Heat-treated durum wheat flour and production method therefor

Abstract

Heat-treated durum wheat flour according to the present invention is obtained by subjecting durum wheat flour to a wet heat treatment, has an average particle size of more than 150 μm, and has a viscosity of 1,000 to 5,000 mPa·s at 10°C with a water content of 180 mass%. This production method for heat-treated durum wheat flour according to the present invention comprises a heating step for heating durum wheat flour in the presence of steam while using a stirring device. At the heating step, if the gluten vitality of the durum wheat flour before undergoing the heating step is 100, the durum wheat flour is heated such that the gluten vitality of the durum wheat flour after undergoing the heating step is more than 50 but less than 70.

Description

Heat-treated durum wheat flour and its manufacturing method

[0001] The present invention relates to heat-treated durum wheat flour.

[0002] Conventionally, wheat flour as a raw material has been subjected to heat treatment in order to improve the texture and other properties of wheat flour-containing foods. Patent Document 1 describes heat-treated durum wheat flour having a gluten vitality of 70 to 95, where the gluten vitality of the raw durum wheat flour is 100, and a gluten swelling degree of 105 to 130, where the gluten swelling degree of the raw durum wheat flour is 100. The heat-treated durum wheat flour described in Patent Document 1 is preferably 150 μm or less in average particle size, and in the Examples, heat-treated durum wheat flour with an average particle size of 95 μm is used. The method for producing heat-treated durum wheat flour described in Patent Document 1 involves supplying raw durum wheat flour to a pressurized, closed mixer supplied with saturated steam, and subjecting the raw durum wheat flour to moist heat treatment under conditions of a residence time in the mixer of 2 to 20 seconds, with the durum wheat flour product temperature at 75 to 95° C. upon discharge from the mixer. The heat-treated durum wheat flour described in Patent Document 1 is said to enable the production of cakes, doughnuts, and fried foods that are excellent in appearance, texture, touch, and flavor.

[0003] U.S. Patent No. 6,010,736

[0004] Some bakery foods, such as confectioneries and breads, which are types of wheat flour-containing foods, require a crispy, crumbly texture or a crunchy texture. The heat-treated durum wheat flour described in Patent Document 1 is suitable for producing bakery foods with such a texture, but in recent years, consumers have been demanding higher levels of texture in bakery foods, and a technology that can meet these demands is needed.

[0005] While the use of heat-treated wheat flour as an ingredient in bakery foods improves the texture of the bakery foods, it may also deteriorate the external appearance of the bakery foods. For example, when heat-treated wheat flour is used as an ingredient in cookies, problems such as distortion of the cookie shape or chipping may occur. In bakery foods such as melon bread, which have a core dough portion and a topping dough portion covering it, using heat-treated wheat flour as an ingredient in the topping dough portion can also cause the same problems of deterioration in the external appearance as described above. Furthermore, when heat-treated wheat flour is used as an ingredient in donuts, problems such as excessive oil absorption and cracking are likely to occur in the donuts. Heat-treated wheat flour that can improve the texture of wheat flour-containing foods without causing deterioration in the external appearance has not yet been provided.

[0006] An object of the present invention is to provide a technique capable of producing wheat flour-containing foods having good texture and appearance.

[0007] The present invention provides heat-treated durum wheat flour obtained by subjecting durum wheat flour to a moist heat treatment, the heat-treated durum wheat flour having an average particle size of more than 150 μm and a viscosity of 1000 to 5000 mPa·s at 10°C with 180% water added.

[0008] The present invention also provides a method for producing the heat-treated durum wheat flour of the present invention, comprising a heating step of heating durum wheat flour in the presence of steam using an agitator, the agitator comprising an airtight container having a supply inlet and a discharge outlet for the material to be stirred and a transfer path connecting these, and an agitator arranged in the transfer path, and configured such that, with steam supplied to the transfer path, the material to be stirred is fed from the supply inlet into the transfer path while being stirred by the agitator, transferred towards the discharge outlet and discharged from the discharge outlet, and the material is heated in the heating step such that, assuming the gluten vitality of the durum wheat flour before being subjected to the heating step is 100, the gluten vitality of the durum wheat flour after being subjected to the heating step is more than 50 but less than 70.

[0009] The present invention also relates to a wheat flour-containing food mix containing cereal flour, in which 1% by mass or more of the total mass of the cereal flour is the heat-treated durum wheat flour of the present invention.The present invention also relates to a wheat flour-containing food produced by heating a dough containing cereal flour, in which 1% by mass or more of the total mass of the cereal flour is the heat-treated durum wheat flour of the present invention.

