Modified wheat flour

Abstract

Modified wheat flour having the following properties (A) and (B):　(A) when the viscosity of an aqueous suspension containing the modified wheat flour is measured using the RVA (here, the aqueous suspension contains 10 parts by mass of the modified wheat flour per 100 parts by mass of water, and when the viscosity is measured, the temperature of the aqueous suspension is first held at 50°C for 1 minute, then raised to 80°C over a period of 5 minutes, held at 80°C for 5 minutes, then raised to 95°C over a period of 2 minutes and 30 seconds, and then held at 95°C for 5 minutes), M2 / M1 is 1.0-4.0, where M1 is the maximum viscosity in the period from the start of the temperature rise from 50°C to the end of the holding at 80°C for 5 minutes, and M2 is the maximum viscosity in the period from the start of the temperature rise from 80°C to the end of the holding at 95°C for 5 minutes; and (B) when the viscosity of an aqueous suspension containing the modified wheat flour is measured using the RVA (here, the aqueous suspension contains 10 parts by mass of the modified wheat flour per 100 parts by mass of water, and when the viscosity is measured, the temperature of the aqueous suspension is first held at 50°C for 1 minute, then raised to 95°C over a period of 7 minutes and 30 seconds, and then held at 95°C for 5 minutes), the peak viscosity P is no higher than 2000 mPa·s.

Description

Modified wheat flour

[0001] The present invention relates to modified wheat flour.

[0002] Many coating materials for deep-fried foods contain wheat flour as a primary ingredient. Wheat flour with improved properties suitable for use as a coating material has been provided. Patent Document 1 describes that modified wheat flour, obtained by heat-treating raw wheat flour, has an RVA peak viscosity of 3500 to 7000 mPa·s and a gelatinization onset temperature 10°C or more lower than that of raw wheat flour, and can provide deep-fried food coatings that have good dispersibility in water, good workability, and a crispy texture. Patent Document 2 describes that the texture or processability of wheat flour-containing foods and beverages can be improved by using wheat flour that contains ungelatinized starch, has an acetic acid-soluble protein content of 25% by mass or less of the total wheat flour protein, and has a maximum RVA viscosity of 2500 mPa·s or less. Patent Document 3 describes modified wheat flour obtained by heat-treating wheat flour, which has a viscosity of 1000 mPa·s or less when a 10% aqueous suspension of the modified wheat flour is heated to 85°C and then cooled to 25°C, and has a degree of dispersion of 90% or less when the aqueous suspension is heated to 85°C, cooled to 25°C, and then allowed to stand for 24 hours.The patent also describes that this modified wheat flour is suitable as a raw material flour for bread and noodle dough, coating materials for fried foods, etc.

[0003] International Publication No. 2017 / 135353 Japanese Patent Application Laid-Open No. 2021-60 International Publication No. 2020 / 213117

[0004] The coating material attached to the ingredients hardens during frying to form the coating for deep-fried foods. However, this hardening of the coating makes the coating more likely to peel off from the ingredients after frying. Therefore, deep-fried coating materials are required to have improved adhesion to ingredients, i.e., the ability to not peel off from the ingredients after hardening during frying to form the coating. The present invention provides modified wheat flour suitable for use as a coating material for deep-fried foods, which has excellent adhesion to ingredients and can produce a deep-fried coating with a good texture.

[0005] The inventors have discovered that by using modified wheat flour having a specific viscosity as a coating material, it is possible to produce fried foods with a coating that has excellent adhesion to ingredients and a good texture.

