JP2012143253A - Method for producing cooked rice by intermittent heating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of producing cooked rice by intermittent heating by which taste and mouthfeel, as well as the aging resistance, of the cooked rice are improved, by devising the heating conditions during the rice-cooking process.SOLUTION: In the method for producing cooked rice by intermittent heating, process of cooking rice is carried out in a plurality of steps, includes carrying out at least once a cooling step, particularly a compulsive cooling step, of once interrupting heating during a rice cooking process of cooking rice by heating a rice cooking container containing rice and cooking water and lowering the temperature in the rice cooking container by 0.1°C to 10°C in 1 to 10 minutes, and finishing rice cooking in the final heating step after carrying out the final cooling step.

Description

  The present invention relates to a method for producing cooked rice by cooking rice by heating a rice cooking container charged with rice and cooking water.

  The rice cooking process to cook rice is performed by putting the rice that has been washed and soaked and the amount of cooking water that matches the amount of rice into the rice cooking container and heating it. Until then, it is generally heated continuously. Moreover, in an electric kettle or a gas kettle, when the temperature of the bottom surface of the rice cooking container (inner kettle) rises to a preset cooking temperature, it is determined that the cooking has been completed and heating is terminated.

  On the other hand, in order to moderately burn the cooked rice after completion of the rice cooking process, it has been proposed to heat for a certain time after elapse of a predetermined time after determining the completion of rice cooking and ending heating (see, for example, Patent Document 1). .) It has also been proposed to suppress the growth of fungi by heating the cooked rice after a certain period of time when the cooked cooked rice is kept at about 70 ° C. (see, for example, Patent Document 2).

JP-A-55-151918 JP 2001-37635 A

  What is described in both patent documents is intended to improve the taste and long-term storage of cooked rice, but those described in Patent Document 1 are those that moderately burn rice after cooking, those described in Patent Document 2 Is intended to suppress the growth of fungi during incubation, and the cooking process itself is performed by a general method, and the cooking process has not been studied at all. In addition, it is also known to cook after cooking, but all are for cooked rice, and the cooking process itself is continuously heated from the start of heating to cooking. There is no change.

  Then, this invention aims at providing the manufacturing method of the cooked rice by intermittent heating which can aim at the improvement of aging tolerance while improving the taste and texture of cooked rice obtained by devising the heating conditions in a rice cooking process. It is said.

  In order to achieve the above object, the method for producing cooked rice by intermittent heating according to the present invention cooks rice by heating the cooked rice container by heating the cooked rice container charged with rice and cooked water. During the rice cooking process, the cooling process for interrupting heating is performed at least once, and the cooling process starts after the inside of the rice cooking container is in a boiling state. The cooling process includes a forced cooling process for forcibly cooling the rice cooking container, the cooling process is performed for 1 to 10 minutes, and the cooling process is performed in the rice cooking container. The temperature is lowered by 0.1 to 10 ° C. relative to the start of the cooling process.

  Furthermore, in the method for producing cooked rice by intermittent heating according to the present invention, in the case where the cooling step is performed once and the heating is divided into two times, after the heating is started, It starts when the weight reaches 100.1 to 110, and after the cooling step is completed, the second heating is performed to cook.

  In the case where the cooling process is performed twice and the heating is divided into three times, the weight of the first cooling process after the start of heating is 100.3 to 115 with respect to the cooked rice weight 100 at the end of the rice cooking process. The second heating is performed after the cooling step is completed, and the second time when the weight in the rice cooking container becomes 100.1 to 110 with respect to the cooked rice weight 100 at the end of the rice cooking step. A cooling process is started, and after the cooling process is completed, the third heating is performed to cook.

  When the cooling process is performed three times and the heating is divided into four times, the first cooling process is performed after the start of heating, and the weight in the rice cooking container is 100.5 to 120 with respect to the cooked rice weight 100 at the end of the rice cooking process. The second heating is performed after the cooling step is completed, and the second time when the weight in the rice cooking container becomes 100.3 to 115 with respect to the cooked rice weight 100 at the end of the rice cooking step. The cooling process is started, the third heating is performed after the cooling process is completed, and the third cooling process is performed when the weight in the rice cooking container becomes 100.1 to 110 with respect to the cooked rice weight 100 at the end of the rice cooking process. And after the cooling step, the fourth heating is performed to cook.

