JP7015985B2 - rice cooker - Google Patents

Description

The present invention relates to a rice cooker capable of cooking the cooked taste to the user's taste.

In recent years, due to the diversification of consumer tastes, there are various demands for the deliciousness of cooked rice, and rice cookers that can cook different physical characteristics and tastes such as hardness and stickiness of cooked rice according to the user's taste. Proposed.

In a rice cooker, a water absorption process (pre-cooking process), a cooking process, and a steaming process are usually performed in sequence, and the water absorption process is characterized to cope with such recent trends.

For example, in the water absorption step of allowing the cooked food to absorb water in order to adjust the sweetness, taste, and physical properties of the cooked rice and to realize finely divided cooking, a first water absorption step and then a first water absorption step. A configuration has been proposed in which a second water absorption step of absorbing water at a higher temperature than the step is performed (see, for example, Patent Document 1).

Specifically, a first water absorption step of causing the rice to absorb water at a water temperature in the temperature range of 40 ° C. or higher and lower than 60 ° C. and a second water absorption step of causing the rice to absorb water at a water temperature in the temperature range of 60 ° C. or higher and lower than 70 ° C. The sweetness, taste, and hardness of the cooked rice are adjusted in sequence to achieve finely divided cooking.

Japanese Unexamined Patent Publication No. 2009-50485

However, in the above-mentioned conventional rice cooker, in the first water absorption step, amino acids that increase the taste of cooked rice are generated, and in the second water absorption step, the sweetness of cooked rice is increased. Although glucose is generated, since the time of the second water absorption step is set longer than the time of the first water absorption step, more glucose is produced than the amino acid, and the rice with a strong sweetness is produced. It will be cooked.

In addition, the gelatinization temperature at which the rice gelatinization reaction generally occurs is 60 ° C. or higher, but in the second water absorption step performed in the temperature range of 60 ° C. or higher, the gelatinization reaction occurs from the surface of the rice. The tissue begins to soften. As a result, the surface of the rice is gelatinized before the inside of the rice is firmly absorbed, and the absorption of water to the inside of the rice is hindered.

Therefore, there is still room for improvement from the viewpoint of increasing the taste of cooked rice and improving the taste of cooked rice.

An object of the present invention is to provide a rice cooker that realizes cooked rice with an emphasis on umami and graininess.

In order to solve the above-mentioned problems having the prior art, the rice cooker of the present invention includes a rice cooker main body, a pot for accommodating a cooked rice containing rice and water, a heating unit for heating the pot, and the pot. A rice cooker that includes a temperature detection unit that detects the temperature of rice cooker and a control unit that controls the heating unit, and executes a water absorption step of causing the rice contained in the pot to absorb water. The maximum temperature does not exceed 60 ° C., and the water absorption step is characterized in that the temperature of the rice cooker is maintained at 40 ° C. or higher and lower than 55 ° C. for a predetermined time.

As a result, the rice is absorbed to the center of the rice, and the rice is cooked to the center without damaging the surface of the rice. It is possible to realize finely divided cooking.

According to the rice cooker of the present invention, it is possible to provide a rice cooker that realizes cooked rice with an emphasis on umami and graininess.

Structural sectional view of rice cooker according to Embodiment 1 of this invention Controlled temperature diagram of water absorption process of Embodiment 1 of this invention The figure which showed the condition of the rice cooking course in Embodiment 1 of this invention. The figure which showed the evaluation of the rice cooked in the rice cooking course of Embodiment 1 of this invention. The figure which showed the data about the enzyme in Embodiment 1 of this invention. Controlled temperature diagram of water absorption process of Embodiment 2 of this invention

The first invention is a rice cooker main body, a pot for accommodating a cooked rice containing rice and water, a heating unit for heating the pot, a temperature detection unit for detecting the temperature of the pot, and the heating unit. A rice cooker that is equipped with a control unit for controlling the temperature of the rice cooker and that executes a water absorption step of absorbing water from rice contained in the pot. The maximum temperature in the water absorption step does not exceed 60 ° C. The rice cooker is characterized in that the temperature of the rice cooker is kept at 40 ° C. or higher and lower than 55 ° C. for a predetermined time in the step.

As a result, the rice is absorbed to the center of the rice, and the rice is cooked to the center without damaging the surface of the rice. It is possible to realize finely divided cooking.

In addition, the higher the temperature, the better the water absorption rate, and gelatinization starts at 60 ° C or higher, so maintaining the temperature so that it is 45 ° C or higher and lower than 55 ° C firmly promotes water absorption to the inside of the rice. Moreover, the rice can be cooked firmly to the center without damaging the surface of the rice by gelatinization.

