HK1111315B - Brown rice having increased contents of functional components and method for manufacturing the same - Google Patents

Description

Brown rice with increased content of functional components and its preparation method

Technical Field

The present invention relates to a method for increasing functional components contained in brown rice and brown rice produced by the method.

Background

Recently, gamma-aminobutyric acid (GABA) has been attracting attention as a substance effective for maintaining health or preventing diseases such as suppression of blood pressure increase in a human body, and for this reason, efforts have been made to increase the content of gamma-aminobutyric acid contained in grains such as brown rice. For example, japanese patent application laid-open No. 2005-52073 discloses a method in which water is added to brown rice to a water content of 20% or more, the water-added brown rice is placed in a separately provided container, and the brown rice is tempered while ventilation is performed in the container, thereby increasing the amount of γ -aminobutyric acid contained in the brown rice.

However, in this method, the already dried brown rice must be added with water again until the water content exceeds 20%, and for this reason, the brown rice must be added with water at a rate of 0.5%/hour (h) or more. In the processing of the brown rice to which water is added again in this way, there is a possibility that the taste of the brown rice is lowered and the particles are broken. In addition, since the already dried brown rice needs to be dried again after adding water again, there is a problem that the manufacturing cost is increased as compared with the usual brown rice.

Therefore, in order to prevent the deterioration of taste, and further, in order to reduce the cost required for adding water to the brown rice and the cost required for redrying, it is strongly desired to suppress the addition of water to the brown rice to a required minimum and to slow down the rate of water addition in order to prevent damage such as breakage of the grains.

It is also known that gamma-aminobutyric acid contained in brown rice can be greatly increased by germinating the brown rice. However, as disclosed in, for example, Japanese patent application laid-open No. 2005-168444, it is considered that germinated brown rice obtained by germinating brown rice has a taste inferior to that of ordinary white rice. Therefore, it is desirable that the amount of gamma-aminobutyric acid contained in the brown rice is increased as compared with that in the usual brown rice without germinating the brown rice.

Disclosure of Invention

In view of the above problems, it is an object of the present invention to provide a technique for minimizing the addition of water to brown rice and for increasing the amount of functional components such as gamma-aminobutyric acid contained in rice grains to a greater extent than in normal brown rice even when water is added at a slow water addition rate.

In order to solve the problems, the invention adopts the technical means that: the method comprises circulating brown rice in a device having the same structure as a grain dryer by introducing high-humidity air into the device, increasing the water content of the brown rice to 16.5-18.5% at a water addition rate of 0.3%/hr or less, and standing the brown rice in the device with the ventilation and circulation stopped to increase the functional components such as gamma-aminobutyric acid contained in the brown rice.

The present invention also provides a method for producing brown rice having an increased content of functional components, comprising milling the brown rice to produce polished rice (incomplete rice milled by adjusting the amount of rice bran removed from the brown rice), germinated rice (rice milled with residual germs), and polished rice (rice from which 10% of rice bran has been removed from the brown rice), and further processing the polished rice into non-washed incomplete polished rice, non-washed germinated rice, and non-washed rice. The term "wash-free rice" as used herein means rice to the extent that washing with water (rice washing) is not necessary when rice is refined into rice.

According to the method for producing brown rice having an increased content of functional ingredients of the present invention, it is not necessary to increase the moisture content of brown rice as a raw material to more than 18.5%. This makes it possible to add water at a very slow water addition rate and prevent damage such as chipping of the particles. In addition, the cost required for adding water can be reduced, and the cost required for drying after adding water can also be reduced. Furthermore, since the moisture content of the brown rice as a raw material is not more than 18.5%, the brown rice does not germinate. Therefore, the deterioration of the taste due to germination can be prevented, and when the brown rice is ground into white rice, the white rice can be eaten as ordinary cooked rice.

Drawings

Fig. 1 is a flowchart illustrating a method for increasing functional components contained in brown rice according to the present invention.

Fig. 2 is a schematic front view, partly in section, of a watering drying apparatus in which the method of the invention is to be carried out.

Fig. 3 is a schematic side view, partly in section, of the watering drying apparatus shown in fig. 2.

Fig. 4 is a cross-sectional view showing a water adding and drying section of the water adding and drying apparatus shown in fig. 2, and illustrates flows of humidified air flow and hot air.