[0010] The heat-treated durum wheat flour of the present invention is obtained by subjecting durum wheat flour to a moist heat treatment, and is a moist heat-treated product of durum wheat flour. The heat-treated durum wheat flour of the present invention can be produced using a known moist heat treatment method, provided that it has the properties described below (average particle size and viscosity each falling within a specific range). The production method of the present invention described below is a preferred embodiment of the heat-treated durum wheat flour production method of the present invention, and the production method of the heat-treated durum wheat flour of the present invention is not limited to the production method of the present invention described below.

[0011] In the present invention, "durum wheat flour" refers to flour made from durum wheat. "Durum wheat" as used herein refers to wheat that belongs to the "double wheat" botanical classification. Durum wheat is tetraploid and has four sets of genomes, whereas wheat, which is used as a raw material for soft flour and other flours commonly used in processed foods, is hexaploid and has six sets of genomes, and belongs to the "hexaploid wheat" botanical classification. Thus, durum wheat is a botanically distinct species from the hard wheat, medium wheat, and soft wheat flours.

[0012] In addition to durum wheat flour, durum semolina and durum whole wheat flour have been known as wheat flour derived from durum wheat. Durum semolina is obtained by coarsely grinding durum wheat after removing the bran (epidermis) and germ, while durum wheat flour is obtained by further grinding and powdering durum semolina. The main difference between durum semolina and durum wheat flour is particle size, with durum semolina generally having a larger average particle size than durum wheat flour. Durum whole wheat flour is obtained by grinding durum wheat as is and differs from durum semolina and durum wheat flour, which are substantially free of bran and germ, in that it contains these substances. The heat-treated durum wheat flour of the present invention is a moist heat-treated product of durum wheat flour and does not include durum semolina, durum whole wheat flour, or their moist heat-treated products.

[0013] In the present invention, "moist heat treatment" refers to a treatment in which the object to be treated (durum wheat flour) is heated while maintaining its moisture content or while adding moisture to it. In the moist heat treatment, water or steam can be used as the moisture added to the object to be treated, with saturated steam being preferred as the steam. The heating method in the moist heat treatment is not particularly limited, and examples include a method in which a heat medium such as hot air is directly brought into contact with the object to be treated, and a method in which the object to be treated is indirectly heated in a high-humidity atmosphere. The apparatus used to carry out the moist heat treatment is not particularly limited, and examples include an autoclave, a steam oven, and a single- or twin-screw extruder.

[0014] The heat-treated durum wheat flour of the present invention has an average particle size of more than 150 μm. In the present invention, "average particle size" refers to the volume cumulative particle size D50 at 50% cumulative volume when measured dry using a laser diffraction / scattering particle size analyzer (e.g., Nikkiso Co., Ltd.'s "Microtrac Particle Size Analyzer 9200FRA"). Bakery foods produced using heat-treated durum wheat flour with an average particle size of more than 150 μm can have a crispy or crunchy texture. If the average particle size of the heat-treated durum wheat flour is 150 μm or less, it may be difficult to impart such a crispy texture to bakery foods. The average particle size of the heat-treated durum wheat flour of the present invention is preferably 200 to 300 μm, more preferably 230 to 270 μm. If the average particle size of the heat-treated durum wheat flour is too large, the texture of bakery foods using the heat-treated durum wheat flour may be unpleasantly rough.

[0015] The heat-treated durum wheat flour of the present invention has a viscosity of 1000 to 5000 mPa·s, preferably 1500 to 3000 mPa·s, and more preferably 2000 to 2500 mPa·s at 10°C with 180% water content. Details of the viscosity measurement method are as follows. When the viscosity of the heat-treated durum wheat flour is within the specific range, combined with the average particle size of the heat-treated durum wheat flour being greater than 150 μm, bakery foods produced using the heat-treated durum wheat flour can have good texture and appearance. If the viscosity is less than 1000 mPa·s, the texture (crispyness) of the bakery food may be particularly deteriorated, while if the viscosity is greater than 5000 mPa·s, the appearance of the bakery food may be particularly deteriorated. The viscosity can be adjusted by adjusting the heat treatment conditions of the raw durum wheat flour during the production of the heat-treated durum wheat flour. The heat treatment conditions include, for example, the heating temperature of the raw durum wheat flour (in the production method of the present invention described below, the temperature of the steam in the transfer path of the agitator) and the heating time of the raw durum wheat flour (in the production method of the present invention described below, the residence time of the raw durum wheat flour in the transfer path of the agitator).

