JPH07111868A - Method for cooking rice for business and the cooked rice - Google Patents

Abstract

PURPOSE:To provide a method for cooking rice for business, satisfying the optimal conditions on a complicated rice-cooking theory by an extremely simple method and capable of simply cooking a large amount of rice by anyone, while using a cooker used for business and having a receiving volume of >=4 liter, and to provide the cooked rice. CONSTITUTION:A method for cooking rice for business comprises a heating and temperature-raising process for starting the cooking of the rice with a cooker used for business and having a receiving volume of >=4 liter and subsequently raising the temperature in the cooker up to the boiling point for 20-40min, and a heating process following the heating and temperature-raising process, and the cooked rice obtained by the method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the production of cooked rice in the food industry where a large amount of rice is cooked and the food service industry, which enables the rice to be cooked with the maximum capacity of the rice cooker and the dipping process before cooking. Can be omitted, and further, even if unwashed rice is cooked under such conditions, abnormal rice does not occur,
The present invention relates to a commercial rice cooking method and a cooked rice which can obtain cooked rice having an excellent taste with good reproducibility.

[0002]

2. Description of the Related Art A large amount of cooked rice is industrially produced in the food industry, the restaurant industry and the like. In this commercial rice production process, there are four main processes: a rice washing process to sharpen and wash rice, a dipping process to soak in water for about 1 hour, a rice cooking process to cook rice over high heat, and a steaming process using residual heat. Is going through. Such a rice cooker used in the cooked rice manufacturing process is called a commercial rice cooker, and generally stores the amount (the amount of raw rice stored in the rice cooker, which is the amount of rice that has not been subjected to the washing or dipping process). It is a large one (hereinafter referred to as a cauldron) of 4 liters or more (hereinafter referred to as a cauldron), and has a single pot and a conveyor pot, both of which are heated by gas fire from the bottom of the rice cooker. For the above-mentioned dipping step, a method is adopted in which dipping containers for dipping several tens to hundreds of rice per day are placed in the order of dipping at the expense of a vast area.

In this process of producing cooked rice for business use, naturally, it is required to reduce the production cost of cooked rice, which is a commodity.
Many efforts have been made to produce in as little time and as little work area as possible. In particular, shortening the manufacturing time of cooked rice is directly linked to the reduction of labor cost, which has a high cost ratio, and the pursuit of this is intense. Under these circumstances, currently, the following two methods are mainly used or attempted individually or in combination in order to reduce the time required for the cooked rice production.

First of all, the rice is actually cooked in the shortest possible time according to the traditional theory that the rice is delicious when cooked on a high heat, and for the purpose of shortening the time. . This is to cook rice in a shorter time than the cooking time in a small household rice cooker (hereinafter referred to as a small pot).
The time required from the start of heating to the temperature of the water in the pot reaching 98 ° C is about 15 minutes in the domestic cauldron, whereas it is about 11 minutes in the cooked rice for business use. Therefore, in cooking rice for business use, the heating power is large relative to the size of a rice cooker compared to household rice cookers.

Secondly, the rice washing process before cooking rice is omitted to reduce the labor and time required for rice washing. The so-called "non-washed rice" that can be cooked without the need for washing rice is used for this. What is this non-washed rice?
It is rice produced by the present inventors who have been debranched with water or other means in advance and need not be washed before cooking rice. Therefore, in the second method, by using the unwashed rice, it is possible to omit the rice washing step as a work using water. In this way, you can shorten the cooking time as much as possible,
It is the actual condition of cooked rice for commercial use that strives to improve the efficiency of cooking rice.

[0006]

[Problems to be Solved by the Invention] However, the above-mentioned 2
Even if one of the two methods is used, it is not possible to achieve a sufficient time reduction in cooked rice production due to the following problems. First of all, when a large amount of rice is cooked in the rice cooker, abnormal rice cookers sometimes remain, in which a lump of freshly cooked rice (hereinafter referred to as dango rice) remains, mainly near the center of the rice cooker. Although the cause of the abnormal rice cooking is unknown, it is empirically known that it can be prevented to some extent by setting the amount of rice cooked at one time to about 80% or less of the maximum capacity of the rice cooker. Therefore, conventionally, the amount of rice to be stored needs to be about 80% or less of the maximum storage amount of the rice cooker, and the rice cooking efficiency is extremely poor. That is, the amount of rice to be stored in the rice cooker at one time must be reduced by 20%, which eventually leads to an increase in the number of rice cooks. In the conventional rice cooking method for business use, although the boiling point is reached in about 11 minutes after the heating is started, it takes about 6 minutes before the heating is stopped, that is, about 17 minutes in the rice cooking process. The total required time is about 5 minutes for the rice washing process, about 60 minutes for the dipping process, about 17 minutes for the rice cooking process, about 20 minutes for the steaming process, for a total of about 102 minutes.
It becomes a minute. Therefore, an increase in the number of cooked rice leads to a great increase in working time. On the contrary, if the maximum amount of rice that can be stored in the rice cooker is cooked, the time can be shortened, but the yield of cooked rice will be deteriorated, and this will also be a factor in increasing costs.

