JP2019115373A - Method for producing rice flour bread that does not include gluten or thickener - Google Patents

Abstract

To provide a method for producing rice flour bread that does not include gluten or thickener conveniently.SOLUTION: A method for producing rice flour bread includes fermenting and burning bread dough that contains rice flour having 5% or less of a starch damage rate and 80% or less of a water absorption, water and yeast and does not include gluten or thickener. There is also provided bread dough for use in the method and rice flour bread obtained by the method.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing rice flour bread free of gluten and thickener.

  In recent years, development of rice flour bread has been encouraged for the purpose of expanding consumption of rice flour. On the other hand, since gluten (wheat gluten) contained in wheat flour bread is known to cause wheat allergy and celiac disease symptoms etc., rice flour bread using rice flour as a substitute for wheat flour is a food for those patients. Is also attracting attention.

  Gluten is an important ingredient in making puffy bread. In general production of wheat flour bread, by adding water to the wheat flour and kneading, the protein gliadin and glutenin contained in the wheat flour produce "gluten" rich in tenacity and elasticity, which is the extensibility and elasticity of the dough. It is known that the flour bread after fermentation / baking comes to have good puffiness and softness by enhancing the property.

  However, bread dough using only rice flour containing no gliadin or glutenin as a main ingredient does not produce gluten even if the dough is mixed. For this reason, in general, in the same bread making method as wheat flour bread, bread using 100% of rice flour as grain flour is considered not to fully swell. Therefore, wheat flour and gluten are mixed in most of commercially available rice flour bread and commercially available rice flour for producing rice flour bread. However, such products contain relatively high amounts of wheat gluten and therefore can not be taken by wheat allergic patients or celiac disease patients.

  Development of technology to produce gluten-free rice flour bread is also in progress. For example, a method of baking using a plastic foam molding technique (Patent Document 1), a method of using a dough compounded with pregelatinized rice flour or pregelatinized starch (Patent Documents 2 and 3 etc.), a method of adding a thickener (patent Literature 4 et al.). However, rice flour bread produced by these methods has a problem that the quality is remarkably inferior in terms of feeling of softness and softness as compared to wheat flour bread and rice flour bread produced by adding gluten.

  The inventor of the present invention has developed a method for producing rice flour bread with a good expansion and fine texture by blending glutathione with rice flour (Patent Document 5). Furthermore, a method for producing rice flour bread using rice flour and sorghum flour has also been developed (Patent Document 6). However, there is still a need to develop a method which can produce rice flour bread free of gluten and thickener in a simpler method without using special auxiliary materials such as glutathione and sorghum flour.

Unexamined-Japanese-Patent No. 2003-189786 JP, 2006-174822, A JP 2007-215401 A JP, 2005-245409, A International Publication WO2011 / 033994 Unexamined-Japanese-Patent No. 2015-107081

  An object of the present invention is to provide a simple method for producing a puffy rice flour bread free of gluten and thickener.

  As a result of intensive studies to solve the above problems, the present inventor can use rice flour exhibiting predetermined properties to produce rice flour bread with good swelling without using gluten, thickeners and the like. The present invention has been completed.

That is, the present invention includes the following.
[1] A rice flour bread comprising fermenting and baking a bread dough comprising rice flour, water and yeast exhibiting a damaged starch ratio of 5% or less and a water absorption coefficient of 80% or less and containing no gluten and no thickener. Manufacturing method.
[2] The method according to the above [1], wherein the damaged starch rate of rice flour is 3% or more and the water absorption rate is 72% or more.
[3] The method according to the above [1] or [2], wherein the bread dough further comprises one or more selected from sugar, salt and fats and oils.
[4] The method according to any one of the above [1] to [3], wherein the bread dough is fermented to a specific volume of 4 mL / g or more.
[5] The method according to any one of the above [1] to [4], which comprises the step of preparing the bread dough.
[6] A bread dough comprising rice flour, water and yeast showing a damaged starch ratio of 5% or less and a water absorption of 80% or less, and containing no gluten and no thickener.
[7] The bread dough according to the above [6], wherein the damaged starch rate of rice flour is 3% or more and the water absorption rate is 72% or more.
[8] The bread dough according to the above [6] or [7], further comprising one or more selected from sugar, salt, and fats and oils.
[9] The bread dough according to any one of the above [6] to [8] which is fermented.
[10] The dough according to the above [9], which has a specific volume of 4 mL / g or more.
[11] A gluten-free and thickener-free rice flour bread produced using the dough according to any one of the above [6] to [10].