[0016] <Viscosity Measurement Method> Heat-treated durum wheat flour to be measured is mixed with 100% by mass of the heat-treated durum wheat flour and 180% by mass of water at a product temperature of 10°C, and the mixture is stirred appropriately to prepare a mixture. Next, the mixture is stirred using a mixer at a rotation speed of 139 rpm for 30 seconds, followed by stirring at a rotation speed of 285 rpm for 240 seconds. The viscosity of the mixture immediately after the second stirring is measured using a Brookfield viscometer, and this measured value is the "viscosity at 10°C with 180% by mass of water added" of the heat-treated durum wheat flour to be measured. When measuring the viscosity of the mixture using a Brookfield viscometer, an M3 rotor is used as the rotor to be placed in the mixture, and the rotor rotation speed is set to 12 rpm. For example, an "N-50" manufactured by Hobart Japan Co., Ltd. can be used as the mixer. For example, a "TVB10" manufactured by Toki Sangyo Co., Ltd. can be used as the Brookfield viscometer.

[0017] The heat-treated durum wheat flour of the present invention is obtained by subjecting durum wheat flour to a moist heat treatment. The gluten vitality of the durum wheat flour after the moist heat treatment (hereinafter also referred to as the "gluten vitality ratio") is preferably greater than 50 and less than 70, where the gluten vitality of the durum wheat flour before the moist heat treatment is 100. Gluten vitality is an index of the degree of protein denaturation in the wheat flour and is closely related to the texture, particularly tooth brittleness or crispness, of processed foods such as bakery foods made using the wheat flour. Gluten vitality can be measured by the following method. Generally, the smaller the gluten vitality value, the better the tooth brittleness or crispness of processed foods made using the wheat flour. Having the gluten vitality ratio of the heat-treated durum wheat flour within the above-mentioned preferred range can further improve the texture of bakery foods made therewith. The gluten vitality ratio of the heat-treated durum wheat flour of the present invention is preferably 55 to 65, more preferably 58 to 62. The gluten vitality of heat-treated durum wheat flour can be adjusted by appropriately adjusting the type of durum wheat flour used as the raw material and the conditions of the moist heat treatment (heating temperature, heating time, etc.) applied to the raw material.

[0018] <Method for measuring gluten vitality> This measurement method is carried out in the following order: (i) measuring the soluble crude protein content in a sample, (ii) measuring the total crude protein content in a sample, and (iii) calculating gluten vitality. In steps (i) and (ii), the crude protein content can be measured by known methods such as the Kjeldahl method or the combustion method. Here, the case where the Kjeldahl method is used will be described.

[0019] (i) Measurement of soluble crude protein content in a sample (a) Accurately weigh out 2 g of sample (wheat flour) into a 100 mL beaker. (b) Add 40 mL of 0.05 N acetic acid to the beaker and stir at room temperature for 60 minutes to prepare a suspension. (c) Transfer the suspension obtained in (b) to a centrifuge tube and centrifuge at 5000 rpm for 5 minutes, then filter using filter paper to recover the filtrate. (d) Wash the beaker with 40 mL of 0.05 N acetic acid, transfer the washings to a centrifuge tube and centrifuge at 5000 rpm for 5 minutes, then filter using filter paper to recover the filtrate. (e) Combine the filtrates recovered in (c) and (d) and measure up to 100 mL. (f) 25 mL of the liquid obtained in (e) is placed in a Kjeldahl tube of ...

[0020] Soluble crude protein content (%) = 0.14 x (T - B) x F x N x (100 / S) x (1 / 25) (A1) In the formula (A1), the symbols represent the following: T: Amount (mL) of 0.1 N sulfuric acid required for titration B: Amount (mL) of 0.1 N sulfuric acid required for titration of blank F: Titer of 0.1 N sulfuric acid used for titration (measure immediately before use or use a commercially available product with a labeled titer) N: Nitrogen protein conversion factor (5.70) S: Amount (g) of sample (wheat flour)