Secondly, when the above-mentioned unwashed rice is used, in addition to the unevenness of hardness and softness occurring in the cooked rice grains in the entire pot, abnormal rice cooked with the dango rice often occurs. In order to prevent such abnormal rice cooking, it is necessary to set the amount of rice cooked at one time to about 50% or less of the maximum storage capacity of the rice cooker, which significantly reduces the rice cooking efficiency. In other words, despite the fact that unwashed rice is used and the rice washing process is omitted, the amount of rice stored at one time is 50%.
%, A large amount of rice has to be thinned out, so that the advantage of omitting the rice washing step is offset by an increase in the number of times rice is cooked, or the efficiency of rice cooking is further reduced. Therefore, the non-washed rice has excellent characteristics but is difficult to be used for business purposes.

[0008] In order to cook deliciously even a little, a method has been proposed as a new rice cooking method, in which rice is cooked on a low heat and then heated to a high heat or stopped on the way. This is to cook rice with a strong heat power that compensates for the low heat and heating pauses until high heat, and in all, the time from starting heating to reaching 98 ° C is set within 15 minutes, and the heat power is changed. It is almost the same as the cooking time in the case of non-cooked rice. In addition, there is a method of cooking rice that takes 25 minutes or more to reach 98 ° C from the start of heating in a domestic rice cooker, but it starts cooking with extremely low heat and strengthens the heating power on the way. , Middle pappa ”.

However, even with such a new rice cooking method, the above-mentioned problems in the rice cooking process for business have not been solved yet.

[0010]

The inventors of the present invention have made extensive studies on the causes of these problems and have found the following. In other words, conventionally, there was a common sense that heat conduction in a pan when cooking an object was performed by convection circulation of broth, but the present inventors have found that it does not work for rice cooking. Of. Further, it has been conventionally believed that the rice grains during rice cooking do not move convectively much, but the water (hot water) circulates vigorously in convection, whereby heat is exchanged to conduct heat. However, this is a false recognition, most of the rice grains are in a static state, and there is little convection circulation of water (hot water), and heat is gradually transferred from the rice grains near the inner wall of the rice cooker to the rice grain in the center of the rice cooker. It was also found that the heat conduction due to convection circulation of water is only slight. Therefore, in the case of a domestic cauldron, there is no problem at all, whereas in the case of a commercial cauldron,
When the maximum amount of rice stored in the rice cooker is cooked, it takes time for the heat to reach the rice grains in the center of the rice cooker. Cooking will be over. And it turned out that this was the cause of dango rice.

Further, in the case of non-washed rice, it was found that the surface of the rice grain had numerous depressions in the unit of micron, and the air was trapped therein. Since this unwashed rice is naturally not washed with water, and due to such a structure, even if the rice is washed or an immersion process is provided, the air cannot be easily expelled. It was found that the air forms a film of air on the surface of the rice grains in water, which impedes heat conduction during rice cooking, so that the above-mentioned problems become more remarkable in the case of unwashed rice.

[0012] Further, even if the polished rice is cooked and soaked after the dipping process at 80% or less of the maximum capacity of the rice cooker, abnormal rice may occasionally occur, but this is broken rice (crushed rice).
It was also found that when a large amount of is contained, this crushed rice becomes a viscous substance by the hot water at the bottom of the rice cooker, increasing the viscosity of the hot water and further inhibiting slight convection, resulting in so-called premature cutting. .

In addition, the rice starch begins to be gelatinized at 60 ° C.
They also found that it is extremely important to carry out sufficient heat exchange to homogenize the temperature distribution in the kettle between the vicinity and 98 ° C. when boiling begins.

As described above, the present inventors have overturned the conventional rice cooking theory with new knowledge by clarifying the heat conduction mechanism during rice cooking, and completed the present invention capable of solving the above-mentioned conventional problems all at once. Came to do. In addition, the present invention as described above satisfies the optimal conditions on the complicated rice cooking theory by an extremely simple method, and anyone can easily cook a large amount of rice while using a commercial rice cooker having a storage capacity of 4 liters or more. It provides a commercial rice cooking method and the cooked rice. The content thereof is a rice cooking method comprising a heating and raising step of raising the temperature in the rice cooker to a boiling temperature over 20 to 40 minutes after starting rice cooking, and a heating step following the heating and raising step. By using the above, it is possible to completely solve the above problems, and thereby to provide cooked rice for business use.

Here, in the heating and raising step, it takes 20 to 40 minutes to raise the temperature in the rice cooker to the boiling temperature, but the temperature rise at this time may be a linear one. May be changed. It is preferable to raise it by a constant heating power. Further, the boiling temperature is generally 100 ° C. in water, but when the rice is cooked in water, the inventor has found that the boiling temperature is slightly lower than this temperature. The preferred elevated temperature in the present invention is 98 ° C. It can be used at a temperature slightly lower than this temperature as long as it does not affect the taste and texture of cooked rice. As described above, the boiling temperature in the present invention means that not only the physical boiling temperature at the time of cooking rice in the above meaning but also the temperature at which the rice can be cooked to such an extent that it does not interfere with the taste and texture as cooked rice for business use can be adopted. There is.