  According to the present invention, a glutinous rice flour bread free from gluten and thickener can be easily produced.

FIG. 1 is a photograph showing the state of the cross section of a rice flour bread produced using the rice flour of Samples 1-9. A: sample 1, B: sample 2, C: sample 3, D: sample 4, E: sample 5, F: sample 6, G: sample 7, H: sample 8, I: sample 9. The graph in FIG. 2 shows the relationship between the damaged starch rate of rice flour and the specific volume of bread produced. The graph of FIG. 3 shows the relationship between the water absorption of rice flour and the specific volume of the manufactured bread. The graph of FIG. 4 shows the relationship between the most frequent particle size of rice flour and the specific volume of the manufactured bread.

Hereinafter, the present invention will be described in detail.
The present invention relates to a method for producing rice flour bread using rice flour of a predetermined property without using gluten-constituting proteins and cereal flour (such as wheat flour) containing the same, gluten, thickeners and the like.

  In the present invention, rice flour is used as grain flour which is a main ingredient of bread. Rice flour refers to a powder obtained by grinding rice (Oryza sativa) seeds (raw rice). Although rice used as a raw material of rice flour is not limited, it is preferable to use light rice. The perishable rice may be, for example, Japonica rice, Indica rice, or Javanese rice, and may further be various varieties of rice belonging to them. The variety of rice is not limited to the following, but may be, for example, varieties suitable for rice flour, such as Takanari, Mizuhochikara, Yumewari, etc., and may have a high amylose content, which is moderate Or a low variety or the like. The rice flour may also be a mixture of various varieties of rice flour. In addition, the rice flour used as a raw material by this invention does not need to contain the gelatinization rice flour obtained by drying and pulverizing after gelatinizing (gelatinizing) rice by heating.

  In the present invention, rice flour is used which exhibits a damaged starch ratio of 5% or less and a water absorption of 80% or less. In a preferred embodiment, it is also preferred that the damaged starch rate of rice flour is 3% or more, for example 4% or more. In a preferred embodiment, it is also preferred that the water absorption be 72% or more, for example 74% or more. Although not limited to the following, in a preferred embodiment, the damaged starch rate of rice flour is 3% to 5%, and the water absorption rate is 72% to 80%.

  The damaged starch rate of rice flour can be measured by a conventional method. In the present invention, it is possible to determine the quality of rice flour based on, in particular, the rate of damaged starch determined using a damaged starch measurement kit Starch Damage Assay Kit (Megazyme) or an equivalent kit or reagent. Specifically, as described in the examples below, first, 100 mg of rice flour and amylase solution (50 U / ml) are preincubated in separate containers at 40 ° C. for about 5 minutes, and then 1 mL of amylase solution in rice flour Is added, mixed with a vortex mixer, and reacted at 40 ° C. for 10 minutes. Then add 8 ml of sulfuric acid solution (0.2% v / v), mix by vortex mixer to stop the reaction, and centrifuge at 3,000 rpm for 5 minutes. After taking 0.1 ml of the supernatant, adding 0.1 ml of amyloglucosidase solution and reacting at 40 ° C. for 10 minutes, add 4 ml of glucose measuring reagent GOPOD (glucose oxidase and peroxidase) solution and carry out at 40 ° C. Let react for 20 minutes. Further, the absorbance of the reaction solution is measured at 510 nm. A GOPOD solution is added to a 150 mg / ml glucose standard solution and buffer solution (blank) to make a reaction, absorbance is measured, and a calibration curve is prepared. Based on this calibration curve, the percent damaged starch of rice flour can be determined.