FIG. 5 is a control block diagram of a water-adding drying apparatus for carrying out the method of the present invention.

FIG. 6 is a schematic diagram showing an apparatus for producing milled rice from highly functionalized brown rice to produce milled rice having germ therein.

Fig. 7 is a partial longitudinal sectional view of an abrasive rice mill constituting the milled rice with germ of fig. 6.

FIG. 8 is a view showing a method for producing wash-free rice.

Detailed Description

The above and other objects and features of the present invention will become more apparent from the following description of the embodiments with reference to the attached drawings.

A method for increasing a functional ingredient contained in brown rice and an apparatus for performing the method according to the present invention will be described with reference to fig. 1 to 5.

The watering drying device 1 has substantially the same structure as a general circulation type grain dryer, and includes: a storage part 2 for storing the brown rice; a water-adding drying section 7 for blowing high-humidity air (hereinafter referred to as "humidifying air flow") or hot air to the brown rice; and a discharging part 10 for discharging the brown rice from the water-adding drying part 7 to the outside of the device.

In the water-adding drying section 7, an air-blowing duct 3, an air-discharging duct 4, and a grain-flowing-down tank 5 connected to the storage section 2 are formed by being partitioned by a plurality of perforated plates 6 arranged across one side (hereinafter referred to as a side a) and the other side (hereinafter referred to as a side B) in the longitudinal direction shown in fig. 3.

The discharge part 10 is provided with a discharge valve 8 for intermittently discharging the brown rice on the lower end side of a non-porous plate 12 which is inclined while being connected to the grain flow-down tank 5. Further, a lower screw conveyor 9 for horizontally conveying the brown rice discharged from the discharge valve 8 and discharging the brown rice to the outside of the apparatus is disposed below the discharge valve 8. The brown rice discharged by the lower screw conveyor 9 is circularly conveyed to the storage section 2 via the bucket conveyor 11 and the upper screw conveyor 27. A bucket conveyor motor 25c is attached to the upper portion of the bucket conveyor 11, and the upper screw conveyor 27 is driven by power from the bucket conveyor motor 25 in addition to the bucket conveyor 11. Further, a discharge motor 25b is attached to the discharge section 10, and the discharge valve 8 and the lower screw conveyor 9 are driven by power from the discharge motor 25 b.

A hot air generating burner 14 and a humidifier 13 using kerosene as a fuel are provided below the side a, and an exhaust fan 20 having a fan motor 25a is provided below the side B. The hot air generating burner 14 is connected to a flow path switching valve 16. The exhaust fan 20 is connected to the side B of the exhaust duct 4 of the watering drying unit 7, and sucks the hot air in the exhaust duct 4 and discharges the hot air to the outside of the machine. A temperature/humidity sensor 21 for detecting the temperature and humidity of the humidified air flow and the hot air is attached to the vicinity of the supply port of the air duct 3 for supplying the hot air, and a moisture meter 18 for detecting the moisture value of the grain is attached to one side of the bucket conveyor 11.

When water is added to the hot air generated by the hot air generating burner 14, the hot air is converted into a humidified air flow by the humidifier 13 via the flow path switching valve 16 by the suction action of the exhaust fan 20, and is discharged from the exhaust fan 20 to the outside of the machine through the vent 17, the front air duct 15, the air supply duct 3, the grain flow-down tank 5, and the exhaust duct 4. On the other hand, during drying, the air is discharged from the exhaust fan 20 to the outside of the machine through the flow path switching valve 16, the bypass duct 19, the vent 17, the front duct 15, the air supply duct 3, the grain flow-down tank 5, and the exhaust duct 4.

Immediately after the start of drying, in order to prevent the particles of the brown rice from being broken due to rapid drying, a part of the hot air may be passed through the humidifying device 13 to increase the relative humidity of the hot air passed therethrough, and the high-humidity hot air and the hot air passed through the branch duct 19 may be mixed by the connection valve 26 to form hot air having a relative humidity of about 75% and dried by the hot air.

Here, the configurations of the humidifying device 13 and the hot air generating burner 14 will be described with reference to fig. 3.