Next, the heating step subsequent to the heating and rising step may be performed by a constant heating force which continues to the heating and rising step, or the heating force may be reduced. On the contrary, the heating power may be increased, that is, as long as the boiling temperature in the kettle can be maintained. These selections may be appropriately made depending on the amount of rice cooked, the rice cooker, or the difference in rice.

In the present invention, a wide variety of materials can be used, including normal rice such as polished rice, germinated rice, rice with half-baked, rice with 7 minutes and non-washed rice thereof, and usable water is tap water or pure water. Water, distilled water, ion-exchanged water, deaerated water, etc. are used.

As the rice cooker used in the present invention, the commercial cauldron and the water temperature in the cauldron containing rice and water therein are kept under constant heating conditions for 20 minutes after starting heating.
Any device with a heating device capable of raising the temperature to 98 ° C. over 40 minutes may be used. Further, it is also effective to coat the inner surface, the outer surface, or both of the rice cooker with a black heat-resistant substance having excellent endothermic properties and a material having excellent far-infrared radiation performance.

In the method of the present invention, the heating power during rice cooking is not indicated by a calorie. Generally, commercial rice cookers are classified into city gas and propane gas, and there are several kinds for city gas. This is because there are different types, and the amount of heat is different when including those for propane gas, and it was thought that it would be difficult to display typical numerical values. Therefore, it is defined by the relationship between the elapsed time and the reached temperature.

[0020]

According to the rice cooking method of the present invention, the above means act as follows to solve the problem. In the rice cooking method of the present invention, the temperature in the rice cooker, which is conventionally supposed to be finished using the commercial rice cooker, that is, 20 minutes to 40 minutes, is adjusted to the boiling temperature, preferably 98 ° C. Rice is cooked by reaching. In short, the time from when rice starch starts to be gelatinized to 60 ° C. until it reaches the temperature at which boiling begins is about 5 minutes, which is at least 1 time.
As a result, it takes more than 0 minutes to cook the maximum amount of rice, and even if it is non-washed rice with poor heat conduction, the center of the rice grain contacting the inner wall of the rice cooker Even if the cauldron is a commercial cauldron with a long distance, the time required for heat transfer from the inner wall of the rice cooker to the central part of the rice cooker is given, so a large temperature difference does not occur in the cauldron, resulting in dango Normal cooked rice with no unevenness of hardness or softness is cooked. In particular, in the case of unwashed rice, it takes a long time for the water to boil, so the air on the surface of the rice grain that causes abnormal rice cooking expands and becomes bubbles, giving sufficient time to deaerate. Become. In terms of rice cooking efficiency, it is best to cook rice in as short a time as possible, so it is best to shorten the time of high temperature from 60 ℃ when rice starch starts to be gelatinized to 98 ℃ as boiling temperature. desired. Then, under the condition of constant heating, if the temperature in the rice cooker is raised to 98 ° C. over a minimum of 20 minutes from the start of cooking, the minimum necessary time in this high temperature state can be secured. There is a critical meaning here with a lower limit of 20 minutes.

As described above, the rice cooked for a long time is limited to the cauldron capable of cooking a large amount of rice. It has long been said that rice is better cooked over high heat, but this can be said to be the accepted theory when there was no non-washed rice like today and there was rarely an opportunity to cook large quantities of rice. Therefore, from the above action, it is correct that "it is better to cook the cauldron in a short time and the cauldron in a long time". On the other hand, even though it is a long time, there is a limit, and no matter how large the cauldron is, under the condition of constant heating, if it takes 40 minutes or more from the start of heating to reach the boiling point of 98 ° C. It tends to become "rice" and is not desirable in terms of rice cooking efficiency, so it must be made less than that, and there is a critical meaning that the upper limit is 40 minutes. Therefore, inevitably 20 to 40 minutes after the start of heating.
I will say minutes. In the present invention, such long cooking time may cause a deterioration in time efficiency at first glance, but the opposite is true. That is, in the case of the method of the present invention, since it takes a long time to reach the boiling point, the rice grains can sufficiently absorb water during that time, so that the dipping step which is conventionally required can be omitted. Further, the steaming time can be shortened. As a result, the time required to produce cooked rice is shortened by subtraction. Furthermore, when non-washed rice is used, the washing step can be omitted, and the time can be shortened significantly. Then, commercial rice including non-washed rice and regular rice will be provided.

[0022]

EXAMPLES Next, the present invention as described above will be described in more detail based on specific examples, but the present invention is not limited to the following examples.

