JP2002248359A - Method and apparatus for making wash free rice - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and apparatus for making wash free rice which is good in quality and is workably and hygienically desirable. SOLUTION: This method of making the wash free rice has a process step 26 of adding bran to raw material rice and mixing both while cooling and a process step 27 of classifying the wash free rice and the bran obtained by the mixing process step.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for producing non-washed rice which does not require rice washing during cooking.

[0002]

2. Description of the Related Art Conventionally, when cooking rice, it is necessary to wash the rice, which causes problems such as an increase in work and environmental pollution due to sap juice. For these reasons, so-called “washed rice” has recently become a hot topic. This unwashed rice is
Rice can be cooked simply by adding water without washing the rice, and the turbidity of water when immersed in water under predetermined conditions is 60%.
Those with less than ppm are certified as "washed rice".

Here, a general method of polishing rice is described. First, brown rice whose shell has been removed is mechanically polished with a brush, so that primary rice is reduced to reduce the turbidity to about 150 ppm. Next, secondary polishing is performed by the same mechanical polishing to reduce the turbidity to about 80 ppm, and sales are performed in this state. Consumers are washing the rice and cooking it.

[0004] In addition, the non-washed rice currently on the market prevents the outflow of rice components into water by coating the surface of the rice after the above-mentioned secondary milling, and the turbidity as the above-mentioned "unwashed rice". The degree standard (60 ppm or less) is secured.

[0005]

However, in the case of the above-described non-washed rice, although the surface is coated,
It is known that rice components (such as oil) flow out during cooking and remain on the cooked rice. For this reason, there was a problem that the smell remained in the rice or the quality of the rice that had passed several days after cooking decreased.

[0006] Also, a technique for producing unwashed rice by mixing bran with raw rice after secondary rice polishing is being developed. However, there is a problem that the bran is easily oxidized and rots easily. Therefore, there is a risk that the quality of the unwashed rice may be reduced, and there is a problem in hygiene. Furthermore, there is a problem of a so-called bran smell. Further, since the bran cannot be stored for a long period of time, there is a drawback in terms of workability.

[0007] Further, in the prior art for producing unwashed rice using bran, the temperature rises during mixing, making it easy for moisture to escape from the rice, and this also leads to a decrease in the quality of the resulting unwashed rice.

An object of the present invention is to solve the above-mentioned problems, and to provide a method and an apparatus for producing unwashed rice having high quality and preferable from the viewpoint of workability and hygiene.

[0009]

According to a first aspect of the present invention, there is provided a method for producing unwashed rice, comprising the steps of: adding bran to raw rice, mixing while cooling, and the mixing step. A step of separating the washed rice and the bran. In the mixing step, it is preferable to cool the mixture to a temperature of 15 ° C. or lower. In the mixing step, it is preferable to apply pressure. As the bran, it is preferable to use one obtained by heating and sterilizing a degreased raw material bran.

[0010] The apparatus for producing unwashed rice of the present invention comprises a mixing apparatus for adding bran to raw rice and mixing while cooling, and a separating apparatus for separating the obtained unwashed rice and the bran. It is characterized by. In the apparatus for manufacturing rice without washing,
The mixing device has a cylindrical shape, provided with an inlet at one end thereof, a mixer provided with an outlet at the other end, a cooler for cooling the mixer, and a mixer of the mixer A stirring machine that rotates about a central axis as an axis and agitates the mixture in the mixer; and a lid that is urged to close the outlet in a direction of the central axis and at a specified pressure from the outside, and the mixing is performed. When the pressure of the mixture in the machine exceeds the specified pressure, the lid is opened and the mixture is supplied from the outlet to the separation device. In the non-washed rice production apparatus, the sorting apparatus is configured to place a net having a predetermined diameter in a horizontal direction, and sort the mixture according to a particle size by swinging the net in the horizontal direction. It is characterized by.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a view showing an embodiment of the apparatus for producing non-washed rice of the present invention.

Referring to FIG. 1, the apparatus for producing non-washed rice includes a mixing device 10 and a sorting device 40. Mixing device 1
A feed hopper 100 for raw rice and a hopper 110 for bran are installed above the raw rice. It is introduced into the mixing device 10 through 30 and mixed. Then, the mixture is introduced into the sorting device 40 from the outlet side of the device 10, and the obtained unwashed rice is passed through the product outlet 44.
The product is collected by the product collecting device 210, and the separated bran is collected by the bran collecting device 200 from the bran outlet 45.

The mixing device 10 includes a mixer 2, a cooler 4, a lid 6, a stirrer 8, and a substantially donut-shaped upper lid 9 for always closing the upper end of the mixer. The mixer 2 is a substantially frustoconical cylinder, and is arranged with its central axis direction vertical. And, an inflow port is provided at the upper end portion where the diameter is increased,
An outlet is provided at the lower end.

