JPH05316970A - Production of wash-free rice and production apparatus - Google Patents

Abstract

PURPOSE:To prepare a wash-free rice resistant to the proliferation of microorganisms after packaging by washing polished rice with water, etc., to soak the rice with water and cooling the soaked rice after drying. CONSTITUTION:Polished rice is jut into a holding container 11 and washed with the stream of water or an aqueous solution to obtain soaked rice having a water-content of usually 20-45wt.%. The soaked rice is passed through a draining means 20, spread in the form of a thin layer with a grader 15, transferred to a drying means 30 and dried with sterilized air flow sent from a heater 31 and a blower 32. The dried rice is cooled with a cooling means 40 usually to <=20 deg.C, delivered by a mesh conveyor 21, weighed with a weighing apparatus 70 and packaged in vacuum with a vacuum packaging machine 80.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for washing non-washed rice, and more particularly to a method for producing non-washed rice in which the growth of microorganisms after packaging is prevented and a production method suitable for this method. Regarding the device.

[0002]

2. Description of the Related Art Conventionally, polished rice has been sold, and it is cooked after washing the polished rice before cooking and then soaking it in water to absorb water.

On the other hand, so-called non-washed rice which has been washed and soaked in advance and can be cooked immediately has been developed and put into practical use. One of the methods for producing this non-washed rice is 70 ° C.
Wash the polished rice with hot water for several minutes in the front and back, and soak it for a few more minutes to make water-absorbed rice. A method is known in which water is absorbed and the moisture-absorbed rice having a water content of about 20 to 25% is immediately vacuum-packed together with an oxygen scavenger.

[0004]

However, in the conventional production method, the temperature of rice immediately after drying is 30 to 40.
Since the temperature of the package is about 0 ° C. and the block is formed by the vacuum packing, the central portion of the package is kept at a temperature of around 30 ° C. for a long time, and there is a problem that microorganisms grow during the period.

The present invention has been made under such circumstances, and an object of the present invention is to provide a method for producing non-washed rice in which the growth of microorganisms after packaging is prevented, and an apparatus suitable for use in the method. To provide.

[0006]

Means for Solving the Problems The constitution of the present invention for achieving the above-mentioned object is a method for producing non-washed rice which does not require washing rice before cooking, and polished rice and water or an aqueous solution at room temperature or higher. While contacting with and washing rice to absorb water or aqueous solution into the polished rice, to absorb water,
After drying the water-absorbed rice, it is a method for producing non-washed rice, characterized by cooling the dried rice, in an apparatus for producing non-washed rice having washing means, draining means and drying means,
The non-washed rice manufacturing apparatus is provided with cooling means for cooling the rice dried by the drying means.

[0007]

Function Polished rice washed in contact with water or aqueous solution at room temperature or higher is further immersed in these water or aqueous solution to be absorbed rice. Then, the water-absorbed rice is dried, and then cooled. By this cooling, the temperature of the water-absorbed rice after drying is set to a temperature lower than the growth temperature range of microorganisms, and then, for example, if vacuum packaging is performed to form a package, even if it is formed into a block shape, The temperature is maintained at a temperature that prevents the growth of microorganisms. Therefore, the non-washed rice produced by this method has no microbial growth even after packaging and has favorable properties in food hygiene.

On the other hand, in the apparatus for producing non-washed rice of the present invention, the polished rice is washed by being brought into contact with water or an aqueous solution having a temperature of room temperature or higher in the washing means, and immersed in the water or the aqueous solution. It is made water-absorbed rice. The water-absorbed rice is dried by the drying means and then cooled by the cooling means to a temperature lower than the growth temperature range of the microorganisms. The thus-cooled non-washed rice is kept at a temperature lower than the growth range of microorganisms even if it is packaged by, for example, a vacuum pack. Therefore, the non-washed rice produced by this apparatus is prevented from growing microorganisms even after being packaged.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a process diagram showing the structure of the method for producing non-washed rice of this example.
The dipping process 2 → the water draining process 3 → the drying process 4 → the cooling process 5 are carried out in this order, and finally they are vacuum-packed and commercialized.

