JP2016172257A - Method for producing rice slurry - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing rice slurry with which dispersion of rice particles (the rice slurry) obtained by wet crushing rice can be manufactured efficiently.SOLUTION: In a device 1 for producing rice slurry, a crusher 20 wet crushes rice which has been immersed in water for 1.5 hours or more to 6 hours or less by using a stone mill 21 to produce rice slurry 51. A crusher 30 crushes rice particles included in the rice slurry 51 by using a stone mill 31 to produce rice slurry 52. A crusher 40 crushes rice particles in the rice slurry 52 by using a stone mill 41 to produce rice slurry 53. A groove formed in the stone mill 31 has depth deeper than a groove formed in the stone mill 21. A groove formed in the stone mill 42 has depth equal to that of the groove formed in the stone mill 31 or depth deeper than that of the groove formed in the stone mill 31.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a rice slurry production method for producing a dispersion of rice particles (rice slurry) by wet pulverizing rice.

  Various methods of using rice are being studied for the purpose of increasing rice consumption. One method of using rice is the production of rice flour. By making bread, noodles, confectionery, etc. from rice flour, utilization of rice can be promoted. Rice flour is produced by pulverizing rice.

  Non-Patent Document 1 describes wet pulverization as a method for pulverizing foods such as rice. The wet pulverization is a method of pulverizing a raw material after adding 4 to 5% of water to the raw material. The wet pulverization has the following characteristics. The first feature is low power consumption. The second feature is that alteration of the pulverized product due to heat generation during pulverization can be prevented. The third feature is that it has a dustproof effect.

  Non-Patent Document 2 describes a water mill, an airflow mill, a high-speed mill (pin mill), and the like as milling machines for producing rice flour from rice. A water grinder grinds the rice previously immersed in water using a stone mill. Water is supplied to the stone mill along with the immersed rice. The airflow crusher crushes rice by causing the rice to collide with the inner wall of the crushing chamber or to collide with each other in the crushing chamber where the fan rotates at high speed. A pin mill grinds rice by rotating a disk with protrusions on the pin at high speed.

  Patent Document 1 describes a method for producing rice flour by immersing rice in water in 12 hours and pulverizing the rice with an appropriate amount of water.

JP-A-5-268890

“Food Engineering Pocket Book”, 293 pages, Shinichi Taneya, Industrial Research Co., Ltd., issued on November 21, 1994 “About promoting the use of rice flour”, [online], Ministry of Agriculture, Forestry and Fisheries, [Searched on November 7, 2011], Internet <URL: http://www.maff.go.jp/j/soushoku/keikaku/komeko/ k_suisin_kaigi / 07 / pdf / 090317_suisin.pdf>

  However, when rice flour is produced using a water grinder, there is a problem that it takes time to produce rice flour because the raw rice must be immersed in water for a long time. Rice can be wet pulverized using an airflow pulverizer or a high-speed pulverizer (pin mill), but these devices consume a large amount of power and are expensive.

  An object of this invention is to provide the rice slurry manufacturing method which can manufacture efficiently the dispersion (rice slurry) of the rice particle obtained by wet-grinding rice in view of the said problem.

  In order to solve the above-mentioned problems, the invention according to claim 1 includes a step of immersing brown rice in water for a period of 1.5 hours or more and 6 hours or less; And a step of pulverizing the brown rice immersed in the water by rotating the first drawing mill to produce a first rice slurry.

  Invention of Claim 2 is a manufacturing method of the rice slurry of Claim 1, Comprising: Moreover, the said 1st drawing mill is a disk-shaped 1st lower mill and on the said 1st lower mill. A disc-shaped first upper die placed coaxially with the first lower die, and an upper surface of the first lower die and a lower surface of the first upper die A first groove is formed.

  Invention of Claim 3 is a manufacturing method of the rice slurry of Claim 2, Comprising: The said 1st groove | channel is a center part of the upper surface of the said 1st lower mill, or the lower surface of the said 1st upper mill. A first main groove formed radially from the central portion and having a depth of 0.3 to 0.5 mm.