[0006] The present invention provides the following as representative embodiments: [1] Modified wheat flour having the following properties (A) and (B): (A) When an aqueous suspension containing the modified wheat flour is subjected to viscosity measurement using a Rapid Visco Analyzer (RVA) (wherein the aqueous suspension contains 10 parts by mass of the modified wheat flour per 100 parts by mass of water, and the viscosity measurement is carried out by first holding the aqueous suspension at 50°C for 1 minute, then raising the temperature to 80°C over 5 minutes, holding at 80°C for 5 minutes, then raising the temperature to 95°C over 2 minutes 30 seconds, and holding at 95°C for 5 minutes), the maximum viscosity from the start of temperature rise from 50°C to the end of the 5-minute hold at 80°C is M1, and the maximum viscosity from the start of temperature rise from 80°C to the end of the 5-minute hold at 95°C is M2, the ratio M2 / M1 is 1.0 to 4.0; (B) When an aqueous suspension containing the modified wheat flour is measured for viscosity using a Rapid Visco Analyzer (RVA) (wherein the aqueous suspension contains 10 parts by mass of the modified wheat flour per 100 parts by mass of water, and the viscosity is measured by first holding the temperature of the aqueous suspension at 50°C for 1 minute, then raising the temperature to 95°C over 7 minutes and 30 seconds, and then holding at 95°C for 5 minutes), the peak viscosity P is 2000 mPa·s or less. [2] The modified wheat flour according to [1], wherein M2 / M1 in (A) is 1.3 to 3.0. [3] The modified wheat flour according to [1] or [2], wherein the peak viscosity P in (B) is 700 to 2000 mPa·s. [4] A coating material for deep-fried foods, comprising the modified wheat flour according to any one of [1] to [3].[5] A method for producing modified wheat flour, comprising heat-treating raw wheat flour to produce modified wheat flour having the following properties (A) and (B): (A) when an aqueous suspension containing the modified wheat flour is measured for viscosity using a Rapid Visco Analyzer (RVA) (wherein the aqueous suspension contains 10 parts by mass of the modified wheat flour per 100 parts by mass of water, and the viscosity is measured by first holding the aqueous suspension at 50°C for 1 minute, then raising the temperature to 80°C over 5 minutes, holding at 80°C for 5 minutes, then raising the temperature to 95°C over 2 minutes 30 seconds, and holding at 95°C for 5 minutes), the maximum viscosity from the start of temperature rise from 50°C to the end of the 5-minute hold at 80°C is M1, and the maximum viscosity from the start of temperature rise from 80°C to the end of the 5-minute hold at 95°C is M2, the ratio M2 / M1 is 1.0 to 4.0; (B) When the viscosity of an aqueous suspension containing the modified wheat flour is measured using a Rapid Visco Analyzer (RVA) (wherein the aqueous suspension contains 10 parts by mass of the modified wheat flour per 100 parts by mass of water, and the viscosity measurement involves first holding the temperature of the aqueous suspension at 50°C for 1 minute, then raising the temperature to 95°C over 7 minutes and 30 seconds, and then holding at 95°C for 5 minutes), the peak viscosity P is 2000 mPa s or less. [6] The method according to [5], wherein the heat treatment of the raw material wheat flour comprises heating the raw material wheat flour at a temperature of 60°C or higher but lower than 75°C for 400 to 2000 hours, or heating the raw material wheat flour at a temperature of 75°C to 85°C for 160 to 1800 hours. [7] The method according to [5], wherein the heat treatment of the raw material wheat flour comprises heating and stirring the raw material wheat flour at a product temperature of 85°C or higher but lower than 120°C for 2 to 100 hours, or at 120 to 160°C for 0.5 to 36 hours, at 10 to 2,200 rpm. [8] The method according to any one of [5] to [7], wherein M2 / M1 in (A) is 1.3 to 3.0. [9] The method according to any one of [5] to [8], wherein the peak viscosity P in (B) is 700 to 2,000 mPa s.

[0007] The modified wheat flour of the present invention is suitable as a coating material for deep-fried foods. Deep-fried foods can be produced using a coating material containing the modified wheat flour of the present invention, which has excellent adhesion to ingredients and a good texture.