Example 1 A commercial rice cooker (RR-30 type manufactured by Rinnai Co., Ltd.) having a maximum storage capacity of 6 liters was used for 4.6K.
Grains (6 liters by volume) of polished rice are washed for 5 minutes to prepare 11.5 Kg with water at a water temperature of 20 ° C. After igniting the gas without going through the dipping process, adjust the cook and heat. Start the rising process and cook rice with a certain heating power,
24 minutes after ignition, the temperature in the kettle was raised to the boiling temperature, for example, 98 ° C. Then, when it was left with the same heating power as the subsequent heating step, the fire was automatically extinguished 7 minutes after the start of boiling and the cooking of rice was completed. After that, the rice was steamed with residual heat for 15 minutes to obtain cooked rice of Example 1. The total required time is 51 minutes.

(Example 2) Using the same commercial rice cooker as in Example 1, 4.6 kg (6 liters by volume) of polished rice was washed for 5 minutes, and was then washed with water having a water temperature of 20 ° C for 11.5.
It is adjusted to Kg, after immersing for 60 minutes in the gas, after igniting the gas, adjusting the cock to start the heating and raising process to cook rice with a certain heating power, and after 21 minutes of ignition, boil the temperature in the pot. The temperature was raised to, for example, 98 ° C. Then, when it was left with the same heating power as the subsequent heating step, 5 minutes after the start of boiling, the fire was automatically extinguished and the rice cooking was completed. After that, it was steamed with residual heat for 15 minutes to obtain cooked rice of Example 2. The total required time is 106 minutes.

(Example 3) Using the same commercial rice cooker as in Example 1, 6 liters of non-washed rice was added together with water at a water temperature of 20 ° C to prepare 11.6 kg, and gas was passed through without dipping. After ignition, the cook was adjusted to start the heating and raising step to cook rice with a constant heating power, and 25 minutes after ignition, the temperature in the pot was raised to the boiling temperature, for example, 98 ° C. And
When it was left with the same heating power as the subsequent heating step, 7 minutes after the start of boiling, the fire was automatically extinguished and the rice cooking was completed. After that, it was steamed with residual heat for 15 minutes to obtain cooked rice of Example 3. The total required time is 47 minutes.

Example 4 Using the same commercial rice cooker as in Example 1, 4.6 kg (6 liters by volume) of unwashed rice containing 15% by weight of crushed rice was added together with water at a water temperature of 20 ° C. to prepare 1
It was adjusted to 1.3 kg, and after igniting the gas without going through the dipping process, adjusting the cock to start the heating and raising process to cook rice with a constant heating power, and after 24 minutes of ignition, the temperature in the pot was adjusted. The boiling temperature was raised to, for example, 98 ° C. Then, when it was left with the same heating power as the subsequent heating step, 8 minutes after the start of boiling, the fire was automatically extinguished and the rice cooking was completed. After that, it was steamed with residual heat for 15 minutes to obtain cooked rice of Example 4. The total required time is 47 minutes.

The cooked rice that has been steamed in Examples 1 to 4 is
In the rice cooker used, it was loosened with rice scoops and the cooked rice was sampled. In all cases, the cooked rice of Examples 1 to 4 showed no abnormal cooked rice such as dango rice or hard and soft unevenness over the entire amount, and was subjected to a dipping process at a storage amount of 80% or less of the conventional amount. It had the same taste as cooked rice and was very delicious. The same experiment was repeated many times, and the same result was obtained in each case.

However, in each of the above embodiments, the boiling temperature is set to 9
Experiments were carried out at temperatures of 95 ° C and 90 ° C even if the temperature was raised to 8 ° C. As a result, rice with a temperature of 95 ° C could be obtained in a state close to that of 98 ° C. It was in a possible state.

The outer surface of the rice cooker used here has a metal surface exposed, and the portion where the flame tip from the gas stove hits is well heated, but far infrared rays from the gas stove are between the flames. Since it will be reflected, black heat-resistant substance with excellent heat absorption property, or material with excellent far-infrared radiation performance, either on the inner surface or the outer surface of the rice cooker, or both, by coating in combination, An extremely uniform heat distribution can be given to the kettle to uniformly heat the inside of the kettle, and the far infrared rays can be radiated into the kettle to achieve uniform heat penetration. Therefore, the temperature distribution in the entire pot can be made more uniform, and the effect of the present invention can be further enhanced.

[0030]

As described above, according to the method for cooking rice for business use of the present invention, a large amount of rice can be cooked at one time regardless of normal polished rice or non-washed rice, and rice cooking efficiency can be improved. Further, as is clear from the examples, even if the dipping step is omitted or the steaming time is shortened, abnormal rice production does not occur, and the time for producing cooked rice can be dramatically reduced. Furthermore, if unwashed rice is used, the rice washing step as well as the dipping step can be omitted, so that it is possible to realize a time reduction that could not be considered by conventional wisdom. In addition, by omitting the dipping step, it is not necessary to arrange the dipping containers in the order of dipping at the expense of a vast area, and the area required for cooked rice production can be significantly reduced. Thus, the present invention is to solve various problems that the conventional cooked rice production had at once.
Moreover, the practice of the present invention can be realized only by adjusting the thermal power, which is extremely economical. Further, the commercial cooked rice of the present invention can be provided as a delicious dish without dango rice or hard and soft unevenness.