  Invention of Claim 4 is a manufacturing method of the rice slurry of Claim 3, Comprising: The said 1st groove | channel is parallel to the said 1st main groove | channel, and depth is 0.3-0.5 mm. A first sub-groove that is

  Invention of Claim 5 is a manufacturing method of the rice slurry in any one of Claim 1 thru | or 4, Comprising: It supplies to a said 1st drawing mill in the step thrown into a said 1st drawing mill. The amount of the soaked rice is 25 g or more and 40 g or less per minute.

  Invention of Claim 6 is a manufacturing method of the rice slurry in any one of Claim 1 thru | or 5, Comprising: In the step thrown into a said 1st drawing mill, it supplies to said 1st drawing mill The amount of water to be applied is not less than 24 times and not more than 41 times the amount of the soaked rice supplied to the first drawing mill.

  A seventh aspect of the present invention is the method for producing rice slurry according to any one of the first to sixth aspects, wherein the average particle size of the rice particles contained in the rice slurry is 5 μm or less.

  The invention according to claim 8 is the method for producing rice slurry according to any one of claims 1 to 7, wherein the rotational speed of the first mortar is 20 rpm or more and 50 rpm or less.

  In the rice slurry production method of the present invention, the rice immersed in water for 1.5 hours or more and 6 hours or less is pulverized using the first stone mill while supplying water to the first stone mill. Of rice slurry. Rice soaking time can be shortened, so that rice slurry can be produced efficiently.

It is a functional block diagram which shows the structure of the rice slurry manufacturing apparatus by embodiment of this invention. In the rice slurry manufacturing apparatus shown in FIG. 1, it is a top view of the lower die which comprises the stone mill which grind | pulverizes rice first. FIG. 3 is an enlarged top view of the lower die shown in FIG. 2. In the rice slurry manufacturing apparatus shown in FIG. 1, it is a bottom view of the upper mill which comprises the stone mill which grind | pulverizes rice first. In the rice slurry manufacturing apparatus shown in FIG. 1, it is an enlarged top view of the lower mill which comprises the stone mill which grind | pulverizes rice second. In the rice slurry manufacturing apparatus shown in FIG. 1, it is an enlarged top view of the lower mill which comprises the stone mill which grind | pulverizes the rice third. It is a figure which shows the manufacture procedure of a rice slurry when the rice slurry manufacturing apparatus shown in FIG. 1 is used. It is a figure which shows the median diameter and average diameter of the rice particle in Example 1. 2 is a graph showing the particle size distribution of rice particles in Example 1. It is a figure which shows the composition of the ice cream mix prepared in Example 2. It is a figure which shows the scoring result of the rice ice cream prepared in Example 2. FIG. 5 is a graph showing changes with time in the moisture content of rice measured in Example 3. FIG. It is a graph which shows a response | compatibility with the supply_amount | feed_rate of rice and the particle size of a rice particle when changing the supply_amount | feed_rate of rice in Example 4. FIG. It is a graph which shows a response | compatibility with the supply amount of water, the supply amount of rice, and the particle size of rice particle | grains when the supply amount of water is changed in Example 5.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

{1. Configuration of rice slurry production apparatus}
FIG. 1 is a diagram showing a configuration of a rice slurry manufacturing apparatus 1 according to an embodiment of the present invention. A rice slurry manufacturing apparatus 1 shown in FIG. 1 is an apparatus that manufactures rice slurry by wet-grinding rice previously immersed in water using a stone mortar. The rice slurry is a dispersion obtained by wet pulverizing rice immersed in water. The stone mortars 21, 31, 41 and the rotary shafts 26, 36, 46 shown in FIG.

  The rice slurry production apparatus 1 includes a raw material supply apparatus 10 and pulverization apparatuses 20, 30, and 40. The raw material supply device 10 supplies the raw material (water and rice) of the rice slurry to the pulverization device 20. The pulverizer 20 wet-grinds the rice supplied from the raw material supply device 10 to generate a rice slurry 51. The rice slurry 51 is supplied to the pulverizer 30. The pulverizer 30 pulverizes the rice particles contained in the rice slurry 51 to generate the rice slurry 52. The rice slurry 52 is supplied to the crusher 40. The pulverizer 40 pulverizes the rice particles contained in the rice slurry 52 to generate the rice slurry 53.

