JP7520033B2 - Manufacturing method of ground heat-treated wheat flour, ground heat-treated wheat flour, mix for bakery food and manufacturing method thereof - Google Patents

Description

The present invention relates to heat-treated wheat flour used in the production of bakery foods such as bread, and a bakery food mix using the same.

Bakery products such as breads and confectioneries are commercially available with a variety of flavors and textures due to diversifying tastes. Among them, there has been an increasing demand in recent years for products with a moist and/or chewy texture.
2. Description of the Related Art Various methods have been proposed so far for imparting a moist and/or chewy texture to bakery foods such as breads and confectioneries.
For example, a method has been proposed in which pregelatinized starch or pregelatinized grain flour is used as a raw material (Patent Document 1). However, pregelatinized starch or conventional pregelatinized grain flour has the problem that it makes the dough sticky, deteriorating workability, and at the same time, it makes the texture of the resulting food sticky. Furthermore, starch has the drawback of being inferior in flavor to wheat flour.

In addition, the Yudane method is known as a method for producing bread with a chewy texture, in which part of the raw wheat flour is mixed with hot water and then aged at low temperature for a long period of time to gelatinize the starch in the wheat flour (Patent Document 2). However, this method has issues such as the need to control temperature conditions to stabilize quality and the long production time required, making it difficult to implement, especially in small-scale bakeries.

Furthermore, Patent Document 3 describes a method for producing ground heat-treated wheat flour that can produce bakery foods that have a moist and chewy texture and are resistant to deterioration over time, comprising the steps of adding 15 to 40 parts by mass of water to 100 parts by mass of wheat flour to obtain a mixture, heating the mixture at an atmospheric temperature of 70°C to less than 100°C for 3 to 60 seconds, and then grinding it, as ground heat-treated wheat flour that can produce bakery foods that have a moist and chewy texture and are resistant to deterioration over time. However, this method does not sufficiently gelatinize the starch in the wheat flour, so there is still room for improvement in the quality of the resulting bread, etc., particularly in terms of the moist and chewy texture and the suppression of deterioration over time, compared to the use of the processed wheat flour obtained in Patent Documents 1 and 2.

JP 2002-253111 A JP 2000-262205 A JP 2017-35074 A

The object of the present invention is to provide a pulverized, heat-treated wheat flour and a mix for bakery foods that can be used to produce bakery foods that have a moist and chewy texture (hereinafter also referred to simply as "moist and chewy"), sufficient volume and a fine-grained internal structure, and are resistant to deterioration in texture over time, and that have excellent secondary processability and can efficiently produce such bakery foods.

The present invention relates to a method for producing pulverized heat-treated wheat flour, which comprises the steps of combining 100 parts by mass of wheat flour with 20 to 55 parts by mass of water and/or water vapor at 70°C or higher to obtain a mixture, heating the mixture at an ambient temperature of 80°C to 120°C for 3 to 60 seconds, lowering the temperature of the mixture to 80°C to 100°C, and then pulverizing the mixture.

In addition, the present invention has a heat of gelatinization of 10 to 55, where the heat of gelatinization of the untreated product is taken as 100,
The gluten vitality is 50 to 90, where the gluten vitality of the untreated gluten is 100.
The heat-treated ground wheat flour has a particle size distribution in which particles with a particle size of 400 μm or less account for 90% by mass or more, and has a viscosity of 1 Pa·s to 4 Pa·s when water is added in an amount of 500% by mass relative to the flour at 25° C.

The present invention further provides a mix for bakery foods containing the ground heat-treated wheat flour. The present invention also provides a method for producing a mix for bakery foods, which comprises mixing 1 part by mass or more and 40 parts by mass or less of the ground heat-treated wheat flour and 60 parts by mass or more and 99 parts by mass or less of the non-heat-treated wheat flour with respect to a total amount of 100 parts by mass of the ground heat-treated wheat flour and the non-heat-treated wheat flour.

Hereinafter, the present invention will be described based on its preferred embodiments. In this specification, ground and heat-treated wheat flour refers to wheat flour that has been subjected to both grounding and heat treatment.

First, the method for producing the ground heat-treated wheat flour of the present invention will be described. The method for producing the ground heat-treated wheat flour of the present invention includes the steps of combining 100 parts by mass of wheat flour with 20 to 55 parts by mass of water and/or water vapor at 70°C or higher to obtain a mixture, heating the mixture at an ambient temperature of 80°C to 120°C for 3 to 60 seconds, lowering the temperature of the mixture to 80°C to 100°C, and then grinding the mixture.

One of the features of the method for producing ground heat-treated wheat flour of the present invention is that it combines wheat flour with water and/or steam heated to a predetermined temperature or higher to obtain a mixture, and then heat-treats the mixture. Hereinafter, the process of combining wheat flour with water and/or steam to obtain a mixture is also referred to as a mixing process. For example, Patent Document 3 describes heat-treating a mixture of water and wheat flour, but does not describe heat-treating the water to be mixed with wheat flour in advance. On the other hand, the present invention has the advantage that the gelatinization of starch in wheat flour is significantly promoted by heat-treating a mixture of wheat flour and water and/or steam heated to a predetermined temperature or higher, compared to mixing with unheated water. Specifically, the water added to wheat flour is heated to 70°C or higher, preferably 75°C or higher, and more preferably 80°C or higher. By setting the temperature of the water mixed with wheat flour to 70°C or higher, the starch in wheat flour is sufficiently gelatinized, the moist and chewy texture of the bakery food is excellent, and the change in the texture over time is also suppressed. The water temperature referred to in this specification is the water temperature under normal pressure, and the upper limit is usually 100°C.

