JPH0239862A - Production of processed rice for boiled rice - Google Patents

Abstract

PURPOSE:To obtain viscoelastic high-quality boiled rice in a short time by blending polished rice with an aqueous solution of ethanol while adding the aqueous solution and sealing the blend in an airtight container. CONSTITUTION:Unpolished rice is charged, admixtures are removed, unpolished rice is hulled and rice bran is removed to give polished rice having 39-41% whiteness. Then the polished rice is sent to a mixing tank, blended with 5-10% based on weight of polished rice of 10-13mol aqueous solution of ethanol while adding the aqueous solution while stirring, immediately sealed in a sealable container made of a bag of synthetic resin film to give processed rice for boiled rice. Then the processed rice is taken out from the container, lightly washed with water, waste rice, dust, etc., admixed during opening are removed and boiled by a conventional procedure.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a method for producing processed rice for cooking, and in particular, to a method for producing processed rice for cooking, in particular a method for mixing polished rice with an ethanol aqueous solution and sealingly packaging the rice, resulting in rapid cooking and excellent taste and texture. The present invention relates to a method for producing processed rice for cooking, which makes it possible to obtain cooked rice.

(Prior art) Various studies have been conducted since ancient times in order to obtain high-quality cooked rice (flavor, viscosity, elasticity, color) by cooking polished rice. Improvements were made to rice cooking equipment, and adjustments were made to rice cooking operations such as pre-soaking the rice, adjusting the amount of water, boiling time, and curing time. However, no method has yet been proposed in which the rice milling itself has the function of producing high-quality rice by cooking it in a conventional rice cooker, regardless of the variety of rice and whether it is new or old. .

(Problems to be solved by the invention) In order to quickly mill rice (cook it and obtain high quality cooked rice), the relationship between the properties of rice and the rice-cooking action is investigated.

Cooking rice involves alphaning the starch molecules, which are comprised of amylose and amylopectin, contained in rice grains. Rice starch, which accounts for 75% of the components of polished rice, is made up of glycose linked in linear chains and the polysaccharide amylose, which has a molecular weight of several hundred thousand, and glucose, which is also linked in a chain dendritic form, and has a molecular weight of tens of millions. It is composed of the polysaccharide amylopectin, and the average composition ratio in Uruchi rice is 83 parts amylopectin to 17 parts amylose.

In the endosperm part (polished rice part) of rice, the molecules described above form starch single grains, and 5 to 15 single grains are aggregated to form multiple grains. As the rice ripens, it accumulates and fills the amyloblasts, which are starch cells. and amyloblast is 10-1
50,000 pieces come together to form one grain of rice.

Amylose and amylopectin in raw rice starch have glucose molecular chains arranged in bundles, forming a dense aggregate state (micelle-like) that even water molecules cannot penetrate. However, by heating water for a long time, the molecular motion of water and starch increases, and when the kinetic energy exceeds the micelle constituent energy, the micelle structure collapses and becomes randomly arranged, and the gaps between them increase. Water molecules enter and become swollen. Things in this state are easier to digest in the body. Starch that absorbs water and swells in this way is called alpha starch, and becomes susceptible to the action of digestive enzymes by collapsing into micellar form. In addition, in this swollen state, the chain molecules of amylose and amylopectin become entangled with each other in water and cannot move freely, causing viscosity. In the case of cooked rice, the intertwining of these substances is the main cause of viscosity, which is an essential texture element.

Based on the above-mentioned properties and conditions of rice, the relationship with the amount of heat added to smoothly alphanize the rice will be explained.

Normally, purified rice starch can be easily pregelatinized by adding water and heating it to around 65°C to 70°C, but the dried amyloblasts of the rice grains themselves are tightly packed and absorb water. Due to its difficult composition, it requires heating at high temperatures for a long time to completely alphanize the center of the rice grain. High-quality cooked rice must have viscosity and maintain appropriate elasticity, but if the rice is heated and cooked for a long time, the starch in the rice grains will dissolve and the elasticity will decrease. To this end, it is important to prevent starch elution by shortening as much as possible the difference in gelatinization time required between the outer part and the center of the rice grain.

From the above-mentioned changes in the properties and state of polished rice grains during rice cooking, rapid heating at a high temperature is more effective than the length of heating time in achieving complete alphaning of rice grains6.
On the other hand, the reason why cooked rice becomes sticky and gelatinous after cooking is due to the leaching of starch, and this is more influenced by the length of the heating time than by the water temperature.