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[Procedure amendment]

[Submission date] December 22, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction content]

[Document name] Statement

[Title of Invention] Commercial rice cooking method and its cooked rice

[Claims]

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the production of cooked rice in the food industry where a large amount of rice is cooked and the food service industry, which enables the rice to be cooked with the maximum capacity of the rice cooker and the dipping process before cooking. Can be omitted, and further, even if unwashed rice is cooked under such conditions, abnormal rice does not occur,
The present invention relates to a commercial rice cooking method and a cooked rice which can obtain cooked rice having an excellent taste with good reproducibility.

[0002]

2. Description of the Related Art A large amount of cooked rice is industrially produced in the food industry, the restaurant industry and the like. In this commercial rice production process, there are four main processes: a rice washing process to sharpen and wash rice, a dipping process to soak in water for about 1 hour, a rice cooking process to cook rice over high heat, and a steaming process using residual heat. Is going through. Such a rice cooker used in the cooked rice manufacturing process is called a commercial rice cooker, and generally stores the amount (the amount of raw rice stored in the rice cooker, which is the amount of rice that has not been subjected to the washing or dipping process). It is a large one (hereinafter referred to as a cauldron) of 4 liters or more (hereinafter referred to as a cauldron), and has a single pot and a conveyor pot, both of which are heated by gas fire from the bottom of the rice cooker. For the above-mentioned dipping step, a method is adopted in which dipping containers for dipping several tens to hundreds of rice per day are placed in the order of dipping at the expense of a vast area.

In this process of producing cooked rice for business use, naturally, it is required to reduce the production cost of cooked rice, which is a commodity.
Many efforts have been made to produce in as little time and as little work area as possible. In particular, shortening the manufacturing time of cooked rice is directly linked to the reduction of labor cost, which has a high cost ratio, and the pursuit of this is intense. Under these circumstances, currently, the following two methods are mainly used or attempted individually or in combination in order to reduce the time required for the cooked rice production.

First of all, the rice is actually cooked in the shortest possible time according to the traditional theory that the rice is delicious when cooked on a high heat, and for the purpose of shortening the time. . This is to cook rice in a shorter time than the cooking time in a small household rice cooker (hereinafter referred to as a small pot).
The time required from the start of heating to the temperature of the water in the pot reaching 98 ° C is about 15 minutes in the domestic cauldron, whereas it is about 11 minutes in the cooked rice for business use. Therefore, in cooking rice for business use, the heating power is large relative to the size of a rice cooker compared to household rice cookers.

Secondly, the rice washing process before cooking rice is omitted to reduce the labor and time required for rice washing. The so-called "non-washed rice" that can be cooked without the need for washing rice is used for this. What is this non-washed rice?
It is rice produced by the present inventor who does not need to wash rice before cooking rice by removing rice bran left on the surface of polished rice with water or other means. Therefore, in the second method, by using the unwashed rice, it is possible to omit the rice washing step as a work using water. In this way, it is the actual condition of cooked rice production for commercial use that the rice cooking time is shortened as much as possible and efforts are made to improve the rice cooking efficiency.

[0006]

[Problems to be Solved by the Invention] However, the above-mentioned 2
Even if one of the two methods is used, it is not possible to achieve a sufficient time reduction in cooked rice production due to the following problems. First of all, when a large amount of rice is cooked in the rice cooker, abnormal rice cookers sometimes remain, in which a lump of freshly cooked rice (hereinafter referred to as dango rice) remains, mainly near the center of the rice cooker. Although the cause of the abnormal rice cooking is unknown, it is empirically known that it can be prevented to some extent by setting the amount of rice cooked at one time to about 80% or less of the maximum capacity of the rice cooker. Therefore, conventionally, the amount of rice to be stored needs to be about 80% or less of the maximum storage amount of the rice cooker, and the rice cooking efficiency is extremely poor. That is, the amount of rice to be stored in the rice cooker at one time must be reduced by 20%, which eventually leads to an increase in the number of rice cooks. In the conventional commercial rice cooking method, the boiling point is reached in about 11 minutes after the heating is started, but it takes about 6 minutes before the heating stops, that is, about 17 minutes in the rice cooking process. The total required time is about 5 minutes for the rice washing process, about 60 minutes for the dipping process, about 17 minutes for the rice cooking process, about 20 minutes for the steaming process, for a total of about 102 minutes.
It becomes a minute. Therefore, an increase in the number of cooked rice leads to a great increase in working time. On the contrary, if the maximum amount of rice that can be stored in the rice cooker is cooked, the time can be shortened, but the yield of cooked rice will be deteriorated, and this will also be a factor in increasing costs.

Secondly, the above-mentioned non-washed rice (particularly water-washed non-washed rice )
If rice is used, in addition to unevenness of hardness and softness occurring in the cooked rice grains throughout the pot, abnormal rice cooked with the dango rice often occurs. In order to prevent such abnormal rice cooking, it is necessary to set the amount of rice cooked at one time to about 50% or less of the maximum storage capacity of the rice cooker, which significantly reduces the rice cooking efficiency. That is, even though unwashed rice is used and the rice washing step is omitted, the amount of rice to be stored at one time must be thinned to a large amount of 50%. The omitted benefits may be offset, or the efficiency of rice cooking may be further reduced. Therefore, the non-washed rice has excellent characteristics but is difficult to be used for business purposes.

