JPH11216374A - Method for milling parboiled rice - Google Patents

Abstract

PROBLEM TO BE SOLVED: To mill parboiled rice efficiently in a good yield by a method in which brown rice obtained by hulling after being parboiled, after being milled by a specified polishing method, is hydro-milled while being added with a specified amount of water. SOLUTION: Parboiled rice milled by a milling type rice milling machine in a 95% yield is received in the supply tank 16 of a hydro-rice milling machine, hydro-milling is started. Namely, a valve 13 is opened, parboiled rice is introduced into a polishing chamber 4, and a solenoid valve 18 is opened by the output of a grain detector 15. Parboiled rice in a passage 14 is sprayed with water in an amount of about 1-10% of the weight of the rice from an ultrasonic nozzle 10 to be wetted and agitated by a polishing rotor 2 in the chamber 4 to be polished by friction between rice grains. The sugar layer softened by water is peeled off to make separated sugar, which is sent from a compressor and removed from the chamber 4 by pressurized air ejected from numbers of vent holes 8 formed in a pipe shaft 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for milling parboiled rice which is often applied to long grain rice such as indica rice.

[0002]

2. Description of the Related Art Parboiled rice is generally immersed in water at 50 to 70 ° C. for 2 to 4 hours so that a large amount of water is absorbed in the rice, and then high-temperature steam is discharged for 8 to 20 minutes. The paddy is steamed to gelatinize the starchy material of the endosperm. Then, hot air drying is performed until the water content of the rice grains becomes 12 to 14%. Rice grains of paddy obtained by performing such a parboil treatment, since nutrients in the bran layer move into the rice grains during the parboil treatment,
Although the rice grains are slightly colored, it is possible to obtain products with high nutritional value. U.S. Pat. Nos. 5,017,395 and 48
No. 10,511, 2,733,147, 5,045,328, etc., describe a method for producing and improving parboiled rice.

[0003] By the way, the hot-air dried parboiled rice is milled and polished to produce a product. The bran layer of the rice grains (brown rice, hereinafter referred to as parboiled rice) taken out by the hulling is used for steaming and drying. They are bonded to each other and firmly adhere to the rice grain surface. Further, in the case of parboiled rice, the standard of milling is the amount of crude fat relative to the weight of rice grain (crude fat percentage), not the whiteness of rice grain. And although there is no defined standard for the degree of milling of parboiled rice that is distributed in the market, the target is about 0.4 to 0.5% that suppresses the growth of mold and fungi and withstands distribution in the market. It has been.

On the other hand, the bran layer of parboiled rice is very hard,
From the beginning, milling by friction-type or water-milling requires more than twice as much power as usual, so grinding is usually performed by grinding. However, in the grinding method, the only way to remove the bran present in the recesses on the rice grain surface is to grind it. (Weight ratio) must be 90 to 93%, which is uneconomical. Incidentally, the crude fat percentage of parboiled rice before milling is about 2.0%, about 0.75% at a yield of 95% by a grinding-type milling method, and about 0.5% at a yield of 93%.

[0005]

An object of the present invention is to grind parboiled rice efficiently and with good yield.

[0006]

Means for Solving the Problems Brown rice obtained by graining after parboiling is first ground by grinding to a yield of about 94 to 95%. Then, about 1-10 of rice grain weight
Water is added and the water is polished and the yield is about 93%.
Only ~ 94%.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Brown rice obtained by graining after parboil treatment is first ground by grinding to a yield of 95%.
Then, the following rice milling machine is used for water milling. In FIG. 1, a polishing chamber 4 is formed inside a perforated wall ventilating and removing rice bran refining cylinder 1 by hanging a polishing trochanter 2 on a ventilation / humidification pipe shaft 3.
Is provided with a grain feed port 5 and a discharge port 6, the ventilation slots 7 of the milling trochanter 2 are communicated with a large number of ventilation holes 8 provided on the tube shaft 3, and the water supply holes 9 of the tube shaft 3 are provided with water. An ultrasonic nozzle 10 for dispersing fine particles into fine particles is disposed facing the outer surface. The outer periphery of the perforated wall whitening cylinder 1 is surrounded by a ventilation wall 11, and an exhaust fan 12 is connected to an end of the ventilation wall 11. It is set up. On the other hand, an opening / closing valve 13 is inserted into the grain feeding port 5 of the milling chamber 4 so as to be openable and closable on the upper side thereof.
A cereal detection device 15 for detecting the flow of cereals is attached to 4. A supply tank 16 is mounted above the on-off valve 13.

The water supply pipe 17 of the ultrasonic nozzle 10 is connected to a water tank 21 through an electromagnetic on-off valve 18, a water meter 19, and a water flow control valve 20, and the air supply pipe 22 is connected to a water compressor 23 for water addition. It is. The water supply device 24 is configured by the water supply path device and the air supply path device. In addition,
The grain detection device 15 and the electromagnetic on-off valve 18 are electrically connected, and water is supplied from the ultrasonic nozzle 10 only when the grain flows in the grain flow path 14. The supply tank 16 of the rice milling machine has a grinding-type rice milling machine with a yield of 95%.
Filled with milled parboiled rice and start water milling. In this embodiment, the crude fat percentage of the filled parboiled rice is about 0.75% by ordinary milled rice.