The water absorption rate of rice flour can be measured by a conventional method. In the present invention, in particular, the properties of rice flour can be determined based on the water absorptivity measured as described in the following examples. Specifically, 10 g of rice flour (dry state) is placed in a 50 mL tube, ion-exchanged water is added to a scale of 50 mL, and left overnight at room temperature, centrifuged at 3000 rpm for 30 minutes, and then the supernatant is discarded. Measure the weight of rice flour after (total weight of rice flour and water absorbed by rice flour). Based on the measured values, the water absorption rate of rice flour can be calculated by the following equation.
Water absorption rate (%) = (weight of rice flour after water absorption-weight of rice flour before water absorption (10 g)) / weight of rice flour before water absorption (10 g) × 100

  The rice flour used in the present invention may have a mode diameter of preferably 200 μm or less, more preferably 70 to 130 μm, for the purpose of producing a well-defined bread, for example. For rice flour, use a particle size distribution analyzer (LS13320 [Beckman Coulter] or equivalent device), measure the particle size distribution according to the dry method according to the manual, and determine the most frequent particle size of rice flour from the particle size distribution measurement value. Can.

  Although the above-mentioned rice flour used by this invention is not limited, It is preferable to manufacture by a wet air flow grinding method. The above-mentioned rice flour can also be obtained as a commercial product.

  In the present invention, rice flour bread is produced using bread dough containing the above-mentioned rice flour, water and yeast and containing no gluten and no thickener. The amount of water in the dough may be a common amount of water used as a raw material in the manufacture of bread using rice flour but may for example be 70 to 120% by weight of the amount of rice flour. Water in the bread dough may be added as water, but may be added as one component of another raw material. For example, the water in the dough may be water derived from milk, soy milk, beverages such as juice, etc. added to the dough. You may add to rice flour by using as a raw material water, a drink, etc. of normal temperature, and you may add the water or drink etc. which were heated or cooled.

  The yeast incorporated in the bread dough may be any yeast that can be used for fermentation of bread but is typically baker's yeast (Saccharomyces cerevisiae strain used in bread manufacture). The yeast used in the present invention does not secrete gluten-constituting proteins. The yeast may be dry yeast or live yeast. Moreover, yeast may be contained in so-called fermented species (starter). The fermented species is a fermented product obtained by fermenting and growing yeast existing in the natural world, and may contain various microorganisms such as lactic acid bacteria in addition to baker's yeast. Such fermented species may be mixed into bread dough as a source of yeast. However, in order to prepare gluten and thickener-free bread dough, it is necessary to prepare fermented species using gluten- and thickener-free raw materials. A person skilled in the art can appropriately adjust the blending amount of yeast suitable for bread production, but generally, an amount of 0.5 to 5% by mass of the amount of rice flour based on dry weight is used. Just do it. The yeast may be mixed with rice flour from the beginning, for example, or may be added to the dough once mixed and further mixed. The yeast after pre-fermentation may be added to rice flour or bread dough, or the yeast may be added to rice flour or dough without pre-fermentation.

  The bread dough according to the present invention may contain other ingredients as long as it does not contain gluten and a thickener. The bread dough according to the present invention may further include, for example, one or more selected from sugars such as sugar, sodium chloride, and fats and oils. The fats and oils may be vegetable fats and oils such as olive oil, animal fats and oils such as butter, shortenings, optional fats and oils such as margarine, or mixtures thereof, but butter is a preferable example.

  In the present invention, “salt” means food grade or pharmaceutical grade salt (based on sodium chloride). In addition to sodium chloride as the main component, sodium chloride may contain, for example, other inorganic salts such as potassium chloride, calcium chloride, magnesium chloride and the like. Any salt product can be used as the salt to be blended into the bread dough according to the present invention. For example, high purity salts such as commercially available purified salts (containing almost only sodium chloride), unpurified salts (containing sodium chloride as a main component but containing other inorganic salts in a larger amount), etc. are used be able to. When a purified salt (containing 99% or more by dry weight sodium chloride) is added to bread dough, the amount of purified salt is approximately equal to its sodium chloride content, so the salt content in the bread dough is equivalent to the addition of the purified salt It can be calculated based on the quantity. On the other hand, when unrefined salt (containing less than 99% by dry weight sodium chloride) is added to the dough, the salt content in the dough is based on the equivalent sodium chloride calculated from the sodium content of the added unrefined salt Calculate. The sodium chloride equivalent is calculated by multiplying the sodium content by 2.54.