[0021] (ii) Measurement of the total crude protein content in the sample (a) 0.5 g of sample (wheat flour) is weighed and placed in the Kjeldahl tube of the Keltec Auto System of the same company as used in (i) above, and one tablet of the same decomposition accelerator and 5 mL of concentrated sulfuric acid are added thereto. (b) Using the Keltec decomposition furnace of the Keltec Auto System used in (i) above, decomposition treatment is carried out for 1 hour at dial 9 or 10, and then, following this decomposition treatment, the liquid subjected to the decomposition treatment is continuously and automatically distilled and titrated (using 0.1 N sulfuric acid for titration) using the same Keltec distillation titration system as used in (i) above, which is incorporated into the same Keltec Auto System, and the total crude protein content in the sample (wheat flour) is calculated using the following formula (A2):

[0022] Total crude protein content (%) = (0.14 × T × F × N) / S (A2) In the formula (A2), the symbols represent the following: T: amount of 0.1 N sulfuric acid required for titration (mL) F: titer of 0.1 N sulfuric acid used for titration (measured before use) N: nitrogen protein conversion factor (5.70) S: weight of sample (wheat flour) (g)

[0023] (iii) Calculation of gluten vitality The gluten vitality of the sample (wheat flour) is calculated from the soluble crude protein content calculated in (i) above and the total crude protein content calculated in (ii) above using the following formula (A3): GV (%) = (soluble crude protein content / total crude protein content) × 100 (A3)

[0024] The heat-treated durum wheat flour of the present invention is used for wheat flour-containing foods. In the present invention, the term "wheat flour-containing foods" refers to processed foods using wheat flour, more specifically processed foods produced by heating a dough containing wheat flour and having fluidity at room temperature and normal pressure, such as bakery foods, fried foods, noodles, and noodle skins.

[0025] The heat-treated durum wheat flour of the present invention is particularly suitable for bakery foods. In this specification, "bakery foods" refers to foods obtained by heating (e.g., baking or frying) fermented or unfermented dough prepared by stirring dough ingredients containing cereal flour in the presence of water. Specific examples of bakery foods include hard breads; toppings for bread such as melon bread; baked goods such as cookie dough; and fried goods such as cake donuts. The heat-treated durum wheat flour of the present invention is particularly useful for bakery foods that require a crispy, crumbly, or crunchy texture, and specific examples include soft French bread, cookies, tarts, pies, old-fashioned breads, and churros.

[0026] Next, the method for producing heat-treated durum wheat flour of the present invention (hereinafter also simply referred to as "the production method of the present invention") will be described. The object of the production method of the present invention is the above-mentioned durum wheat flour of the present invention.

[0027] The production method of the present invention includes a heating step of heating durum wheat flour in the presence of steam using a stirring device. Through the heating step, the raw material durum wheat flour becomes the heat-treated durum wheat flour to be produced.

[0028] The stirring device is equipped with a sealed container having a supply inlet and discharge outlet for the material to be stirred (durum wheat flour) and a transport path connecting these, and a stirrer arranged on the transport path, and is configured such that, with steam supplied to the transport path, the material to be stirred is introduced from the supply inlet into the transport path and stirred by the stirrer while being transported towards the discharge outlet, and is then discharged from the discharge outlet.

[0029] The storage section may be, for example, a cylindrical pressure vessel. The agitator may include a mechanism for supplying steam to the transfer path. The agitator may include a heating means for heating the contents of the transfer path. The agitator may include, for example, an agitator including an agitator shaft extending in the transfer direction of the object to be agitated and an agitator blade spirally arranged around the agitator shaft. The agitator may be, for example, the agitator described in JP-A-3-83567.

[0030] The durum wheat flour subjected to the heating step is not heat-treated. The term "heat treatment" used herein refers to a heat treatment that can degrade durum wheat flour, but does not include a heat treatment that does not substantially degrade durum wheat flour. The durum wheat flour subjected to the heating step typically has an average particle size of more than 150 μm.

[0031] The heating step is typically carried out by supplying durum wheat flour and high-temperature steam to the transport path of the agitator, contacting the durum wheat flour with the steam to heat the durum wheat flour, and transporting the durum wheat flour toward the outlet while stirring. The durum wheat flour discharged from the outlet is the heat-treated durum wheat flour to be produced. The steam used in the heating step is not particularly limited, and may be saturated steam or superheated steam.

[0032] In the heating step, the durum wheat flour is heated so that the gluten vitality ratio of the durum wheat flour after the heating step, i.e., the heat-treated durum wheat flour to be produced, is more than 50 and less than 70, preferably 55 to 65, and more preferably 58 to 62. The gluten vitality is as described above.