In the present embodiment, the humidifier 13 is a general vaporizing humidifier, but a humidifier using another humidification method such as a steam type may be used. The hot air generating burner 14 may be one generally used in grain dryers. The humidifying device 13 and the hot air generating burner 14 may be connected to each other via a flow path switching valve 16. The flow path switching valve 16 can switch the flow path of the hot air generated by the hot air generating burner 14, and allows all of the hot air to pass through the humidifying device 13 when water is added and to pass through the branch air duct 19 when drying. In order to adjust the humidity of the hot air during drying, the flow path switching valve 16 allows a part of the hot air to pass through the humidifying device 13 and the remaining part to pass through the branch duct 19.

The control of each part of the watering drying apparatus 1 is performed by the control unit 22. The control unit 22 is provided on the side a of the watering drying apparatus 1. As shown in fig. 5, the control unit 22 includes: the CPU22 b; an input/output port 22a, a read-only storage unit (hereinafter referred to as "ROM") 22c, and a write/read storage unit (hereinafter referred to as "RAM") 22d, which are connected to the CPU22 b. The ROM22c stores programs for performing the water adding operation and the drying operation in advance.

The temperature and humidity sensor 21 is connected to the input/output port 22a via an a/D converter 23, and the moisture meter 18 is connected to the input/output port via an a/D converter 24. Further, the humidifying device 13, the hot air generation burner 14, the flow path switching valve 16, and the input unit 29 are connected to the input/output port 22 a. A fan motor 25a, a discharge portion motor 25b, and a bucket conveyor motor 25c are connected to the input/output port 22a via a motor drive circuit 25.

The input unit 29 is provided with: a charge setting switch 29a for setting a charge (fill) amount; a water-adding setting switch 29b for setting a water content value at the time of water addition; a moisture setting switch 29c for setting a finished moisture value; a throw-in button 29d for starting throw-in; a water adding button 29e for starting water adding; a dry button 29f to start drying; and a discharge button 29g for discharging grains. By operating these switches and keys, corresponding control signals are transmitted to the CPU22 b. The CPU22b executes a water adding operation program, a drying operation program, and the like.

Next, the operation of the water adding and drying apparatus 1 of the present invention will be described. First, the water addition operation will be described.

The brown rice as the raw material is charged into the water adding and drying apparatus 1 (step S1), and the charged amount of the brown rice and the target water content value of the water are set by the charging setting switch 29a and the water adding setting switch 29b, respectively. After the setting is completed, when the water adding button 29e is pressed, the CPU22b executes the water adding operation program loaded in the ROM22c (step S2). After the water adding operation program is executed, electric currents are supplied to the fan motor 25a, the discharge portion motor 25b, and the bucket conveyor motor 25c, and the exhaust fan 20, the discharge valve 8, the lower screw conveyor 9, the bucket conveyor 11, and the upper screw conveyor 27, respectively, to start operating.

The humidifier 13 and the hot air generation burner 14 also start operating to start generating a humidified air flow. The set humidity and temperature of the humidified airflow to be blown into the grain flow-down tank 5 of the watering drying section 7 are determined based on the amount of brown rice input and the target watering moisture value set at the start of the watering operation. The combustion level of the hot air generation burner 14 is changed based on the humidity and temperature detected by the temperature/humidity sensor 21 so that the humidity and temperature of the humidified air flow supplied to the grain flow-down tank 5 reach the set humidity and temperature, respectively.

During the water adding operation, the set humidity and temperature are changed based on the moisture value of the grain measured at any time by the moisture meter 18. The combustion level of the hot air generating burner 14 may be changed so that the humidity and temperature of the humidified air flow reach the changed set humidity and temperature.

The air volume ratio of the humidified air flow blown into the grain flow-down tank 5 during the watering operation may be adjusted to be in the range of 0.2 to 0.6 cubic meter/sec/ton, preferably 0.3 to 0.5 cubic meter/sec/ton, and more preferably 0.3 to 0.35 cubic meter/sec/ton. The temperature of the humidified gas flow is preferably 35 ℃ or lower.

The brown rice flowing down from the storage container 2 to the grain flow-down tank 5 of the water-adding drying section 7 is added with water by applying a humidifying gas flow generated by a humidifying device 13 and a hot air generating burner 14. The brown rice added with water in this manner is discharged from the grain flow-down tank 5 through the discharge valve 8, and is circulated and conveyed to the storage vessel 2 via the bucket conveyor 11 and the upper screw conveyor 27. The circulation to the storage container 2 is continued until the water content value measured by the water content meter 18 at any time reaches the water addition target water content value. When the moisture content of the brown rice added with water reaches the water addition target moisture value at circulated and conveyed in the water adding and drying device 1, the water adding operation is ended. After the completion of the water addition operation, the circulation of the brown rice and the ventilation of the humidifying air flow are stopped, and the brown rice to which the water addition has been completed is left standing in the water adding and drying apparatus 1 (step S3).