  In the present invention, as sugar, any sugar such as white sugar, black sugar, millet sugar, sucrose and the like can be used. In addition, other sugars (glucose, fructose, honey, maltose, brown sugar, granulated sugar, etc .; except polysaccharides) can also be used.

  The bread dough according to the present invention is also a food or food material such as meat / fish, nuts, mushrooms, fruits, vegetables, herbs, beans, beverages, dairy products, fermented foods, sweeteners, sweets, spices and the like, for example, eggs Ham, sausage, bacon, almond, carrot, sesame, raisin, apple, edamame, vegetable juice, rosemary, milk, cheese, yoghurt, trehalose, chocolate, cinnamon powder, etc. may be included. The bread dough according to the present invention may also contain food additives such as emulsifiers, preservatives, flavors and colorants, as long as it does not contain gluten and thickeners.

  The bread dough according to the present invention does not contain gluten-constituting proteins or cereal flours containing gluten-constituting proteins (wheat flour, rye flour, barley flour, oat flour, cereal flour of hybrid hybrids thereof, etc.). The bread dough according to the present invention further preferably contains only rice flour as grain flour, and particularly preferably contains only rice flour showing a damaged starch ratio of 5% or less and a water absorption rate of 80% or less. The bread dough according to the present invention also uses any of gluten, gluten-constituting protein, and cereal flour containing gluten-constituting protein (wheat flour, rye flour, barley flour, oat flour, cereal flour of hybrid hybrids thereof, etc.) Contains no gluten because it is made without Here, the bread dough "does not contain" these ingredients means that these ingredients are not present in the bread dough in effective amounts. If gluten, gluten-constituting proteins, or other cereal flours are not used as ingredients for dough, but are incorporated in trace amounts in the bread dough or bread making process, an effective amount of gluten in the dough Because no gluten-constituting proteins or other flours are present, the bread dough is judged to be free of them. More specifically, when the amount of gluten incorporation in bread dough is less than 0.5% by weight (preferably less than 0.1% by weight) of the amount of rice flour, an effective amount of gluten is present in the dough. Without this, such bread dough according to the present invention is gluten free. Also, if the amount of gluten-constituting protein or other cereal flour incorporated in the dough is less than 1.0% by weight (preferably less than 0.1% by weight) of the amount of rice flour, an effective amount of it is included in the dough. In the absence of gluten-constituting proteins or other cereal flours, such bread dough according to the present invention shall be free of gluten-constituting proteins or other cereal flours.

  In a preferred embodiment, the bread dough according to the invention may be more strictly "gluten free". In the present invention, “gluten” includes wheat gluten derived from wheat flour and gluten-like proteins derived from other cereal flours. Gluten is produced by the reaction of gluten-constituting proteins (gliadin and glutenin in the case of wheat flour) contained in cereal flour in the presence of water. The gluten-constituting protein corresponding to gliadin in wheat is called hordein in barley, secalin in rye, and avenin in oats. In the present invention, “gluten free” means that the gluten content is 0.002% or less (20 mg / kg or less) of the total weight (total weight) of the food. This is the value set by the Codex committee in 2008 as a "gluten free" standard. Typically, by manufacturing the bread dough and the like according to the present invention using a manufacturing line dedicated to gluten-free products, it is possible to prevent mixing of flour, gluten and the like and to manufacture gluten-free bread dough.