  The rice slurry 53 is used as a liquid food material. For example, an ice cream mix using only plant-derived materials can be produced by adding sugar, soy protein, nuka oil or the like to the rice slurry 53. Moreover, fermented drinks, desserts, etc. using the rice slurry 53 can be manufactured. Thus, by using rice slurry instead of milk or dairy products, it becomes possible to provide various foods to consumers who are allergic to milk.

  The raw material supply apparatus 10 includes a hopper 11, a raw material supply screw 12, a motor 13, a raw material supply beaker 14, a liquid feed pump 15, and a liquid feed pipe 16. In the hopper 11, rice previously immersed in water is put. The raw material supply screw 12 is rotated by a motor 13 and supplies the rice charged in the hopper 11 to the crusher 20. The liquid feed pump 15 supplies the water in the raw material supply beaker 14 to the pulverizer 20 through the liquid feed pipe 16.

  The motor 13 and the liquid feed pump 15 are controlled by a control device (PC or the like) not shown. Thereby, the quantity of the rice and water supplied to the grinding apparatus 20 can be controlled.

  The crusher 20 includes a stone mortar 21, a shroud 24, and a motor 25. The stone mill 21 includes a lower mill 22 and an upper mill 23. The lower mortar 22 has a disk shape and is rotated around a rotation shaft 26 by a motor 25. The upper die 23 has a disk shape and is placed on the lower die 22. The upper die 23 is disposed coaxially with the lower die 22 and is fixed so as not to rotate.

  The upper die 23 is formed with a through hole 23 a that penetrates the upper die 23 in the vertical direction. Rice and water supplied from the raw material supply apparatus 10 are put into the through hole 23a. When the lower mill 22 is rotated by the motor 26, the rice supplied from the raw material supply apparatus 10 is crushed. The shroud 24 collects the rice slurry 51 flowing out from the gap between the lower die 22 and the upper die 23 and supplies the rice slurry 51 to the grinding device 30.

  The crusher 30 includes a stone mortar 31, a shroud 34, and a motor 35. The stone mill 31 includes a lower mill 32 and an upper mill 33. The lower mortar 32 has a disk shape and is rotated around a rotation shaft 36 by a motor 35. The upper die 33 has a disk shape and is placed on the lower die 32. The upper die 33 is disposed coaxially with the lower die 22 and is fixed so as not to rotate.

  Similar to the upper mill 23, the upper mill 33 is formed with a through hole 33a. The rice slurry 51 discharged from the shroud 24 is put into the through hole 33a. When the lower mill 32 is rotated by the motor 35, the rice particles contained in the rice slurry 51 are crushed. The shroud 34 collects the rice slurry 52 flowing out from the gap between the lower mill 32 and the upper mill 33 and supplies it to the pulverizer 40.

  The crusher 40 includes a stone mill 41, a shroud 44, and a motor 45. The stone mill 41 includes a lower mill 42 and an upper mill 43. The lower mortar 42 has a disk shape and is rotated around a rotation shaft 46 by a motor 45. The upper die 43 has a disk shape and is placed on the lower die 42. The upper die 43 is arranged coaxially with the lower die 42 and is fixed so as not to rotate.

  Similar to the upper mills 23 and 33, the upper mill 43 is formed with a through hole 43a. The rice slurry 52 discharged from the shroud 34 is charged into the through hole 43a. When the lower mill 42 is rotated by the motor 45, the rice particles contained in the rice slurry 52 are pulverized. The shroud 44 collects the rice slurry 53 that flows out from the gap between the lower die 42 and the upper die 43.

