JP7724057B2 - Rice flour composition for bread, rice flour bread dough, and method for producing rice flour bread using the same - Google Patents

Description

The present invention relates to a rice flour composition for bread, rice flour bread dough, and a method for making rice flour bread using these.

Wheat flour is typically used as the main ingredient in bread. However, in recent years, due to fluctuations in grain prices and to accommodate wheat allergy sufferers, research has been ongoing into bread made with rice flour as a substitute for wheat flour. However, unlike wheat flour, rice flour does not contain gluten, which improves the extensibility and elasticity of bread dough, so bread made with rice flour generally has less volume and elasticity. For this reason, to increase the volume of the product, gluten, a wheat protein, is usually added separately during the production of rice flour bread, but this does not eliminate the cause of wheat allergies. For this reason, while technological development has been underway to produce gluten-free rice flour bread, it has been difficult to obtain rice flour bread that has both good rise and texture. Furthermore, conventional rice flour bread has the problem of its moist texture deteriorating over time and not lasting long.

Various approaches to solving these problems have been explored, including the use of food additives, modified starch, alginic acid, and other additives (Patent Documents 1 to 4). However, with consumers becoming increasingly health-conscious in recent years, there is a demand for products that do not contain food additives or that contain reduced amounts of food additives.

Japanese Patent Application Laid-Open No. 2005-245409 Japanese Patent Application Laid-Open No. 2019-87319 Japanese Patent Application Laid-Open No. 2019-126311 JP 2010-239902 A

The object of the present invention is to provide a rice flour composition for bread, rice flour dough, and a method for producing rice flour bread using the same, which have good rise and texture and are inhibited from deteriorating in texture after storage.

The inventors discovered that the above problems could be solved by using a specific amount of roasted rice flour in a rice flour composition for bread, leading to the completion of the present invention.

That is, the present invention includes the following aspects.
[1] A rice flour composition for bread, containing 1.5% by mass or more of the roasted rice flour based on the total amount of rice flour and roasted rice flour.
[2] The rice flour composition for bread according to [1], containing 20% by mass or more of the roasted rice flour relative to the total amount of rice flour and roasted rice flour.
[3] Rice flour bread dough containing the rice flour composition for bread according to [1] or [2].
[4] A method for producing rice flour bread using the rice flour composition for bread according to [1] or [2] or the rice flour bread dough according to [3].

The present invention provides a rice flour composition for bread, rice flour bread dough, and a method for producing rice flour bread using the same, which are used to produce rice flour bread that has good rise or texture and inhibits deterioration of texture after storage. The effects of the present invention can be achieved without using gluten or food additives, thereby avoiding the problem of wheat allergies, contributing to increased consumption of domestically produced rice and rice flour, and also meeting the health-conscious needs of consumers.

The following describes how to implement the present invention.

[Rice flour composition for bread]
The rice flour composition for bread of the present invention contains roasted rice flour. In the present invention, "roasted rice flour" refers to rice flour obtained through a roasting and heating process. In the present invention, simply "rice flour" refers to rice flour that has not been subjected to a roasting and heating process (also referred to as ordinary rice flour). Roasted rice flour may be obtained by roasting and heating rice grains and then grinding them, or by roasting and heating rice flour obtained by grinding rice grains. Roasted rice flour is preferably obtained by roasting and heating rice flour obtained by grinding rice grains. There are no particular limitations on the techniques and devices that can be used for roasting rice flour or rice grains. Examples of roasting devices include hot air roasters, roasters using heat such as gas flames or charcoal fires, and electric roasters. These roasting devices can be equipped with a mixing and stirring function to uniformly roast the rice flour or rice grains. Examples of such mixing and stirring methods include a stirrer, a drum rotation type, and an airflow stirring type.

Roasted rice flour can be produced using known techniques, but for example, it can be obtained by roasting and heating for 5 to 30 minutes using a paddle dryer (for example, manufactured by Nara Machinery Co., Ltd.) at temperatures of 30°C near the inlet, 50 to 150°C at the middle position, and 100 to 200°C near the outlet. These temperatures are those of the rice flour measured with thermometers installed at each point of the paddle dryer.
The moisture content of the roasted rice flour is preferably 8% by mass or less, more preferably 1 to 5% by mass, and even more preferably 1.5 to 3% by mass. The degree of gelatinization of the roasted rice flour is preferably 5 to 50%, more preferably 20 to 40%, and even more preferably 15 to 35%.
The moisture content of roasted rice flour can be determined by drying the roasted rice flour for 1 to 2 hours at an oven temperature of 120 to 150° C. and measuring the difference in mass before and after drying. The degree of gelatinization of roasted rice flour can be measured by any known method, such as the diastase method, glucoamylase method, glucoamylase II method, and β-amylase-pullulanase method.