Therefore, the problem in obtaining cooked rice with elasticity and viscosity is to completely alphanize the rice grains in the shortest possible time. To this end, the problem is that complete alpha conversion can be achieved in an extremely short period of time by incorporating a water absorption promoting function into the rice itself without relying on improvements to external factors such as rice cookers.

In the present invention, ethanol is added to refined milled rice, absorbed by the polished rice, and sealed in an airtight bag. When the rice is cooked, the rice grains rapidly absorb hot water and the starch molecules in the rice grains are dissolved in a short period of time. The purpose is to obtain high-quality cooked rice with viscoelasticity by alphaning it in the process.Furthermore, it is a method for producing processed rice for cooking by simply intervening a simple means of mixing an ethanol aqueous solution in the process of existing rice milling equipment. is intended to provide.

(Means for Solving the Invention) In order to achieve the above object, in the method for manufacturing processed rice according to the present invention, the processing steps are performed in the order of rice polishing, mixing, measuring and packaging.

The rice polishing process consists of charging the raw brown rice, removing impurities, milling, and removing rice bran, and these processes are performed sequentially and rapidly using conventional means or equipment. The degree of milling is tested by a whitening meter, and the whitening of the milled rice is about 39-41%, preferably 40%. This is partly due to the fact that old rice and old rice tend to be more discolored compared to new rice, but depending on the type and quality of the raw brown rice, the automatic flow into the next process, the ethanol mixing tank, is also possible. This is due to the flow rate at the time and the adjustment value of the mechanical control load to achieve a predetermined white discoloration.

The polished rice that has been adjusted to a predetermined white discoloration and sugar-removed as described above is flowed into the mixing tank in the ethanol aqueous solution mixing means by the conveyor conveyance means.

The milled rice flowing into the mixing tank is A, 7<, jl lil! −
A discharge amount controller is installed at the lower end of the milled rice storage hopper which sequentially discharges the rice onto the conveyor in order to convey the rice between the two.

An aqueous ethanol solution in an amount proportional to the amount of milled rice flowing into the mixing tank is added in the form of a spray or shower. Then, this aqueous ethanol solution is stirred and mixed with a stirrer provided in a mixing tank so that it is uniformly mixed with the polished rice. The aqueous ethanol solution is mixed in at a ratio of 10 to 5% of the 10 to 13 molar aqueous solution to the amount of milled rice that has flown in.

A preset weight of polished rice mixed with an ethanol aqueous solution is discharged from the mixing tank by a weighing and packaging machine connected to the mixing tank, and the rice is packed into an airtight bag and sealed. This bag may be a commonly used synthetic resin packaging bag.

(Function) It is preferable that the steps from mixing the ethanol aqueous solution with polished rice to measuring and packaging are carried out as quickly as possible at normal room temperature. This is to prevent ethanol, which has a low vaporization point, from vaporizing and dissipating as much as possible.

The aqueous ethanol solution added by spraying to the polished rice in the mixing tank only applies to the surface of the milled rice grains during stirring and moistens the rice grains, but it gradually penetrates into the rice grains during storage after being packaged and sealed. Then, after several hours, the entire milled rice returns to its dry state after being evenly absorbed to the center of the rice grains. At this point, the process of processing processed rice for cooking based on the production method of the present invention is completed.

Hereinafter, the present invention will be explained in detail along with the process of cooking the processed rice of the present invention to make rice.

While the bagged polished rice is being stored, it is transported to the consumer and cooked. As a pre-treatment for rice cooking, all you need to do is wash it lightly with water. The purpose of washing with water is to remove waste rice generated due to frictional impact during storage and transportation, and dust that is inadvertently mixed in when opening the package.

There is no need to soak the rice in water before cooking. This is the water activity (AW+1.
This is due to the fact that the water activity (AWI) of the aqueous ethanol solution absorbed into processed rice is considerably lower, for example, 0.847 in the case of a 10 molar aqueous solution, compared to 0.

That is, under such conditions, a osmosis phenomenon occurs in which the so-called cooking water added to the outside of the rice grain for cooking rice inevitably moves toward the interior of the rice grain where water activity is low and is absorbed. Therefore, from the beginning of rice cooking, the action of absorbing water into the rice grain, which is an essential condition for promoting the alpha conversion of starch within the rice grain, is extremely promoted by the synergistic action of the thermal energy action and the osmotic pressure action. This effect not only eliminates the need for soaking rice in water before cooking, but also reduces the time required to cook rice for complete alpha conversion, and in other words, reduces the amount of heat required. .