  Furthermore, the present invention includes a method for producing thawed cooked rice, which is obtained by freezing and then thawing the cooked rice produced by the production method.

  According to the method for producing cooked rice by intermittent heating according to the present invention, heating is temporarily interrupted during the rice cooking process, at least one cooling process is performed, and heating during rice cooking is performed intermittently in two or more stages. It can improve the properties of cooked rice, improve the taste and texture of plumpness, etc., and improve the aging resistance during storage and maintain the quality while maintaining the quality. It is done.

It is a figure which shows an example of the temperature change in the rice cooking container when the manufacturing method of the cooked rice by the intermittent heating of this invention is applied. It is a figure which shows an example of the weight change in the rice cooking container when the manufacturing method of the cooked rice by the intermittent heating of this invention is applied. It is a figure which shows the change of the consistency of the cooked rice measured by Example 4. 6 is an electron micrograph showing the internal structure of control cooked rice in Example 4. FIG. It is an electron micrograph which shows the internal structure of the cooked rice of Test 4-2 in Example 4.

  FIG. 1 is a diagram illustrating an example of a temperature change in a rice cooking container when the method for producing cooked rice by intermittent heating according to the present invention is applied. In addition, since it does not specifically limit about the rice washing and immersion which are processes before entering into a rice cooking process, detailed description about these processes is abbreviate | omitted. Moreover, the "temperature in a rice cooking container" as used below represents the temperature of the bottom surface inside the rice cooking container.

  First, rice and cooking water are put into a normal rice cooking container as usual, and a 1st heating process is started. The means for heating the rice cooking container is not particularly limited, and any heating means used in a normal rice cooking process can be selected and used. The heating in the first heating step is performed until the inside of the rice cooking container is immediately before the boiling state, until the boiling state is reached, or until the boiling state is continued for a preset time. For example, the process is performed until the boiling state represented by the point A in FIG. 1 is reached, and then the first cooling process is started. The horizontal dotted line in FIG. 1 indicates the boiling temperature of water. In addition, the time of a 1st heating process changes with rice cooking amounts or a heating means.

  A 1st cooling process is a process of interrupting the heating of a rice cooking container, and cooling the rice in the middle of cooking in a rice cooking container, and only stops the action | operation of a heating means, with the rice cooking container installed in a heating means, or Although it may be performed by natural cooling that cools at room temperature just by removing the rice cooking container from the heating means, it is desirable to perform a forced cooling process for forcibly cooling the rice cooking container. This forced cooling process can be performed using arbitrary cooling means, for example, can be performed by immersing a rice cooking container in cold water or ice water, or spraying cold air or cold water on a rice cooking container.

  The cooling temperature in the first cooling step (point B in FIG. 1) only needs to be lower than the temperature at the start of the first cooling step, that is, the temperature at the end of the first heating step, and the first heating step was performed to the boiling state. In such a case, the inside of the rice cooking container may be simply brought into a non-boiling state. For example, when the inside of the rice cooking container is in a boiling state of 100 ° C., the temperature in the rice cooking vessel may be simply brought into a non-boiling state of 99.9 ° C. Usually, it is desirable to lower by 0.1 to 10 ° C, preferably 0.5 to 5 ° C, more preferably 1 to 2 ° C with respect to the temperature at the start of the first cooling step.

  Moreover, although the time of a 1st cooling process changes with conditions, such as the amount of rice cooking, the heat conductivity of a rice cooking container, the presence or absence of a forced cooling process, 1 to 10 minutes are preferable normally, Preferably 1 to 5 minutes are suitable. When the rice cooking container is cooled at an ice temperature, a sufficient effect can be obtained in 1 to 2 minutes. By selecting an appropriate cooling means and cooling as soon as possible, the effect of the cooling process can be sufficiently obtained. However, the overall process time can be shortened.

  In this first cooling step, the temperature in the rice cooking container can be lowered by 10 ° C. or more, or the cooling time can be increased by 10 minutes or more. However, in order to reduce the temperature by 10 ° C. or more in a short time, special cooling means In addition, if the temperature is too low, heating in the next second heating process takes time and energy consumption increases, and the entire cooking process time becomes too long. Decreases. The same applies when the cooling time is longer than necessary, but in this case, the amount of water absorbed by the rice increases, the taste of the cooked rice changes after cooking, the cooking water becomes insufficient, and is unnecessary for subsequent heating. Burning may occur.