In the present invention, when water vapor is used as the moisture to be added to wheat flour, the temperature of the water vapor is, for example, preferably from 100°C to 150°C in terms of gelatinization of starch and the associated moist and chewy texture and suppression of changes therein over time, and more preferably from 110°C to 130°C.

In the mixing process, the mixture of wheat flour and water and/or steam does not need to be a homogenous mixture, but may be in a mixed state. In addition, in this specification, the process of combining wheat flour with water and/or steam to obtain a mixture of wheat flour and water and/or steam does not necessarily require a homogenizing operation such as stirring. However, homogenizing processes such as stirring when obtaining a mixture of wheat flour and water and/or steam are not excluded from the present invention, and can be performed appropriately depending on the intended use and quality of the desired ground heat-treated wheat flour. The mixture of wheat flour and water and/or steam may be obtained by adding water and/or steam to wheat flour, or may be obtained by adding wheat flour to water and/or steam, but adding water and/or steam to wheat flour is advantageous in terms of uniformity and ease of mixing and stirring.

In the method for producing the ground heat-treated wheat flour of the present invention, the amount of water and/or steam mixed with the wheat flour in the mixing process is a predetermined amount. The amount of water and/or steam refers to the amount of water when only water is added, the amount of steam when only steam is added, and the total amount of both when water and steam are added. The amount of water and/or steam mixed with the wheat flour must be 20 parts by mass or more and 55 parts by mass or less per 100 parts by mass of wheat flour. By adding 20 parts by mass or more of water, the starch in the wheat flour is sufficiently gelatinized, a moist and chewy good texture is obtained, and the texture is maintained over time. On the other hand, by setting the amount to 55 parts by mass or less, the decrease in stickiness during bread making due to the heat denaturation of the protein in the wheat flour can be suppressed, and there is an advantage in that the workability is excellent. The amount of water and/or water vapor to be mixed with the wheat flour is preferably 23 parts by mass or more and 50 parts by mass or less, more preferably 23 parts by mass or more and less than 50 parts by mass, and particularly preferably 25 parts by mass or more and 45 parts by mass or less, per 100 parts by mass of wheat flour.

The water and/or steam (hereinafter sometimes referred to as "moisture") to be combined with the wheat flour may be only water or only steam, but containing water is preferable in that it allows the starch to be gelatinized more uniformly. When using a combination of water and steam, it is preferable in terms of starch gelatinization that the proportion of water in the total amount of both is 50% by mass or more and 95% by mass or less, and more preferably 65% by mass or more and 90% by mass or less. Note that a specific amount of steam can be obtained by using all of that amount of water as steam.

As described above, the mixture of wheat flour and water and/or steam at a predetermined temperature is heated at an ambient temperature of 80°C to 120°C for 3 to 60 seconds (hereinafter, this treatment is also simply referred to as "heat treatment"). The "ambient temperature" here refers to the air temperature in the space surrounding the mixture (wheat flour) that is the object to be heated, and is not the temperature of the object to be heated itself (the temperature of the mixture). By setting the ambient temperature to 80°C or higher and the heating time to 3 seconds or longer, it is easy to set the temperature of the mixture to 80°C or higher, and the starch in the wheat flour is easily gelatinized. By setting the ambient temperature to 120°C or lower and the heating time to 60 seconds or shorter, it is easy to set the temperature of the mixture to 100°C or lower. From these points of view, the heating time is preferably 4 to 30 seconds. Also, the ambient temperature is preferably 92°C to 110°C. In the present invention, the mixing of wheat flour and water and the heating may be performed simultaneously, or the heating may be performed after mixing. For example, by putting wheat flour and water into a container whose internal atmosphere has been heated in advance, wheat flour and water can be mixed together while being heated. In this case, the heating time starts when the wheat flour and water are put into the container.

One of the features of the method for producing ground heat-treated wheat flour of the present invention is that the temperature of the mixture is 80°C or higher and 100°C or lower in the heat treatment. When the temperature of the mixture is 80°C or higher, the starch in the wheat flour is sufficiently gelatinized, and a moist and chewy good texture is obtained. When the temperature of the mixture is 100°C or lower, a moist and chewy good texture is obtained, and bakery foods excellent in terms of workability, appearance (volume), and internal phase are obtained. From these points of view, the temperature of the mixture is preferably 83°C or higher and 98°C or lower, and more preferably 85°C or higher and 95°C or lower. In the method for producing ground heat-treated wheat flour of the present invention, the temperature of the mixture may reach 80°C or higher and 100°C or lower at least once during the heat treatment. For example, the temperature of the mixture can be measured at the completion of the heat treatment, but as described above, the temperature of the mixture at the completion of the heat treatment may be outside the range of 80°C or higher and 100°C or lower as long as it reaches 80°C or higher and 100°C or lower at least once during the heat treatment. In order to set the temperature of the mixture within the above range, the temperature and amount of water to be mixed with the wheat flour in the mixing process should be set within the above range, and the time from when the wheat flour and water are mixed to when the heat treatment starts should be adjusted, and further, the atmospheric temperature and heating time in the heat treatment should be set within the above range. It is preferable to continuously mix the wheat flour with water at a predetermined temperature and heat the mixture so that the temperature of the mixture at the end of heating is within the range described below. Continuously means, for example, that the mixing of the wheat flour with water at a predetermined temperature and the start of heating are performed within a few seconds, including the above-mentioned case where the wheat flour and water are each put into a container whose internal atmosphere has been heated in advance. When measuring the temperature of the mixture in the heat treatment device, for example, when a device is used for the heat treatment in which the contents are heated while being transferred from the inlet to the outlet in the container by an internal extruder, the temperature of the mixture can be the temperature of the mixture at the outlet.

