JPH0731453A - Preparation of steamed rice using deaerated water - Google Patents

Abstract

PURPOSE:To obtain steamed rice having high gelatinization degree, white and glossy appearance, hard shell and soft core and excellent moisture-retainability and visco-elasticity and suitable for the brewing of SAKE (Japanese rice wine) by immersing washed rice grains in a specific deaerated water and heating the rice with steam. CONSTITUTION:Rice grains are washed with deaerated water free from dissolved gas and immersed in deaerated water free from dissolved gas. The immersion- treated rice grains are heated by supplying steam to obtain steamed rice.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved method for producing steamed rice, for example, steamed rice used for brewing sake.

[0002]

2. Description of the Related Art Cooked rice in which rice grains are steamed (hereinafter referred to as steamed rice) is used as it is, and is also used, for example, in the production of sake and shochu.

Steamed rice as described above is usually manufactured through the following steps. Washing process: Removes dirt, bran, etc. from the surface of polished rice. Immersion step: In a subsequent heating step, about 30% by weight of water is infiltrated into the rice grain in a step for performing uniform heating via water. (Note that this soaking time (moisture content) differs slightly depending on the type of sake (including cloudy sake) to be obtained and the degree of milling of the polished rice.) Steaming process: Rice cooking process That is, steam is passed through the above-mentioned soaked polished rice, and heating and water addition are performed at the same time as in ordinary cooking. By this step, the rice grains are uniformly heated through the water permeated into the rice grains to gelatinize (gelatinize) the starch in the rice grains. Steaming step: In this step, the steamed rice that has been steamed is aged, and sufficient gelatinization and excess water are removed from the steamed rice to remove stickiness and the like on the surface of the steamed rice.

The steamed rice obtained as described above gives a cooked rice which is less likely to boil over as compared with cooked rice obtained by ordinary rice cooking.

[0005]

With respect to the conventional method for producing steamed rice, it is a fixed idea that each of the above-mentioned steps must be performed in order to obtain high quality rice. Therefore, washing rice, Immersion, steaming (watering / heating)
The respective steps are carried out without any change from the conventional one.

However, in recent years, among the above steps, a method of shortening the rice washing step has been proposed, and the amount of water used at that time is reduced to the same amount as the weight of the original rice. So-called non-washed rice, which has been subjected to a treatment that makes it possible to omit washing rice after polishing, is being adopted, and the overall manufacturing time is being shortened, but the steps of soaking, steaming, and steaming are almost the same as before. ing. As described above, when steamed rice is produced, the dipping step requires a predetermined time, and this time cannot be shortened. Therefore, it was necessary to start the operation in anticipation of this time.

As described above, in the rice washing process, the use of the same amount of rice and the appearance of non-washed rice have made it possible to reduce the amount of water used and the time, or to omit it. Only the device regarding the shape of the tank and the technique regarding the dipping procedure can be seen. In particular, this dipping process requires the longest time in all the processes, and the equipment cost required for the dipping device accounts for 1/4 to 1/3 of the whole. Therefore, in order to reduce the production cost and improve the production efficiency, the omission or reduction of the dipping step is a problem.

However, if the dipping process is simply shortened, only steamed rice having a watery surface and a hard interior and poor quality can be obtained. In particular, steamed rice used for sake brewing is a so-called "outer hard inner soft" with a hard outer surface and soft inside.
The state is the best finish because of the good crushing preparation at the time of koji making, the good handling of steamed rice, etc.When manufacturing steamed rice for sake brewing in this way, in addition to the conventional method, (Mr. Mori) requires experience and intuition, and it is difficult to shorten the dipping process.

That is, at present, there is not yet a method capable of significantly shortening the time of the dipping process while maintaining the quality of steamed rice. Therefore, the inventor has carried out research on a method of greatly shortening the dipping step, which has been conventionally indispensable, while maintaining at least the quality of steamed rice, and completed the present invention.

[0010]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. It is performed by immersing washed rice grains with degassed water from which dissolved gas has been removed, The first characteristic is to obtain steamed rice by supplying steam to rice grains to heat them, and then wash the rice grains with degassed water from which dissolved gas has been removed, and then degassed water from which dissolved gas has been removed. Dip using, for the rice grains after this dipping,
The second method is a method for producing steamed rice using deaerated water, which is characterized in that steamed rice is obtained by supplying steam and heating.

[0011]

According to the method for producing steamed rice using deaerated water according to the present invention, the following effects are obtained. (1) Since the step of dipping rice grains can be significantly shortened, the steamed rice production time can be significantly shortened. (2) Oxidation can be prevented so that nutrients (particularly reducing sugars) are less decomposed and yellowing due to browning is suppressed. (3) Since the dissolved gas content in the immersion water is low, surface cells are prevented from being destroyed (boiled down) due to foaming during heating, and it is possible to produce steamed rice with excellent luster and viscoelasticity that is also resistant to aging. Is.

[0012]

EXAMPLES An example of a method for producing steamed rice using degassed water according to the present invention will be described below with reference to the process chart shown in FIG.

