JP5704556B2 - New method for producing brown rice flour for bread and brown rice flour produced by the method - Google Patents

Description

  The present invention relates to the technical field of a method for producing rice flour. More specifically, this invention relates to the technical field of the manufacturing method of the brown rice flour which can be used for manufacture of bread.

  Rice is the only self-sufficient cereal resource in Japan, but its consumption is steadily decreasing, and there is a strong demand for developing applications that lead to increased demand. In the use of rice flour aimed at improving the food self-sufficiency rate (especially rice flour bread), the use of whole grain brown rice is desired from the viewpoint of high nutritional value and cost reduction. Until now, bread using brown rice has been sold at some small bakery shops, but most of it has been in the form of mixing cooked brown rice (cooked brown rice) into wheat bread.

  In addition, as a technique for using rice for bread production, for example, rice flour for bread dough (Patent Document 1) prepared by enzyme treatment, rice cake flour for gluten and maltose is added. For bread making, the average particle size of which is specified by pulverizing trehalose or maltitol into raw rice such as rice bread crumb (Patent Document 2), brown rice, polished rice or germinated rice, and adjusting the water content by partial drying. Rice flour (Patent Document 3), rice flour prepared by subjecting polished rice to water addition such as washing and soaking, and coarsely pulverizing with a roll mill, then further pulverizing with an airflow pulverizer (Patent Document 4), etc. It has been known.

Japanese Patent Publication No.7-59173 JP20009-22306 Reissue 2004/047561 JP 04-063555

  In recent years, the use of brown rice flour for bread is also spreading, and commercial products are also seen as mixed flour with wheat flour.

  However, when brown rice is pulverized by a pin mill or a barrel-type pulverization method, there is a problem that rice bran oil or the like causes powder residue to the pulverizer. In addition, breadmaking with brown rice flour has a problem that sufficient swelling cannot be obtained.

  The conventional method of mixing brown rice or germinated brown rice as a grain with bread dough tends to reduce the shape, texture and flavor of the bread if the amount of added brown rice is large, and there is a problem that the amount added is limited. It was. On the other hand, brown rice whole grains prepared by conventional pin mills and the like have also had a problem that the amount of rice flour added is still limited because sufficient bread swell cannot be obtained.

  Then, this invention makes it the 1st subject to provide the brown rice flour for bread-making, and the manufacturing method of the brown rice flour using the whole grain flour of brown rice as a bread-making raw material.

  Furthermore, this invention makes it a 2nd subject to provide the brown rice flour manufactured by the manufacturing method of this bread | pan manufacturing method and this brown rice flour by an efficient and simple manufacturing process.

  Moreover, this invention makes it a 3rd subject to provide the manufacturing method of brown rice flour and this brown rice flour which can manufacture bread fully expanded when it bakes.

  The present invention provides a method for producing unpolished whole rice flour for bread production from unpolished rice by an unprecedented and simple means of milling unpolished rice whose water absorption time has been adjusted by a grinding method using an air-flow mill. To do.

  More specifically, the present invention can produce bread that is sufficiently swelled and fluffy by pulverizing by vortex crusher (super powder mill) after soaking brown rice in water for 12 hours or more. The present invention provides a method for producing brown rice flour for use and the brown rice flour produced by the method.

  According to the present invention, unlike conventional wet milling methods, brown rice whole grains having a low degree of damage can be obtained without adding other components during water absorption, leading to reduction in milling costs. Furthermore, omission of milled rice not only reduces the cost of milling rice, but also improves the yield, realizing a lower cost than conventional white rice flour. In addition, the method of the present invention does not require any additives, two-stage pulverization, etc., and although it can be simplified, it has an excellent effect that brown rice can be efficiently pulverized with little powder remaining in the pulverizer. Also play. Powdered rice having excellent processing characteristics has been cultivated so far, but difficult to polish rice has been a problem, but if it can be used as brown rice by the present invention, it will be used for processing and processing of powdered rice. Greatly contribute.

  Moreover, in this invention, since bread-making is performed using the brown rice whole grain powder by a water absorption process, it is thought that functional components, such as GABA ((gamma) -aminobutyric acid) and (beta) -glucan, are included.