The heat treatment according to the present invention can be carried out using any known heating device without any particular limitation, but preferably, a device that adds water and/or steam to gelatinize the starch in the wheat flour and performs heat treatment can be used. The heat treatment can be carried out using known heating devices such as an autoclave or a steam oven. One example of the heat treatment according to the present invention is a process in which wheat flour and water and/or steam are sealed in an aluminum pouch or a heatable sealed container using a heat jacket and heated under pressure. Before the introduction of wheat flour and water and/or steam, the atmosphere inside the sealed container may be heated to a desired temperature in advance. A mechanism for appropriate stirring may also be provided inside the sealed container. Pressurization may also be performed by heated steam in the sealed container. Another example of the heat treatment according to the present invention is a process in which wheat flour and water are introduced into a sealed container, and while stirring the mixture as necessary, saturated steam is introduced into the container simultaneously with, before, or after the introduction (preferably simultaneously with, or before the introduction) and heated under pressure (the amount of saturated steam in this case is included in the amount of steam added to the wheat flour). These treatments can be carried out, for example, using a single-screw or twin-screw extruder. In these cases, the steam introduced into the vessel comes into direct contact with the wheat flour, so the treatment is a heat treatment in which the steam comes into direct contact with the wheat flour.

Examples of wheat flour used as the raw material for the ground heat-treated wheat flour of the present invention include strong flour, semi-strong flour, medium-strength flour, weak flour, and durum wheat flour, and these may be used alone or in combination of two or more. In particular, wheat flour milled from domestically grown (Japanese) wheat (hereinafter also referred to as "domestic wheat flour") is preferable as the raw material for the ground heat-treated wheat flour of the present invention. As can be seen by comparing the texture evaluation of Examples 21 to 23 described below with other Examples, the present invention uses domestic wheat flour as the raw material, which provides a particularly excellent moist and chewy texture. The quality of wheat varies greatly depending on the soil and climate in which it is grown, and the quality of wheat of the same variety varies depending on the place of origin. It is believed that the above evaluation results differ because there is a difference in quality between domestically grown and foreign wheat.

As the wheat used as the raw material for the domestic wheat flour used in the present invention, both existing domestic wheat varieties and wheat varieties derived therefrom (wheat varieties resulting from the selective breeding of existing domestic wheat varieties) can be used. In the present invention, one type of domestic wheat flour made from a wheat variety selected from the group consisting of existing domestic wheat varieties and their derived varieties can be used alone, or two or more types can be used in combination.

Examples of the currently existing domestic wheat varieties include the following wheat varieties that have been registered in Japan to date.
Aoba no Koi, Akitakko, Abukumawase, Ayahikari, Iwainodaichi, Kitakamikomugi, Kitasachiho, Kitanokaori, Kitahonami, Kitamoe, Kinuakari, Kinuazuma, Kinuiroha, Kinu no Nami, Kinuhime, Koyukikomugi, Sato no Sora, Sanuki no Yume 2000, Sanuki no Yume 2009, Shunyou, Shirasagikomugi, Shiranekomugi, Shiroganekomugi, Seto Kirara, Taisetsukomugi, Takunekomugi, Double 8, Tamaizumi, Chikugoizumi, Chikushi W2, Chihokukomugi, Tsurukichi, Tsurupikari, Nambukomugi, Nishinokaori, Nishihonami, Ne Norigoshi, Nebarigoshi, Hanamante, Haruib, Haru Kirari, Haruhinode, Haruyutaka, Harebuki, Hareyutaka, Bandowase, Fusetsu, Fukuakari, Fukusayaka, Fuku Haruka, Fukuhonoka, Hokushin, Holosirikomugi, Mochihime, Yukichikara, Yukiharuka, Yumeakari, Yumeasahi, Yumekaori, Yumekirari, Yumeshihou, Yumeseiki, Yumechikara, Ginga no Chikara, Koiku No. 21, Haru no Kagayaki, Haruyokoi, Nagasaki W No. 2, Tokai No. 103, Tokai No. 104, Higashiyama No. 42, Norin No. 61, Fukui Prefectural University No. 3, Tone No. 3, Double No. 8, Minami no Kaori.

Domestic wheat varieties are broadly classified into weak (sometimes called "weak flour"), medium (sometimes called "medium strength flour") and strong (sometimes called "strong flour") types from the viewpoint of the characteristics of the variety and milling properties. The wheat used as the raw material for the domestic wheat flour used in the present invention is preferably medium or strong. Strong domestic wheat varieties usually have a protein content of 10.5 to 14% by mass, and medium domestic wheat varieties usually have a protein content of 8.0 to 10.5% by mass. The protein content here can be measured as the total crude protein content in the gluten vitality measurement described below. Among the above domestic wheat varieties, at least one selected from Yumechikara, Haruyutaka, Haruyokoi, Kitahonami, Chikugoizumi, and derivative varieties of these varieties is preferably used in the present invention in terms of ease of availability and the moist and chewy texture of the resulting bakery food. Among the domestically grown wheat varieties planted in fiscal year 2016, Kitahonami accounted for 43% of the total planted area in Japan, Haruyokoi 6%, Yumechikara 6%, Chikugoizumi 6%, etc., and these are representative varieties of domestically grown wheat.