  Although thickeners are usually used in the production of gluten-free rice flour bread, the bread dough according to the present invention contains not only gluten but also thickeners. Thickeners include a wide variety of thickeners that can be used in the food field, such as thickening polysaccharides, gelling agents, and the like. Examples of thickeners include alginic acid, gum arabic, carrageenan, carboxymethylcellulose, guar gum, xanthan gum, locust bean gum, pectin, cellulose, tamarind seed gum, psyllium seed gum, glucomannan, gelatin, agar, soy polysaccharides, tapioca There are, but not limited to, starch, corn starch, mulberry starch, corn starch, potato starch and derivatives thereof (acetylated products, esterified products, degradation products, etc.). In addition, even if ingredients having a thickening action are produced from rice flour, yeast or other raw materials during bread dough or bread production of the method of the present invention, such ingredients shall not be included in the "thickener". . Here, the bread dough according to the present invention "contains no thickener" means that no effective amount of thickener is present in the bread dough. The present invention does not use thickener as a raw material of dough, but when it is mixed in a very small amount in bread dough or bread making process, no effective amount of thickener is present in the dough, so the present invention Such bread dough according to is determined to be free of thickener. More specifically, when the amount of thickener mixed in the dough is less than 0.05% by weight (preferably less than 0.005% by weight) of the amount of rice flour, the effective amount is increased in the dough. There is no viscosity, and such bread dough according to the invention is free of thickener.

  In the present invention, gluten, gluten-constituting protein, cereal flour other than rice flour, or the above-mentioned standard that "contains no thickener" applies not only to bread dough but also to rice flour bread.

  The bread dough according to the present invention can be prepared from bread ingredients as described above by a conventional method, and specifically, it is prepared by mixing rice flour, water, yeast, and other ingredients in one or more steps. be able to. In the food processing field, "mixing" refers to kneading of a raw material mixture containing powder and liquid so as to uniformly disperse its components. In the present invention, the mixing can be performed by, for example, a stirring device such as a mixing device or a home bakery, or can be performed by hand. The mixing may be performed at a usual temperature used for mixing in bread making, and is not particularly limited, but generally it is performed at about room temperature, for example, about 4 ° C. to 32 ° C., preferably 15 to 30 ° C. Good. The mixing can be performed in a conventional mixing time known to those skilled in the art, for example, about 3 minutes to 40 minutes per mixing step, but preferably about 10 to 30 minutes per mixing step. The mixing may be performed once or plural times.

  The bread dough according to the present invention may be prepared by a method including mixing rice flour, water, yeast and, if necessary, other ingredients into one, and mixing them in one step. Alternatively, the bread dough according to the present invention can be prepared by a method including two or more mixing steps. In one embodiment, for example, after mixing and mixing rice flour, water, and optionally one or more other ingredients into one, yeast, saccharides such as sugar, and optionally one or more other The bread dough according to the present invention can also be prepared by further adding and mixing the raw materials. After final mixing, other ingredients (eg, nuts, cheese, fruits, etc.) may be further added (eg, mixed, wrapped, topped or embedded). After mixing the rice flour and water, it may be left for a given time to allow a sufficient immersion time, and then other raw materials such as yeast may be added.

  The bread dough prepared as described above may be fermented by any method used for bread production, after being put in a container, divided or shaped as needed. The bread dough according to the present invention is usually, for example, usually about 20 minutes to 4 hours (more usually 25 minutes to 2 hours) under a temperature suitable for fermentation (4 to 50 ° C., usually 25 to 45 ° C.) It can be fermented by putting it for about time. Fermentation may be performed in only one fermentation step, or may be performed in two or more fermentation steps. For example, with regard to bread dough, primary fermentation (also referred to as floor time) which is preferably fermented by placing at relatively low temperature (for example, 15 to 32 ° C.) for about 15 minutes to 2 hours (more generally, about 30 minutes to about 90 minutes) You may go. At the stage where the fermentation has progressed to some extent by the primary fermentation, it is usually further added at 4 ° C. to 45 ° C. (more preferably 25 to 42 ° C.) for usually 15 minutes to 2 hours (more generally 30 minutes to 90 minutes) May be fermented (final fermentation called hiruo). The bread dough according to the present invention may be subjected to the fermentation process without interruption until completion of the final fermentation by first placing the dough in a pan-forming container (type) after mixing and starting the fermentation process.

  In the present invention, the bread dough according to the present invention can be significantly expanded at the fermentation stage. According to the invention, in a preferred embodiment, the specific volume of the dough at the end of the fermentation stage can be 3 mL / g or more, in particular 4 mL / g or more. In the method of the present invention, it is preferable to ferment the bread dough according to the present invention to a specific volume of 3 mL / g or more, particularly 4 mL / g or more. Here, the specific volume of the dough can be calculated by dividing the volume (mL) of the fermented dough by the weight of the dough.