  If the 1st cooling process of time and temperature set beforehand is completed (point B of Drawing 1), the 2nd heating process which heats a rice-cooking container again will be started. This second heating step can be performed basically using the same heating means as the first heating step, but it is preferable to use a heating means that can bring the inside of the rice cooking container into a boiling state as quickly as possible. For example, it is preferable to heat as quickly as possible by performing operations such as increasing electric power (voltage, current) in the case of electric heating or increasing the gas flow rate in the case of gas heating. This 2nd heating process is complete | finished when the inside of a rice cooking container will be in a boiling state, or when the boiling state has passed for a predetermined time (point C of FIG. 1).

  After performing the predetermined second heating step, the heating is interrupted again, the second cooling step similar to the first cooling step is performed, and after finishing the second cooling step, the heating of the rice cooking container is resumed. A third heating step similar to the two heating step is performed. Further, if necessary, the first and second cooling steps and the second and third heating steps are repeated an arbitrary number of times, and the last heating step (see FIG. 1) after finishing the last cooling step (point D in FIG. 1). Heating is continued until cooking is completed at point E), and when the cooking temperature is reached (point F in FIG. 1), the predetermined rice cooking process is terminated. Thereafter, steaming similar to that at the end of the normal rice cooking process may be performed, and it is possible to incorporate heating for scorching.

  In the above description, it is described that the cooling step is performed three times or more. However, in the present invention, the cooling step can be performed once or twice. In this case, the final heating step (for example, the second heating step or the third heating step) is a final heating step in which heating is continued until the above-described cooking, and when the cooking temperature is reached, the predetermined cooking step is terminated. The same method is used.

  FIG. 2 is a diagram illustrating an example of a weight change in the rice cooking container when the method for producing cooked rice by intermittent heating according to the present invention is applied. Each heating step and cooling step can be performed basically in the same manner as the description based on FIG. 1, and thus detailed description thereof will be omitted.

  First, in the first heating step, the water temperature rises due to the temperature rise due to heating, the amount of water evaporation increases, the boiling temperature approaches, and when the boiling state is reached, the weight in the rice cooker decreases rapidly. The weight in the rice cooking container when ending this first heating process varies depending on the number of times the cooling process is performed during the rice cooking process.

  For example, when performing a cooling process only once, when the weight in a rice cooking container became 100.1-110 with respect to the cooked rice weight (point X of FIG. 2) 100 at the time of a rice cooking process completion | finish at a 1st heating process. The cooling process is started, and as described above, the temperature in the rice cooking container is lowered by 0.1 to 10 ° C, preferably 0.5 to 5 ° C, more preferably 1 to 2 ° C with respect to the temperature at the start of the cooling process. The cooling step is performed for 1 to 10 minutes, preferably 1 to 5 minutes. In this cooling process, since the temperature inside the rice cooking container is lowered, the amount of water evaporation decreases, and when the rice cooking container is covered and sealed, there is almost no transpiration of water to the outside. The decrease in the weight of the inside becomes slight, and rice can be cooked in a stable state. On the other hand, when the rice cooking container is opened without being covered, the transpiration of water to the outside increases and the weight is reduced compared to when the lid is covered, but it cools to a predetermined temperature in a short time. can do. If a predetermined | prescribed cooling process is complete | finished, a 2nd heating process will be started and the rice in a rice cooking container will be cooked.

  Moreover, when performing a cooling process twice, a 1st cooling process is started when the weight in a rice cooking container turns into 100.3-115 with respect to the cooked rice weight 100 at the time of completion | finish of a rice cooking process at a 1st heating process. . After finishing the predetermined first cooling process, the second heating process is started, and the second heating process is performed when the weight in the rice cooking container becomes 100.1 to 110 with respect to the cooked rice weight 100 at the end of the rice cooking process. End and start the second cooling step. Furthermore, after finishing the predetermined second cooling step, a third heating step is performed to cook rice in the rice cooking container.