In the present invention, the proportion of wheat flour of domestic wheat varieties in the wheat flour used as the raw material for the ground heat-treated wheat flour is preferably 30% by mass or more, more preferably 50% by mass or more, particularly preferably 70% by mass or more, and may be 100% by mass, in terms of improving the texture described above. Even when foreign wheat flour is used as the raw material for the ground heat-treated wheat flour, it is preferable to use medium or strong foreign wheat flour. Strong foreign wheat flour varieties usually have a protein content of 10.5 to 14% by mass, and medium foreign wheat flour varieties usually have a protein content of 8.0 to 10.5% by mass.

In the method for producing ground heat-treated wheat flour of the present invention, a mixture containing wheat flour and heated water is heat-treated as described above, and the heat-treated wheat flour obtained is ground. In the present invention, it is preferable to grind the heated mixture after heat treatment without going through a granulation process. The granulation process refers to a process of granulating the heated mixture into dough particles. Examples of the granulation process include a granulation process using an extrusion granulator, a mixing granulator, etc. In addition, a process of stretching the heated mixture with two rolls, cutting the stretched dough into granules, or a process of cutting the mixture extruded from a kneader into small pieces and granulating them when a kneader is used for the above-mentioned heat treatment. The particle diameter of the dough particles can be 1 mm to 50 mm, and preferably 5 mm to 20 mm. In the present invention, the heated mixture is ground without going through a granulation process, which has the advantage of shortening the production time and saving the space of the production equipment.

When the heat-treated wheat flour obtained by the heat treatment is ground, the method of the grinding process is not particularly limited and known methods can be used, such as roll grinding, impact grinding, airflow grinding, and pin mill grinding, among which pin mill grinding and airflow grinding are preferably used. The grinding is preferably performed to a particle size of the ground heat-treated wheat flour of the present invention described later, specifically a particle size in which the proportion of particles of 400 μm or less is 90% by mass or more, more preferably 91.5% by mass or more, and even more preferably 93% by mass or more.

In the present invention, the heat-treated wheat flour may be dried prior to grinding. As described above, heat-treated wheat flour is usually in a wet state, so the grinding process can be more appropriately performed by drying it before grinding. The drying process can be performed by known methods such as shelf drying, hot air drying, and fluidized bed drying. Drying may also be performed simultaneously with grinding. If the heat-treated wheat flour is not dried before grinding, it is preferable to dry it after grinding to improve its storage stability. The drying temperature during drying is preferably higher than 100°C and lower than 170°C in terms of shortening the drying time and workability in bread making using the heat-treated flour, more preferably 105°C to 170°C, and particularly preferably 120°C to 150°C.

Next, the ground heat-treated wheat flour of the present invention will be described. Ground heat-treated wheat flour of the present invention has a heat of gelatinization of 10 to 55 when the heat of gelatinization when untreated is taken as 100, a gluten vitality of 50 to 90 when the gluten vitality when untreated is taken as 100, a particle size distribution in which particles with a particle size of 400 μm or less account for 90% by mass or more, and a viscosity of 1 Pa·s to 4 Pa·s when water is added to the flour in an amount of 500% by mass at 25°C.

The ground heat-treated wheat flour of the present invention has excellent water absorption and swelling properties due to the gelatinization heat of 55 or less, and when bread is prepared, the bread has a good chewy texture. On the other hand, when the gelatinization heat is 10 or more, when bread is prepared, the stickiness of the dough is suppressed, and a good moist and chewy texture is obtained, and workability is improved. From these points of view, the gelatinization heat is preferably 13 to 50, and more preferably 15 to 47.

The heat-treated wheat flour of the present invention has a gluten vitality of 90 or less when the gluten vitality of the untreated wheat flour is taken as 100, so that the resulting bakery food has a moist and chewy good texture. When the gluten vitality of the untreated wheat flour is 50 or more when the gluten vitality of the untreated wheat flour is taken as 100, for example, breads obtained using the wheat flour have a large volume, a fine texture of the inner phase, and a moist and chewy good texture. From this viewpoint, the gluten vitality is preferably 55 or more and 85 or less, more preferably 60 or more and 80 or less.

The heat-treated wheat flour of the present invention has a viscosity of 1 Pa·s or more, which improves the water absorption and swelling properties of the wheat flour, and when bread is made using the wheat flour, for example, the bread has a chewy texture. The viscosity of 4 Pa·s or less suppresses the collapse of starch granules, making the dough non-sticky, and delays water release to increase the volume after baking. In addition, a fine internal phase is obtained, and the bread has a moist and chewy texture. From these viewpoints, the viscosity of the heat-treated wheat flour of the present invention is preferably 1.1 Pa·s or more and 3.7 Pa·s or less, and more preferably 1.2 Pa·s or more and 3.5 Pa·s or less.

The pulverized heat-treated wheat flour of the present invention has a ratio of particles with a particle size of 400 μm or less of 90% by mass or more, so that, for example, when preparing dough for bread, the wheat flour dissolves quickly in water and the dough is less sticky. In addition, the texture after baking is excellent and chewy, and roughness can be suppressed. From these points of view, it is more preferable that the pulverized heat-treated wheat flour of the present invention has a ratio of particles with a particle size of 400 μm or less of 91.5% by mass or more, and even more preferable that it has a ratio of 93% by mass or more.

The ground, heat-treated wheat flour having the above-mentioned gelatinization heat, gluten vitality, particle size and viscosity each falling within the above-mentioned ranges is suitably produced by the method for producing ground, heat-treated wheat flour of the present invention described above.