[0033] From the viewpoint of reliably adjusting the gluten vitality ratio to fall within the specific range, the heating step preferably satisfies at least one of the following conditions A and B, and most preferably satisfies all of the following conditions A and B. Condition A: The product temperature of the durum wheat flour at the time of discharge from the mixer (specifically, the discharge port) is preferably 95 to 105°C, more preferably 98 to 102°C. Condition B: The residence time of the durum wheat flour in the mixer is preferably 2 to 20 seconds, more preferably 2 to 10 seconds. The residence time is the time from when the durum wheat flour is introduced into the supply port to when the durum wheat flour is discharged from the discharge port.

[0034] From the same viewpoint as above, in addition to satisfying condition A and / or B, it is preferable to further satisfy at least one of the following conditions C to G, and it is most preferable to satisfy all of the following conditions C to G. - Condition C: The temperature of the steam supplied to the stirrer is preferably 100 to 143°C, more preferably 120 to 133°C. - Condition D: The flow rate of the steam when supplied to the stirrer is preferably 15 to 30 kg / hour, more preferably 20 to 25 kg / hour. - Condition E: The air pressure in the transfer path is preferably 0 to 130 kPa, more preferably 0 to 120 kPa. - Condition F: The flow rate of durum wheat flour when supplied to the stirrer is preferably 100 to 300 kg / hour, more preferably 200 to 250 kg / hour. Condition G: The peripheral speed of the tip of the agitator of the agitator in the direction of transport of the material to be agitated (durum wheat flour) is preferably 4 to 10 m / sec, more preferably 5 to 7 m / sec.

[0035] The production method of the present invention may include a particle size adjusting step of adjusting the average particle size of the durum wheat flour after the heating step. In the particle size adjusting step, the heat-treated durum wheat flour obtained in the heating step is typically pulverized using a known pulverizing means such as a roll mill or a pin mill to adjust the average particle size of the heat-treated durum wheat flour.

[0036] Next, the wheat flour-containing food mix of the present invention (hereinafter also simply referred to as the "mix of the present invention") will be explained. Regarding the mix of the present invention, differences from the heat-treated durum wheat flour of the present invention described above will be explained. For points not specifically explained about the mix of the present invention, the explanation of the heat-treated durum wheat flour of the present invention described above will be applied as appropriate.

[0037] The mix of the present invention contains cereal flours. In the present invention, "cereal flours" refers to grain-derived powdery substances at room temperature and pressure, including cereal flour and starch. "Starch" here refers to "pure starch" isolated from plants such as wheat, and is distinguished from starch inherently contained in cereal flour or whole grain flour. The heat-treated durum wheat flour of the present invention (hereinafter also simply referred to as "heat-treated durum wheat flour") described above is a type of cereal flour.

[0038] Cereal flours constitute the main component of the mix of the present invention. The content of cereal flours in the mix of the present invention is preferably adjusted appropriately depending on the type of wheat flour-containing food to be produced using the mix. For example, when the mix of the present invention is used to produce baked goods or fried goods, the content of cereal flours in the mix is ​​preferably 10 to 30% by mass, more preferably 15 to 25% by mass, based on the total mass of the mix. Furthermore, when the mix of the present invention is used to produce breads (including hard breads and toppings for breads such as melon bread), the content of cereal flours in the mix is ​​preferably 5 to 20% by mass, more preferably 10 to 15% by mass, based on the total mass of the mix.

[0039] The mix of the present invention is characterized in that heat-treated durum wheat flour accounts for 1% by mass or more, preferably 5 to 30% by mass, and more preferably 10 to 20% by mass of the total mass of the cereal flours contained in the mix. Due to this characteristic, the mix of the present invention can provide wheat flour-containing foods, such as bakery foods, with good texture and appearance. If the heat-treated durum wheat flour content in the mix is ​​too low, there is little point in using it, while if the content is too high, problems may arise with the appearance of the wheat flour-containing food.

[0040] Examples of flours that can be used in combination with heat-treated durum wheat flour in the mix of the present invention include wheat flours such as strong flour, medium-strength flour, and soft flour; rice flour, corn flour, potato flour, tapioca flour, and sweet potato flour. These flours are preferably untreated flours that have not been heat-treated. Other specific examples of flours include flours containing at least the husk and / or germ, such as "bran" primarily composed of the husk, and "whole wheat flour" containing the three main components of endosperm, husk, and germ. Examples of starches that can be used in combination with heat-treated durum wheat flour in the mix of the present invention include unprocessed starches such as tapioca starch, wheat starch, potato starch, corn starch, waxy corn starch, sweet potato starch, sago starch, and rice starch; and processed starches obtained by subjecting unprocessed starches to one or more of the following treatments: gelatinization, etherification, esterification, acetylation, cross-linking, oxidation, and oil / fat processing. In the mix of the present invention, one type of cereal flour other than heat-treated durum wheat flour can be used alone or in combination of two or more types.