[0008] As used herein, modified wheat flour refers to wheat flour obtained by modifying raw wheat flour. The raw wheat flour for the modified wheat flour of the present invention can be any wheat flour milled by conventional methods from edible wheat grains, without particular limitations. Preferably, the raw wheat flour is unmodified wheat flour that has not been subjected to any modification treatment (e.g., heat treatment, chemical treatment, enzyme treatment, UV treatment, granulation treatment, etc.) after milling. Examples of raw wheat flour include hard wheat flour, semi-hard wheat flour, all-purpose flour, weak wheat flour, durum wheat flour, semolina flour, and whole wheat flour. Any one or a combination of two or more of these can be used. When the modified wheat flour of the present invention is used as a coating material for deep-fried foods, weak wheat flour is preferred. Furthermore, the presence of cereal flour or starch other than wheat flour during the modification treatment of raw wheat flour makes it difficult to obtain the desired properties. Therefore, the flour to be modified preferably contains no more than 5% by mass, and more preferably no more than 3% by mass, of components other than the raw wheat flour.

[0009] The present invention provides modified wheat flour that has been modified to have a specific viscosity. The modified wheat flour of the present invention has the following properties (A) and (B): (A) When an aqueous suspension containing the modified wheat flour is subjected to viscosity measurement using a Rapid Visco Analyzer (RVA) (the aqueous suspension contains 10 parts by mass of the modified wheat flour per 100 parts by mass of water, and the viscosity measurement is carried out by first holding the aqueous suspension at 50°C for 1 minute, then raising the temperature to 80°C over 5 minutes, holding at 80°C for 5 minutes, then raising the temperature to 95°C over 2 minutes 30 seconds, and holding at 95°C for 5 minutes), the maximum viscosity from the start of temperature increase from 50°C to the end of the 5-minute hold at 80°C is M1, and the maximum viscosity from the start of temperature increase from 80°C to the end of the 5-minute hold at 95°C is M2, the ratio M2 / M1 is 1.0 to 4.0; (B) When the viscosity of an aqueous suspension containing the modified wheat flour is measured using a Rapid Visco Analyzer (RVA) (here, the aqueous suspension contains 10 parts by mass of the modified wheat flour per 100 parts by mass of water, and in the viscosity measurement, the product temperature of the aqueous suspension is first held at 50°C for 1 minute, then raised to 95°C over 7 minutes and 30 seconds, and then held at 95°C for 5 minutes), the peak viscosity P is 2000 mPa·s or less.

[0010] A Rapid Visco Analyzer (RVA) is an instrument for measuring the viscosity of a suspension of a sample (starch or flour). In viscosity measurements using an RVA, the sample suspension (measurement target) is filled into a container equipped with a paddle (stirring bar), and the viscosity of the target is measured by rotating the paddle and measuring the resistance force applied to the paddle. By measuring the viscosity while heating the container, the viscosity change associated with the gelatinization of starch can be measured. When flour is used as a sample, the viscosity change is also affected by the interactions between components in the flour, such as starch, protein, and lipids. RVA devices are commercially available, and RVAs are widely used for quality testing of foods containing a large amount of starch.

[0011] An example of the procedure for measuring the viscosity of the modified wheat flour of the present invention using RVA is described below. An aqueous suspension containing 10 parts by weight of the modified wheat flour of the present invention per 100 parts by weight of water is prepared as the measurement object. 25 mL of the aqueous suspension is added to an aluminum can (container for the measurement object) attached to a Rapid Visco Analyzer (RVA) (e.g., Newport Scientific's Series 4 RVA-4), and then the paddle (stirring bar) attached to the device is inserted and the aluminum can is set in the tower of the device. While rotating the paddle at a rotation speed of 160 rpm / min, the contents of the aluminum can (the aqueous suspension) are heated under specified heating conditions, and the viscosity is measured. The heating conditions can be input into the RVA in advance. The viscosity measurement results also include the temperature of the aqueous suspension and the viscosity (mPa·s) corresponding to that temperature.