  When performing a cooling process 3 times, a 1st cooling process is started when the weight in a rice cooking container turns into 100.5-120 with respect to the cooked rice weight 100 at the time of completion | finish of a rice cooking process at a 1st heating process, predetermined After the first cooling step, the second heating step is started. This 2nd heating process is complete | finished when the weight in a rice cooking container turns into 100.3-115 with respect to the cooked rice weight 100 at the time of the completion of a rice cooking process, and starts a predetermined | prescribed 2nd cooling process. The third heating step is performed after the second cooling step, and the third heating step is terminated when the weight in the rice cooking container becomes 100.1 to 110 with respect to the cooked rice weight 100 at the end of the rice cooking step. Start the cooling process. And after complete | finishing a predetermined 3rd cooling process, the 4th heating process is performed and the rice in a rice cooking container is cooked.

  Moreover, when switching a heating process and a cooling process based on such a weight change, adjusting the property of the cooked rice by making the addition amount of the cooking water first thrown into a rice cooking container into more than usual. Is also possible. That is, when the amount of cooking water added is increased, in order to make the final water absorption of the cooked rice substantially the same, it is necessary to set a longer time for each heating step and increase the amount of water evaporated in each heating step. However, when the amount of moisture transpiration in each heating step is increased in this way, the texture of the cooked cooked rice becomes sticky, the stickiness improves, and the aging resistance tends to increase. This is presumably because the cell structure of rice is destroyed, homogenized, or gelatinized by relatively long heating and cooling. However, if the time of the whole heating process is lengthened, the cooked water becomes deficient due to the water absorption of the rice, and the scorch tends to occur. Although the amount of cooking water added varies depending on the number of heating processes after the second time, the amount of water transpiration is usually 0.01 to 0.1, preferably 1 to the weight of raw rice in the second and subsequent heating processes. It is preferable to set in the range of 0.03 to 0.07.

  In this way, during the period from the start of the first heating process in the rice cooking process to the completion of cooking, the process of interrupting heating and cooling is performed at least once, and the heating process is performed in multiple steps intermittently. Thus, cooked rice with improved taste and aging resistance can be obtained compared to cooked rice cooked by the conventional method. The number of implementations of the heating process may be two or more (one or more cooling processes), the type and properties of rice, the amount of rice cooked, the shape of the rice cooking container, the type of heating means, the taste and aging expected of cooked rice Although it can be set as appropriate according to conditions such as tolerance, the effect of improving the taste and aging resistance of cooked cooked rice is relatively small if the number of times of the heating process is two times, and the heating process is performed. If the number of times is increased too much, as described above, the time for the entire rice cooking process becomes longer, the practicality is lowered, and the management and adjustment of the process tends to be difficult.

  Therefore, the optimum number of times for the heating step is 3 (2 cooling steps) or 4 (3 cooling steps). When 5 or 6 times, the aging resistance is improved, but the cooked rice becomes soft. The texture is like glutinous rice. In addition, the heating time in each heating step when the cooling step is performed after the second time is preferably within a few minutes, for example, within 3 minutes, in order to prevent the shortage of cooking water and the occurrence of scorching. Furthermore, the cooking state can be easily managed by setting each cooling step and each heating step after the second time to the same conditions. In addition, when performing the rice cooking process with a lid on the rice cooking container, the amount of water transpiration will change if the lid of the rice cooking container is opened during the rice cooking process, so that the lid remains attached during the rice cooking process. It is preferable.

  In addition, in the weight in the rice cooking container when performing the cooling process a plurality of times, the upper limit side of the weight range at the start of the second and subsequent cooling processes is from the transpiration of moisture in the heating process performed before the cooling process, In other words, when the cooling process is performed twice, the weight at the start of the first cooling process is 100 with respect to the cooked rice weight 100 at the end of the rice cooking process. .3 to 115, the weight at the start of the second cooling process is less than the weight at the start of the first cooling process from 100.1 to the cooked rice weight 100 at the end of the rice cooking process, and when the cooling process is performed three times, The weight at the start of the first cooling process is 100.5 to 120 with respect to the cooked rice weight 100 at the end of the rice cooking process, and the weight at the start of the second cooling process is 100.3 to the cooked rice weight 100 at the end of the cooking process. Less than the weight at the start of 1 cooling process, 3rd cooling Degree at the start of the weight is less than the weight at the start of the second cooling step from 100.1 respect cooked rice weight 100 at the cooking step is completed.