[0041] The mix of the present invention may contain ingredients other than cereal flours such as heat-treated durum wheat flour. The other ingredients may be any ingredients used in the production of bakery foods using the mix, without any particular limitation, and include, for example, sugars such as glucose, sucrose, oligosaccharides, maltose, trehalose, fructose, etc.; proteins such as milk protein and soy protein, vegetable or animal fats and oils, emulsifiers such as sucrose fatty acid esters, egg powders such as whole egg powder, egg yolk powder, and egg white powder, leavening agents such as baking powder, yeast, spices, dried fruit, nuts, enzymes, flavorings, thickeners, dietary fiber, etc., and these may be used alone or in combination in appropriate amounts.

[0042] The mix of the present invention is typically obtained by mixing various ingredients including heat-treated durum wheat flour. The mix of the present invention is typically in the form of a powder, granules, or other powder at room temperature and normal pressure.

[0043] The production of wheat flour-containing foods using the heat-treated durum wheat flour or the mix of the present invention can be carried out according to conventional methods. For example, a method for producing bakery foods, which are a type of wheat flour-containing food, typically includes a dough preparation step in which a dough is prepared and a heating step in which the dough is heated. The dough preparation step is typically carried out by adding a liquid to a mix to obtain a mixture and stirring the mixture in a mixer. The dough to be prepared may be a clay-like dough (so-called dough) with a relatively low liquid content, or a paste-like dough (so-called batter) with a relatively high liquid content, and can be appropriately selected depending on the type of bakery food to be produced. Examples of liquids to be added to the mix include water, oil, seasonings, egg liquid (whole egg, egg white, egg yolk), and milk. These can be used alone or in combination of two or more. The amount of liquid added to the mix is ​​not particularly limited, but is generally preferably 15 to 60 parts by weight, more preferably 20 to 55 parts by weight, per 100 parts by weight of the mix. When calculating the amount of liquid to be added to the dough, the water content of the whole eggs used as the liquid is 76% by mass, and the water content of the milk used as the liquid is 88% by mass. The method for heating the dough in the heating step is not particularly limited, and examples include baking and deep-frying. If necessary, the dough may be fermented after the dough preparation step and before the heating step.

[0044] The present invention includes wheat flour-containing foods prepared by heating (e.g., baking or frying) dough containing cereal flour. The wheat flour-containing foods of the present invention are characterized in that heat-treated durum wheat flour accounts for 1% by mass or more, preferably 10 to 40% by mass, and more preferably 20 to 30% by mass of the total mass of the cereal flour contained in the wheat flour-containing foods. Due to these characteristics, the wheat flour-containing foods of the present invention have good texture and appearance. The above-mentioned explanations regarding the heat-treated durum wheat flour of the present invention and the mix of the present invention are also applicable to the wheat flour-containing foods of the present invention, as appropriate.

[0045] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0046] (Production of Heat-Treated Durum Wheat Flours A to K) Using the agitator described in JP-A-3-83567, untreated durum wheat flour was subjected to a moist heat treatment in the presence of saturated steam to produce heat-treated durum wheat flours A to K. If necessary, the heat-treated durum wheat flour obtained by the moist heat treatment was ground using a pin mill to adjust the average particle size to the desired range. Nisshin Flour Milling Co., Ltd.'s "Leone G" (average particle size: 236 μm) was used as the untreated durum wheat flour. During the moist heat treatment, the steam temperature when supplied to the agitator was 120°C, the pressure within the agitator's transfer path was 117.7 kPa, the durum wheat flour flow rate when supplied to the agitator was 200 kg / hr, and the peripheral speed of the tip of the agitator's agitator in the direction of transport of the material being agitated was 5.5 m / sec. Table 1 below shows the moist heat treatment conditions and the characteristics of the heat-treated durum wheat flour produced.

[0047]

[0048] Examples 1 to 12 and Comparative Examples 1 to 6: Production of Wheat Flour-Containing Food Mixes Powdered wheat flour-containing food mixes were produced at room temperature and pressure using any one of the heat-treated durum wheat flours A to K. Specifically, three types of bakery food mixes (cookie mix, donut mix, and soft French bread mix) were produced for each type of heat-treated durum wheat, and a set of these three mixes constituted one Example or Comparative Example. Details of the produced mixes are as follows, and the compositions of the cereal flours in the mixes are shown in Tables 1 and 2 below.