  The dough according to the invention prepared as described above may be packaged in any way, for example in a sealed container or a sealed bag. The bread dough according to the present invention may be subjected to treatments such as sterilization, refrigeration, freezing and the like.

  The present invention provides a method of preparing (producing) bread dough as described above. The bread dough preparation method according to the present invention may optionally include one or more optional steps such as a dividing step, a forming step, one or more fermentation steps, a packaging step, a sterilization step, and a refrigeration or freezing step, in addition to the mixing step. May be included.

  The present invention also provides a bread dough according to the present invention prepared by the method as described above. The bread dough according to the present invention refers to those before baking is completed. The bread dough according to the present invention also includes bread dough which has been subjected to treatments such as sterilization, refrigeration or freezing. The bread dough according to the present invention may be a retort pouch product. The bread dough according to the invention also includes dough which has been partially baked but which has not yet been baked. The bread dough according to the present invention includes those obtained by mixing the dough prepared by mixing or the like into a container, forming the dough, mixing, wrapping, placing or embedding other food in the dough as long as it is before baking.

  A rice flour bread can be manufactured by fermenting the bread dough which concerns on this invention, and also baking (baking). The baking of the dough can be carried out by a conventional method. Specifically, the baking step may be performed by heating (for example, heating at 100 ° C. to 240 ° C.) the dough by any means such as an oven, a microwave oven, or a kettle. The firing time is generally about 5 minutes to 100 minutes. The baking temperature and the baking time can be appropriately adjusted by those skilled in the art. The bread dough according to the present invention exhibits good swelling even after baking. The rice flour bread according to the present invention preferably has a specific volume after baking of 3 mL / g or more, particularly 4 mL / g or more. Here, the specific volume of the bread (bread specific volume) can be calculated by dividing the volume (mL) of the baked bread by the weight of the bread.

  It is also possible to produce confectionery bread, cooked bread, etc. by further topping nuts, fruits, cream, syrup, etc., sandwiching prepared foods, ham, etc. on baked bread. The bread processed in this way is also included in the scope of the bread according to the present invention. The rice flour bread according to the present invention may be any form of bread, such as bread, rolls, round bread, side bread, confectionery bread and the like. The present invention also provides a method for producing the above-mentioned rice flour bread using the bread dough according to the present invention. The method for producing the rice flour bread of the present invention may further include the step of preparing the bread dough according to the present invention. Accordingly, the present invention also provides a method for producing rice flour bread comprising preparing bread dough according to the method for preparing bread dough of the present invention, fermenting as described above, and baking. In the bread manufacturing method of the present invention, a series of operations from mixing of raw materials to fermentation / baking may be performed continuously in one home bakery or bread manufacturing line.

  The rice flour bread produced from the bread dough according to the present invention by the method of the present invention exhibits good puffiness despite the absence of gluten and thickeners. According to the method of the present invention, bread dough and rice flour bread can be produced which show good swelling without blending glutathione in rice flour. The rice flour bread according to the present invention, especially gluten-free rice flour bread, is manufactured without using gluten-containing protein or cereal flour containing gluten-constituting proteins such as wheat flour as a raw material, and therefore contains no gluten-constituting protein or gluten It is particularly suitable for people who should avoid gluten intake, such as wheat allergic patients and celiac disease patients.

  Hereinafter, the present invention will be more specifically described using examples. However, the technical scope of the present invention is not limited to these examples.

  In the following examples, as rice flour, rice flour of samples 1 to 9 used as raw materials for glutinous rice and marketed as rice flour for confectionery and bread making was used. Samples 1 to 9 do not contain any cereal flour containing gluten-constituting proteins such as wheat flour, gluten-constituting proteins, gluten and thickeners. The purified salt having a sodium chloride content of 99% or more was used as a salt.