From the above situation, the above effect becomes stronger as a large amount of highly concentrated ethanol aqueous solution is absorbed, but in actual cooking, especially when cooking a large amount of rice in a large pot for commercial use, processed rice at the bottom of the pot is However, the molar concentration range of the ethanol aqueous solution to be absorbed is limited because water spray alphaning occurs too rapidly, impeding the uniformity of the circulation of the cooking water, and causing problems such as uneven cooking. 13~
It is preferable to limit the absorption rate to 5% to 10%.

The boiling point of ethanol absorbed in rice grains is 78
．． Since the temperature is 3°C and the ethanol is vaporized and dissipated by the final stage of cooking, it is natural that no residual ethanol is found in the cooked rice.

(Experiment example) Raw brown rice 1 made from old rice called Yukihikari from Hokkaido
．． 0 kg was milled using a device installed at a rice mill, impurities were removed, milled to remove 40% white discoloration, and bran was removed to obtain 8.8 kg of polished rice. This polished rice was put into a container, and while stirring, 0.88 kg of a 10 molar ethanol aqueous solution was added while spraying. Thereafter, the container was immediately sealed with a lid and allowed to stand for 8 hours.

Thereafter, the lid was opened, and 300 g of processed rice was taken out, and the rest was sealed in a vinyl chloride packaging bag. On the other hand, 300g of processed rice was taken out and placed in a small container, water was poured into it, stirred, and the water was drained after confirming that all dust had been removed.

And 450 c of water in a 5-cup gas rice cooker made by Tokyo Gas.
By adding the ingredients together with c, the preparation for cooking the rice was completed.

Then, immediately, the ignition switch of the rice cooker was turned on to start heating. The rice starts to boil 5 minutes after the start of cooking,
The heating switch was turned off 6 minutes after the start of boiling.

Thereafter, the rice cooking process was continued for 5 minutes and the rice cooking process was completed.

The resulting cooked rice weighed 695 g, and five panelists consisting of housewives observed the appearance of the cooked rice and tasted it. At the same time, the subjects were asked to observe and taste cooked rice made from 300 g of unprocessed old rice from Hokkaido, Yukihikari. When comparing the unprocessed polished rice with 500 cc of boiling water, 18 minutes of heating time, and 10 minutes of soaking time, the cooked rice obtained from the processed rice of the present invention was superior to the cooked rice obtained from the conventionally polished rice. Everyone unanimously confirmed that the rice was cooked fluffy and had excellent taste and elastic viscosity.

(Effects) Rice prepared by cooking processed rice according to the production method of the present invention has the following effects.

First, the method of the present invention does not require any soaking in water before rice cooking, resulting in extremely large savings in time, labor costs, water charges, etc. in commercial rice cooking, which requires emergency quickness.

In addition, the time required for cooking rice can be significantly shortened, which not only meets the demands of customers, but also greatly reduces fuel consumption.

In addition to cooking a large amount of rice, even when cooking a small amount of rice, it is possible to obtain well-cooked rice that is equivalent to that obtained when cooking a large amount of rice. Since it has much better flavor, hue, elasticity, viscosity, etc., it has the effect of being able to maintain rice of excellent quality not only for home use but also for commercial use.

Claims (5)

[Claims] (1) Rice is milled by charging brown rice, removing impurities, milling, and removing bran, and then stirring while adding an aqueous ethanol solution with a molar concentration of 13 to 10, which is 5 to 10% based on the weight of the polished rice. A method for producing processed rice for cooking, which is mixed and immediately sealed in an airtight container. (2) The method for producing processed rice for cooking rice according to claim (1), wherein the brown rice is milled to a whiteness of 39 to 41%. (3) The method for producing processed rice for cooking according to claim (1), wherein the airtight container is a bag made of synthetic resin film. (4) The method for producing processed rice for cooking according to claim (1), wherein the aqueous ethanol solution added to the polished rice is in the form of a spray or shower. (5) The surface of the rice grains is moistened during mixing by adding the ethanol aqueous solution to the polished rice, but it is sufficiently and uniformly absorbed into the rice grains after several hours have elapsed after being filled in an airtight container and sealed. ) Method for producing processed rice for cooking.