[0049] (Cookie mix) Cereal flours: 65% by mass Sugars (granulated sugar, DM Mitsui Sugar Co., Ltd.'s "Granulated Sugar"): 34.5% by mass Leavening agent (baking powder, Oriental Yeast Co., Ltd.'s "Baking Powder O#1"): 0.5% by mass As the cereal flours, soft flour (Nisshin Flour Milling Inc.'s "Flour") and one of the heat-treated durum wheat flours of the above Examples and Comparative Examples or the above untreated durum wheat flour were used.

[0050] (Donut mix) - Grain flour: 75% by mass - Sugars (granulated sugar): 22% by mass - Leavening agent (baking powder): 3% by mass The grain flours used were weak flour ("Flour" manufactured by Nisshin Flour Milling Co., Ltd.) and one of the heat-treated durum wheat flours of the above examples and comparative examples or the above untreated durum wheat flour.

[0051] (Mix for soft French bread) - Flours: 95% by mass - Sugars (granulated sugar): 3% by mass - Bread improver ("BBJ" manufactured by Lesaffre): 0.2% by mass - Salt: 1.8% by mass The flours used were strong flour ("Risdoor" manufactured by Nisshin Flour Milling Co., Ltd.) and one of the heat-treated durum wheat flours from the examples and comparative examples or the untreated durum wheat flour.

[0052] (Cookie Production) Cookies, a type of baked confectionery (bakery food), were produced using the cookie mix. Specifically, 18 parts by mass of whole eggs and 15 parts by mass of margarine were added to 100 parts by mass of the mix, and the mixture was placed in a commercially available mixer and stirred at low speed for 4 minutes and at medium speed for 1 minute (kneading temperature: 25°C) to prepare dough. The prepared dough was formed into a sheet, and then divided into multiple pieces, each weighing 30 g. The divided pieces were then formed into a predetermined shape and baked in an oven at 180°C for 15 minutes to produce the desired cookies.

[0053] (Production of Donuts) Cake donuts, a type of fried confectionery (bakery food), were produced using the donut mix. Specifically, 25 parts by mass of whole eggs, 20 parts by mass of milk, and 4 parts by mass of shortening were added to 100 parts by mass of the mix, and the mixture was placed in a commercially available mixer and stirred at low speed for 2 minutes and at high speed for 2 minutes (kneading temperature: 25°C) to prepare a dough. The prepared dough was divided into multiple pieces using a sanitary cutter so that each donut weighed 40 g. The divided pieces were molded into a predetermined shape and then placed in cooking oil at 180°C and fried for 1 minute. The divided pieces were then inverted and fried for 1 minute to produce the desired cake donuts.

[0054] (Production of Soft French Bread) The soft French bread mix was used to produce soft French bread, a type of bread (bakery food). Specifically, 100 parts by weight of the mix was mixed with 64 parts by weight of water and 4 parts by weight of shortening, and the mixture was placed in a commercially available mixer and stirred at low speed for 2 minutes and at medium speed for 8 minutes (kneading temperature 27°C) to prepare dough. The prepared dough was fermented for 60 minutes under conditions of 27°C and 75% relative humidity, and then divided into several pieces so that each soft French bread weighed 200g and rolled into balls. After 20 minutes of bench time, the dough was molded into a predetermined shape, proofed (under an atmosphere of 32°C and 75% relative humidity) for 60 minutes, and then baked in an oven at 220°C for 20 minutes to produce the desired soft French bread.

[0055] [Evaluation Test] The texture and appearance of the produced bakery foods (cookies, donuts, soft French bread) were evaluated. Specifically, after the bakery foods had cooled immediately after production, 10 expert panelists tasted the bakery foods and evaluated the texture and appearance according to the following evaluation criteria. The average scores of the 10 expert panelists for texture and appearance were used as the evaluation results for the bakery foods evaluated. The results are shown in Tables 2 and 3 below.

[0056] <Evaluation criteria for cookie texture> 5 points: Quite hard and crispy texture, sufficiently brittle, extremely good. 4 points: Hard and crispy texture, brittle, good. 3 points: Somewhat hard and crispy texture, slightly brittle, acceptable level. 2 points: Slightly lacking in hard and crispy texture, not brittle enough, somewhat heavy texture, poor. 1 point: Not hard and crispy texture, heavy texture without brittleness, extremely poor. <Evaluation criteria for cookie appearance> 5 points: No distortion in the external shape, very well balanced, very good. 4 points: Almost no distortion in the external shape, well balanced, good. 3 points: Some distortion in the external shape, but balanced and acceptable level. 2 points: Some distortion in the external shape, unbalanced, poor. 1 point: The appearance is significantly distorted and extremely poor.