{2. Details of millstones 21, 31, 41}
Hereinafter, the grooves formed in the stone mortars 21, 31, and 41 will be described. Grooves are formed on the lower surfaces of the lower dies 22, 32, and 42 and the upper surfaces of the upper dies 23, 33, and 43. The rice or rice particles thrown into the stone mills 21, 31, 41 are refined by the grinding and shearing forces generated by the rotating lower mill and the fixed upper mill. The degree of refinement of the rice particles can be changed by changing the depth of grooves formed on the upper surface of the lower die and the lower surface of the upper die.

  Initially, the groove | channel formed in the stone mill 21 is demonstrated. FIG. 2 is a top view of the lower mill 22. As shown in FIG. 2, eight main grooves 22 c are formed on the upper surface 22 b of the lower mill 22. The eight main grooves 22 c are formed radially from the rotary shaft 26 toward the outer edge 22 e of the lower mill 22.

  Sub-grooves 22d, 22d,... Are formed on the upper surface 22b. In FIG. 2, only some of the sub-grooves are denoted by reference numerals. The sub-groove 22d is parallel to any one of the eight main grooves 22c. Eight parallel sub-grooves 22d are formed for one main groove 22c. The depth of the main groove 22c and the sub groove 22d is 0.3 to 0.5 mm, preferably 0.4 mm.

  FIG. 3 is an enlarged top view of the lower mill 22. In FIG. 3, the ends of the main groove 22c and the sub-groove 22d are connected by a one-dot chain line (virtual line). As shown in FIG. 3, the distance d1 from the outer edge 22e of the lower mill 22 to the main groove 22c and the sub-groove 22d is 3 to 5 mm. In FIG. 3, the distance d1 is the same for each groove. However, the distance d1 may be different for each groove. The distance d1 may be in the range of 3 to 5 mm.

  FIG. 4 is a bottom view of the upper mill 23. As shown in FIG. 4, the groove pattern formed on the lower surface 23 b of the upper die 23 is the same as the groove pattern (see FIG. 2) formed on the upper surface 22 b of the lower die 22. Eight main grooves 23c are formed in the lower surface 23b. Sub-grooves 23d, 23d,... Are formed on the lower surface 23b. The arrangement and depth of the main groove 23c are the same as those of the main groove 22c, and the arrangement and depth of the sub groove 23d are the same as those of the sub groove 22d.

  Next, the groove | channel formed in the stone mill 31 is demonstrated, referring FIG. FIG. 5 is an enlarged top view of the lower mill 32. Eight main grooves 32c are formed radially on the upper surface 32b of the lower mill 32, like the main grooves 22c. FIG. 5 shows a part of the main groove 32c. The depth of the main groove 32c is 0.5 to 0.7 mm, preferably 0.6 mm. A plurality of sub-grooves 32d, 32d,... Are formed on the upper surface 32b. The sub-groove 32d is parallel to any one of the eight main grooves 32c. Eight sub-grooves 32d are formed for one main groove 32c. The depth of the minor groove 32d is 0.4 to 0.6 mm, preferably 0.5 mm.

  In FIG. 5, the ends of the main groove 32c and the sub-groove 32d are connected by an alternate long and short dash line (virtual line). The distance d2 from the outer edge 32e of the lower mill 32 to the main groove 32c and the sub-groove 32d is 3 to 8 mm. In FIG. 5, the distance d2 of each groove | channel corresponds. However, the distance d2 may be different for each groove. The distance d2 should just be in the range of 3-8 mm.

  Although the same main groove and subgroove as the lower surface 32b of the lower mill 32 are formed on the upper surface of the upper mill 33, the detailed description thereof is omitted.

  Next, the groove | channel formed in the stone mill 41 is demonstrated, referring FIG. FIG. 6 is an enlarged top view of the lower mortar 42. Eight main grooves 42c are formed radially on the upper surface 42b of the lower mortar 42, like the main grooves 22c. FIG. 6 shows a part of the main groove 42c. The depth of the main groove 42c is 0.5 to 0.7 mm, preferably 0.6 mm. A plurality of sub-grooves 42d, 42d,... Are formed on the upper surface 42b. The sub-groove 42d is parallel to any one of the eight main grooves 42c. Unlike the sub-grooves 22d and 32d, six sub-grooves 42d are formed for one main groove 42c. The depth of the sub-groove 42d is 0.6 to 0.8 mm, preferably 0.7 mm.