In the washing step 1, the milled rice as a raw material is washed in contact with water or an aqueous solution at room temperature or higher. The temperature of the water or aqueous solution used for this washing is room temperature or higher. If this temperature is lower than room temperature, a sufficient water content may not be obtained.
More specifically, the temperature of water or an aqueous solution used for this washing is usually 50 ° C. or higher, preferably 65 ° C. or higher. Further, as the above aqueous solution that may be used, for example, adipic acid aqueous solution having a preservative effect,
Examples include citric acid aqueous solution. The rice washing method used in this rice washing step 1 is not particularly limited.
Any stirring method or the like can be suitably adopted, and the washing time of rice is usually about several minutes.

The polished rice thus washed is then immersed in water or an aqueous solution in the immersion step 2 to obtain water-absorbed rice. The immersion time of the polished rice in the immersion step 2 is usually about 30 seconds to 20 minutes, preferably about 2 minutes, and the water content of the water-absorbed rice obtained is usually 20.
It is about 45% by weight, preferably about 25-40% by weight. Next, the water-absorbed rice is transferred to the draining step 3, but the water or the aqueous solution partially transferred to the draining step together with the water-absorbed rice is removed in the draining step 3.

In the drying step 4 following the draining step 3, the water-absorbed rice from which excess water or aqueous solution adhering to the surface is removed is dried, and the water content is usually about 16 to 35% by weight, preferably It is adjusted to about 20 to 30% by weight.

Then, the water-absorbed rice transferred to the cooling step 5 is
The temperature of the central portion is cooled to a temperature lower than the growth temperature range of microorganisms. Specifically, the water-absorbed rice that has been drained and dried has a central temperature lower than 30 ° C, more specifically, usually 0 to 20 ° C, preferably 0 to 10 ° C. It is cooled by air. Here, air cooling can be performed by applying normal temperature air or cold air that has passed through a cooler to the water-absorbed rice.

The water-absorbed rice thus cooled to a temperature lower than the growth temperature range of the microorganisms is vacuum-packaged into a product. In this vacuum package, even if the water-absorbed rice has a block shape, the temperature of its central portion is maintained at a temperature lower than the growth temperature range of microorganisms. Therefore, the non-washed rice produced by this method can prevent the growth of microorganisms.

In the method for producing non-washed rice having such advantages, for example, the production apparatus shown in FIG. 2 can be preferably used. As shown in FIG. 2, this non-washed rice manufacturing apparatus includes a rice washing means 10, a draining means 20,
The drying means 30 and the cooling means 40 are provided.

The rice washing means 10 comprises a storage container 11 for storing polished rice and water or an aqueous solution. In the storage container 11 storing the polished rice, water or an aqueous solution at room temperature or higher is continuously supplied. Is supplied to. That is, the polished rice stored in the storage container 11 is washed in contact with the water or the aqueous solution by the water flow of the water or the aqueous solution. It should be noted that the storage container 11 is provided with a drain port for removing the continuously supplied water or aqueous solution from the inside of the storage container 11 in a state where it is separated from the polished rice. Here, the temperature of the water or aqueous solution to be used is room temperature or higher temperature as described above, and examples of the aqueous solution include adipic acid aqueous solution and citric acid aqueous solution. Also,
The cleaning time is usually about several minutes.

The washed milled rice is then further immersed in water or an aqueous solution in the container 11 to obtain water-absorbed rice. The immersion time at this time is usually about 30 seconds to 20 minutes, preferably about 2 minutes, and the water content of the polished rice is usually 20 to 45% by weight, preferably 25 to 40% by weight. Adjusted.