In the second invention, particularly in the first invention, in the water absorption step, the temperature of the pot is the first water absorption step of continuing for a predetermined time so that the temperature of the pot is 40 ° C. or higher and lower than 50 ° C., and the temperature of the pot is It is a rice cooker characterized by sequentially performing a second water absorption step of continuing for a predetermined time so that the temperature becomes 45 ° C. or higher and lower than 55 ° C.

This enhances the activity of each enzyme present in the center, promotes the efficient and short-time decomposition of proteins, polysaccharides (starch), and oligosaccharides by the enzymes, and promotes the sweetness, taste, and hardness of cooked rice. You can adjust the amount. In particular, in the first water absorption step, the decomposition of polysaccharides (starch) and oligosaccharides can be promoted to adjust the sweetness of cooked rice, and in the second water absorption step, the decomposition of proteins can be promoted and cooked. You can adjust the taste of the cooked rice.

The third invention, particularly in the second invention, is predetermined in a temperature range (third water absorption step) in which the temperature of the pot is lower than that of the first water absorption step, further prior to the first water absorption step. It is characterized by the continuation of time.

This activates the optimum enzyme at each temperature, promotes decomposition by the enzyme, and further enhances the activity of the enzyme that decomposes polysaccharides (starch) and oligosaccharides, thereby enhancing the sweetness of cooked rice. can do.

The fourth invention is characterized in that, in particular, in the third invention, the time of the third water absorption step is shorter than the time of the first water absorption step and the second water absorption step.

As a result, the water content can be increased in a short time, and the rice can be made into rice that brings out the sweetness and umami.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the present embodiment.

(Embodiment 1)
FIG. 1 shows a configuration diagram of a rice cooker according to the first embodiment of the present invention. In the present invention, the configuration of the rice cooker is the same as the conventional one, and the rice cooker main body 1 and the rice cooker main body 1 are housed in the rice cooker main body 1, the pot 2 for accommodating the cooked rice containing rice and water, and the rice cooker main body. Based on the temperature detection unit 4 that detects the temperature of the rice cooker 2 and the temperature detection unit 4 that is arranged in the rice cooker body 1 and the heating unit 3 that heats the pot, and the temperature detected by the temperature detection unit 4. A control unit 5 for controlling the heating unit 3 is provided, and the control unit 5 controls the heating unit 3 to execute a water absorption step of causing the rice cooked in the pot 2 to absorb water.

Next, the water absorption process of cooked rice by the rice cooker having the above configuration will be described. In normal rice cooking, in addition to the water absorption step of absorbing water, the temperature raising step of raising the temperature to the boiling state, the boiling maintenance step of maintaining the boiling state, and the steaming step of steaming the rice are sequentially performed. It is characterized by the water absorption process of absorbing water.

FIG. 2 is a diagram showing a water absorption step in the rice cooker according to the first embodiment.

As shown in FIG. 2, the water absorption step of the present invention includes a second water absorption step of keeping the temperature of the temperature detection unit 4 for detecting the temperature of the pot at about 50 ° C. for a predetermined time, and a temperature detection. There is a first water absorption step that keeps the temperature detected by the part 4 at about 40 ° C. for a predetermined time. Then, in the water absorption step, the second water absorption step is performed after the first water absorption step is executed.

Generally, in a rice cooker, the water absorption rate of rice increases as the temperature during the water absorption process increases. However, since gelatinization starts at 60 ° C or higher, if the water absorption in this temperature range becomes too long, the texture of the surface of the rice is softened by the gelatinization reaction, and the components in the rice are easily eluted or the surface. Since the portion is gelatinized, water absorption is rather hindered, so that the surface of the cooked rice tends to crumble or become hard.

Therefore, in the water absorption step executed by the rice cooker in the present embodiment, the temperature of the water is maintained at about 50 ° C. for a predetermined time so that the maximum temperature does not reach 60 ° C. In the present embodiment, the temperature of water is maintained so as to be about 50 ° C., but it may be controlled to be kept constant in the temperature range between 45 ° C. and 55 ° C.

In the water absorption process, enzymes contained in rice act on polysaccharides (starch), oligosaccharides, and proteins to produce various sugars and amino acids by hydrolysis, and the produced sugars and amino acids are final. It is the source of the taste of cooked rice.

However, each enzyme has an optimum temperature, which is the temperature at which the action of the enzyme is most exerted. Those that act on starch and work best at low temperatures of 40 ° C or higher and lower than 60 ° C and contribute to umami and sweetness, those that work best at high temperatures of 60 ° C or higher and lower than 70 ° C and contribute to sweetness, and those that act on proteins. Then, there are those that most produce amino acids that are the source of umami at 40 ° C or higher and 55 ° C or lower.