The cooler 4 is composed of a flexible tube through which cooling water flows, and is arranged on the outer periphery of the mixer 2.

The stirrer 8 is composed of a plurality of screw blades, and is driven by a motor 36 disposed below the mixer 2.
The mixture is agitated by rotating about the center axis via an extension shaft 34 extending along the center axis of the mixture. A screw 8a is connected coaxially to the upper side of the stirrer 8. This screw 8a is
Is disposed in the pipe section 30 outside the central opening of the pipe section 30, and rotates in conjunction with the rotation of the stirrer 8.
The mixture inside is sent (conveyed) to the mixer 2.

The lid 6 is arranged outside the outlet, and a spring is provided between the lid 6 and the underframe 32 in the direction of the center axis of the mixer 2 and the outlet from the outside at a specified pressure. It is urged to close. Then, a sufficient amount of the mixture is fed into the mixer 2 by the screw 8a, and when the pressure in the mixer 2 rises and exceeds the spring biasing force of the lid 6, the lid 6 is opened, and the outlet of the mixer 2, and The mixture is supplied to the separation device 40 via the outlet 38. That is, the mixture of the raw rice and the bran is introduced from above the mixer 2, sufficiently stirred under pressure, and then flows out from below the mixer 2.

The sorting apparatus 40 has a net 40a of a predetermined diameter (for example, a net having a mesh of 1.5 mm) placed horizontally, and an inlet 42 for introducing a mixture into the net 40a and a product outlet 44. , A bran outlet 45, a bran collecting hopper 48 as a housing, and a vibration motor 46 connected to the net 40a to separate the mixture according to the particle size by swinging the net horizontally. In addition, what is usually sold as rice is usually regulated to about 1.5 mmφ, and since the grain size of the bran is smaller than this (about 0, 2 to 0, 5 mmφ), the bran falls from the net 40a by sorting, Unwashed rice remains on the net.

The product recovery device 210 is provided with a predetermined finishing rotary drum, agitates the separated non-washed rice to remove fine powder adhering to the surface thereof, and further performs finishing by a dust collector.

Next, with reference to FIG. 2, a method for producing the non-washed rice of the present invention will be described. In this figure, brown rice is supplied (step 20) and primary rice polishing is performed (step 22). 1
The secondary rice polishing is performed by brushing for mechanically polishing the surface of the rice, and the rice is immersed in water under predetermined conditions until the turbidity becomes about 150 ppm (turbidity is a predetermined turbidity. (Used by the Waterworks Bureau, etc.). Next, secondary rice polishing is performed (step 24). The secondary milled rice is mechanically polished in the same manner as described above until the turbidity becomes about 80 ppm. Excessive secondary milling is not preferred because the umami component is removed from the rice surface and the flavor of the rice is reduced, but the turbidity cannot be further improved. When rice is shipped in this state, conventional rice washing is required.

Next, the bran is mixed with secondary milled rice (raw rice) (step 26). Usually, the mixing ratio (volume ratio) of both is 1: 1. Since the bran is defatted, components (oil etc.) on the rice surface that could not be removed by secondary milling can be effectively removed (adsorbed). Thereafter, the mixture is sieved to separate unwashed rice and bran. In this case, what is sold as rice is usually specified to be about 1.5 mmφ. Therefore, if the grain size of the bran is selected in advance to about 0, 2 to 0, and 5 mmφ, it is easy to separate it from rice. In this way, washed rice having a turbidity of 60 ppm or less is produced.

FIG. 3 is a detailed view of FIG. First, after passing through the above steps 20 to 24 and the transporting step 24A, the process proceeds to the mixing step 26 of the bran and the raw rice. In the mixing step, the mixture is cooled in order to prevent the temperature from rising due to heat generated when the mixture is stirred.
It is cooled so that: This suppresses a decrease in the quality (flavor) of the non-washed rice due to an increase in temperature during mixing and loss of rice moisture. In particular, the water content of the rice lost in the mixing step is from 0.2 to 0.4% without cooling, but is reduced to 0.1 to 0.2%.

Further, it is preferable to carry out the mixing under pressure, since the effect of removing the components of the rice (oil and the like) by the rice is improved. The pressure may be, for example, 98 to 196 kPa.
For example, by pressurizing, the effect of removing the components of rice by the bran is improved, and the oil component that causes deterioration in the quality of rice is sufficiently removed. It will improve to about 3 months.