In the present invention, the gelatinization heat, gluten vitality, particle size, and viscosity are measured as follows. Hereinafter, the term "untreated flour" refers to flour before heat treatment, which is obtained by milling the same brand of wheat as the ground and heat-treated flour to be measured.
<<Measurement of heat of gelatinization>>
Using a differential scanning calorimeter (Seiko), an aluminum capsule containing 4 times the amount of distilled water relative to the dry matter weight of the ground heat-treated wheat flour and an aluminum capsule containing only the same amount of distilled water were heated at 5°C per minute from 25°C to 140°C, and the difference in endothermic energy between the two capsules was measured. The endothermic energy generated during gelatinization was expressed as heat of gelatinization (J/g) per gram of dry matter. The heat of gelatinization of the ground heat-treated wheat flour was determined as a relative value to the heat of gelatinization of the untreated flour, which was set at 100.

<Measurement of gluten vitality>
(1) Measurement of soluble crude protein content of wheat flour:
(a) 2 g of sample (wheat flour) is weighed out and placed in 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) The suspension obtained in (b) is transferred to a centrifuge tube and centrifuged at 5,000 rpm for 5 minutes, and then filtered using filter paper to recover the filtrate.
(d) The beaker used above is washed with 40 mL of 0.05 N acetic acid, the washings are transferred to a centrifuge tube, and centrifuged at 5,000 rpm for 5 minutes, followed by filtering using filter paper to recover the filtrate.
(e) The filtrates recovered in (c) and (d) are combined and the total volume is adjusted to 100 mL.
(f) 25 mL of the liquid obtained in (e) is placed in a Kjeldahl tube of a Kjeldahl Autosystem manufactured by Tickator (Sweden) using a volumetric pipette, and one tablet of a decomposition accelerator ("Keltab C" manufactured by Nippon General Co., Ltd.; potassium sulfate:copper sulfate = 9:1 (mass ratio)) and 15 mL of concentrated sulfuric acid are added.
(g) Using the Keltec decomposition furnace (DIGESTION SYSTEM 20 1015 type) incorporated in the above-mentioned Keltec auto system, decomposition treatment is performed for 1 hour at dial 4, and further decomposition treatment is automatically performed for 1 hour at dial 9 or 10. 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 Keltec distillation titration system (KJELTEC AUTO 1030 type) incorporated in the same Keltec auto system, and the soluble crude protein content of the sample (wheat flour) is calculated by the following formula.
(Equation 1)
Soluble crude protein content (%) = 0.14 x (TB) x F x N x (100/S) x (1/25)
In the formula,
T = amount of 0.1 N sulfuric acid required for titration (mL)
B = the amount of 0.1 N sulfuric acid required to titrate the blank (mL)
F = titer of 0.1 N sulfuric acid used in titration (measure when used or use a commercially available product with a titer indicated)
N = nitrogen protein conversion factor (5.70)
S = weight of sample (g)

(2) Measurement of total crude protein content of wheat flour:
(a) 0.5 g of the sample (wheat flour) is weighed out and placed in a Kjeldahl tube of the same Ticator Keltec Autosystem as used in (1) above, and one tablet of the same decomposition accelerator used in (1)(f) above and 5 mL of concentrated sulfuric acid are added to the sample.
(b) Using the same Keltec decomposition furnace of the Keltec auto system as used in (1) 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 above is continuously and automatically distilled and titrated (using 0.1 N sulfuric acid for titration) using the same Keltec distillation and titration system as used in (1) above, which is incorporated in the same Keltec auto system, to determine the total crude protein content of the sample (wheat flour) using the following formula.
(Equation 2)
Total crude protein content (%) = (0.14 x T x F x N) / S
In the formula,
T = Amount of 0.1 N sulfuric acid required for titration (mL)
F = Titer of 0.1 N sulfuric acid used in titration (measured at the time of use)
N = nitrogen protein conversion factor (5.70)
S = weight of sample (g)

(3) Calculation of gluten vitality:
The gluten vitality of the sample (wheat flour) is calculated from the soluble crude protein content of the sample (wheat flour) calculated in (1) above and the total crude protein content of the sample (wheat flour) calculated in (2) above, using the following formula. The gluten vitality value thus obtained for the untreated flour is taken as 100, and the relative value is taken as the gluten vitality of the heat-treated ground wheat flour.
(Equation 3)
Gluten vitality (%) = (soluble crude protein content/total crude protein content) x 100

Viscosity measurement
(1) Preparation of batter Pour 500 mL of water at 25°C into a bowl (manufactured by Hobart) and add 100 g of ground heat-treated wheat flour (with a moisture content of 8.0% to 15.0% by mass). Stir appropriately with a wire whip (manufactured by Hobart) to mix the flour and water, then stir with a mixer (manufactured by Hobart) for 1st = 30 seconds and 2nd = 240 seconds.
(2) Measurement Method Using a BM type viscometer, the viscosity is measured at 25° C. 10 minutes after stirring in the mixer.

<Particle size measurement>
500 g of wheat flour is sieved by hand for 60 seconds using a test sieve with 400 μm openings. The weight of the wheat flour remaining on the test sieve is measured and divided by 500 g. The room temperature and humidity during measurement are 25°C and 70°C, respectively. The moisture content of the wheat flour during particle size measurement is within the range of 8.0% to 15.0% by mass. The moisture content can be measured by a heat drying method.

The ground heat-treated wheat flour of the present invention can be used for various food applications after secondary processing, and a representative application is bakery food. Bakery food in the present invention refers to food obtained by subjecting a fermented or non-fermented dough obtained by adding secondary ingredients such as yeast, leavening agents, water, salt, and sugar as necessary to grain flour as the main ingredient, and subjecting the dough to heat treatment such as baking, steaming, and frying. Examples of bakery food to which the present invention can be applied include breads and confectioneries. Examples of breads include white bread, French bread, rolls, bread rolls, croissants, and pizza. Examples of confectioneries include donuts, dorayaki, sponge cake, butter cake, hotcakes, pancakes, muffins, and cookies.