The above-mentioned rice flour is made by finely crushing rice (non-glutinous rice or glutinous rice) into granules using a known crusher (e.g., cutter mill, pin mill, hammer mill, roll mill, automatic stone mill, airflow crusher, etc.). The above-mentioned rice is preferably polished rice. The crushed rice may also be sieved using a sifter to size the grain. The moisture content of rice flour is generally around 11% by mass.

The rice flour composition for bread of the present invention contains 1.5% by mass or more of the roasted rice flour relative to the total amount of rice flour and roasted rice flour. When the roasted rice flour content is equal to or greater than the above-mentioned lower limit, rice flour bread can be obtained that combines good rise and texture and suppresses deterioration of texture. Furthermore, when the roasted rice flour content is equal to or greater than the above-mentioned lower limit, the bread production time can be shortened compared to when roasted rice flour is not included. Specifically, bread dough that does not include roasted rice flour generally has a low viscosity, which makes it easy for gas generated by fermentation to escape. However, by using roasted rice flour in which the starch is partially pregelatinized, the viscosity of the dough can be increased, improving the gas retention ability and shortening the fermentation time of the dough. Furthermore, because the water absorption of roasted rice flour is superior to that of non-roasted rice flour, the time required to mix the rice flour composition with water can be shortened. Furthermore, because the roasted rice flour is already partially heated, the baking time of the dough can be shortened.
The content of the roasted rice flour is preferably 2% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, even more preferably 20% by mass or more, particularly preferably 30% by mass or more, preferably 90% by mass or less, and more preferably 80% by mass or less, based on the total amount of rice flour and roasted rice flour. If the content of the roasted rice flour is more than 15% by mass but less than 95% by mass, rice flour bread can be obtained that is voluminous, has a good pore size, and has a moist and soft texture. The content of the roasted rice flour may be 100% by mass based on the total amount of rice flour and roasted rice flour, and the rice flour composition for bread of the present invention does not need to contain (unroasted) rice flour.

The rice flour composition for bread of the present invention may further contain secondary ingredients in addition to the roasted rice flour. Examples of such secondary ingredients include powdered milk, salt, dietary fiber, grain flour other than rice flour, starch, coloring, sugars, fats and oils (butter, lard, etc.), eggs, seasonings, dairy products, and spices. When the rice flour composition for bread contains the above secondary ingredients, the content of each of the above secondary ingredients can be set to an exclusive ratio of 0.1 to 10 parts by mass per 100 parts by mass of the rice flour composition for bread. The rice flour composition for bread of the present invention can also be pre-mixed with the above secondary ingredients and used as a rice flour bread mix.

The rice flour composition for bread of the present invention can be used to produce rice flour bread that combines good leavening and texture even without containing gluten, so it is preferable that it is substantially free of wheat flour-derived gliadin, glutenin, or gluten. Note that "substantially free" means that the content is less than 0.5% by mass, preferably less than 0.1% by mass, of the total amount of rice flour and roasted rice flour. It is also preferable that the rice flour composition for bread of the present invention is substantially free of food additives such as thickening polysaccharides.

[Rice flour bread dough]
The rice flour bread dough of the present invention can be obtained by kneading the rice flour composition for bread described above, which may optionally contain auxiliary ingredients, together with water. The method for producing the rice flour bread dough may be the same as the method for producing ordinary rice flour bread dough.