  In FIG. 6, the ends of the main groove 42c and the sub-groove 42d are connected by a one-dot chain line. The distance d3 from the outer edge 42e of the lower mill 42 to the main groove 42c and the sub-groove 42d is 11 to 12 mm. In FIG. 6, the distance d3 of each groove is the same. However, the distance d3 may be different for each groove. The distance d3 should just be in the range of 11-12 mm.

  Although the same main groove and subgroove as the lower surface 42b of the lower die 42 are formed on the upper surface of the upper die 43, the detailed description thereof will be omitted.

  As described above, the depth of each of the main grooves 22c, 32c, and 42c is preferably 0.4 mm, 0.6 mm, and 0.6 mm. The depths of the sub grooves 22d, 32d, and 42d are preferably 0.4 mm, 0.5 mm, and 0.7 mm. That is, the groove formed in the stone mill 31 is deeper than the groove formed in the stone mill 21. The groove formed in the millstone 41 is the same depth as the groove formed in the millstone 31 or is deeper than the groove formed in the millstone 31. Thus, as the pulverization of rice particles proceeds, the residence time of the rice particles in the stone mortar can be increased by increasing the depth of the groove formed in the mortar. Therefore, a rice slurry having a small particle size can be produced.

  Note that the groove pattern formed on the upper surface of the lower die and the groove pattern formed on the lower surface of the upper die need not be the same. The pattern of grooves formed on the upper and lower dies of the stone dies 21, 31, 41 may be different from each other. For example, the number of main grooves may be different in any one of the millstones 21, 31, 41. Further, the main groove and the sub groove may be curved.

{Manufacture of rice slurry}
The manufacturing procedure of the rice slurry using the rice slurry manufacturing apparatus 1 will be described in detail. FIG. 7 is a flowchart showing the procedure for producing rice slurry.

  First, before putting rice into the hopper 11, the rice is immersed in water (step S1). The immersion time is preferably 1.5 hours or more and 6 hours or less, more preferably 1.5 hours or more and 4 hours or less, and further preferably 1.5 hours or more and 2 hours or less. Since the dipping time can be shortened compared to the conventional case, the rice slurry can be produced efficiently.

  Next, the soaked rice is supplied to the crusher 20. Specifically, the immersed rice is put into the hopper 11. The soaked rice is supplied to the crushing device 20 by rotating the raw material supply screw 12. The supply amount of the soaked rice is preferably 27 g or more and 40 g or less per minute, and more preferably 32 g or more and 40 g or less per minute. By setting the rice supply amount to 27 to 40 (g / min), the residence time of the rice in the stone mill 21 can be lengthened. As a result, the number of times that the rice comes into contact with the stone mill 21 and the number of times that the rice comes into contact with each other increase, so that the refinement of the rice particles contained in the rice slurry 51 can be promoted.

  Further, the water in the raw material supply beaker 14 is supplied to the pulverizer 20 using the liquid feed pump 15. If the amount of water supplied is too small relative to the amount of rice supplied, the fluidity of rice will be reduced in the stone mills 21, 31, 41, and the pulverization efficiency will be reduced. On the other hand, when the supply amount of water is too much with respect to the supply amount of rice, the rice floats in the stone mortars 21, 31, 41, so that the pulverization efficiency decreases. Therefore, the supply amount of water is preferably 24 to 41 times the supply amount of immersed rice, more preferably 32 to 36 times the supply amount of immersed rice. Moreover, the solid content density | concentration (rice particle | grain density | concentration) in the rice slurries 51-53 can be adjusted by changing the supply amount of water.

  In the pulverizing apparatus 20, the supplied rice is wet pulverized by rotating the lower mill 22 (step S2). Thereby, the rice slurry 51 is produced | generated. The rotational speed of the lower mill 22 is not particularly limited, but is preferably 20 to 50 rpm (Round Per Minute).