[0012] Regarding (A) above, the heating conditions for viscosity measurement by RVA are as follows: (a1) First, the aqueous suspension of the modified wheat flour of the present invention is held at a product temperature of 50°C for 1 minute; then, (a2) the product temperature is raised to 80°C over 5 minutes; then, (a3) ​​the temperature is held at 80°C for 5 minutes; then, (a4) the aqueous suspension is heated to 95°C over 2 minutes and 30 seconds; then, (a5) the temperature is held at 95°C for 5 minutes. The viscosity of the aqueous suspension is measured during this heating period ((a1) to (a5)). In (A) above, the maximum viscosity (M1) of the aqueous suspension from the start of temperature rise from 50°C to the end of the 5-minute hold at 80°C ((a2) to (a3)) and the maximum viscosity (M2) from the start of temperature rise from 80°C to the end of the 5-minute hold at 95°C ((a4) to (a5)) are determined. Next, the ratio of M2 to M1 (M2 / M1) is calculated. M2 / M1 represents the tendency for viscosity to increase in a relatively low temperature range and the degree of viscosity increase in a high temperature range relative to the viscosity in the low temperature range.

[0013] Regarding (B) above, the heating conditions for viscosity measurement by RVA are as follows: (b1) First, the aqueous suspension of the modified wheat flour of the present invention is held at a product temperature of 50°C for 1 minute; then, (b2) the temperature is raised to 95°C over 7 minutes and 30 seconds; and then, (b3) the suspension is held at 95°C for 5 minutes. In (B) above, the maximum viscosity of the aqueous suspension during this heating period ((b1) to (b3)) is obtained and defined as the peak viscosity P. The procedure for measuring the peak viscosity P as described above conforms to the general procedure for measuring RVA peak viscosity.

[0014] The M2 / M1 ratio for the modified wheat flour of the present invention is preferably 1.0 to 4.0, more preferably 1.3 to 3.0, and even more preferably 1.6 to 2.5. When the M2 / M1 ratio for the modified wheat flour is within the above range, the resulting batter has improved binding ability with ingredients and improved texture. The peak viscosity P for the modified wheat flour of the present invention is preferably 2000 mPa·s or less, more preferably 700 to 2000 mPa·s, and even more preferably 800 to 1600 mPa·s. If the peak viscosity P of the modified wheat flour is too high, the resulting batter has reduced binding ability with ingredients and improved texture. Therefore, since the modified wheat flour of the present invention has both properties (A) and (B), using the modified wheat flour as a batter material makes it possible to produce fried foods with a batter that has excellent binding ability with ingredients and excellent texture.

[0015] The modified wheat flour of the present invention can be produced by modifying raw wheat flour so that it has both the properties (A) and (B) described above. The method for modifying the raw wheat flour is not particularly limited, but typically includes stirring, heat treatment, and a combination thereof. Stirring involves stirring the raw wheat flour in a powdered state to cause collisions between the flour and the stirring means or between the flour particles themselves. Specific examples of stirring include placing the raw wheat flour in a container equipped with a stirring means such as a stirring spring, stirring blade, stirring rod, or stirring disk, and stirring the raw wheat flour at a temperature of 5 to 45°C and 20 to 4,000 rpm (the rotation speed of the stirring means, the same applies hereinafter) for 12 to 100 hours, preferably at a temperature of 10 to 40°C and 50 to 3,500 rpm for 18 to 96 hours, and more preferably at a temperature of 20 to 30°C and 70 to 3,000 rpm for 24 to 90 hours. Furthermore, because pressure can cause wheat flour to break down and become smaller molecules, processes including high-pressure extrusion are not included in the mixing process of the present invention, even if they include mixing of the ingredients. For example, processing using an extruder that performs high-pressure extrusion is not included in the mixing process of the present invention.

[0016] The heat treatment of the raw wheat flour can be carried out under conditions where the wheat flour product temperature is preferably 60° C. or higher but lower than 75° C. for 400 to 2000 hours, or 75° C. to 85° C. for 160 to 1800 hours, and more preferably 63° C. or higher but lower than 75° C. for 600 to 1800 hours, or 75° C. to 83° C. for 180 to 1400 hours. If the wheat flour is heat-treated at a product temperature of 85° C. or higher until it has the properties (A) and (B), problems such as discoloration of the wheat flour, generation of a burnt odor, or insufficient firmness in the texture of the batter may occur.