In the present invention, the moisture content of the brown rice when water is added is suppressed to 18.5% or less, and therefore, the brown rice can be left standing without carrying out circulation or ventilation. The time for the standing is about 10 hours, although it varies depending on the amount of the gamma-aminobutyric acid to be increased. The time can be easily changed, and it is only necessary to adjust the time within a range of 2 to 25 hours, preferably 8 to 12 hours, and more preferably 9 to 11 hours.

After the brown rice is left to stand, the drying operation is started (step S4). The drying completion target moisture value is set, and the drying operation is started by the CPU22b executing the drying operation program loaded in the ROM22c by pressing the drying button 29 f. After the drying operation program is executed, electric current is supplied to the fan motor 25a, the discharge portion motor 25b, and the bucket conveyor motor 25c, and the exhaust fan 20, the discharge valve 8, the lower screw conveyor 9, the bucket conveyor 11, and the upper screw conveyor 27, which have been stopped so far, start to operate. The hot air generation burner 14 also starts to operate to start the generation of hot air.

The set hot air temperature of the hot air blown into the grain flow-down tank 5 of the water adding and drying section 7 is determined based on the target moisture value after drying set at the start of the drying operation. The combustion level of the hot air generation burner 14 may be changed so that the temperature detected by the temperature/humidity sensor 21 reaches the set hot air temperature. During the drying operation, the set hot air temperature is changed based on the moisture value of the grain measured at any time by the moisture meter 18. The combustion level of the hot air generation burner 14 can be changed so that the temperature of the hot air blown into the grain flow-down tank 5 reaches the changed set hot air temperature.

The brown rice flowing down from the storage container 2 to the grain flow-down tank 5 of the water-adding drying section 7 is dried by ventilation with hot air generated by a hot air generating burner 14. In this way, the dried brown rice is circulated and conveyed to the storage container 2 in the grain flow-down tank 5 via the discharge portion 10, the bucket conveyor 11, and the upper screw conveyor 27. The circulation transfer to the storage container 2 is continued until the moisture value of the brown rice measured by the moisture meter 18 at any time reaches the target moisture value after the drying. In this way, when the brown rice reaches the target moisture value after the brown rice is dried, the drying operation is ended.

The brown rice after drying can be treated in the same manner as ordinary brown rice. In addition, in the present invention, since the drying process using hot air is performed after the water adding operation, the propagation of fungi in the water adding and drying apparatus 1 can be prevented, and the apparatus is sanitary.

Next, a method of processing (milling) brown rice (hereinafter referred to as "enriched-functionalized brown rice") having an increased content of functional components such as γ -aminobutyric acid, which is produced by the production method of the present invention, will be described. The highly functionalized brown rice produced by the production method of the present invention has the same other properties as normal brown rice except that the amount of gamma-aminobutyric acid contained in the rice grains is increased. Therefore, the treatment can be performed in the same manner as in the case of ordinary brown rice.

First, a rice milling method is explained. The rice milling may be performed in a general method, and may be performed to mill incomplete white rice, germ rice, and white rice according to purposes (step S5).

For grinding the above-mentioned highly functionalized brown rice into milled rice having germ-like grains, a known method described in, for example, Japanese patent application laid-open No. 6-209724 can be used. The outline of this method is described with reference to fig. 6 and 7. Fig. 6 is a schematic diagram showing an apparatus 31 for producing milled rice from highly functionalized brown rice into milled rice having milled.

The milled rice manufacturing apparatus 31 is composed of a microwave heating apparatus 32, cooling containers 33A and 33B, and a grinding type rice mill 34. The grains supplied to the hoppers 35 and 36 provided at the lower part of the grain elevator 37 such as a bucket conveyor are lifted by the grain elevator 37, and are discharged from the discharge port at the upper end of the grain elevator 37 and supplied to the loading container 38. The rice grains dropped from the input container 38 are sent into the main body of the microwave heating apparatus 32 through the input duct 39.