As shown in Table 1, 100 g of fresh rice (brand: Kirara 397) was used to set various cooling times and cooling temperatures in the first cooling step, and control (no cooling step), test 1-1, test 1- 2, 6 types of rice cooking processes of test 1-3, test 1-4, and test 1-5 were performed. Each temperature shown in Table 1 is obtained by measuring the average temperature of cooked rice. In the cooling step, water cooling is performed by immersing the rice cooking container in cooling water, ice cooling is performed by immersing the rice cooking container in ice water, and the others are room temperature. It was performed by air cooling. The second heating time is the time until cooking. In addition, the control in each following Example is the cooked rice cooked by the same method as a present Example.

The physical properties of each cooked rice obtained in Controls and Tests 1-1 to 1-5 were measured as follows using a physical property measuring instrument (texture analyzer). The rice grains were placed on the support of the texture analyzer, the rice grains were weighted (g) in the vertical direction with a rod, and the weight when crushed was measured as the hardness. Subsequently, the rod was pulled up, and the peel force (g) when the rod separated from the crushed rice grains was measured as adhesion. The values of hardness and adhesion were measured on the rice surface when the rice grains were compressed by 30%, and the value when the rice grains were compressed by 90%. The moisture content was determined by measuring the weight of cooked rice immediately after cooking and cooked rice dried at 105 ° C. for 12 hours. The results are shown in Table 2.

  From this result, the cooked rice obtained in Test 1-1 is more adherent (sticky) than the control cooked rice cooked in the normal rice cooking process without performing the cooling process, and obtained in Test 1-2. It can be seen that the cooked rice has further increased adhesion (stickiness). However, the cooked rice in which the cooling time of Test 1-3 was 10 minutes resulted in cooked rice having different properties from the others due to the increase in water absorption. In addition, the cooked rice obtained in Test 1-4 and Test 1-5 in which the cooling temperature was lowered while the first cooling time was shortened by water cooling or ice cooling was increased in stickiness, and obtained in Test 1-5. It can be seen that the cooked rice is more sticky. Moreover, the cooked rice obtained in Test 1-2 and the cooked rice obtained in Test 1-5 had substantially the same physical properties.

As shown in Table 3, the cooling process is performed three times, the heating process is divided into four times, the respective heating times in the second heating process to the fourth heating process are adjusted, and the water is skipped in each heating process. The rice was cooked by the five types of methods of Test 2-1, Test 2-2, Test 2-3, Test 2-4, Test 2-5 with different amounts. The heating time was adjusted by calculating the steam generation rate of the rice cooker and adjusting it according to the amount of water to be reduced, and adjusting the amount of water added to the raw rice accordingly.

The sensory test of the cooked rice obtained in the control and tests 2-1 to 2-5 was performed. The results are shown in Table 4. The result of the sensory test was evaluated in the range of −3 to +3 in 0.5 increments for the cooked rice obtained in each test with the cooked rice obtained in the control as the reference (0). The aging resistance was evaluated by subjecting the cooked rice to a sensory test after freezing the cooked rice and then chilled and thawed for 6 hours.

  From this result, it can be seen that as the amount of water to be blown in one heating step increases, the cooked rice has a soft and sticky texture, increases its stickiness, and improves aging resistance. If the amount of water to be blown in one heating step is small as in Test 2-1, a sufficient effect cannot be obtained. This is because the larger the amount of steam, the more the rice structure is destroyed, homogenized, and gelatinized. Guessed.

  On the other hand, the more the amount of moisture that is removed in one heating step, the more scorching occurs. This is because if the amount of water to be skipped per heating process is increased, the time of the heating process after the second heating process will be long, and the cooked rice will absorb water and the amount of cooking water will be insufficient. Guessed. Therefore, in the case of a present Example, the water | moisture content skipped by the heating process 1 time of the 2nd time or more is the range of 0.48-4.3% by the weight with respect to cooking, Preferably it is the range of 1.4-3.3%. Since the weight of water is suitable, in the range of the amount of water generally used at the time of rice cooking, the amount of water to be skipped in the second and subsequent heating steps is 0.3 to 5.0 in terms of the weight of the cooked rice. % Weight, preferably in the range of 1.0 to 3.5%.