Example 1 Production of Rice Flour Bread 160 g of rice flour of any of Samples 1 to 9 and 140 g of water were put in a bread case of a home bakery (SD-BH105, manufactured by Panasonic Corporation), and a program of "Dry yeast course" was used. The mixture was stirred at room temperature for 20 minutes. To this, add 15 g of sugar, 5 g of dry yeast for bread (Nisshin Foods Co., Ltd.), 2 g of butter (manufactured by Calpis Co., Ltd.) and 1.6 g of sodium chloride, and then use the program of “Dry yeast course” Furthermore, it mixed by stirring for 20 minutes at room temperature. 175 g of the dough thus obtained was weighed in a square pan case (volume 800 mL) and fermented at 40 ° C. for about 30 minutes in an oven range (EMO-C16C, Sanyo Electric Co., Ltd.). At the end of this fermentation stage the appearance of the dough was observed. Subsequently, the fermented dough (fermented dough) was baked at 180 ° C. for 24 minutes to produce rice flour bread free of gluten and thickener.

  The next day after baking, each bread was subjected to weight measurement and shape measurement with a laser volume meter (SELNAC-WinVM2100A, Astex Co., Ltd.), and the measured value of the specific volume (mL / g), which is an index of the expansivity of bread. Obtained. The specific volume is expressed as volume of bread per gram of bread (mL / g). The obtained results are shown in Table 1. Table 1 also describes the milling methods used to produce each rice flour.

  As shown in Table 1, even with rice flour bread produced by the same method, the specific volume of the bread produced was different depending on the rice flour used.

  Furthermore, the cross section after cutting about each bread was photographed and observed (FIG. 1). In each of the breads (Samples 1, 2 and 7) having a bread specific volume of 4 mL / g or more after baking, the dough was swollen up to the top of the square pan case at the end of the fermentation stage before baking. Since the weight of the dough used for fermentation is 175 g and the volume of the square pan case is 800 mL, the bread using samples 1, 2 or 7 already has a specific volume of 4 mL / g or more at the end of the fermentation stage Was shown. Bread using wheat flour swells greatly at the baking stage after fermentation, but it has been shown that the rice flour bread according to the present invention swells largely at the fermentation stage and does not swell so much at the baking stage.

  In addition, when the rice flour of sample 7 was used, a well-baked bread similar to a bread containing wheat flour and gluten as a raw material was manufactured (FIG. 1G). Sample 1 provided a softer, slightly more fragile bread than sample 7 (FIG. 1A). When sample 2 was used, the loin was easy to get into the bread (FIG. 1B).

  In the flour of rice flour bread using flour and gluten as raw materials, the network of sticky gluten protein causes the bread to swell by trapping the fermented gas, but the rice flour bread without gluten does not have such a network of gluten. However, according to the test results in this example, it was shown that rice flour bread having good swelling can be produced without using gluten, by using rice flour showing predetermined properties. It is considered that gluten-free rice flour bread using the rice flours of Samples 1, 2 and 7 achieved good swelling by a mechanism different from gluten-containing rice flour bread.

[Example 2] Relation between evaluation of properties of rice flour and specific volume of bread In order to investigate the properties of rice flour capable of enhancing the specific volume of rice flour bread containing neither gluten nor thickener, damage to the rice flour of samples 1 to 9 The starch rate, water absorption rate, and the most frequent particle size were measured.

1) Measurement of Damaged Starch Rate The damaged starch rate of each rice flour was determined as follows using a damaged starch measurement kit (Starch Damage Assay Kit; Megazyme).

First, 100 mg of rice flour was placed in a tube, and this tube and amylase solution (50 U / ml) were preincubated at 40 ° C. for about 5 minutes. 1 mL of amylase solution was added to rice flour in a tube, mixed with a vortex mixer, and allowed to react at 40 ° C. for 10 minutes. The reaction was stopped by adding 8 ml of sulfuric acid solution (0.2% v / v) and mixing with a vortex mixer. Then, it was centrifuged at 3,000 rpm for 5 minutes. 0.1 ml of the supernatant was collected and placed in another tube, to which 0.1 ml of amyloglucosidase solution was added and reacted at 40 ° C. for 10 minutes. Further, 4 ml of a glucose measuring reagent GOPOD (glucose oxidase and peroxidase) solution was added and reacted at 40 ° C. for 20 minutes. Absorbance was measured at 510 nm for the reaction solution. On the other hand, a GOPOD solution was added to and reacted with 150 mg / ml of glucose standard solution and buffer solution (blank), and the absorbance was measured to prepare a calibration curve. The percent damaged starch of each rice flour was determined based on this calibration curve.
The results are shown in Table 2.