[Method for producing rice flour bread]
The method for producing rice flour bread of the present invention can be a conventional bread-making method, except that the rice flour composition for bread or the rice flour bread dough is used. Examples of such methods include a kneading step in which the rice flour composition for bread, which may optionally contain auxiliary ingredients, water, and yeast are added and kneaded, a fermentation step in which the rice flour bread dough obtained in the kneading step is fermented, and a heating step in which the fermented rice flour bread dough obtained in the fermentation step is shaped as desired and heated.
The water may be partially or entirely replaced with a liquid other than water, such as milk, soy milk, etc. The yeast may be any yeast commonly used as baker's yeast, and examples thereof include live yeast, dry yeast, and natural yeast.
The kneading can be performed by hand or using a commercially available kneader. The temperature, speed, time, etc. can be appropriately set according to conventional methods. The rice flour bread dough obtained in the kneading step may be aged under low-temperature ripening conditions, for example, at 0 to 5°C, before being subjected to the fermentation step.
Fermentation can be carried out at room temperature or in an incubator at a temperature of 20 to 40°C, preferably 30 to 38°C, for 20 to 40 minutes, preferably 25 to 35 minutes (primary fermentation). Secondary fermentation and maturation may be carried out under similar conditions. The primary fermentation can be omitted.
The fermented rice flour bread dough that has been optionally aged is molded into a mold appropriate for the type of bread and heated to obtain rice flour bread. The heating method is preferably baking using a heater such as an oven, but other methods such as microwave heating, frying, boiling, or steaming may also be used.

Rice flour breads obtainable by the rice flour bread manufacturing method of the present invention include white bread, rolls, sweet buns, donuts, bagels, and cooked bread. Examples of white bread include white bread, French bread, variety bread, and English muffins. Examples of rolls include table rolls, butter rolls, buns, sweet rolls, and buns. Examples of sweet buns include bread filled with fillings such as bean paste buns, jam buns, cream buns, and curry buns, as well as melon bread, raisin bread, Danish pastries, croissants, brioches, and steamed buns. Examples of cooked breads include hamburgers, hot dogs, and pizza.

The rice flour bread can also be crushed and sieved in the usual way to produce rice breadcrumbs separated by particle size. The resulting rice breadcrumbs can be used in applications typically associated with breadcrumbs, such as coatings for deep-fried foods and as a binder for fish paste.

The present invention will be explained in more detail below using examples, but the present invention is not limited to these examples.

Production Example 1: Production of roasted rice flour. 150 kg of rice flour obtained by grinding polished non-glutinous rice using an airflow grinder was placed in a paddle dryer (set temperature: 150°C) manufactured by Nara Machinery Manufacturing Co., Ltd. and heated for 15 minutes with stirring to obtain roasted rice flour. Thermometers installed near the entrance, middle position, and exit of the paddle dryer gave readings of 30°C, 75°C, and 150°C, respectively.
The roasted rice flour thus obtained had a moisture content of 2% by mass and a degree of gelatinization of 29%. The moisture content was determined by spreading the roasted rice flour evenly in a glass container to a height of 5 mm or less, placing it in a dry heat dryer at a temperature of 135°C without a lid, and leaving it for 2 hours. The moisture content was then calculated by subtracting the mass after drying from the mass before drying and dividing the difference by the mass before drying. The degree of gelatinization was measured by the diastase method.

Production Example 2: Production of rice flour bread The flour ingredients, liquid ingredients, and oil ingredients shown in the recipe below were placed in a mixer (vertical mixer, manufactured by Kanto Mixing Machinery Co., Ltd.) and kneaded at low speed for 1 minute, medium speed for 1 minute, and high speed for 5 minutes to obtain rice flour bread dough. The kneading temperature was 25°C. 500 g of the obtained rice flour bread dough was placed in a loaf mold for loaf bread and fermented for 35 minutes at 38°C and a relative humidity of 85%. The obtained fermented rice flour bread dough was baked for 35 minutes in a fixed oven at an internal temperature of 180°C to obtain rice flour bread. In the recipe below, "regular rice flour" refers to unroasted rice flour obtained by air-milling non-glutinous rice, and "roasted rice flour" refers to rice flour obtained by roasting the above-mentioned regular rice flour.

The resulting rice flour bread was subjected to a taste evaluation by 10 experienced panelists according to the following evaluation criteria table at three points: immediately after cooling, after frozen storage and thawing (quick freezing at -30°C, storage at -20°C for 7 days, and then thawing at room temperature), and after sealing in a plastic bag and storing at room temperature for 3 days. For the evaluation, rice flour bread that did not contain roasted rice flour (Control Example 1) was rated 3 points immediately after cooling.