  Furthermore, the bread produced using the whole grain of brown rice has a “sweet” taste unique to brown rice and a “moist” texture, which is superior to conventional bread and white rice bread.

It is a photograph which shows the swelling of the brown rice flour bread | pan by water absorption. In each of the two photographs, the left bread is the bread produced by the control (water absorption for 2 hours), and the right bread is the bread that has absorbed water for 60 hours. The arrow in the left-hand photo shows the pot elongation (braking), the right-hand photo shows the cross section, and the specific volume is also shown. It is a photograph which shows the time-dependent change of the swelling by water absorption time. The result of the taste test which produced and produced bread using the whole grain flour of brown rice is shown. The taste test expresses the evaluation of brown rice whole grain bread in five stages when the evaluation of each item is 3 for bread made with white rice flour.

1. Introduction Use of brown rice Brown rice contains more functional components such as GABA (γ-aminobutyric acid) and β-glucan than polished rice, and contains more phytic acid. Phytic acid has a chelating action and binds to minerals to form phytate. Brown rice contains more vitamin B1 than polished rice, and brown rice is said to have higher nutritional value than polished rice.

  Therefore, when expanding the range of use of rice as rice flour, it is important to develop brown rice flour for the production of other foods such as bread.

2. Novel brown rice flour production method The present inventors have made various attempts to prepare brown rice whole grain flour that can be used for bread production in order to effectively use brown rice in view of the above-described problems.

  After various trials and errors, the inventors used brown rice flour pulverized by airflow pulverization treatment after brown water was pretreated for a certain period of time and then used for bread production without damaging starch. In that case, it was found that brown rice bread with sufficient bulge could be produced.

2-1. Pre-grinding treatment The present invention is characterized by immersing brown rice in water or an aqueous solution for a certain period of time or more before pulverization treatment, specifically, for 12 hours or more to absorb water. Preferably, it is immersed in water to absorb water. The time for immersion in water (also referred to as water absorption time) is preferably 12 hours or more and 72 hours or less, more preferably 12 hours or more and 48 hours or less, and further preferably 12 hours or more and 24 hours or less. Can do.

  Examples of the water in which the brown rice is immersed include tap water, mineral water, pure water, and ultrapure water. Further, the water may be an aqueous solution to which ingredients such as seasonings, colorants, emulsifiers, and / or quality-improving substances such as enzymes, which are usually used in bread production, are added.

  Moreover, before making it soak, brown rice may be wash | cleaned and an immersion process and a washing process may be performed simultaneously. Furthermore, the immersion treatment can be usually performed at room temperature.

2-2. Airflow pulverization treatment Brown rice immersed in water can be pulverized into fine particles by an airflow pulverizer, preferably after removing water on the surface of the brown rice with a centrifugal dehydrator.

  The airflow pulverization treatment can include all treatments using a pulverization method using the force of airflow. Examples of the apparatus for performing the airflow crushing process include a jet mill and a cross jet mill. A jet mill pressurizes and injects air or nitrogen gas, and pulverizes the raw materials (rice) with each other by the jet gas. The cross jet mill, like the jet mill, injects air and nitrogen gas under pressure, but the high-speed jet stream intersects in the pulverizer, and the raw material (rice) is caught in the stream. Then, it is pulverized by repeating friction and collision.

  The airflow crushing process includes a vortex crushing process, and an apparatus for performing the eddy crushing process includes, for example, a super powder mill. The super powder mill rotates a large blade at a high speed to create a high-speed vortex in the pulverizer and self-pulverizes the raw material (rice).

  In the present invention, a vortex crusher, specifically, a super powder mill can be preferably used for the airflow crushing treatment. For example, when using a super powder mill (vortex type fine powder crusher) SPM-R290, Nishimura Machinery Co., Ltd., the blade rotation speed is preferably 40 Hz to 50 Hz, and the sample supply speed (feeder) is preferably level 1 or 2. .

