according to Production Example 4, except that 50 parts by mass of rice flour and 50 parts by mass of wheat flour, as listed in Table 6, were used instead of 100 parts by mass of wheat flour, and evaluated according to Evaluation Example 1. For the evaluation, "crisp" in the sensory evaluation criteria table was replaced with "soft and tender." The amount of water added was adjusted as in Test Example 1. The texture of the donuts made with each type of rice flour was slightly better with rice flour G, and improved as the ratio of mode diameter to D50 decreased (from rice flour H to K). In the donuts the following day, similar to Test Example 2, the decrease in evaluation score was smaller with rice flours H to K than with rice flour G, indicating that texture deterioration was suppressed.

[0041] [Table 6]

[0042] <Manufacturing Example 5: Manufacturing of Cake Donuts 3 (Pregelatinized Dough)> The powder ingredients listed in Table 3 below were put into a mixer (KitchenAid, KSM5) and mixed, then the oil ingredients were added and mixed further to obtain a mixed powder. Water was added to this mixed powder and mixed at medium speed for 3 minutes, then the egg mixture was added and mixed at low speed for 1 minute and then at medium speed for 3 minutes to obtain a homogeneous gelatinized dough for cake donuts. The kneading temperature was 30°C. The kneaded dough was divided into 36g / ring-shaped dough using a donut cutter (Belshaw, F-cutter and plunger) and placed in a fryer. Standard choux donuts were obtained by frying in 190°C oil for 2 minutes 30 seconds (turn), 3 minutes (turn), and 30 seconds (fry).

[0043] Formulation Table 3 TIFF0007853792000010.tif65150

[0044] <Test Example 5: Examination of Whole Grain Rice Flour (Gelatinized Dough)> The donuts were manufactured according to Manufacturing Example 5, except that β-starch was replaced with rice flour as listed in Table 7, and evaluated according to Evaluation Example 1. For the evaluation, "crisp" in the sensory evaluation criteria table was reinterpreted as "soft and fluffy." The amount of water added was adjusted as in Test Example 1. The texture of the donuts made with each type of rice flour was slightly better with rice flour G, and improved as the ratio of mode diameter to D50 decreased (from rice flour H to K). In the donuts the following day, similar to test examples 2 and 4, the decrease in evaluation score was smaller with rice flours H to K than with rice flour G, indicating that texture deterioration was suppressed.

[0045] [Table 7]

Claims

1. Rice flour for donuts, having a volume-based median diameter (D50) of 130 to 450 μm, and a value obtained by dividing the volume-based mode diameter (M) by the volume-based median diameter (D50) (M / D50) of 1.5 or less.

2. Rice flour for donuts according to claim 1, wherein the M / D50 is 1.4 or less.

3. A donut mix containing the donut rice flour described in claim 1 or 2, wherein the content of the donut rice flour is 35 to 70% by mass relative to the total amount of starchy raw materials contained in the donut mix.

4. A donut dough comprising the donut rice flour described in Claim 1 or 2, wherein the content of the donut rice flour is 35 to 70% by mass relative to the total amount of starchy raw materials contained in the dough.

5. A method for producing rice flour for donuts, comprising the step of grinding rice grains to obtain rice flour such that the volume-based median diameter (D50) is 130 to 450 μm and the value obtained by dividing the volume-based mode diameter (M) by the volume-based median diameter (D50) (M / D50) is 1.5 or less.

6. A method for producing rice flour for donuts according to claim 4, further comprising the step of sizing the rice flour such that |Y - Z| ≥ 0.1, where Y is the M / D 50 before sizing and Z is the M / D 50 after sizing.

7. A method for producing donuts, comprising producing donuts from donut dough containing donut rice flour according to claim 1 or 2, wherein the content of donut rice flour is 35 to 70% by mass relative to the total amount of starchy raw materials contained in the donut dough.

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