[0017] When the heat treatment is combined with the stirring treatment, the temperature conditions (wheat flour temperature) can be adjusted to 85°C or higher. This combined treatment shortens the treatment time required to modify the wheat flour, so even if the wheat flour temperature is increased, problems caused by high temperatures, such as discoloration of the wheat flour, the generation of a burnt odor, or a hard texture in the fried batter, can be prevented. The combined heat treatment and stirring treatment conditions are, for example, 10 to 2200 rpm, preferably 14 to 1800 rpm, and a temperature of 85°C or higher but lower than 120°C for 2 to 100 hours, or 120 to 160°C for 0.5 to 36 hours, preferably 85°C or higher but lower than 120°C for 4 to 80 hours, or 120 to 160°C for 1 to 24 hours. Such a combined treatment of heat treatment and agitation treatment can be carried out by adjusting the operating conditions using a commercially available agitation drying device such as a paddle dryer (e.g., manufactured by Nara Machinery Co., Ltd.) or a disk dryer (e.g., manufactured by Ohno Chemical Machinery Co., Ltd.). Alternatively, the combined treatment can be carried out using a powder / granular heating device equipped with a heating means and agitation means that can heat wheat flour to a predetermined temperature and perform the agitation treatment. An example of such an apparatus is described in Japanese Patent No. 2784505, which comprises a cylindrical pressure vessel having an inlet for powder or granular material near one end, an outlet for powder or granular material near the other end, and an inlet for blowing saturated steam, and a stirring means disposed within the pressure vessel for stirring the powder or granular material introduced through the inlet and transporting it toward the outlet, the stirring means having a plurality of rod-shaped blades on a rotating shaft whose dimensions are close to the inner diameter of the cylinder, the rod-shaped blades being spirally arranged around the rotating shaft and arranged so that the rotational loci of the rod-shaped blades, viewed from a direction perpendicular to the rotating shaft, are aligned almost tightly in the axial direction of the rotating shaft.

[0018] The modified wheat flour of the present invention is suitable for use as a coating material for deep-fried foods. By using a coating material for deep-fried foods containing the modified wheat flour of the present invention, it is possible to produce a coating for deep-fried foods that has excellent adhesion to ingredients and a good texture. Therefore, the present invention also provides a coating material for deep-fried foods containing the modified wheat flour of the present invention. The coating material for deep-fried foods of the present invention (hereinafter also simply referred to as "coating material") may consist essentially of the modified wheat flour of the present invention, or may be a composition containing the modified wheat flour of the present invention and other ingredients. The coating material of the present invention is preferably in powder form. The content of the modified wheat flour of the present invention in the coating material is preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 50% by mass or more, even more preferably 70% by mass or more, based on the total mass of the coating material, and may even be 100% by mass.

[0019] Examples of other ingredients that can be used in the coating material of the present invention include, but are not limited to, flours other than the modified wheat flour of the present invention; starches; whole egg flour and egg white flour; oils and fats; sugars such as dextrin, starch syrup, and sugar alcohols; salts; seasonings; leavening agents; emulsifiers; thickeners; enzymes. Examples of flours other than the modified wheat flour of the present invention include unmodified wheat flour, barley flour, rye flour, rice flour, corn flour, sorghum flour, and soy flour. Examples of starches include unmodified starches such as potato starch, tapioca starch, corn starch, waxy corn starch, and wheat starch, as well as modified starches (gelatinized starch, etherified starch, esterified starch, acetylated starch, cross-linked starch, etc.). The coating material of the present invention can contain one or more of the above-listed other ingredients depending on the type of fried food to be produced using the coating material. The content of the other ingredients in the coating material of the present invention is preferably 90% by mass or less, more preferably 80% by mass or less, even more preferably 50% by mass or less, and even more preferably 30% by mass or less of the remainder of the modified wheat flour of the present invention contained in the coating material.

[0020] In the production of fried foods using the coating material of the present invention, the coating material of the present invention is attached to ingredients to produce a fried food material. In this case, the coating material of the present invention can be used as is in powder form or prepared into a batter. Examples of powder coating materials include blenders such as dusting flour and fried chicken flour. Examples of batters include batters for tempura, batters for deep-frying, and batters for breaded fried foods.