As shown in Table 5, rice was cooked by the three methods of Test 3-1, Test 3-2 and Test 3-3 by changing the heating time from the second heating step to the fourth heating step. Adjustment of the heating process time was performed by adjusting the voltage of the electric rice cooker used as a heating means.

A sensory test was conducted on each of the obtained cooked rice. The results are shown in Table 6. In the sensory test, the cooked rice obtained in the control was set to 0, and the cooked rice obtained in each test was evaluated in a range of −3 to +3 in 0.5 increments.

  From this result, it can be seen that the steaming of rice quickly increases the stickiness of the cooked rice and makes it feel like sticky rice when the second heating step to the fourth heating step are performed in a short time.

As shown in Table 7, after the first heating step, the rice was cooked by the three methods of Test 4-1, Test 4-2, and Test 4-3 in which the number of cooling steps was 1 to 3. It was.

After freezing each obtained cooked rice, each frozen cooked rice was chilled and thawed at 5 ° C., and refrigerated for the time shown in Table 8 for a sensory test. The results are shown in Table 8. The sensory test was evaluated in the range of 1 to 5 in 0.5 increments.

    At the same time, the viscosity of cooked rice that had been refrigerated at 5 ° C. was measured using a rapid visco analyzer (manufactured by Foss Japan). Put 1.5g of cooked rice flour and 25g of water in the cell, 30 ° C (0 to 30 seconds), 5 ° C / minute temperature rise (30 seconds to 13 minutes 30 seconds), 95 ° C (13 minutes 30 seconds to 18 minutes 30) Second), the temperature was changed to 5 ° C./min (18 minutes 30 seconds to 27 minutes 30 seconds) and 50 ° C. (27 minutes 30 seconds to 37 minutes 30 seconds), and the change in viscosity at that time was measured. The numerical value of “(final viscosity) − (minimum viscosity)” in viscosity measurement is called consistency, and is reported to be closely related to starch aging. FIG. 3 shows an example of changes in the consistency measured for the refrigerated cooked rice. Furthermore, the result of having observed the internal structure of the control cooked rice at the time of a rice cooking process and the cooked rice of the test 4-2 with an electron microscope is shown in FIG.4 and FIG.5.

  From this result, if the refrigerated storage time is 0, the cooked rice is very good in taste, but when the refrigerated storage time is 6 hours, the control cooked rice deteriorated in taste, It can be seen that the cooked rice of each test has a good taste. Furthermore, when the refrigerated storage time was 24 hours, the taste of the control rice was greatly deteriorated, whereas that of Test 4-1 and 4-2 was slightly good, and that of Test 4-3 was good. It turns out that aging tolerance improves greatly by performing a cooling process in a process and dividing a heating process into multiple times and cooking rice. Furthermore, it can be seen that by increasing the number of times of cooling, the change in consistency with time is reduced, and it is easy to maintain an initial good state.

  Moreover, from the observation result with an electron microscope, many large cracks (cracks) exist in the control cooked rice shown in FIG. 4, and the cooked rice of test 4-2 shown in FIG. In this case, cracks are greatly reduced to form a fine structure, and it is presumed that destruction and homogenization of the structure are occurring.

As shown in Table 9, 100 g of fresh rice (brand: Kirara 397) is mixed with water and sugar, and the number of cooling steps after performing the control (no cooling step) and the first heating step is 2-5 times. The five types of rice cooking processes of Test 5-1, Test 5-2, Test 5-3, and Test 5-4 were performed. The cooling process was performed 2-5 times after the first heating. For example, in Test 5-1, each of the two cooling steps is naturally cooled for 5 minutes at room temperature, and the second and third heating steps for 2 minutes each are performed. The mixing ratio of water to raw rice in each rice cooking process was set so that the weight after cooking was about 240 g.

25 g of vinegar (sushi vinegar) was added to each of the obtained cooked rice (240 g), and stirred to produce sushi rice, which was frozen. Each obtained frozen sushi rice was chilled and thawed at 5 ° C. and stored in the refrigerator for the time shown in Table 10, and then the same sensory test as in Example 4 was performed. The results are shown in Table 10.