[0008] In order to cook deliciously even a little, a method has been proposed as a new rice cooking method, in which rice is cooked on a low heat and then heated to a high heat or stopped on the way. This is to cook rice with a strong heat power that compensates for the low heat and heating pauses until high heat, and in all, the time from starting heating to reaching 98 ° C is set within 15 minutes, and the heat power is changed. It is almost the same as the cooking time in the case of non-cooked rice. In addition, there is a method of cooking rice that takes 25 minutes or more to reach 98 ° C from the start of heating in a domestic rice cooker, but it starts cooking with extremely low heat and strengthens the heating power on the way. , Middle pappa ”.

However, even with such a new rice cooking method, the above-mentioned problems in the rice cooking process for business have not been solved yet.

[0010]

The inventors of the present invention have made extensive studies on the causes of these problems and have found the following. In other words, conventionally, there was a common sense that heat conduction in a pan when cooking an object was performed by convection circulation of broth, but the present inventors have found that it does not work for rice cooking. Of. Further, it has been conventionally believed that the rice grains during rice cooking do not move convectively much, but the water (hot water) circulates vigorously in convection, whereby heat is exchanged to conduct heat. However, this is a false recognition, most of the rice grains are in a static state, and there is little convection circulation of water (hot water), and heat is gradually transferred from the rice grains near the inner wall of the rice cooker to the rice grain in the center of the rice cooker. It was also found that the heat conduction due to convection circulation of water is only slight. Therefore, in the case of a domestic cauldron, there is no problem at all, whereas in the case of a commercial cauldron,
When the maximum amount of rice stored in the rice cooker is cooked, it takes time for the heat to reach the rice grains in the center of the rice cooker. Cooking will be over. And it turned out that this was the cause of dango rice.

Further, in the case of non-washed rice, it was found that the surface of the rice grain had numerous depressions in the unit of micron, and the air was trapped therein. Since this unwashed rice is naturally not washed with water, and due to such a structure, even if the rice is washed or a dipping process is provided, the air cannot be easily expelled. It was found that the air forms a film of air on the surface of the rice grains in water, which impedes heat conduction during rice cooking, so that the above-mentioned problems become more remarkable in the case of unwashed rice.

[0012] Further, even if the polished rice is cooked and soaked after the dipping process at 80% or less of the maximum capacity of the rice cooker, abnormal rice may occasionally occur, but this is broken rice (crushed rice).
It was also found that when a large amount of is contained, this crushed rice becomes a viscous substance by the hot water at the bottom of the rice cooker, increasing the viscosity of the hot water and further inhibiting slight convection, resulting in so-called premature cutting. .

In addition, the rice starch begins to be gelatinized at 60 ° C.
They also found that it is extremely important to carry out sufficient heat exchange to homogenize the temperature distribution in the kettle between the vicinity and 98 ° C. when boiling begins.

As described above, the present inventors have overturned the conventional rice cooking theory with new knowledge by clarifying the heat conduction mechanism during rice cooking, and completed the present invention capable of solving the above-mentioned conventional problems all at once. Came to do. And, according to the present invention as described above, the optimum conditions on the complicated rice cooking theory are satisfied by an extremely simple method, and anyone can easily cook a large amount of rice while using a commercial rice cooker having a storage capacity of 4 liters or more. It provides a commercial rice cooking method and the cooked rice. The content is that the capacity is 4 liters or more.
Commercial rice cooker comprising a heating and raising step of starting rice cooking using a commercial rice cooker and raising the temperature in the rice cooker to a boiling temperature over 20 to 40 minutes, and a heating step following the heating and raising step. By using the method, it is possible to completely solve the above problems and provide cooked rice for business use.
It

Here, in the heating and raising step, it takes 20 to 40 minutes to raise the temperature in the rice cooker to the boiling temperature, but the temperature rise at this time may be a linear one. May be changed. It is preferable to raise it by a constant heating power. In addition, the temperature at which boiling begins is generally 100 for water.
The inventor has found that the temperature is slightly lower than this temperature when it is cooked by putting rice in water although it is at a temperature of ℃. The preferred temperature for starting boiling in the present invention is 98 ° C. It can be used at a temperature slightly lower than this temperature as long as it does not affect the taste and texture of cooked rice. As described above, the boiling temperature in the present invention means that not only the physical boiling temperature at the time of cooking rice in the above meaning but also the temperature at which the rice can be cooked to such an extent that it does not interfere with the taste and texture as cooked rice for business use can be adopted. There is.

Next, the heating step subsequent to the heating and rising step may be performed by a constant heating force which continues to the heating and rising step, or the heating force may be reduced. On the contrary, the heating power may be increased, that is, as long as the boiling temperature in the kettle can be maintained. These selections may be appropriately made depending on the amount of rice cooked, the rice cooker, or the difference in rice.