  The rice particles contained in the rice slurry 51 are further pulverized using the pulverizer 30 (step S3). Specifically, the rice slurry 51 is put into a through-hole 33 a formed in the upper mill 33. The rice particles contained in the rice slurry 51 are pulverized by rotating the lower mill 32. Thereby, the rice slurry 52 is produced | generated. The rotational speed of the lower mill 32 is the same as the rotational speed of the lower mill 22 of the grinding device 20.

  The rice particles contained in the rice slurry 52 are further pulverized using the pulverizer 40 (step S4). Specifically, the rice slurry 52 is put into a through hole 43 a formed in the upper mill 43. The rice particles contained in the rice slurry 52 are pulverized by rotating the lower die 42. Thereby, the rice slurry 53 is produced | generated. The rotational speed of the lower mill 42 is the same as the rotational speed of the lower mill 22 of the grinding device 20.

  Thus, by using the rice slurry production apparatus 1, milky white rice slurry 53 can be produced in a short immersion time. The rice slurry manufacturing apparatus 1 can manufacture the rice slurry 53 having an average particle diameter of 5 μm or less by repeating wet pulverization of rice.

  The rice slurry 53 may be homogenized or heat sterilized. By sterilizing the rice slurry 53 by heating, a rice slurry in which rice particles are gelatinized can be obtained.

  The use of the rice slurry 53 is not particularly limited. For example, by adding plant-derived soy protein, sake lees, nuka oil, sugar and the like to the rice slurry 53, a milk-like food material can be generated. Milk-like ingredients can be used as an alternative to milk and dairy products, and therefore can provide various foods to consumers who have milk allergies.

  The rice slurry 53 may be used as a raw material for beverages such as fermented beverages and foods such as desserts. Unheated rice particles are not absorbed by the human body. For this reason, the rice slurry 53 can be used to produce a low calorie beverage or food. Moreover, since the average diameter of the rice particles contained in the rice slurry 53 is 5 μm or less, the consumer can drink a beverage containing the rice slurry 53 without feeling the presence of the coarse particles.

  Examples of the present invention will be described below.

{Example 1 (Production of rice slurry)}
In Example 1, the sample rice was pulverized using the rice slurry manufacturing apparatus 1 and the particle size of the rice particles contained in the rice slurries 51 to 53 was measured.

  First, sample rice (Hokuriku 193 brown rice) was immersed in distilled water at 2 ° C. for 1.5 hours. The rotational speed of the screw 12 was adjusted so that a certain amount (20 g per minute) of the immersed sample rice was supplied to the pulverizer 20. Further, the water supply pump 15 was controlled so that 85 ml of water was supplied to the pulverizer 20 per minute. Rice slurries 51-53 were manufactured by setting the rotational speed of the lower mills 22, 32, 42 to 50 rpm. The particle size distribution, median diameter and average diameter of the rice particles contained in the rice slurries 51 to 53 were measured using a laser diffraction particle size distribution analyzer (SALD-2200, manufactured by Shimadzu Corporation).

  FIG. 8 shows the median diameter and average diameter of the rice particles in the rice slurries 51, 52, and 53. FIG. 9 shows the particle size distribution of the rice particles in the rice slurries 51, 52, and 53.

  As shown in FIG. 8, the median diameter and the average diameter of the rice particles become smaller as the number of pulverizations increases. In particular, the average particle size of the rice particles contained in the rice slurry 53 is 4.218 μm. It was revealed that rice slurry 53 having an average particle size of 5 μm or less can be produced by repeatedly wet-grinding rice immersed in water using stone mortars 21, 31, and 41.

  As shown in FIG. 9, the appearance frequency of particles having a particle size of 100 μm or more decreases as the number of pulverizations increases. In particular, in the rice slurry 53, there are no rice particles having a particle size of 100 μm or more. It has been clarified that rice particles soaked in water can be prevented from remaining in the rice slurry by repeated wet pulverization using the stone mills 21, 31, and 41 to wet the rice particles having a large particle size (100 μm or more). It was.