The ground, heat-treated wheat flour of the present invention can be used as an ingredient in mixes for bakery foods.
The bakery food mix of the present invention contains the ground heat-treated wheat flour obtained by the method for producing ground heat-treated wheat flour of the present invention or the ground heat-treated wheat flour of the present invention. The inventors have found that by using the ground heat-treated wheat flour obtained by the method for producing ground heat-treated wheat flour of the present invention or the ground heat-treated wheat flour of the present invention, bakery foods having a moist and chewy texture, sufficient volume and fine internal phase, and texture that is unlikely to deteriorate over time can be obtained. However, there are various physical properties and characteristics of the ground heat-treated wheat flour obtained by the method for producing ground heat-treated wheat flour of the present invention, and it is practically impossible in the field of food with a short product life to disclose all of them and to apply for them, since it is necessary to develop a method for specifying the physical properties, and long-term research is required. Therefore, in this application, it is decided to specify the composition of the bakery food mix to contain the ground heat-treated wheat flour obtained by the method for producing ground heat-treated wheat flour of the present invention. As described above, there were circumstances in which it was impossible or almost impractical to directly specify the product by its structure or characteristics other than those described in this specification at the time of filing.

The bakery food mix of the present invention preferably contains non-heat-treated wheat flour in addition to the ground heat-treated wheat flour obtained by the method for producing ground heat-treated wheat flour of the present invention or the ground heat-treated wheat flour of the present invention, which is easy to improve the workability, texture, appearance, and internal phase. As the non-heat-treated wheat flour, untreated wheat flour that has not been heat-treated can be used, for example, strong flour, semi-strong flour, medium-strength flour, weak flour, durum flour, etc., and one of these can be used alone or two or more can be used in combination. As the non-heat-treated wheat flour, wheat flour made from either foreign or domestic wheat can be used. In particular, when domestic wheat flour is used as the raw material for the ground heat-treated wheat flour, it is preferable to use wheat flour made from foreign wheat as the non-heat-treated wheat flour in terms of ease of availability.

When the bakery food mix of the present invention contains non-heat-treated wheat flour, the amount of ground heat-treated wheat flour is preferably 1 part by mass or more and 40 parts by mass or less out of a total of 100 parts by mass of ground heat-treated wheat flour and non-heat-treated wheat flour. By making the amount of ground heat-treated wheat flour 1 part by mass or more, the texture improvement effect in bakery foods is more easily obtained. By making the amount of ground heat-treated wheat flour 40 parts by mass or less, the confectionery and bread making properties are improved. From these viewpoints, the amount of ground heat-treated wheat flour in the bakery food mix is more preferably 5 parts by mass or more and 40 parts by mass or less out of a total of 100 parts by mass of ground heat-treated wheat flour and non-heat-treated wheat flour, and even more preferably 10 parts by mass or more and 40 parts by mass or less.

In the bakery food mix of the present invention, out of a total of 100 parts by mass of the ground heat-treated wheat flour and non-heat-treated wheat flour, the amount of non-heat-treated wheat flour is preferably 60 parts by mass or more and 99 parts by mass or less, more preferably 65 parts by mass or more and 95 parts by mass or less, and even more preferably 70 parts by mass or more and 90 parts by mass or less, in view of its high effect of improving workability, texture, appearance, and internal phase.
Furthermore, the total amount of the ground heat-treated wheat flour and the non-heat-treated wheat flour in the bakery food mix is preferably 50% by mass or more, more preferably 55% by mass or more, and particularly preferably 60% by mass or more. In particular, the above amount is preferred for general bread use because it is highly effective in improving workability, texture, appearance, and internal phase.

The bakery food mix may contain ingredients other than the ground heat-treated wheat flour and non-heat-treated wheat flour. For example, cereal flours other than wheat flour, such as rye flour, barley flour, buckwheat flour, rice flour, soybean flour, corn flour, etc.; potato starch, corn starch, waxy starch, wheat starch, and processed starches obtained by subjecting these to pregelatinization, etherification, esterification, crosslinking, oxidation, etc.; leavening agents or yeast, such as sodium hydrogen carbonate, baking powder, ammonium carbonate, ammonium hydrogen carbonate, and ammonium chloride; fats and oils, such as salad oil; sugars, such as sugar; eggs, such as whole eggs, egg whites, and egg yolks; dairy products, such as milk, skim milk powder, and butter; salts, such as salt; emulsifiers, thickeners, acidulants, flavorings, spices, colorings, fruit juice, fruits, vitamins, etc., which may be used alone or in combination of two or more. These other ingredients may be mixed together when the ground heat-treated wheat flour and the non-heat-treated wheat flour are mixed, or may be mixed in advance with either the ground heat-treated wheat flour or the non-heat-treated wheat flour, or may be further mixed after the ground heat-treated wheat flour and the non-heat-treated wheat flour are mixed.

The present invention has been described above based on its preferred embodiments, but the preferred configurations described in the above or below examples can be combined with any other preferred configurations described above or below. Note that the preferred configurations referred to here are not limited to more preferred, particularly preferred, etc., and can be combined with any other configuration at any stage.

Examples are provided to illustrate the present invention in detail, but the present invention is not limited to the following examples.