Therefore, in the water absorption step of the present invention, the first water absorption step is performed in a temperature range where the gelatinization reaction does not occur. In this step, water absorption is not hindered and it is unlikely that elution will occur from the surface of the rice, so the rice will be able to absorb water and heat up to the center. At the same time, it acts on starch, hydrolyzes various sugars, and also acts on proteins to promote the production of amino acids. By performing this first water absorption step, the sweetness factor is increased in the cooked rice.

After that, the second water absorption step is carried out. By absorbing water at a temperature higher than that of the first water absorption step and lower than the gelatinization temperature of rice, not only the elution from the surface of the rice is suppressed, but also the water content is increased in a short time, and the water absorption time, that is, rice cooking. The time can be shortened, the proteolytic enzyme can be activated, and the amount of amino acid produced can be efficiently adjusted. By performing this second water absorption step, the element of umami is increased in the cooked rice.

Here, the rice cooking process of the rice cooker in the present embodiment will be described by taking as an example the case where 3 go (450 g) of polished rice is stored in the pot 2.

FIG. 3 shows an example of the temperature conditions of each rice cooking course and the water absorption process. The rice cooking course of the first embodiment can be freely selected by the user in the input operation unit 6, and in FIG. 3, the temperature and time of the first water absorption process and the temperature and time of the second water absorption process are shown in FIG. Is shown.

Further, FIG. 3 shows the temperature conditions and times different from those of the first embodiment in which the water absorption step is heat-controlled in two stages as Comparative Example 1 and Comparative Example 2. Comparative Example 1 shows a condition in which the water absorption step is heat-controlled in two steps, and Comparative Example 2 shows a condition in which the water absorption step is heat-controlled in one step.

FIG. 4 shows data on each rice cooking course and cooked rice of Embodiment 1 and Comparative Examples 1 and 2 in FIG. The sweetness was the amount of glucose, the umami was the total amount of amino acids, and the hardness was the result of sensory evaluation. The amount of glucose and the total amount of amino acids are the amounts per 150 g of rice. The sensory evaluation is evaluated by a comparative method, and shows the evaluation of the taste when the water absorption step is heated and controlled in one step based on Comparative Example 2.

First, polished rice and a specified amount of water are stored in the pot 2, the rice cooking course according to the first embodiment is selected by the input operation unit 6, and the rice cooking button is pressed to detect the temperature detection unit 4 of the pot 2. The water absorption process is started based on the temperature.

Under the conditions of the rice cooking course in the first embodiment shown in FIG. 3, the first water absorption step is executed at 40 ° C. for 5 minutes including the temperature rise, and then the second water absorption step is performed at 50 ° C. including the temperature rise of 20. Minutes are executed, and then each process of cooking (heating, maintaining boiling) and steaming is performed, and the rice cooking is completed.

The result of analysis of the cooked rice under each condition of FIG. 3 is shown in FIG. 4, and in the cooked rice course of the first embodiment, the glucose amount was 32 mg and the total amino acid amount was 500 mg.

FIG. 5 shows data on the enzyme. The optimum temperature for each enzyme (the temperature at which it works most effectively), the substrate (substance that acts and decomposes), and the taste quality that increases with each enzyme decomposition are shown.

In the water absorption step of the rice cooking course, first, the first water absorption step controlled at 40 ° C. is performed for 5 minutes. It decomposes starch with enzymes A and B, which have an optimum temperature of 40 ° C., to produce sweetness and umami. Enzyme A shown in FIG. 5 is mainly present in the outer layer portion, and 40 ° C. is the optimum temperature to decompose starch and produce oligosaccharide which is the source of umami. In the first water absorption step, water mainly exists in the outer layer portion and is maintained at 40 ° C., so that it can act most effectively.

In addition, enzyme B is also present in the outer layer, decomposes starch, produces glucose, which is the source of sweetness, has an optimum temperature of 40 ° C, and can act most effectively in the water absorption step at 40 ° C. ..

Oligosaccharide is a general term for sugars to which monosaccharide glucose is bound to 2 to 10, and maltose is a typical example contained in rice. As a characteristic of taste, although it has less sweetness than glucose, it is a taste-modifying substance that emphasizes sweetness, and also has umami and rich taste.