[0021] In one embodiment, when the coating material of the present invention is used as a batter, a liquid is added to the powdered coating material and mixed to prepare a batter. The liquid can be water, egg liquid, or the like. The obtained batter can be attached to ingredients by coating them, etc., to produce a fried food material. In another embodiment, when the coating material of the present invention is used as a dusting powder, the powdered coating material is attached to ingredients by a normal procedure such as dusting. Then, other blenders or a batter can be attached to the ingredients to produce a fried food material. In another embodiment, when the coating material of the present invention is used as a blender, the powdered coating material can be attached to ingredients by a normal procedure such as dusting, to produce a fried food material.

[0022] When the coating material of the present invention is used as a dusting powder, a blender, or a batter, a further coating material may be applied over the ingredient to which the dusting powder, blender, or batter has been applied, if necessary. The further coating material may be an appropriate one depending on the type of fried food to be produced. For example, the further coating material may be the coating material of the present invention or a batter containing the same, or it may be another blender (e.g., breadcrumbs, fried chicken flour, grain flour, starch flour, etc.) or another batter (e.g., egg liquid, tempura batter, fried chicken batter, batter for breaded fried foods, etc.).

[0023] The ingredients to which the coating material of the present invention is applied are not particularly limited and include, for example, various food ingredients such as meats such as chicken, pork, beef, lamb, goat, etc.; seafood such as squid, shrimp, fish, shellfish, etc.; vegetables; and imitation meats such as soy meat, etc. If necessary, the ingredients may be seasoned or dusted with flour before the coating material of the present invention is applied.

[0024] The fried food material coated with the coating material of the present invention may be fried immediately, or may be refrigerated or frozen as necessary. Deep-fried food is produced by frying the fried food material. In producing fried food using the coating material of the present invention, the procedures for producing fried food, such as applying the coating material to the ingredients and frying, can be carried out in accordance with the procedures for producing ordinary fried food. Fried foods produced using the coating material of the present invention are not particularly limited, and examples include breaded fries such as cutlets, tempura, fried chicken, and fried chicken.

[0025] The present invention will be described in more detail below by showing examples, but the present invention is not limited to the following examples.

[0026] (Test Example 1) (1) Production of modified wheat flour (Production Examples 1 to 7, Comparative Examples 1 and 2) 2 kg of raw wheat flour (weak flour: moisture content 13% by mass) was placed in a temperature-controlled chamber and heated without stirring at the temperature (product temperature) and for the time shown in Table 1 to produce modified wheat flour.

[0027] (Production Examples 8 to 14, Comparative Examples 3 to 5) 2 kg of raw wheat flour (weak flour: moisture content 13% by mass) was placed in a paddle dryer (Nara Machinery Manufacturing Co., Ltd.) and heated and stirred at the temperature (product temperature), time, and rotation speed shown in Table 2 to produce modified wheat flour.

[0028] (2) Viscosity Measurement The viscosity of the obtained modified wheat flour as a sample was measured using an RVA according to the following procedure. <Viscosity Measurement Procedure> 10 parts by mass of the modified wheat flour prepared in (1) above was added to 100 parts by mass of water to prepare an aqueous suspension of sample wheat flour. 25 mL of the aqueous suspension was added to an aluminum can attached to a Rapid Visco Analyzer (RVA) (Series 4 RVA-4, Newport Scientific), and then the paddle (stirring bar) attached to the device was placed inside, and the aluminum can was set in the tower of the device. While rotating the paddle at a rotation speed of 160 rpm / min, the contents of the aluminum can (aqueous suspension containing the sample) were heated, and the viscosity was measured. Specifically, heating and viscosity measurements were performed under the following conditions (A) and (B), respectively. (A) (a1) The aqueous suspension was held at a product temperature of 50 ° C. for 1 minute; then, (a2) the product temperature was raised to 80 ° C. over 5 minutes; then, (a3) ​​the temperature was held at 80 ° C. for 5 minutes; then, (a4) the aqueous suspension was heated to 95 ° C. over 2 minutes and 30 seconds; then, (a5) the temperature was held at 95 ° C. for 5 minutes. The viscosity of the aqueous suspension was measured during this heating period, and the maximum viscosity (M1) from the start of the temperature rise from 50 ° C. to the end of the 5-minute hold at 80 ° C. ((a2) to (a3)) and the maximum viscosity (M2) from the start of the temperature rise from 80 ° C. to the end of the 5-minute hold at 95 ° C. ((a4) to (a5)) were determined. M2 / M1 was calculated. (B) (b1) The aqueous suspension was held at a product temperature of 50°C for 1 minute, then (b2) the product temperature was raised to 95°C over 7 minutes and 30 seconds, and then (b3) the suspension was held at 95°C for 5 minutes. The maximum viscosity of the aqueous suspension during this heating period ((b1) to (b3)) was taken as the peak viscosity P.