Deaerated water is prepared in advance as water to be used for washing rice. The degassed water is water obtained by removing dissolved gas from tap water, well water, or the like by using a vacuum degassing method, a membrane degassing method, or the like. The degree of degassing generally depends on the dissolved oxygen concentration (DO
The value) is usually 1 ppm or less (more preferably 0.5 ppm or less). It should be noted that nitrogen, oxygen (ratio 2: 1) and carbon dioxide gas are dissolved in ordinary water that has not been deaerated (hereinafter referred to as ordinary water). Since it is degassed, it is generally indicated by the amount of oxygen that is easy to measure.

Then, the rice grains (polished rice) to be steamed rice are washed with deaerated water (rice washing step). In this operation, the rice bran and dust adhering to the rice grains are mainly stirred and washed away in a large amount of water, and at the same time, continuous washing with overflow or washing once for a short time is done so as not to produce broken rice. In multiple times. Normally, during this rice washing operation,
It is known that about 10% of the weight of rice is absorbed.

Next, steam is passed through the washed rice grains,
Water is added at the same time as heating (steaming process). Here, since the amount of dissolved air in deaerated water that has penetrated into rice grains is smaller than that in normal water, the generation of bubbles from inside the rice grains during heating is small, and as a result, cell collapse on the surface of rice grains is suppressed, and However, the amount of stickiness due to the outflow of starch also decreases. Therefore, since the cell destruction of the rice grain surface is suppressed, the finished steamed rice surface is tense, and since water (deaerated water) permeates evenly into the rice grain as described above, As a result, the so-called "outer-hard-inner-soft" steamed rice can be easily obtained.

In this steaming step, when rice grains that have been immersed in normal non-degassed tap water or the like are used and heating is started in the same manner, a paste layer is formed on the surface layer of the rice grains. The heat transfer of is impeded. Further, when water is usually used, the permeation into the rice grain is hindered by the air inside the rice grain, so the starch in the rice grain is heated before it swells, and the starch inside the rice grain is sufficiently gelatinized. Not done
Therefore, the surface of the steamed rice is watery and the inside is hard rice, so-called "nakagome" steamed rice, and it is difficult to obtain the above-mentioned "outer hard-inner soft" steamed rice. From this, the superiority of the steamed rice production method according to the present invention can be confirmed.

After the steaming step, the steaming step is carried out in the same manner as in the prior art, in which the heat of steamed rice is maintained and the rice grains are sufficiently gelatinized. After that, various processing and coating are performed depending on the purpose of various final products. It is sent to each process such as attachment and molding.

As described above, according to the method of the present invention, when steamed rice is produced by immersing rice grains in degassed water, water permeation into the rice grains is good, and starch, protein,
Oxidation of lipids and tissue destruction of rice grains can be suppressed, and (1) "lustrous" steamed rice with excellent moisture retention and viscoelasticity can be obtained. (2) There is little deterioration in flavor and it steams white. (3) Steamed rice with little color change can be produced. The quality is improved.

This provides steamed rice particularly suitable for applications such as steamed rice used for sake brewing, which does not use steamed rice immediately after steaming (rice) but is cooled once and then subjected to koji etc. It shows that you can do it.

The steamed rice obtained by the present invention is
As described above, since the α-formation rate is good, fermentation by koji during brewing, that is, starch consumption is efficiently performed, and the yield of alcohol production is improved.

From the above, not only the quality of steamed rice but also the effect of improving productivity and reducing production cost, that is, the production line can be simplified by shortening the dipping process, the production time can be shortened, and the amount of water used can be greatly reduced. Moreover, it shows that the yield of steamed rice can be improved.

In the above description, the method of using deaerated water in the rice washing step and the dipping step has been described, but in the method of the present invention, the rice washing step may be performed with normal water.

[0023]

As described above, according to the method of the present invention, in the dipping step, water uniformly penetrates into the rice grains, which facilitates heat conduction during heating, resulting in gelatinization of the rice grains (starch conversion). It has a high degree of alpha conversion (hard to age), has excellent moisturizing properties and viscoelasticity, and is white, glossy, and does not lose its shape. The steamed rice can be easily obtained. The above-mentioned "outer-hard-inner-soft" steamed rice is particularly suitable as steamed rice for sake brewing. Moreover, since this steamed rice has a high α-conversion rate as described above, it is well decomposed by koji mold during brewing. Yield is good.

[Brief description of drawings]

FIG. 1 is a schematic diagram for explaining a process diagram to which a method for producing steamed rice using deaerated water according to the present invention is applied.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Naofumi Ida 7 Horie-cho, Matsuyama-shi, Ehime Miura Industry Co., Ltd.

Claims (2)

[Claims] 1. The washed rice grains are immersed in degassed water from which dissolved gas has been removed, and the rice grains after the immersion are immersed in
A method for producing steamed rice using deaerated water, characterized in that steamed rice is obtained by supplying steam and heating. 2. The rice grain is washed with degassed water from which dissolved gas has been removed, and then immersed in degassed water from which dissolved gas has been removed, and steam is supplied to the rice grain after immersion. A method for producing steamed rice using deaerated water, characterized in that steamed rice is obtained by heating.