  From this result, if it was in the state immediately after manufacture of the sushi rice of refrigerated storage time 0, all the sushi rice was very good in taste. When the refrigerated storage time becomes longer, the taste of the control sushi rice deteriorates significantly, and Test 5-1 and Test 5-2, which have a small number of cooling steps, tend to deteriorate when the refrigerated storage time reaches 36 hours. . On the other hand, in Test 5-3 and Test 5-4 where the number of cooling steps was large, a good taste was obtained even when the refrigerated storage time exceeded 36 hours. Therefore, also in sushi rice, it turns out that aging tolerance improves greatly by performing a cooling process during a rice cooking process, and dividing a heating process into multiple times and cooking.

In order to achieve the above object, the method for producing cooked rice by intermittent heating according to the present invention is a method of cooking rice by heating a rice cooking container charged with rice and cooking water, and heating the rice cooking container with a heating means. during cooking step to improve cooked rice, once heated to interrupt, in the cooking container which is characterized and TURMERIC least one row of cooling step of cooling by removing from the heating means, the cooling step, It starts after the inside of the rice cooking container is in a boiling state, and the inside of the rice cooking container is set to a non-boiling state during the cooling process, is performed at room temperature, or is performed for 1 to 10 minutes, or the temperature in the rice cooking container is set. It is characterized by being lowered by 0.1 to 10 ° C. relative to the start of the cooling process.

Claims (11)

  In the method for producing cooked rice in which rice is cooked by heating the cooked rice container containing rice and cooked water, the cooling process for interrupting heating is performed at least once during the rice cooking process in which the rice cooker is heated to cook rice. A method for producing cooked rice by intermittent heating.   The method for producing cooked rice by intermittent heating according to claim 1, wherein the cooling step is started after the inside of the rice cooking container is in a boiling state, and the inside of the rice cooking vessel is brought into a non-boiling state during the cooling step.   The method for producing cooked rice by intermittent heating according to claim 1, wherein the cooling step includes a forced cooling step of forcibly cooling the rice cooking container.   The method for producing cooked rice by intermittent heating according to any one of claims 1 to 3, wherein the cooling step is performed for 1 to 10 minutes.   5. The method for producing cooked rice by intermittent heating according to claim 1, wherein the cooling step lowers the temperature in the rice cooking container by 0.1 to 10 ° C. relative to the start of the cooling step.   The cooling process is started when the weight in the rice cooking container becomes 100.1 to 110 with respect to the cooked rice weight 100 at the end of the rice cooking process after the start of heating, and the second heating is performed after the end of the cooling process. The method for producing cooked rice by intermittent heating according to any one of claims 1 to 5, wherein the rice is cooked.   The first cooling step is started when the weight in the rice cooking container becomes 100.3 to 115 with respect to the cooked rice weight 100 at the end of the rice cooking step after the start of heating, and the second heating is performed after the end of the cooling step. The second cooling process is started when the weight in the rice cooking container becomes 100.1 to 110 with respect to the cooked rice weight 100 at the end of the rice cooking process, and the third heating is performed after the cooling process is completed. The method for producing cooked rice by intermittent heating according to any one of claims 1 to 5, wherein the rice is cooked.   The first cooling process is started when the weight in the rice cooking container becomes 100.5 to 120 with respect to the cooked rice weight 100 at the end of the rice cooking process after the start of heating, and the second heating after the end of the cooling process. The second cooling process is started when the weight in the rice cooking container becomes 100.3 to 115 with respect to the cooked rice weight 100 at the end of the rice cooking process, and the third heating is performed after the cooling process is completed. The third cooling process is started when the weight in the rice cooking container becomes 100.1 to 110 with respect to the cooked rice weight 100 at the end of the rice cooking process, and the fourth heating is performed after the cooling process is finished. The method for producing cooked rice by intermittent heating according to any one of claims 1 to 5, wherein the rice is cooked.   The method for producing cooked rice by intermittent heating according to any one of claims 1 to 8, wherein the rice cooking container is covered and a rice cooking process is performed.   The method for producing cooked rice by intermittent heating according to any one of claims 1 to 8, wherein the rice cooking step is performed without covering the rice cooking container.   A method for producing thawed cooked rice, which is obtained by freezing and then thawing cooked rice produced by the production method according to any one of claims 1 to 10.

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