  As shown in FIG. 8, the average diameter of the rice particles contained in the rice slurry 51 is 10.567 μm, and the average diameter is smaller than that of the rice particles obtained by conventional wet pulverization. From this, it became clear that even with wet grinding using only the stone mill 21, a rice slurry containing rice particles having a smaller particle diameter than before can be produced.

{Example 2 (Production of ice cream using rice slurry)}
In Example 2, a sensitivity test of ice cream (rice ice cream) using rice slurry 53 as a raw material was performed.

  In FIG. 10, the composition of the ice cream mix used for manufacture of rice ice cream is shown. As shown in FIG. 10, an ice cream mix was prepared by adding 27 g of sake lees powder, 51 g rice bran, 299 g sugar, 0.4 g emulsifier, 416 g water, and 187 ml rice bran oil to rice slurry 53 (1020 g). The prepared ice cream mix weighs 2000 g. Rice ice cream was produced by freezing the prepared ice cream mix.

  127 evaluators, both men and women, sampled rice ice cream and scored rice ice cream. The lowest score is 0, and the highest score is 100. In addition, when each evaluator eats favorite ice cream, evaluation of favorite ice cream is set to 50 points.

  FIG. 11 shows the average score of each evaluator. As shown in FIG. 11, the evaluation of rice ice cream was the same as that of ordinary ice cream for both men and women. From the results shown in FIG. 11, it was revealed that rice ice cream having a texture equivalent to that of milk ice cream can be produced from rice slurry produced using the rice slurry production apparatus 1.

{Example 3 (Dip conditions for rice)}
In Example 3, rice immersion conditions were confirmed by confirming changes in the moisture content of the sample rice (Hokuriku 193 brown rice) immersed in water. Specifically, the sample rice was immersed in distilled water at a temperature of 2 ° C., and the temporal change in the moisture content of the sample rice was measured. The weight ratio of sample rice to water is 2: 1.

  FIG. 12 shows the change over time in the moisture content of the sample rice. As shown in FIG. 12, the water content rapidly increases after the sample is immersed in water. After the water content becomes about 25%, the increase in the water content becomes moderate. The moisture content became 30.6% after 6 hours, and then reached an equilibrium state where it hardly increased. From this, it became clear that the time for immersing rice in water should be within 6 hours.

  In addition, when the immersion time is 1.5 hours as described in Example 1, the average diameters of the rice particles contained in the rice slurries 51, 52, and 53 are 10.567 μm, 7.215 μm, and 4. It was 218 micrometers (refer FIG. 8). That is, a rice slurry having an immersion time of about 1.5 hours and an average particle size of 10 μm or less can be obtained. From this, it has become clear that the immersion time may be 1.5 hours or longer.

{Example 4 (Supply conditions for soaked rice)}
In Example 4, the supply condition of rice was confirmed by examining the correspondence between the amount of rice supplied to the pulverizer 20 and the particle size of the rice particles contained in the rice slurry 51.

  Specifically, Hokuriku 193 brown rice (sample rice) was immersed in distilled water at 2 ° C. for 6 hours. The change in the particle size of the rice particles contained in the rice slurry 51 was measured when the supply amount of the soaked rice was changed in the range of 7.31 to 36.2 (g / min). At this time, the amount of water supplied to the pulverizer 20 is constant at 130 (ml / min), and the rotational speed of the lower mill 22 is 20 (rpm).

  FIG. 13 shows the correspondence between the amount of rice supplied and the particle size of the rice particles contained in the rice slurry 51. As shown in FIG. 13, when the supply amount of rice is larger than 26.5 (g / min), it has been clarified that the median diameter of the rice particles decreases rapidly (becomes 2 μm or less). .

  It was also confirmed that the median diameter tends to decrease as the amount of rice supply exceeds 26.5 (g / min). From this, it is expected that the particle size of the rice particles can be reduced by increasing the supply amount of rice. However, when the supply amount of rice is too large, it is expected that the fluidity of rice in the stone mill will be low and the grinding efficiency will be reduced. Therefore, the upper limit of the rice supply amount is preferably about 40 (g / min).