[0029] The results of viscosity measurements of each modified wheat flour in (A) and (B) are shown in Tables 1 and 2. As a reference example, untreated weak flour (raw wheat flour) had an M2 / M1 ratio of 7.4 and a P of 1,450 mPa s.

[0030] (3) Production of Pork Cutlets Batters were prepared by mixing 30 parts by weight of each modified wheat flour prepared in (1), 10 parts by weight of whole eggs, and 45 parts by weight of cold water. 40 g of the prepared batter was applied to the entire surface of pork loin (120 g slice, 1 cm thick), followed by breadcrumbs and frying in salad oil heated to 175°C for 4 minutes to produce pork cutlets. The produced pork cutlets were stored at room temperature (approximately 25°C) for 1 hour. After storage, the pork cutlets were cut with a knife, and the adhesion of the coating was evaluated. The texture of the coating was also evaluated when the cutlets were eaten without reheating after storage. Evaluation was performed by 10 expert panelists according to the following evaluation criteria. In this case, pork cutlets were produced and evaluated using the same procedure as above using raw wheat flour instead of the modified wheat flour (Reference Example), and the texture was assigned a score of 2, and the texture was evaluated based on this score. The average score of the 10 panelists was calculated. The results are shown in Tables 1 and 2.

[0031] <Evaluation criteria> (Batter adhesion) 5 points: When the fried food is cut with a knife, the batter does not come off at all, very good. 4 points: When the fried food is cut with a knife, the batter hardly comes off, good. 3 points: When the fried food is cut with a knife, the batter comes off in an area corresponding to less than 10% of the circumference of the cut surface, but the adhesion is acceptable. 2 points: When the fried food is cut with a knife, the batter comes off in an area corresponding to more than 10% but not more than 40% of the circumference of the cut surface, poor. 1 point: When the fried food is cut with a knife, the batter comes off in an area corresponding to more than 40% of the circumference of the cut surface, very poor. (Batter texture) 5 points: The batter is very crisp and easy to bite off, very good. 4 points: The batter is crisp and easy to bite off, good. 3 points: The batter is crisp and feels slightly hard when biting off, but is acceptable. 2 points: The crispness of the batter was slightly weak, resistance was felt when biting through, making it slightly difficult to bite through, poor (same as the reference example) 1 point: The crispness of the batter was barely felt, resistance was strong when biting through, making it difficult to bite through, extremely poor.

[0032]

[0033]

[0034] (Test Example 2) Using the device described in Japanese Patent No. 2784505 as a reference, a powder / granular heating device capable of heating the temperature inside the device up to 160 ° C and stirring at a stirring spring speed of up to 3000 rpm was prepared. Using this device, 2 kg of raw wheat flour, or a mixture of wheat flour and corn starch (CS) in a mass ratio of 80:20, was heated and stirred at the temperature (product temperature), time, and rotation speed shown in Table 3 to prepare modified wheat flour. Pork cutlets were produced and evaluated using the prepared modified wheat flour using the same procedure as in Test Example 1. The results are shown in Table 3.

[0035]

[0036] A comparison between Production Examples 16 and 18 revealed that the effect of the modified wheat flour tended to be reduced when the stirring speed was 2000 rpm compared to 1000 rpm. A comparison between Production Example 18 and Comparative Example 6 revealed that a higher heating temperature or a longer heating time made it more difficult to obtain modified wheat flour having the properties of the present invention. A comparison between Production Example 16 and Comparative Example 7 revealed that a mixture of starch and wheat flour as the starting wheat flour made it more difficult to obtain modified wheat flour having the properties of the present invention.