In the present invention, a wide variety of materials can be used, including normal rice such as polished rice, germinated rice, rice with half-baked, rice with 7 minutes and non-washed rice thereof, and usable water is tap water or pure water. Water, distilled water, ion-exchanged water, deaerated water, etc. are used.

As the rice cooker used in the present invention, the commercial cauldron and the water temperature in the cauldron containing rice and water therein are kept under constant heating conditions for 20 minutes after starting heating.
Any device with a heating device capable of raising the temperature to 98 ° C. over 40 minutes may be used. Further, it is also effective to coat the inner surface, the outer surface, or both of the rice cooker with a black heat-resistant substance having excellent endothermic properties and a material having excellent far-infrared radiation performance.

In the method of the present invention, the heating power at the time of cooking rice is not displayed as calories. Generally, commercial rice cookers are classified into city gas and propane gas, and there are several types for city gas. This is because it is considered that it is difficult to display typical numerical values because the calorific value differs for propane gas. Therefore, it is defined by the relationship between the elapsed time and the reached temperature.

[0020]

According to the rice cooking method of the present invention, the above means act as follows to solve the problem. In the rice cooking method of the present invention, the temperature inside the rice cooker is set to 98 ° C, which is the boiling start temperature, over the time that rice cooking should have conventionally been completed using a commercial rice cooker, that is, 20 minutes to 40 minutes. Reach and heat
The rice will continue to be cooked until it is stopped . In short, it takes about 5 minutes to reach the temperature at which boiling starts from 60 ° C at which rice starch begins to be gelatinized, that is, at least 10 minutes or more, resulting in the maximum capacity of rice. Even if it is cooked, it is a non-washed rice with poor heat conduction, or a commercial cauldron with a long distance from the rice grain group that is in contact with the inner wall of the rice cooker to the center, Since the time required to transfer the heat from the inner wall to the center of the kettle is given, a large temperature difference does not occur in the kettle, and as a result, normal rice cooked with dango rice and firm and soft unevenness is cooked. In particular, in the case of unwashed rice, it takes a long time for the water to boil, so the air on the surface of the rice grain that causes abnormal rice cooking expands and becomes bubbles, giving sufficient time to deaerate. Become. In terms of rice cooking efficiency, it is best to cook rice in as short a time as possible, so it is best to shorten the time of high temperature from 60 ℃ when rice starch starts to be gelatinized to 98 ℃ as boiling temperature. desired. And under the condition of constant heating,
By raising the temperature in the rice cooker to 98 ° C. over a minimum of 20 minutes from the start of cooking, the minimum necessary time for this high temperature state can be secured. There is a critical meaning here with a lower limit of 20 minutes.

As described above, the rice cooked for a long time is limited to the cauldron capable of cooking a large amount of rice. It has long been said that rice is better cooked over high heat, but this can be said to be the accepted theory when there was no non-washed rice like today and there was rarely an opportunity to cook large quantities of rice. Therefore, from the above action, it is correct that "it is better to cook the cauldron in a short time and the cauldron in a long time". On the other hand, even though it is a long time, there is a limit, and no matter how large the cauldron, under the condition of constant heating, if it takes 40 minutes or more from the start of heating to reach the boiling point of 98 ° C. It tends to become "rice" and is not desirable in terms of rice cooking efficiency, so it must be made less than that, and there is a critical meaning that the upper limit is 40 minutes. Therefore, inevitably 20 to 40 minutes after the start of heating.
I will say minutes. In the present invention, such long cooking time may cause a deterioration in time efficiency at first glance, but the opposite is true. That is, in the case of the method of the present invention, since it takes a long time to reach the boiling point, the rice grains can sufficiently absorb water during that time, so that the dipping step which is conventionally required can be omitted. Further, the steaming time can be shortened. As a result, the time required to produce cooked rice is shortened by subtraction. Furthermore, when non-washed rice is used, the washing step can be omitted, and the time can be shortened significantly. Then, commercial rice including non-washed rice and regular rice will be provided.

[0022]

EXAMPLES Next, the present invention as described above will be described in more detail based on specific examples, but the present invention is not limited to the following examples.

Example 1 A commercial rice cooker (RR-30 type manufactured by Rinnai Co., Ltd.) having a maximum storage capacity of 6 liters was used for 4.6K.
Grains (6 liters by volume) of polished rice are washed for 5 minutes to prepare 11.5 Kg with water at a water temperature of 20 ° C. After igniting the gas without going through the dipping process, adjust the cook and heat. Start the rising process and cook rice with a certain heating power,
24 minutes after ignition, the temperature in the kettle reached 98 ° C and boiling started.
It was Then, as a subsequent heating step, the temperature was raised to about 100 ° C. immediately after being left with the same heating power, and 7 minutes after the start of boiling, the fire was automatically extinguished and the rice cooking was completed. After that, the rice was steamed with residual heat for 15 minutes to obtain cooked rice of Example 1. Total time required is 5
1 minute.