  From the above, if the amount of rice supplied is 26.5 to 40 (g / min), it is considered that the rice particles in the rice slurry can be further refined.

  The change in the 25% diameter of the rice particles is small compared to the change in the median diameter. However, it was confirmed that when the supply amount of rice is larger than 26.5 (g / min), the 25% diameter of the rice particles tends to be small.

{Example 5 (water supply conditions)}
In Example 5, the supply condition of water was confirmed by examining the correspondence between the amount of water supplied to the pulverizer 20 and the particle size of the rice particles contained in the rice slurry 51.

  Specifically, Hokuriku 193 brown rice (sample rice) was immersed in distilled water at 2 ° C. for 6 hours. The rice contained in the rice slurry 51 when the supply amount of water is changed in the range of 130 to 370 (ml / min) while the supply amount of the soaked rice is maintained at 7.31 (g / min). The change in particle size of the particles was measured. The rotational speed of the lower mill 22 is 20 (rpm).

  FIG. 14 shows the correspondence between the amount of water supplied and the particle size of the rice particles contained in the rice slurry 51. As shown in FIG. 14, it was confirmed that the median diameter of the rice particles was reduced when the amount of water supplied was in the range of 180 to 300 (ml / min). When the supply amount of water is 180 ml, the ratio between the supply amount of rice (7.31 (g / min)) and the supply amount of water is 1: 24.6. When the supply amount of water is 300 ml, the ratio of the supply amount of rice (7.31 (g / min)) and the supply amount of water is 1: 41.06. Therefore, it has been clarified that the rice particles contained in the rice slurry 51 can be refined by supplying the pulverizer 30 with water that is 24 to 41 times the supply amount of rice.

DESCRIPTION OF SYMBOLS 1 Rice slurry manufacturing apparatus 10 Raw material supply apparatus 20,30,40 Crushing apparatus 21,31,41 Stone mill 22,32,42 Lower mill 22c, 23c, 32c, 42c Main groove 22d, 23d, 32d, 42d Subgroove 23,33, 43 Upper mill 51,52,53 Rice slurry

Claims (8)

Immersing brown rice in water for a period of 1.5 hours or more and 6 hours or less;
With the brown rice soaked in water, throwing water into the first mortar;
Pulverizing the brown rice immersed in the water by rotating the first drawing mill to produce a first rice slurry;
A method for producing rice slurry. The method for producing rice slurry according to claim 1, further comprising:
The first drawing mill is
A disk-shaped first lower mill,
A disc-shaped first upper die placed on the first lower die and arranged coaxially with the first lower die;
With
A method for producing rice slurry, wherein a first groove is formed on an upper surface of the first lower die and a lower surface of the first upper die. A method for producing rice slurry according to claim 2,
The first groove is
A first main groove formed radially from the center of the upper surface of the first lower mill or the center of the lower surface of the first upper mill and having a depth of 0.3 to 0.5 mm;
A method for producing rice slurry comprising A method for producing rice slurry according to claim 3,
The first groove is
A first sub-groove parallel to the first main groove and having a depth of 0.3 to 0.5 mm;
A method for producing rice slurry comprising A method for producing a rice slurry according to any one of claims 1 to 4,
The method for producing rice slurry, wherein in the step of feeding into the first mill, the amount of the soaked rice supplied to the first mill is 25 g or more and 40 g or less per minute. A method for producing a rice slurry according to any one of claims 1 to 5,
In the step of feeding into the first mill, the amount of water supplied to the first mill is not less than 24 times the amount of the immersed rice supplied to the first mill. The manufacturing method of the rice slurry which is below 2 times. A method for producing a rice slurry according to any one of claims 1 to 6,
The method for producing rice slurry, wherein the average particle size of the rice particles contained in the rice slurry is 5 μm or less. A method for producing a rice slurry according to any one of claims 1 to 7,
The method for producing rice slurry, wherein the rotation speed of the first drawing mill is 20 rpm or more and 50 rpm or less.

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