The rice grains discharged from the discharge duct 40 of the microwave heating device 32 are sent to the pair of cooling containers 33A and 33B by the belt conveyor 41, the hopper 42, the winnower 43, and the switching valve 44. The rice grains discharged from the discharge gates 45A and 45B provided in the discharge portions of the cooling containers 33A and 33B are supplied to the supply hopper 50 of the rice mill 34 through the belt conveyor 46, the hopper 47, the winnower 48, and the switching valve 49.

The microwave heating device 32 is of a type in which a spiral cylinder 52 rotationally driven by rotation of a main shaft (not shown) is provided in a vertically installed resin cylinder 53, and a downflow path 54 of brown rice is formed in a space formed by the spiral cylinder 52 and the cylinder 53. Further, 2 wave guides 56A and 56B are attached to a machine frame 57 having a cover cylinder 58 connected to the upper end thereof, and one ends of the wave guides 56A and 56B are made to face the cylindrical body 53, and oscillators 55A and 55B are connected to the other ends thereof, whereby microwaves are irradiated to the brown rice flowing down along the flow-down passage 54. A discharge duct 40 is provided at the lower part of the microwave heating device 32, and rice grains dropped from the discharge duct 40 are sent to a belt conveyor 41 outside the machine.

As shown in fig. 7, the rice mill 34 of the polishing type is composed of a porous wall fine grinding cylinder 59 disposed with its axis directed in the horizontal direction, a main shaft 60 rotatably provided on the porous wall fine grinding cylinder 59, a screw rotor 61 provided on the main shaft 60, and a polishing fine grinding rotor 62. One of the fine grinding chambers 63 mainly composed of the porous wall fine grinding cylinder 59 and the fine grinding rotor 62 is connected to the brown rice supply port 64, and the other is connected to the rice milling discharge port 65. A resistance plate 67 urged by a weight 66 is provided at the rice milling outlet 65, and the rice discharged from the rice milling outlet 65 is dropped along a discharge duct 68 and sent to the outside of the machine.

The rice bran falling through the holes of the porous wall fine grinding cylinder 59 is collected in the bran collecting chamber 69. The bran collection chamber 69 is connected to a dust collection duct (not shown). A supply hopper 50 is provided above the brown rice supply port 64. The pulley 70 mounted on the main shaft 60 is connected by a pulley 72 mounted on a motor 71 and a belt 73.

Next, the operation of the milled rice manufacturing apparatus 31 shown in fig. 6 and the operation of the rice milling machine 34 shown in fig. 7 will be described.

The highly functionalized brown rice in the input hopper 35 is conveyed upward by the winnower 37, sent to the input container 38, flows downward along the input duct 39 connected to the input container 38, and falls to the upper end of the spiral cylinder 52. The highly functionalized brown rice dropped to the upper end of the spiral cylinder 52 flows down the flowing-down passage 54 by the rotation of the spiral cylinder 52. The highly functionalized brown rice flowing down the flow-down passage 54 is heated by the microwaves oscillated by the microwave oscillator 55A, transmitted through the waveguide 56A and irradiated. The rich-functionalized brown rice heated by the microwave oscillator 55A flows down along the down channel 54, and is then heated again by the microwaves oscillated by the microwave oscillator 55B and transmitted and irradiated through the waveguide 56B. The enriched functionalized brown rice heated by the maser microwave oscillator 55B further flows down the lower passage 54, is discharged from the discharge duct 40, and is supplied onto the belt conveyor 41.

The enriched functional brown rice heated by the microwave is sent from the belt conveyor 41 to the switching valve 44 via the hopper 42 and the winnower 43, and is supplied from there to the cooling container 33A or the cooling container 33B according to the switching state of the switching valve 44.

The enriched functional brown rice heated by the microwave heating device 32 is cooled to the valley temperature before heating or lower in the cooling containers 33A and 33B. The highly functionalized brown rice cooled in the cooling container 33A or 33B is discharged to the belt conveyor 46 by opening the shutter 45A or 45B. The enriched functional brown rice transferred from the cooling container 33A or 33B to the belt conveyor 46 is transferred to the switching valve 49 via the hopper 47 and the winnower 48, and is supplied from the switching valve 49 to the microwave heating device 32 via the hopper 36, the winnower 37, the input container 38, and the input duct 39, and is again heated by microwaves.