[0057] <Evaluation criteria for doughnut texture> 5 points: Quite a firm and crispy texture, with a sufficient degree of crunchiness, extremely good. 4 points: A firm and crispy texture, with a crunchiness that is good. 3 points: A moderate firm and crispy texture, with a slight crunchiness, acceptable level. 2 points: A slightly lacking firm and crispy texture, with a slightly insufficient crunchiness and a somewhat heavy texture, poor. 1 point: No firm and crispy texture, a heavy texture with no crunchiness, extremely poor. <Evaluation criteria for doughnut appearance> 5 points: No defects at all on the surface, very clean, very good. 4 points: Almost no defects on the surface, clean, good. 3 points: Some cracks on the surface, but acceptable level. 2 points: A few cracks on the surface, poor. 1 point: Many cracks on the surface, extremely poor.

[0058] <Evaluation criteria for the texture of soft French bread> ・5 points: Very crisp, extremely good. ・4 points: Crisp, good. ・3 points: Slightly lacking in crispness, but still acceptable. ・2 points: Not very crisp, slightly chewy, poor. ・1 point: Not crisp, very chewy, extremely poor. <Evaluation criteria for the appearance of soft French bread> ・5 points: Plenty of volume, fairly thin crust, extremely good. ・4 points: Volume, thin crust, good. ・3 points: Somewhat volume, somewhat thick crust, still acceptable. ・2 points: Somewhat less volume, thick crust, poor. ・1 point: Significantly less volume, fairly thick crust, extremely poor.

[0059]

[0060] As shown in Table 2, the mixes of the examples used heat-treated durum wheat flours A to G, which have an average particle size of more than 150 μm and a viscosity of 1000 to 5000 mPa·s at 10°C with 180% water by mass. Therefore, the texture and appearance of the bakery food were highly evaluated compared to the mixes of the comparative examples, which used heat-treated durum wheat flours H to K, which did not meet these requirements.

[0061]

[0062] According to the present invention, heat-treated durum wheat flour is provided that can be used to produce wheat flour-containing foods with good texture and appearance. For example, when the present invention is applied to bakery foods, which are a type of wheat flour-containing food, the texture can be crispy and brittle or crisp, and the appearance can be balanced without distortion, with no defects such as cracks on the surface, and with a voluminous appearance (a relatively thin crust), although this will vary slightly depending on the type of bakery food. According to the method for producing heat-treated durum wheat flour of the present invention, high-quality heat-treated durum wheat flour can be efficiently produced.

Claims

1. Heat-treated durum wheat flour obtained by subjecting durum wheat flour to a moist heat treatment, wherein the average particle size is greater than 150 μm, and the viscosity at 10°C with 180% water is 1000 to 5000 mPa·s.

2. A method for producing heat-treated durum wheat flour as set forth in claim 1, comprising a heating step of heating durum wheat flour in the presence of steam using an agitator, the agitator comprising an airtight container having a supply inlet and a discharge outlet for the material to be agitated and a transfer path connecting these, and an agitator arranged in the transfer path, and configured such that, with steam supplied to the transfer path, the material to be agitated is fed from the supply inlet into the transfer path while being agitated by the agitator, and transferred towards the discharge outlet, and then discharged from the discharge port, and in the heating step, the durum wheat flour is heated so that, assuming that the gluten vitality of the durum wheat flour before being subjected to the heating step is 100, the gluten vitality of the durum wheat flour after being subjected to the heating step is more than 50 but less than 70.

3. The method for producing heat-treated durum wheat flour according to claim 2, wherein the temperature of the durum wheat flour when discharged from the stirring device is 95 to 105°C.

4. The method for producing heat-treated durum wheat flour according to claim 2 or 3, wherein the residence time of the durum wheat flour in the stirring device is 2 to 20 seconds.

5. A wheat flour-containing food mix containing cereal flour, wherein 1% by mass or more of the total mass of the cereal flour is the heat-treated durum wheat flour described in claim 1.

6. A wheat flour-containing food product obtained by heating a dough containing cereal flour, wherein 1% by mass or more of the total mass of the cereal flour is heat-treated durum wheat flour as described in claim 1.

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