Claims

1. Modified wheat flour having the following properties (A) and (B): (A) When an aqueous suspension containing the modified wheat flour is subjected to viscosity measurement using a Rapid Visco Analyzer (RVA) (wherein the aqueous suspension contains 10 parts by mass of the modified wheat flour per 100 parts by mass of water, and the viscosity measurement is carried out by first holding the aqueous suspension at 50°C for 1 minute, then raising the temperature to 80°C over 5 minutes, holding at 80°C for 5 minutes, then raising the temperature to 95°C over 2 minutes 30 seconds, and holding at 95°C for 5 minutes), the maximum viscosity from the start of temperature increase from 50°C to the end of the 5-minute hold at 80°C is M1, and the maximum viscosity from the start of temperature increase from 80°C to the end of the 5-minute hold at 95°C is M2, the ratio M2 / M1 is 1.0 to 4.0; (B) When the viscosity of an aqueous suspension containing the modified wheat flour is measured using a Rapid Visco Analyzer (RVA) (here, the aqueous suspension contains 10 parts by mass of the modified wheat flour per 100 parts by mass of water, and in the viscosity measurement, the product temperature of the aqueous suspension is first held at 50°C for 1 minute, then raised to 95°C over 7 minutes and 30 seconds, and then held at 95°C for 5 minutes), the peak viscosity P is 2000 mPa·s or less.

2. The modified wheat flour according to claim 1, wherein the M2 / M1 ratio in (A) is 1.3 to 3.

0.

3. The modified wheat flour according to claim 1, wherein the peak viscosity P of (B) is 700 to 2000 mPa·s.

4. A coating material for deep-fried foods, comprising the modified wheat flour according to any one of claims 1 to 3.

5. A method for producing modified wheat flour, comprising heat-treating raw wheat flour to produce modified wheat flour having the following properties (A) and (B): (A) When the viscosity of an aqueous suspension containing the modified wheat flour is measured using a Rapid Visco Analyzer (RVA) (wherein the aqueous suspension contains 10 parts by mass of the modified wheat flour per 100 parts by mass of water, and the temperature of the aqueous suspension is first held at 50°C for 1 minute, then raised to 80°C over 5 minutes, held at 80°C for 5 minutes, then raised to 95°C over 2 minutes 30 seconds, and held at 95°C for 5 minutes), the maximum viscosity from the start of temperature rise from 50°C to the end of the 5-minute hold at 80°C is M1, and the maximum viscosity from the start of temperature rise from 80°C to the end of the 5-minute hold at 95°C is M2, then M2 / M1 is 1.0 to 4.0; (B) When the viscosity of an aqueous suspension containing the modified wheat flour is measured using a Rapid Visco Analyzer (RVA) (wherein the aqueous suspension contains 10 parts by mass of the modified wheat flour per 100 parts by mass of water, and the viscosity is measured by first holding the temperature of the aqueous suspension at 50°C for 1 minute, then raising the temperature to 95°C over 7 minutes and 30 seconds, and then holding at 95°C for 5 minutes), the peak viscosity P is 2000 mPa s or less.

6. The method according to claim 5, wherein the heat treatment of the raw material wheat flour comprises heating the raw material wheat flour at a product temperature of 60°C or higher but lower than 75°C for 400 to 2,000 hours, or heating the raw material wheat flour at a product temperature of 75°C to 85°C for 160 to 1,800 hours.

7. The method according to claim 5, wherein the heat treatment of the raw material wheat flour comprises heating and stirring the raw material wheat flour at a temperature of 85°C or higher but lower than 120°C for 2 to 100 hours, or at 120 to 160°C for 0.5 to 36 hours, at a speed of 10 to 2,200 rpm.

8. The method according to claim 5, wherein M2 / M1 in (A) is 1.3 to 3.

0.

9. The method according to claim 5, wherein the peak viscosity P in (B) is 700 to 2000 mPa·s.

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