Thus, after repeating the heating by the microwave heating device 32 and the cooling by the cooling container 33a plurality of times, the water content of the highly functionalized brown rice becomes 13% or less and the temperature thereof becomes not more than the temperature before the heating. Then, by switching the switching valve 49, the high-functionalized brown rice is supplied from the winnower 48 to the polishing type rice mill 34 through the switching valve 49 and the supply hopper 50.

The highly functionalized brown rice supplied from the screw rotor 61 through the supply port 64 of the rice mill 34 is horizontally transferred to the fine grinding chamber 63 by the screw rotor 61. In the fine grinding chamber 63, the highly functionalized brown rice is finely ground by the fine grinding action of the rotation of the fine grinding rotor 62 to become highly functionalized germinated rice.

Dust such as bran generated by the fine grinding action of the fine grinding chamber 63 is discharged from the through-holes of the fine porous grinding cylinder 59 to the bran collecting chamber 69 by the suction action of a suction machine (not shown), and is sent from the bran collecting chamber 69 to a bran collecting device such as a cyclone collecting cylinder (not shown).

The functionalized rice with germ enriched by finely grinding the functionalized brown rice flows out from the outlet 65 against the resistance of the resistance plate 67, and flows down the discharge duct 68 to be discharged outside the machine. The number of milling is not limited to 1 as in the present embodiment, and the rice milling may be performed by arranging the winnowing machines in parallel in the horizontal direction and circulating the rice milling a plurality of times, or by arranging a plurality of grinding rice mills 34 in a series stroke. The rice mill is not limited to a grinding type, and a general rice mill can be used.

When the functional-enriched brown rice produced by the production method of the present invention is milled into milled rice with germ, the milled rice may be milled by adjusting the raw material utilization rate during milling with a known rice mill without performing microwave heating.

However, since most of the moisture is emitted to the outside of the rice grains through the germ part during drying of the coarse rice grains, the moisture in the joint part between the germ and endosperm of the rice grains becomes the highest. In addition, since the energy of the microwave is absorbed into the moisture, the heat of the primary coat is the largest at the joint between the germ and the endosperm where the moisture is the highest, and as a result, the germ and the endosperm are gelatinized and bonded. Since the embryo and the endosperm are gelatinized and combined, even if the brown rice is milled, the embryo rice with high survival rate of embryo is produced because the bud is difficult to be removed. Further, since the rice is milled at a low temperature by cooling in the cooling container 33, the rice can be made into delicious staple rice without spoiling the taste.

The incomplete polished rice, the milled rice with embryo, and the polished rice (hereinafter referred to as "incomplete polished rice with enriched functionalization", "milled rice with enriched embryo", and "rice with enriched functionalization", respectively) obtained by milling the brown rice with enriched functionalization obtained by the production method of the present invention can be treated in the same manner as the incomplete polished rice, the milled rice with embryo, and the polished rice distributed in the general market. Therefore, the non-clean rice can be easily processed into the non-clean rice with rich functionality, the non-clean rice with rich functionality and germ can be easily processed into the non-clean rice with rich functionality and the non-clean rice with rich functionality by using the well-known non-clean rice processing technology (step S6).

Here, the washing-free rice processing technology will be briefly described by taking the above-mentioned enriched rice as an example. As a technique for producing wash-free rice, for example, a method for producing wash-free rice described in Japanese patent application laid-open No. 2001-259447 can be used. The gist of the method for producing wash-free rice will be described with reference to FIG. 8.

FIG. 8 is a view showing steps of a method for producing wash-free rice. The production of the wash-free rice is carried out by using the water adding means 79, the stirring and mixing means 80, and the separating means 81. The moisture is added to the enriched rice by the moisture adding mechanism 79. The water-containing rice is added to the rice, and the milled rice is mixed by the stirring and mixing mechanism 80 and stirred in this state to grind the rice. Then, the ground and functionalized rice is separated from the used and pulverized rice by the separation means 81.