Next, the temperature of 50 ° C. is maintained for 20 minutes by the second water absorption step. This is because the enzyme C, which has an optimum temperature of 50 ° C., works to produce amino acids that are delicious. The enzyme C is a proteolytic enzyme that breaks down proteins into amino acids, and the optimum temperature is 50 ° C. However, some of them are inactivated at 60 ° C and lose their functions. Is not generated. Therefore, in Comparative Example 1 and Comparative Example 2 of FIG. 4, since the temperature is maintained at 60 ° C., amino acids are not produced so much.

In addition, enzymes A'and B'do not work unless they are at 60 ° C, but they work at 50 ° C, although they work weaker than 60 ° C. From FIG. 4, it is known that when the temperature of 50 ° C. is set for a long time, glucose equivalent to that of the comparative example is detected, and not only the umami but also the sweetness is sufficiently increased.

Therefore, in the rice cooking course in the first embodiment, the five enzymes, Enzyme A, Enzyme A', Enzyme B, Enzyme B', and Enzyme C, work effectively in a well-balanced manner to obtain the same sweetness as in Comparative Examples 1 and 2. And the taste has increased.

Furthermore, since 60 ° C. is near the gelatinization temperature range, the structure of the surface of the rice is softened, the components in the rice are easily eluted, and the surface of the rice is gelatinized first, so that water is absorbed to the center. It can't be done, it's sticky, and the inside becomes hard.

It can be seen from FIG. 4 that by absorbing water at a temperature lower than the gelatinization start temperature, the rice is cooked more firmly to the center than in Comparative Examples 1 and 2, and the rice surface is firm.

In this way, when the temperature and time in the water absorption process are adjusted, the amount of sweetness and umami changes because the enzymes that work differ. Variations can be expanded by freely selecting each condition depending on where the weight is placed in sweetness, umami, and hardness.

As described above, in the invention of the present embodiment, the absorption of water is promoted into the rice, and the rice is cooked with firmness so that the rice can be cooked firmly to the center without damaging the surface of the rice by the optimum temperature setting. By adjusting the sweetness, umami, and hardness of rice, it is possible to realize finely divided cooking, and it is possible to meet the tastes of more advanced consumers.

(Embodiment 2)
FIG. 6 is a control temperature diagram of the water absorption process of the rice cooker according to the second embodiment of the present invention. note that,
The configuration of the rice cooker is the same as that of the first embodiment, and detailed description thereof will be omitted.

The water absorption step of the rice cooker according to the second embodiment is different from the first embodiment in that a third water absorption step is provided before the first water absorption step in the first embodiment.

In the water absorption step of the second embodiment, as the third water absorption step, a step of continuing for a predetermined time is provided so that the temperature detected by the temperature detection unit 4 becomes 35 ° C.

By providing the third water absorption step in this way, the enzyme A and the enzyme B shown in FIG. 5 can be further activated, and the sweetness and umami of the cooked rice can be adjusted. Furthermore, because the temperature is maintained in a lower temperature range, the components in the rice do not elute, and water can be absorbed slowly to the center of the rice, so the surface of the rice is firm and the rice is cooked with a grainy texture. Can be.

Further, the time of the third water absorption step is shorter than the time of the first water absorption step and the second water absorption step. That is, the water content can be increased in a short time by lengthening the time of 50 ° C. or higher from the temperature of less than 50 ° C., and the rice can be made into rice that brings out the sweetness and umami.

As described above, the rice cooker according to the present invention can be applied to rice cookers in general because it can cook sweetness, umami, and physical properties more finely according to the advanced tastes of consumers.

1 Rice cooker body 2 Pot 3 Heating unit 4 Temperature detection unit 5 Control unit 6 Input operation unit

Claims (1)

A rice cooker main body, a pot for accommodating cooked rice containing rice and water, a heating unit for heating the pot, a temperature detection unit for detecting the temperature of the pot, and a control unit for controlling the heating unit. A rice cooker that performs a water-absorbing step of absorbing water from rice contained in the pot, wherein the maximum temperature in the water-absorbing step does not exceed 60 ° C. A first water absorption step in which the temperature is continued for a predetermined time so that the temperature is 40 ° C. or higher and lower than 55 ° C., and in the water absorption step, the temperature of the pot is continued for a predetermined time so as to be 40 ° C. or higher and lower than 50 ° C. A second water absorption step is sequentially performed so that the temperature of the pot is 45 ° C. or higher and lower than 55 ° C. for a predetermined time, and the temperature of the pot is the first water absorption before the first water absorption step. A rice cooker which is continued for a predetermined time in a temperature zone lower than the step (third water absorption step), and the time when the temperature of the pot is 50 ° C. or higher is longer than the time when the temperature of the pot is less than 50 ° C.

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