2) Measurement of water absorption rate 10 g of rice flour (in a dry state) was placed in a 50 mL tube, ion exchange water was added to a scale of 50 mL, and left overnight at room temperature. The tube was centrifuged at 3000 rpm for 30 minutes, the supernatant was discarded, and the weight of rice flour after water absorption (total weight of rice flour and water absorbed by rice flour) was measured. The water absorption rate was calculated by the following equation.
Water absorption rate (%) = (weight of rice flour after water absorption-weight of rice flour before water absorption (10 g)) / weight of rice flour before water absorption (10 g) × 100
The water absorption determined for each rice flour is shown in Table 2.

3) Measurement of Mode Particle Size If the specification information provided by the maker of each rice flour includes the mode particle size, it is shown in Table 2. For rice flour whose mode particle size is not disclosed, the particle size distribution is measured by the dry method according to the manual using a particle size distribution measuring apparatus LS13320 (Beckman Coulter), and the mode particle size is determined from the particle size distribution measurement value. The The measurement results are also shown in Table 2.

  Moreover, the graph which shows the relationship between each of a damaged starch rate, a water absorption, and the most frequent particle size, and the bread specific volume shown in Table 1 was shown in FIG.2, FIG.3, and FIG.4.

  As shown in FIG. 2, the damaged starch rate of rice flour showed a strong correlation with the bread specific volume. In particular, it was found that the damaged starch rate of rice flour suitable for obtaining bread specific volume of 4 mL / g or more is 5% or less.

  As shown in FIG. 3, the water absorption rate of rice flour showed a strong correlation with the bread specific volume. In particular, the water absorption of rice flour suitable for obtaining a bread specific volume of 4 mL / g or more was found to be 80% or less.

  On the other hand, as shown in FIG. 4, the particle size of rice flour (particularly, the mode particle size) showed almost no correlation with the bread specific volume.

  From the above results, by using rice flour showing a damaged starch ratio of 5% or less and a water absorption rate of 80% or less for the production of rice flour bread, rice flour bread having a good swelling even without using gluten or thickeners. It has been shown that it can be manufactured. Unlike gluten-containing rice flour bread, considering that gluten-free rice flour bread has no gluten network, the use of such rice flour makes glutinous or thickener-free rice flour bread free of gluten and thickeners. The fact that it could be manufactured is a surprising result.

  Using the present invention, it is possible to easily produce glutinous and thickener free floured rice flour bread.

Claims (11)

  A method for producing a rice flour bread comprising fermenting and baking a bread dough containing rice flour, water and yeast showing a damaged starch ratio of 5% or less and a water absorption of 80% or less and containing no gluten and no thickener. .   The method according to claim 1, wherein the damaged starch rate of rice flour is 3% or more and the water absorption rate is 72% or more.   The method according to claim 1 or 2, wherein the bread dough further comprises one or more selected from sugar, salt and fats and oils.   The method according to any one of claims 1 to 3, wherein the dough is fermented to a specific volume of 4 mL / g or more.   The method according to any one of claims 1 to 4, comprising the step of preparing the bread dough.   A bread dough comprising rice flour, water and yeast exhibiting a percent damaged starch of less than 5% and a water absorption of less than 80% and free of gluten and thickener.   The bread dough according to claim 6, wherein the damaged starch rate of rice flour is 3% or more and the water absorption rate is 72% or more.   The bread dough according to claim 6, further comprising one or more selected from sugar, salt, and fats and oils.   The bread dough according to any one of claims 6 to 8, which is fermented.   The bread dough according to claim 9, which has a specific volume of 4 mL / g or more.   A gluten and thickener-free rice flour bread produced using the dough according to any one of claims 6 to 10.

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