The moisture addition mechanism 79 includes: a cylindrical fine grinding guide drum 82; and a screw rotor 83 rotatably provided in the fine grinding guide cylinder 82. A moisture adding device 87 including a water tank 84, an electromagnetic valve 85, a water pipe 86, and the like is connected to the fine grinding guide tube 82 at any position thereof. Then, while the enriched white rice is fed from the hopper 76, the rice grains are rotated by rotating the screw rotor 83 in the fine grinding guide drum 82, and moisture (for example, moisture in an amount of 3 to 5% by weight of the rice grains) from the moisture adding device 87 is added to the rice grains. Further, by setting the time for the highly functionalized rice to pass through the fine grinding guide drum 82 to, for example, about 15 seconds, it is possible to prevent the rice grains from cracking, and to safely add water to the highly functionalized rice. The surface of the functionalized rice to which water has been added is slightly changed to a soft state.

The above-mentioned enriched functionalized rice discharged from the water adding means 79 is immediately put into the stirring and mixing means 80 for mixing and stirring with the milled rice. The stirring and mixing mechanism 80 is composed of a roller-shaped machine frame 88 and a stirring device 89 rotatably provided in the machine frame 88. A fine grinding supply duct 90 for receiving rice grains discharged from the moisture adding mechanism 79 and a crushed rice supply duct 91 for crushed rice conveyed by the conveying mechanism are connected to one end of the casing 88. As a conveying mechanism for supplying the crushed rice to the crushed rice supply duct 91, for example, in the case of conveying by using wind power, a cyclone 92 for air flow separation is connected to an upper end of the crushed rice supply duct 91, and a crushed rice discharge duct 77 branched from the crushed rice supply duct 91 is connected from the cyclone 92.

The stirring device 89 is provided with a plurality of stirring blades 93, and is rotated by power of a motor or the like. When the stirring blade 93 rotates, the enriched white rice and the milled rice are mixed and stirred in the machine casing 88, and the mixed rice grains are discharged from a discharge port 94 provided at the other end of the machine casing 88.

The enriched rice put into the stirring and mixing mechanism 80 is stirred and mixed with the crushed rice whose water content is 5% or less. By this action, moisture-containing and swollen aleurone (aleurone) near the surface of the functionalized rice is adsorbed by the milled rice and floats from the aleurone barrier layer, and the surface of the functionalized rice is polished by a slight rubbing action between the particles of the functionalized rice and the milled rice. The mixing ratio of the enriched functionalized white rice and the milled rice is preferably 5-30 parts by weight relative to 100 parts by weight of the enriched functionalized white rice.

The separating means 81 may have any structure as long as it is a sieving device capable of separating the enriched white rice and the pulverized rice, and may be, for example, a rougher 96 having a sieve 95 provided thereon. Further, the roughing mill 96 may be vibrated by the power of a motor (not shown).

As described above, the functionalized rice obtained by the separation means 81 becomes the rice without washing from which bran remaining on the surface of the rice grains is removed. Further, in order to improve the whiteness of the wash-free rice and to improve the productivity, the 2 nd stirring and mixing mechanism 98 and the 2 nd separating mechanism 99 may be provided in a step subsequent to the separating mechanism 81. Thus, glossy and functional wash-free rice with improved whiteness can be produced by completely removing bran remaining on the surface of rice grains.

The non-functionalized rice and the functionalized rice with germ can be processed into wash-free rice by using a wash-free rice processing technique using steam as described in, for example, Japanese patent laid-open publication No. 2002-166485. Of course, this wash-free rice technology can also be used on the rich functionalized rice. In addition, if superheated steam is used instead of steam, the thermal sterilization process of rice grains can be performed at a higher temperature (step S7).

As one example of the present invention, brown rice having a variety name of "コシヒカリ" (produced in guangdland county, japan, harvested in 2004) was processed using the production method of the present invention. Water was added at a rate of 0.2%/hour or less using the water-adding drying apparatus 1 shown in FIGS. 2 and 3 so that the moisture content of the "コシヒカリ" brown rice was not more than 18.5%. In this water addition operation, the relative humidity of the humidified gas flow was set to 95% or more, the temperature of the humidified gas flow was set to 15 ℃ 2 hours after the start of water addition, the temperature was raised by 5 ℃ every 2 hours thereafter, and finally ventilation for water addition was performed for 16 hours with the humidified gas flow of 35 ℃. After the completion of the water addition operation, the "コシヒカリ" was left to stand in the storage container 2 of the water addition drying apparatus 1 for 10 hours to increase the amount of γ -aminobutyric acid contained in the "コシヒカリ". After standing still, the resultant was dried by a drying operation to obtain "コシヒカリ" rich functionalized brown rice. Further, the highly functionalized brown rice is subjected to rice milling by a usual rice milling method to obtain highly functionalized white rice. The enriched functionalized brown rice and enriched functionalized white rice can be obtained under the same conditions for the variety name "ひとめぼれ" (produced in Guangdong island county of Japan, harvested in 2004) and the variety name "きらら 397" (produced in Hokkaido of Japan, harvested in 2004).