(Examples 1 to 23, Comparative Examples 1 to 8)
A sealed container equipped with a heat jacket and a single-screw extruder was heated in advance to the atmospheric temperature shown in Table 1. Specifically, the sealed container was heated from the outside by a heat jacket using steam as a heat source, and the atmospheric temperature inside the container was heated to the temperature shown in Table 1.
Thereafter, wheat flour was prepared by milling the varieties and brands of wheat listed in Table 1. Water and steam heated to the predetermined temperatures listed in Table 1 were prepared in the amounts listed in Table 1. Wheat flour and the heated water and/or steam were mixed in the sealed container, heated for the predetermined time listed in Table 1 in the sealed container set to the predetermined atmospheric temperature, and then discharged from the sealed container. The temperature of the mixture at the completion of heating (the temperature of the mixture at the outlet of the sealed container) was the temperature shown in Table 1. The mixture after the heat treatment was dried at 130°C by shelf drying without going through a granulation process, and then pulverized so that the pulverized heat-treated wheat flour obtained had the particle size listed in Table 1 using a pin mill, and the mixture particles were collected as pulverized heat-treated wheat flour. The particle size of the obtained pulverized heat-treated wheat flour, the heat of gelatinization (gelatinization heat ratio) when the heat of gelatinization when untreated was set to 100, the gluten vitality (gluten vitality ratio) when the gluten vitality when untreated was set to 100, and the viscosity when water was added to 500% by mass of the flour at 25°C were each measured by the above-mentioned method. The inside of the container was heated under pressure by the water and steam used above.

(Comparative Example 9)
Heat-treated wheat flour was obtained in the same manner as in Example 18, except that no pulverization was performed after the heat treatment. The particle size, heat of gelatinization (gelatinization heat ratio) when the heat of gelatinization when untreated was set to 100, gluten vitality (gluten vitality ratio) when the gluten vitality when untreated was set to 100, and viscosity when water was added to 500% by mass of the flour at 25°C were measured by the above-mentioned methods.

(Comparative Example 10)
Wheat flour milled from the varieties of wheat listed in Table 1 was directly pulverized in a pin mill, and the particle size, heat of gelatinization (heat of gelatinization ratio) when the heat of gelatinization when untreated was taken as 100, gluten vitality (gluten vitality ratio) when the gluten vitality when untreated was taken as 100, and viscosity when water was added to 500% by mass of the flour at 25°C were measured using the methods described above.

(Test Example 1)
Using the ground heat-treated wheat flour of Examples 1 to 23 and Comparative Examples 1 to 8 and the treated wheat flour of Comparative Examples 9 and 10, bread, a type of bakery food, was produced by the following method. The obtained bread was left to stand at room temperature (25°C) for one day, and then the texture and appearance of the obtained bread were evaluated by 10 expert panelists based on the following evaluation criteria. The 10 expert panelists also evaluated the workability during bread production, and also evaluated the texture of the obtained bread after leaving it to stand at room temperature (25°C) for three days based on the following evaluation criteria. The average evaluation scores of each panelist are shown in Table 1.

(Method of manufacturing bread)
In a mixing bowl of a commercially available bread mixer (Dalton Co., Ltd., universal mixer model 5DM-03-r), 320 g of wheat flour milled from 1CW wheat, 80 g of ground heat-treated wheat flour or treated wheat flour to be evaluated, 8 g of salt, 32 g of sugar, 9.2 g of fresh yeast (Oriental Yeast Co., Ltd., "Oriental Yeast"), 0.4 g of yeast food (Oriental Yeast Co., Ltd., "C Yeast Food"), and an appropriate amount of water were added, and a mixing process was carried out to prepare bread dough. Specifically, mixing was performed at low speed for 4 minutes, followed by mixing at high speed for 2 minutes, and then 16 g of oil was added and mixed at low speed for 4 minutes, followed by kneading at high speed for 1 minute (kneading temperature 27°C). The dough thus obtained was fermented for 1 hour under conditions of 27°C and 75% relative humidity, then divided into 450g portions and rolled into balls, rested for 30 minutes, and then rolled into a loaf of bread mold. The dough was then proofed for 60 minutes (under an atmosphere of 38°C and 85% relative humidity), and then baked at 200°C for 30 minutes to obtain loaf of bread.

(Evaluation criteria for workability during bread production)
5 points: The dough is not sticky throughout the entire bread production process and is suitable for secondary processing.
4 points: The dough becomes sticky during part of the bread making process, but this does not cause any problems in secondary processing.
3 points: The dough becomes sticky throughout the entire bread-making process, but this does not cause any problems in secondary processing.
2. The dough becomes sticky throughout the entire bread-making process, making secondary processing difficult unless special care is taken when handling the dough.
1 point: The dough was extremely sticky throughout the entire bread production process, making secondary processing difficult.

(Evaluation criteria for bread texture)
5 points: The whole product has a sufficiently moist and chewy texture, and the taste and texture are good.
4 points: Although it may lack moistness or softness in some parts, overall it has a moist and chewy texture and there are no problems with taste or texture.
3 points: Slightly moist and chewy.
2 points: Not very moist or chewy overall, and dry in some areas.
1 point: Overall the food is too soft or has a dry texture, and the taste and texture are poor.

(Evaluation criteria for bread appearance (volume))
5 points: Very large and good volume.
4 points: Large and good volume.
3 points: The volume is a little large.
2 points: The volume is rather small and poor.
1 point: The volume is small and poor.

(Evaluation criteria for the crumb quality of bread)
5 points: The texture of the inner phase is very fine and good.
4 points: Fine and good texture.
3 points: Some fineness is observed.
2 points: The texture is slightly coarse and poor.
1 point: The texture is rough and poor.