3. 3. Production of novel brown rice flour and bread using the same 3-1. New brown rice flour 2. Since the brown rice flour produced by the method described in 1) has a low damaged starch content, it was found that in bread production, the bread swells well during baking and is an excellent bread crumb. The damaged starch content depends on the water absorption time of the pulverization pretreatment, and the damaged starch content becomes the highest in 2 hours (control) of water absorption, but decreases with the passage of water absorption time and becomes almost constant after 12 hours. Moreover, when the brown rice powder was prepared by performing water absorption by water immersion of brown rice, which was a pretreatment for pulverization, and bread was produced, the specific volume of the bread was 12 hours of water immersion (water absorption time). It turned out that it became constant at the peak of time, and it changed without a big fall after that.

3-2. Production of bread using new brown rice flour Gluten is added to brown rice flour so that the total amount is 100 parts by weight together with 15-30 parts by weight of gluten. Suitably, gluten is added so that it may become 15-20 weight part of gluten, and 80-85 weight part of brown rice flour. Furthermore, for example, a mixture of 80 parts by weight of brown rice flour and 20 parts by weight of gluten, or a mixture of 70 parts by weight of wheat flour and 30 parts by weight of brown rice flour plus 5 parts by weight of gluten is used for making bread. It can also be a premixed powder. Ingredients that are usually added to a premix for making bread can be added, for example, by adding enzymes such as salt, sugar, emulsifiers, yeast food, colorants, thickeners, and amylases, A premix powder for production can be produced.

  As a bread manufacturing method using brown rice flour of the present invention, gluten, yeast, seasonings, and / or emulsifiers are added to brown rice flour, and the water is added to this, and the water is mixed with a mixer or the like. The process may include a primary fermentation process (floor time), a division (rounding) process, a dough resting process (bench time), a secondary fermentation process, a molding process, and a baking process.

  More specifically, as the step of adding water, the moisture contained in the rice flour and gluten is measured in advance, and finally 72 to 78%, preferably 74 to 76%, more preferably, of the total amount of the components, Water can be added to 75%.

  As for the degree and time of kneading in the kneading process, brown rice flour preferably has a stronger kneading or longer kneading than white rice flour. For example, when using Kanto Mixer Kogyo's “Can Tho Mixer” For rice flour, 10 minutes at a mixer speed of 2 is usually sufficient, but for brown rice flour, a mixer speed of 2 to 3 and 10 to 15 minutes is preferred. Moreover, a primary fermentation process is the same grade as bread manufacture of white rice flour, and can be made into 10 to 20 minutes.

  The bread produced using the brown rice flour of the present invention is baked sufficiently plumply, regardless of the bread produced using white rice flour, and has a “sweet” taste and a “moist” texture. Something excellent. Moreover, the bread manufactured using the brown rice flour of the present invention is a bread excellent in nutrition including functional ingredients such as GABA (γ-aminobutyric acid) and β-glucan as well as vitamins derived from brown rice.

[Example 1] Improvement of swelling by adjusting water absorption treatment time of brown rice After brown rice (Koshihikari) was absorbed for 60 hours, surface moisture was removed by centrifugation for about 10 minutes with a dehydrator. It was milled using a super powder mill (vortex-type fine powder crusher) (Nishimura Machine SPM-R290 mill). As a control, brown rice was absorbed in the same manner for 2 hours.

  80 parts by weight of brown rice flour prepared above and 20 parts by weight of gluten make 100 parts by weight of flour, 7 parts by weight of sugar, 3 parts by weight of skim milk powder, 1.5 parts by weight of salt, 8 parts by weight of shortening, dry yeast 1.5 parts by weight was added, and water was added to 75% by weight of the total weight of the components. This was kneaded with a mixer (Kanto Blender Kogyo Co., Ltd. “Canto Mixer”) at room temperature of 23 to 26 ° C. for 3 minutes at 1st speed and for 10 to 15 minutes at 2nd to 3rd speed to prepare bread dough. After a floor time of 10 to 15 minutes at the same temperature, the dough was divided and 400 g was weighed and rounded, and then a bench time of 10 minutes was taken. After the molding, it was put into a mold for mountain type bread and fermented with a proofer at 38 ° C. and 80% humidity until the upper end of the dough reached the upper end of the mold (about 50 to 60 minutes). After that, it was baked in a home oven at 200 ° C. for 26 minutes to prepare bread. The white rice flour bread was prepared with the same composition except that the same weight part of commercially available white rice flour (Hari Co., Ltd. “Super Miracle Powder”) was used instead of the brown rice flour. This was kneaded at a room temperature of 23-26 ° C. for 3 minutes at the first speed and for 10 minutes at the second speed, and the following steps were performed in the same manner as the brown rice bread. One day after baking, the specific volume was measured by the following rape method.