Then, through a sorting step 27, transport of the obtained unwashed rice (step 28A), a finishing step 28B of unwashed rice by the product recovery device 210, and a transport step 28C, the unwashed rice as a product is stored in the storage tank. (Step 28D), the bag is shipped as appropriate (Steps 28E and 28F). On the other hand, step 2
The bran separated in step 7 is appropriately collected and reused (step 2
9). Normally, a predetermined amount (about 5%) of the collected bran is discarded, and new bran is replenished for that amount, and then reused.

The bran used in the present invention is manufactured, for example, as follows. First, a raw material bran (defatted bran) is prepared. The defatted bran is usually obtained by defatting rice bran to remove oil (an oil residue ratio of about 2 to 3%). Next, the raw material bran is appropriately classified into fine powders, the particle size of the bran is adjusted, and the bran is conveyed to a heating and stirring vessel. In a heating stirrer, roast the raw material bran and sterilize by heating. The heating condition is, for example, a heating temperature of 60 to 100.
C. and a heating time of about 2 to 5 minutes. If the heating conditions are less than these values, sufficient heat sterilization cannot be performed, and if the heating conditions exceed these values, the bran may be burnt, causing inconvenience. Further, it is preferable that the moisture content of the obtained bran is substantially 0%, because components (oil and the like) contained in rice are more adsorbed when mixed with the raw rice.

Since the rice bran thus obtained is sterilized by heating, it is not easily oxidized or decomposed, and is easy to store for a long time, and is sanitary. Further, since there is no so-called bran odor, no odor adheres to the non-washed rice when mixed with the raw rice to produce the non-washed rice. In addition to these, it is harmless if it remains adhered to rice after the production of washed rice.

Further, when the moisture content is below the above range, since it is dry, there is little sticking of bran to equipment during handling, and it is easy to handle. Moreover, since it is dry, after mixing with raw rice to produce unwashed rice, the rice bran can be easily separated from the obtained rice. Further, the removal of components from the raw rice during the production of unwashed rice is further promoted, which contributes to the production of high-quality unwashed rice.

[0027]

As described above, according to the present invention,
Since the raw rice and the bran are mixed while being cooled, the temperature is prevented from rising due to the mixing and the water content of the rice is suppressed, and the quality (flavor) of the obtained unwashed rice is improved. For example, the moisture of rice lost in the mixing step is 0.2-
0.4% is reduced to 0.1-0.2%.

Further, when the mixing is performed under pressure, the effect of removing the components of the rice (oil, etc.) with the rice is improved, and the oil which causes the deterioration of the quality of the rice is sufficiently removed. The storage period becomes longer. For example, the storage period is 10 to 10
It is improved to about 3 months compared to 30 days.

In addition, the use of heat-sterilized bran is hygienic and has no so-called bran odor, so that no odor adheres to the obtained unwashed rice. It is also harmless if the bran remains on the rice after the production of the unwashed rice.

[Brief description of the drawings]

FIG. 1 is a view showing an apparatus for producing non-washed rice of the present invention.

FIG. 2 is a process chart showing a method for producing non-washed rice.

FIG. 3 is a detailed view of FIG. 3;

[Explanation of symbols]

 2 Mixer 4 Cooler 6 Lid 8 Stirrer 10 Mixing device 26 Mixing process 27 Separation process 40 Sorting device

Claims (7)

[Claims] 1. A method for producing unwashed rice, comprising the steps of adding bran to raw rice and mixing while cooling, and separating the bran and the bran obtained in the mixing step. Method. 2. The method for producing unwashed rice according to claim 1, wherein in the mixing step, the temperature of the mixture is cooled to 15 ° C. or less. 3. The method for producing unwashed rice according to claim 1, wherein pressure is applied in the mixing step. 4. The method for producing unwashed rice according to claim 1, wherein a degreased raw material bran is heat-sterilized as the bran. 5. A method for producing unwashed rice, comprising: a mixing device for adding bran to raw rice and mixing while cooling, and a separating device for separating the obtained unwashed rice and the bran. apparatus. 6. A mixer having a cylindrical shape, an inlet provided at one end and an outlet provided at the other end, and a cooler for cooling the mixer. A stirrer that rotates about the center axis of the mixer and stirs the mixture in the mixer, and a lid that is urged to close the outlet at a specified pressure in the direction of the center axis and from the outside from outside. When the pressure of the mixture in the mixer exceeds the specified pressure, the lid is opened and the mixture is supplied from the outlet to the sorting device, wherein the non-washed rice according to claim 5, Manufacturing equipment. 7. The separation device, wherein a net having a predetermined diameter is placed in a horizontal direction, and the mixture is separated according to a particle size by swinging the net in the horizontal direction. The apparatus for producing rice without washing according to claim 5.