(Example 2) Using the same commercial rice cooker as in Example 1, 4.6 kg (6 liters by volume) of polished rice was washed for 5 minutes, and was then washed with water having a water temperature of 20 ° C for 11.5.
After adjusting to a Kg, igniting the gas through a dipping process for 60 minutes, adjusting the cock to start the heating and raising process to cook rice with a constant heating power, and 21 minutes after ignition, the temperature in the pot is 9
The temperature reached 8 ° C and boiling started. Then, as the subsequent heating process , the product was left with the same heating power, and soon it reached about 100 ° C.
Ri, rice has been completed and automatic extinguishing the start of boiling 5 minutes later.
After that, it was steamed with residual heat for 15 minutes to obtain cooked rice of Example 2. The total required time is 106 minutes.

(Example 3) Using the same commercial rice cooker as in Example 1, 6 liters of non-washed rice was added together with water at a water temperature of 20 ° C to prepare 11.6 kg, and gas was passed through without dipping. After ignition, the cook was adjusted to start the heating and raising process to cook rice with a constant heating power, and the temperature in the pot reached 98 ° C. 25 minutes after ignition, and boiling started. Then, as a subsequent heating step, the same heating power was left for about 10 minutes.
The temperature reached 0 ° C, and 7 minutes after the start of boiling, the fire was automatically extinguished and cooking was completed. After that, it was steamed with residual heat for 15 minutes to obtain cooked rice of Example 3. The total required time is 47 minutes.

Example 4 Using the same commercial rice cooker as in Example 1, 4.6 kg (6 liters by volume) of unwashed rice containing 15% by weight of crushed rice was added together with water at a water temperature of 20 ° C. to prepare 1
Was adjusted to be 1.3 kg, after ignition to gas without passing through the dipping process, the start of the heating rise step by adjusting the cock performs cooking with a constant heating power, the temperature of Kamanai after ignition 24 minutes 9
The temperature reached 8 ° C and boiling started. Then, as the subsequent heating process , the product was left with the same heating power, and soon it reached about 100 ° C.
Ri, rice has been completed with automatic fire extinguishing after the start of boiling 8 minutes.
After that, it was steamed with residual heat for 15 minutes to obtain cooked rice of Example 4. The total required time is 47 minutes.

The cooked rice that has been steamed in Examples 1 to 4 is
In the rice cooker used, it was loosened with rice scoops and the cooked rice was sampled. In all cases, the cooked rice of Examples 1 to 4 showed no abnormal cooked rice such as dango rice or hard and soft unevenness over the entire amount, and was subjected to a dipping process at a storage amount of 80% or less of the conventional amount. It had the same taste as cooked rice and was very delicious. The same experiment was repeated many times, and the same result was obtained in each case.

The outer surface of the rice cooker used here has a metal surface exposed, and the portion where the tip of the flame from the gas stove hits is well heated, but far infrared rays from the gas stove are between the flames. Since it will be reflected, black heat-resistant substance with excellent heat absorption property, or material with excellent far-infrared radiation performance, either on the inner surface or the outer surface of the rice cooker, or both, by coating in combination, An extremely uniform heat distribution can be given to the kettle to uniformly heat the inside of the kettle, and the far infrared rays can be radiated into the kettle to achieve uniform heat penetration. Therefore, the temperature distribution in the entire pot can be made more uniform, and the effect of the present invention can be further enhanced.

[0029]

As described above, according to the method for cooking rice for business use of the present invention, a large amount of rice can be cooked at one time regardless of normal polished rice or non-washed rice, and rice cooking efficiency can be improved. Further, as is clear from the examples, even if the dipping step is omitted or the steaming time is shortened, abnormal rice production does not occur, and the time for producing cooked rice can be dramatically reduced. Furthermore, if unwashed rice is used, the rice washing step as well as the dipping step can be omitted, so that it is possible to realize a time reduction that could not be considered by conventional wisdom. In addition, by omitting the dipping step, it is not necessary to arrange the dipping containers in the order of dipping at the expense of a vast area, and the area required for cooked rice production can be significantly reduced. Thus, the present invention is to solve various problems that the conventional cooked rice production had at once.
Moreover, the practice of the present invention can be realized only by adjusting the thermal power, which is extremely economical. Further, the commercial cooked rice of the present invention can be provided as a delicious dish without dango rice or hard and soft unevenness.

Claims (4)

[Claims] 1. A rice cooker for business use having a capacity of 4 liters or more is used to start cooking rice, and the temperature in the rice cooker is kept at 20 minutes to 40 minutes.
A commercial rice cooking method comprising: a heating and raising step of raising the boiling temperature over a period of time; and a heating step that follows the heating and raising step. 2. The commercial rice cooking method according to claim 1, wherein the boiling temperature is 98 ° C. 3. The temperature in the pot is 20 minutes to 4 after starting the rice cooking.
Commercial cooked rice cooked by raising it to the boiling temperature over 0 minutes. 4. The cooked rice for commercial use according to claim 3, wherein the non-washed rice is used.