Test Example 1: Production of rice flour bread using roasted rice flour Rice flour bread was produced according to Production Example 2, except that the blending amounts (parts by mass) of regular rice flour and roasted rice flour were as shown in Tables 1 to 3 below, and a taste evaluation was carried out at each time point. Table 1 shows the results immediately after cooling, Table 2 shows the results after frozen storage and thawing, and Table 3 shows the results after sealing in a plastic bag and storing at room temperature for 3 days.

As can be seen from Table 1, the rice flour bread of Example 1, which contained 1.5 parts by mass of roasted rice flour, had improved moistness compared to the rice flour bread of Control Example 1, which did not contain roasted rice flour. As the roasted rice flour content increased, both the appearance and texture improved. Although the volume, openness, and softness decreased slightly when the roasted rice flour content exceeded 70 parts by mass, they were still significantly better than Control Example 1. The rice flour bread of Comparative Example 1, which contained 1 part by mass of roasted rice flour, was evaluated as being equivalent to Control Example 1.

As can be seen from Table 2, the texture of the rice flour bread of Control Example 2 deteriorated after freezing and thawing. On the other hand, Examples 9 to 16, which contained 1.5 parts by mass or more of roasted rice flour, showed less deterioration in texture than Control Example 2. Generally, rice flour bread immediately after baking tends to have a soft but sticky texture due to the gelatinized starch. When rice flour bread is frozen and thawed, the gelatinized starch undergoes appropriate retrogradation, eliminating the stickiness and bringing out the softness. This tendency was stronger in the frozen-thawed rice flour breads of Examples 12 to 16, which contained 20 parts by mass or more of roasted rice flour, which tended to have a softer texture than Examples 4 to 8, which correspond to rice flour bread immediately after baking, and this tendency became stronger as the roasted rice flour content increased.

As can be seen from Table 3, the texture of the rice flour bread of Control Example 3 deteriorated after three days of storage at room temperature. On the other hand, Examples 17 to 24, which contained 1.5 parts by mass or more of roasted rice flour, showed less deterioration in texture than Control Example 3.

Test Example 2: Production of rice flour bread using roasted rice flour The bread production times were compared between rice flour bread produced according to Production Example 2 using the bread-making ingredient combinations listed in the recipe above and a control rice flour bread that did not contain roasted rice flour. The mixing time was measured by mixing the flour ingredients, liquid ingredients, and oil ingredients at a constant speed until the dough was homogenized, and the proofing time was measured by measuring the time until the dough volume rose to twice its original volume. The results are shown in Table 4 below. For reference, the production time for a typical wheat flour bread that does not use rice flour is also listed.

Table 4 shows that in Example 25, which used roasted rice flour, at least the mixing time and proofing time were shorter than in Control Example 4, which did not use roasted rice flour.

Claims (7)

A rice flour composition for bread, which is composed of rice flour and roasted rice flour and is used to produce fermented bread that is frozen and does not contain any grain flour other than rice flour, wherein the rice flour composition contains 10 to 90 mass% of the roasted rice flour relative to the total amount of rice flour and roasted rice flour, and the roasted rice flour is roasted rice flour of non-brown rice. The rice flour composition for bread according to claim 1, containing 20 to 80% by mass of the roasted rice flour based on the total amount of rice flour and roasted rice flour. 3. The rice flour composition for bread according to claim 1 , wherein the moisture content of the roasted rice flour is 1.5 to 3% by mass. A rice flour bread dough for producing rice flour bread that can be stored frozen , comprising the rice flour composition for bread according to any one of claims 1 to 3 and containing no grain flour other than rice flour. A method for producing rice flour bread that can be stored frozen , using the rice flour composition for bread according to any one of claims 1 to 3 or the rice flour bread dough according to claim 4 . a kneading step of adding water and yeast to the rice flour composition for bread according to any one of claims 1 to 3 and any other optional secondary ingredients (however, the secondary ingredients do not include grain flour other than rice flour), and kneading the mixture; and a fermentation step of fermenting the rice flour bread dough obtained by the kneading step.
The method for producing fermented rice flour bread dough for producing rice flour bread to be frozen and stored includes the steps of: A method for producing rice flour bread to be frozen and stored , comprising a heating step of optionally shaping and heating the fermented rice flour bread dough obtained by the method according to claim 6 .