The water-absorbed rice is then transferred to the draining means 20. The draining means 20 is configured by using, for example, a mesh conveyor 21 which also serves as a conveying means, and unnecessary water or aqueous solution transferred to the mesh conveyor 21 together with the water-absorbed rice is drained from the mesh conveyor 21. Next, the water-absorbed rice on the mesh conveyor 21 is removed by the blade 15
Thus, it is conveyed to the drying / cooling zone 50 in which the drying means 30 and the cooling means 40 are continuously provided while being thinly stretched. The mesh conveyor 21 is installed so that the height on the side of the rice washing means 1 is lower than the height on the side of the drying / cooling zone 50, and unnecessary water or aqueous solution is always fed from the side of the drying / cooling zone 50 due to this gradient. Drained to side 1. The drying / cooling zone 50 has a chamber structure, and the chamber 55 is provided with an exhaust port 60 for releasing the heat of the drying process in order to prevent the heat of the drying process from being transferred to the cooling process. ing.
Further, the blade 15 has an elevating function, whereby the stretched thickness of the water-absorbed rice on the mesh conveyor 21 can be arbitrarily adjusted.

The drying means 30 comprises a heater 31, a blower 32, and a sterilization filter 33, and the air blown from the blower 32 is sterilized by the sterilization filter 33, and a mesh is blown from an outlet 34 provided on the chamber ceiling. The water-absorbed rice is sprayed onto the water-absorbed rice on the conveyor 21 to be dried. On the other hand, the absorbed water on the mesh conveyor 21 is also dried by the radiant heat from the heater 31, and the water content of the absorbed rice is usually 16 to 35% by weight, preferably 20 to 30% by weight. It is considered as a degree. The air used for drying does not necessarily have to be sterilized, but from the standpoint of food hygiene, it is desirable that the sterilized filter 33 be used for sterilization.

The water-absorbed rice dried by the drying means 30 while being placed on the mesh conveyor 21 while being moved is conveyed by the mesh conveyor 21 as it is to the cooling means 4.
It is cooled at 0.

The cooling means 40 comprises a blower 41 and a cooler 42.
And a sterilization filter 43, the wind sent from the blower 41 is cooled by the cooler 42, further sterilized by the sterilization filter 43, and the mesh conveyer 21 from the cooling air outlet 44 provided in the chamber ceiling. Sprayed on the absorbent rice above. By this cooling, the temperature of the central part of the water-absorbed rice is usually cooled to a temperature of 20 ° C. or lower. The temperature of the cooling air is usually set to about 0 to 10 ° C.

The water-absorbed rice cooled to a temperature lower than the growth temperature range of microorganisms by the cooling means 40 is carried out of the chamber 55 by the mesh conveyor 21, and is usually
A predetermined amount is weighed by the weighing device 70 and vacuum-packed by the vacuum packaging machine 80.

The non-washed rice produced by this apparatus, even if it is formed into a vacuum package, keeps the temperature of the center of the package at a temperature lower than the growth temperature range of microorganisms. This is a preventive measure.

[0024]

According to the present invention, the water-absorbed rice after the drying treatment is cooled to a temperature lower than the growth temperature range of microorganisms, so that microorganisms do not grow even in a vacuum package. Since the method for producing non-washed rice is provided and the cooling means is provided together with the drying means, it is possible to efficiently produce non-washed rice in which microorganisms do not grow even in a vacuum package, and thus the method described above. An apparatus for producing non-washed rice suitably used in 1. is provided.

[Brief description of drawings]

FIG. 1 is a process diagram showing a method of manufacturing non-washed rice in the present embodiment in process order.

FIG. 2 is an explanatory diagram showing a configuration of a non-washed rice manufacturing apparatus of this embodiment.

[Explanation of symbols]

 10 ... Washing means 20 ... Draining means 30 ... Drying means 40 ... Cooling means

Claims (2)

[Claims] 1. A method for producing non-washed rice, which does not require washing rice before cooking, by washing the polished rice with water or an aqueous solution at room temperature or higher and washing the polished rice with the water or the aqueous solution. A method for producing non-washed rice, which comprises absorbing water to absorb water, drying the absorbent rice, and cooling the dried rice. 2. An apparatus for producing non-washed rice, comprising: a rice washing means, a draining means, and a drying means, wherein a cooling means for cooling the rice dried by the drying means is provided. ..