(Rapeseed method)
Using a wooden cocoon, measure the rape-filled rapeseed (with the top of the cocoon flattened cleanly). Take out the measured rapeseed, put the bread in the bowl, and put the rapeseed again from above. Measure the weight of the remaining rape after cleaning the top. The specific gravity of rapeseed was measured in advance, and the volume of rapeseed was converted into the volume of bread. The specific volume (ml / g) was calculated by dividing this by the bread weight.

(result)
There was a clear difference in the bulge of bread due to both brown rice flours (Fig. 1), and in particular, the water-absorbing brown rice flour had a remarkable pot elongation (braking). Furthermore, “moist feeling” was added compared with white rice flour, and the taste was expected to improve.

[Example 2] Relationship between damaged starch content and specific volume due to adjustment of water absorption treatment time The water absorption time of brown rice was changed to 2, 5, 12, 24, 36, and 48 hours in the same manner as in Example 1. The bread was prepared. Changes in specific volume and damaged starch over time at each water absorption time were examined. The damaged starch content was measured by the following method using Starch Damage Assay Kit (Megazyme).

(Damage starch content measurement method)
Damaged starch content was determined using Starch Damage Assay Kit (Megazyme).
1. Take 100mg of rice flour and put into a tube.
Pre-incubate 2 and 1 tubes and amylase solution (50 U / ml) at 40 degrees for about 5 minutes.
When 3,1 mL of amylase solution is added, mix with a vortex mixer and react for 10 minutes at 40 degrees.
4. Add 8 ml of sulfuric acid solution (0.2% v / v) and mix with a vortex mixer to stop the reaction.
Centrifuge at 53,000 rpm for about 5 minutes.
6. Take 0.1 ml from the centrifugation supernatant and place in the bottom of another tube.
7. Add 0.1 ml of amyloglucosidase solution and react at 40 degrees for 10 minutes.
Add 8.4 ml of GOPOD solution and react at 40 degrees for 20 minutes.
Measure absorbance at 9,510 nm. (Create a calibration curve with two points: 150 mg / ml standard solution and buffer solution)

(result)
The specific volume of bread became constant at the peak of 12 hours, and thereafter remained unchanged without any significant decrease (FIG. 2). On the other hand, the damaged starch content was highest for 2 hours of water absorption (control), and decreased with the passage of water absorption time, and became almost constant after 12 hours as with the specific volume. There was a correlation between an increase in specific volume and a decrease in damaged starch content with the passage of water absorption time (Table 1).

[Example 3]
For brown rice that had been subjected to water absorption treatment for 24 hours, bread was prepared using the whole brown rice powder prepared by the method described in Example 1, and for white rice flour bread, bread was prepared in the same manner as in Example 1, and the taste test was performed. went. The taste test evaluated the brown rice whole grain bread | pan in five steps, when the evaluation of each item was set to 3 about the bread produced with white rice flour. FIG. 3 shows the average evaluation values obtained from 29 men and women. Bread made from whole brown rice grains was evaluated as equal or better than white rice bread overall. In particular, it was evaluated as having a “sweet” taste and a “moist” texture unique to brown rice.

  The present invention can be used in the fields of brown rice flour milling, bread manufacturing using brown rice flour, and other food industries.

Claims (5)

Manufacture of brown rice flour for bread making after immersing brown rice in water selected from tap water, mineral water, pure water, or ultrapure water for 12 hours or more and 72 hours or less, followed by dehydration by centrifugation and pulverization with an airflow crusher Method.   2. The method according to claim 1, wherein the airflow crusher is a vortex crusher. 3. The method according to claim 1, wherein the content of damaged starch contained in the starch of the brown rice flour is 2.5% or less.   Brown rice flour produced by the method according to any one of claims 1 to 3.   A bread produced using the brown rice flour according to claim 4.

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