Table 1 shows the amounts of γ -aminobutyric acid and the degrees of whiteness of the "コシヒカリ" rich-functionalized brown rice and the "コシヒカリ" rich-functionalized white rice thus obtained. The amounts of γ -aminobutyric acid and the degrees of whiteness of the highly functionalized brown rice and the highly functionalized white rice are shown in tables 2 and 3, respectively, for "ひとめぼれ" and "きらら 397". The amount of γ -aminobutyric acid was measured by a high-speed liquid chromatograph (LC-VP, Shimadzu corporation), and the whiteness was measured by a whiteness meter (C-300, scientific research institute ケツト, K.K.).

[ TABLE 1 ]

"コシヒカリ" (produced in Guangdong island of Japan, harvested in 2004)

	Whiteness degree	The content of gamma-aminobutyric acid is mg/100g
			Raw material dry rice	20.7	8.8
Functionalized dry rice	20.6	18.0
			Raw material rice	41.5	3.1
Functionalized rice	39.6	10.1

[ TABLE 2 ]

"ひとめぼれ" (produced in Guangdong island of Japan, harvested in 2004)

	Whiteness degree	The content of gamma-aminobutyric acid is mg/100g
			Raw material dry rice	20.3	4.8
Functionalized dry rice	21.2	11.9
			Raw material rice	40.4	1.6
Functionalized rice	40.2	8.1

[ TABLE 3 ] きらら 397 (produced in North China, 2004 Harvest)

	Whiteness degree	The content of gamma-aminobutyric acid is mg/100g
			Raw material dry rice	20.2	6.3
Functionalized dry rice	20.1	13.0
			Raw material rice	37.6	2.4
Functionalized rice	38.3	6.4

In table 1, in order to show the increasing ratio of the amount of γ -aminobutyric acid in the highly functionalized brown rice and the highly functionalized white rice, "コシヒカリ" brown rice used as the raw material was referred to as "raw material brown rice," and the white rice milled from the brown rice was referred to as "raw material white rice. The content of gamma-aminobutyric acid in the brown rice rich in the functional group is more than 2 times of that in the brown rice rich in the raw material, and the content of gamma-aminobutyric acid in the white rice rich in the functional group is about 3.3 times of that in the white rice rich in the raw material. In addition, no clear difference was observed in the whiteness between the raw brown rice and the high-functionalized brown rice, and between the raw white rice and the high-functionalized white rice.

In addition, with respect to "ひとめぼれ" and "きらら 397", experimental results having the same tendency as "コシヒカリ" were obtained.

Claims (5)

1. A method for preparing brown rice with increased content of functional components comprises the following steps:

adding water to the brown rice circularly conveyed in the device;

standing the brown rice after the completion of the water addition in a state where the circulation conveyance and the ventilation are stopped; and a step of drying the brown rice after standing; the method is characterized in that:

in the step of adding water to the brown rice, water is added at a water adding rate of 0.2% or less per hour by ventilation of high humidity air with a relative humidity of 95% or more so that the moisture of the brown rice is 16.5 to 18.5%,

and the temperature of the air is 15 ℃ 2 hours after the start of adding water, the temperature is increased by 5 ℃ every 2 hours, and finally the air is heated to 35 ℃;

in the step of leaving the brown rice to stand, the brown rice is left to stand for 2 to 25 hours.

2. The method of producing brown rice according to claim 1, wherein the content of the functional ingredient is increased by: in the step of adding water to the brown rice, the air volume applied to the brown rice is 0.2-0.6 m³And/sec.ton.

3. A brown rice having an increased content of a functional ingredient, which is produced by the production method according to claim 1.

4. An incomplete polished rice, a germinated rice or polished rice, which is obtained by milling the brown rice of claim 3 to increase the content of functional components.

5. A wash-free incomplete polished rice, a wash-free germ rice or a wash-free rice, which is obtained by subjecting the incomplete polished rice, the germ rice or the polished rice of claim 4 to wash-free polishing, respectively, to increase the content of functional components.