When the open / close valve 13 of the supply tank 16 is opened, the parboiled rice is guided to the refining chamber 4. As a result, the grain detection device 15 opens the electromagnetic on-off valve 18 to open the flow path 14.
Water is sprayed on the parboiled rice from the ultrasonic nozzle 10 to wet the surface of the rice grains. The amount of water added is about 5% based on the weight of rice grains. Parboiled rice with wet surface is used for polishing room 4
Inside, it is agitated by milling trochanter 2 and milling is performed by friction between rice grains. The bran layer softened by the moisture on the surface of the rice grain due to the grain friction is peeled off to form a separated bran. The separated bran is supplied from the air compressor for water addition 23 to the air supply pipe 22.
And the outer periphery of the perforated wall fine cylinder 1 is surrounded by a ventilation wall 11, and a blower 12 is connected to an end of the ventilation wall 11. Due to the structure, it is immediately removed from the refining chamber 4. As a result, the parboiled rice near the discharge port 6 at the end of the refining chamber 4 is milled rice having almost no bran layer on the surface.

The milled parboiled rice has a crude fat ratio of 0.4 to 0.5%, and the yield at this time is about 93 to 94%. The yield can be adjusted by adjusting the pressing force of the pressure adjusting plate 25 provided at the discharge port 6, as in a normal rice mill. By ordinary milling without water, the yield must be 90-93% in order to make the crude fat ratio 0.4-0.5%, whereas the yield is 93- 94%
The purpose can be achieved by bran, which is difficult to remove by grinding-type grinding, enters into the fine recesses of the rice grain surface and is hardened and bonded by the steaming process peculiar to parboiled rice by softening with water, and reducing the grain friction It is considered that this is due to the action of pulling out the bran in the concave portion by the adhesion of the bran that has increased in viscosity due to the addition of water. Then, it is considered that by adding water to the rice grain surface during the milling, the viscosity of the rice grain surface increases, and the action of exfoliation at once appears more strongly.

FIG. 2 shows parboiled rice using a rice milling machine (milling with a grinding method to a yield of 95%, a crude fat ratio of about 0.75).
%) Shows the change in the crude fat percentage when the amount of water added was changed in the milling of%). According to this, only 1
% Addition of water results in a decrease of 0.2% compared to the case without addition, and after that, there is a gradual decrease of about 0.1% until the addition of 5%, and thereafter the value is almost the same. If the amount of water exceeds 15%, the action of removing the bran from the refining chamber 4 due to the pressurized air and the wind is hindered. Therefore, the amount of water to be added is about 1 to 15%, preferably 10%. Up to a degree is appropriate.

FIG. 3 shows the relationship between the yield and the percentage of crude fat. The solid line indicates the case of water-milling, and the broken line indicates the case of grinding-type milling. In this figure, the yield of the parboiled rice at the start of the water-milling was 95% by the previous grinding-milling.
%, And the ratio of crude fat is about 0.75%. As can be seen, water milling is clearly advantageous in reducing the crude fat percentage of parboiled rice. On the other hand, the yield is 94
% Or less, there is almost no decrease in the crude fat ratio. From the above, in order to obtain milled finished parboiled rice having a crude fat ratio of about 0.4 to 0.5%, a yield of 95 is considered in consideration of the efficiency of milling.
It is the most advantageous in terms of the work efficiency and the product yield that the grinding yield is about 94% and the yield is about 94% by using water-milling. Note that 9
When the parboiled rice ground by grinding to about 5% is polished with a large load when the water is polished with a lower yield, the rice grains may be broken. is there.

[0013]

EFFECT OF THE INVENTION Crude fat ratio about 0.4 which can withstand distribution in the market
Up to 0.5% of finished milled parboiled rice efficiently and
High yield can be obtained.

[Brief description of the drawings]

FIG. 1 is a front view schematically showing a mechanism of a rice milling machine.

FIG. 2 is a diagram and a table showing the relationship between crude fat percentage and water addition amount.

FIG. 3 is a diagram and a table showing the relationship between crude fat percentage and yield.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Perforated wall ventilation bran refining cylinder 2 Refining trochanter 3 Tube axis 4 Refining room 5 Feeding port 6 Drainage port 7 Ventilation groove 8 Ventilation hole 9 Ventilation hole 10 Ultrasonic nozzle 11 Ventilation wall 12 Ventilator 13 Opening / closing valve Reference Signs List 14 Grain flow path 15 Grain detector 16 Supply tank 17 Water supply pipe 18 Electromagnetic on-off valve 19 Water meter 20 Water flow control valve 21 Water tank 22 Air supply pipe 23 Air compressor 24 Watering device 25 Pressure adjusting plate

Claims (1)

[Claims] 1. A brown rice obtained by graining after parboiling is ground and ground to a yield of about 94 to 95%, and then water-milled while adding water of about 1 to 10% of the weight of rice grains. And a method for milling parboiled rice, wherein the yield is kept at about 93-94%.