As shown in Table 1, in each example in which the method of the present invention is used and the specific heat of gelatinization, gluten vitality, particle size distribution, and viscosity are satisfied, workability, a moist and chewy texture, a voluminous appearance, a fine internal phase, and suppression of deterioration of texture over time are realized. On the other hand, Comparative Examples 1 and 2 in which the amount of water in the mixing process is less than 20 parts by mass or more than 55 parts by mass per 100 parts by mass of wheat flour, Comparative Examples 3 and 4 in which the temperature of the water in the mixing process is less than 70°C, Comparative Examples 5 to 7 in which the temperature of the mixture at the end of heating is less than 80°C or more than 100°C or the heating time is less than 3 seconds or more than 60 seconds, Comparative Example 9 in which grinding was not performed, and Comparative Example 10 in which heat treatment was not performed are outside the range of heat of gelatinization, gluten vitality, particle size distribution, or viscosity of the present invention, and are inferior in any of workability, texture, appearance, and internal phase.

(Test Example 2)
In Test Example 1, the ground heat-treated wheat flour obtained in Example 2 or 6 was used as the ground heat-treated wheat flour to be evaluated, and the blending amount of this and the strong flour (wheat flour milled from wheat 1CW) as the non-heat-treated wheat flour was appropriately changed to the predetermined amount shown in Table 2, and bread was produced by the above (bread production method). The obtained bread was left to stand at room temperature (25°C) for one day. The workability during bread production, and the texture, appearance (volume) and internal phase of the bread were evaluated by 10 expert panelists based on the same evaluation criteria as in Test Example 1. The results are shown in Table 2.

As shown in Table 2, the bakery food mixes of each of the manufacturing examples, which contain 1 to 40 parts by mass of ground heat-treated wheat flour out of a total of 100 parts by mass of ground heat-treated wheat flour and non-heat-treated wheat flour, are found to have excellent workability, texture, appearance, and internal structure.

The ground heat-treated wheat flour produced by the manufacturing method of the present invention, the ground heat-treated wheat flour of the present invention, and the bakery food mix using them can produce bakery foods that have a moist and chewy texture, sufficient volume and a fine internal structure, and are less likely to deteriorate in texture over time. Furthermore, the ground heat-treated wheat flour produced by the manufacturing method of the present invention, the ground heat-treated wheat flour of the present invention, and the bakery food mix using them are excellent in secondary processing suitability, so that the dough is less likely to become sticky during the manufacturing process, have excellent workability, and the bakery food can be efficiently manufactured.

Claims (9)

100 parts by mass of wheat flour and 20 to 55 parts by mass of water and/or water steam at 70° C. or higher are mixed under conditions in which 17 parts by mass or more of water is added per 100 parts by mass of wheat flour to obtain a mixture;
The method for producing the heat-treated pulverized wheat flour includes a step of heating the mixture at an atmospheric temperature of 80°C to 120°C for 3 seconds to 60 seconds to reduce the temperature of the mixture to 80°C to 100°C, and then pulverizing the mixture. The method for producing the heat-treated ground wheat flour according to claim 1, in which the heated mixture is ground without going through a granulation process. The method according to claim 1 or 2, wherein the wheat flour is wheat flour milled from domestically produced wheat. The method according to any one of claims 1 to 3, wherein the pulverizing step adjusts the pulverized heat-treated wheat flour to a particle size distribution in which particles with a particle size of 400 μm or less make up 90% by mass or more. The heat of gelatinization of the untreated product is 10 to 55,
The gluten vitality is 50 to 90, where the gluten vitality of the untreated gluten is 100.
A ground, heat-treated wheat flour having a particle size distribution in which particles having a particle size of 400 μm or less account for 90% by mass or more, and a viscosity of 1 Pa·s to 4 Pa·s when water is added in an amount of 500% by mass relative to the flour at 25° C. A mix for bakery foods containing ground heat-treated wheat flour produced by the method according to any one of claims 1 to 4 or the ground heat-treated wheat flour according to claim 5. The bakery food mix according to claim 6, further comprising non-heat-treated wheat flour, the amount of the ground heat-treated wheat flour being 1 part by mass or more and 40 parts by mass or less, and the amount of the non-heat-treated wheat flour being 60 parts by mass or more and 99 parts by mass or less, relative to 100 parts by mass of the total amount of the ground heat-treated wheat flour and the non-heat-treated wheat flour. A method for producing a mix for bakery foods, comprising a step of mixing the ground heat-treated wheat flour produced by the method according to any one of claims 1 to 4 or the ground heat-treated wheat flour according to claim 5 with non-heat-treated wheat flour, in which the mixing ratio is 1 part by mass to 40 parts by mass of the ground heat-treated wheat flour and 60 parts by mass to 99 parts by mass of the non-heat-treated wheat flour per 100 parts by mass of the total amount of the ground heat-treated wheat flour and the non-heat-treated wheat flour. 100 parts by mass of wheat flour is mixed with 20 parts by mass to 55 parts by mass of water and/or water steam at 70°C or higher to obtain a mixture;
The method for producing the ground heat-treated wheat flour includes a step of heating the mixture at an atmospheric temperature of 80° C. to 120° C. for 3 seconds to 60 seconds to reduce the temperature of the mixture to 80° C. to 100° C., and then grinding the mixture,
A method for producing heat-treated ground wheat flour, wherein water at 70° C. or higher is used, and when water and steam are used in combination, the proportion of water in the total amount of both is 50% by mass or more and 95% by mass or less.