JP3160636B2 - Cooking utensils - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooking appliance, and more particularly, to a cooking appliance that controls heat retention so as to stop the progress of food spoilage.

[0002]

2. Description of the Related Art For example, many rice cookers are configured so that cooked rice cooked after cooking is kept at a constant temperature so that hot rice can be provided for a long time. The rice cooker is a rice cooker for storing rice, etc.,
Heating means for heating the rice cooker for cooking and heat retaining means for keeping the rice cooker at a predetermined temperature are provided. As a heating means, a gas heater such as a gas burner, an electric heater,
An induction heating device or the like is employed. On the other hand,
Electric heaters are often employed.

It is desirable to keep the rice cooked at a high temperature close to freshly cooked rice. However, in order to prevent deterioration due to the temperature of the cooked rice, the rice is kept at about 70 ° C.

[0004]

However, in a rice cooker, when about 15 to 20 hours have passed since the lid was opened and closed to take out the cooked rice, an unpleasant odor was generated from the cooked cooked rice and the taste was sharply increased. May fall. It is considered that this is because the spoilage of cooked rice is advanced by microorganisms that have entered the container.

[0005] In the air, various microorganisms are floating together with dust. When the lid of the container is opened to loosen the cooked rice after steaming, the microorganism is directly from the air or through a rice paddle inserted into the container. It is considered that microorganisms have invaded. In general, microorganisms produce various enzymes, and when the number of solids in a food exceeds a certain number, the microorganism starts to participate in decomposition and spoilage of the food together with the enzymes of the food. As a result, the taste of the food is reduced, or an unpleasant odor is generated due to a decomposition product or the like.

[0006] Its effect depends on the type of food and microorganism.
Rice rice has a solid count of 10 ⁷ -10⁸ Pieces / gra
When the rice has multiplied to the number of
You. In particular, Bacillus subtilis that promotes the decay of carbohydrates such as cooked rice
Forms spores and has high heat resistance.
Some survive sometimes. In addition, the maximum temperature that can grow
Reaches as high as 75 ° C to 85 ° C. Therefore, keep warm rice
It can grow sufficiently at a temperature of 70 ° C.

[0007] Therefore, even when a small number of microorganisms invade when the lid is opened, the number of the solids increases with the passage of time, and after a certain period of time, reaches the number of solids involved in spoilage. Therefore, rice cooked in a rice cooker is desirably eaten within at least 12 hours after opening and closing the lid. However, when the rice left over at dinner is served for breakfast the next day, the rice is kept warm for at least 12 hours after cooking. In addition, since the lid is opened, the probability that microorganisms enter the rice cooker is increased, and in the next morning, decay proceeds and the taste is greatly reduced. For this reason, conventionally, it has to be taken out of the rice cooker and refrigerated, and it cannot be said that the heat retaining function of the rice cooker is fully utilized.

The present invention has been conceived in view of the above circumstances, and stops the decay of heat-retained food even when microorganisms invade and start growing when the lid is opened. It is an object of the present invention to provide a heating cooker that can maintain the taste of warm food for a long time.

[0009]

Means for Solving the Problems To solve the above problems, the present invention takes the following technical means. The invention described in claim 1 of the present application provides a container for storing and cooking food, a lid for opening and closing the opening of the container, a heating means for heating the container, and A heating cooker comprising: a heat retaining means for holding at a temperature; and a control means for controlling operations of the heating means and the heat retaining means, wherein the control means is stored in the container by the heat retaining means after cooking. While keeping the food at about 70 ° C., about 5 hours after opening and closing the lid,
The temperature in the container is temporarily raised to 80 ° C. or higher, which is a sterilizable temperature, by the heating means, so that the propagation of microorganisms is controlled to be prevented.

[0010] The present invention is, for example, a rice cooker, etc.
The present invention can be applied to various cooking utensils configured to keep food warm after cooking. Further, the present invention is not limited to general household appliances, but also includes commercial cooking appliances used in restaurants, food factories, and the like. The heating means and the heat retaining means are not particularly limited, and may be ones based on combustion of a gas such as a gas burner, or ones based on electricity such as an electric heater or an induction heater. Further, the heating means and the heat retaining means can be shared by one device. In order to prevent deterioration of the food due to heat, it is preferable to heat the food in the container rapidly so that the temperature can be raised to the sterilization temperature in a short time.

[0011] The heat retention temperature varies depending on the type of food and the like, but it is necessary to prevent the deterioration of the food by heat as much as possible. For this reason, for example, cooked rice is often kept at about 70 ° C. Microorganisms that spoil foods vary depending on the food, but bacteria, molds, and the like can be considered.
For example, Bacillus subtilis, butyric acid bacteria, and the like are considered as spoilers of carbohydrate-based foods such as cooked rice. In addition to the above-mentioned bacteria, modified bacteria, micrococcus and the like can be considered as those that spoil proteins. Bacillus subtilis is heat-resistant because it forms spore cells, and is a ubiquitous bacterium that is involved in the spoilage of various foods.

The number of solids at which microorganisms start to take part in the off-flavor due to food spoilage varies depending on the type of food and the like. For example, about 10 ⁷ to 10 ⁸ pieces / g for cooked rice and about 10 ⁹ pieces / g for egg-yaki. It is believed that. Also, the time required to reach the number of solids involved in spoilage varies depending on the type of food, the type of microorganism, and the heat retention temperature. For example, in the case of cooked rice, 7 days after cooking,
When the temperature is kept at 0 ° C., the growth of Bacillus subtilis starts about 5 to 6 hours after the microorganisms enter the rice cooker.
This is because when Bacillus subtilis invaded or adhered to the rice cooker germinated and changed into vegetative cells, and continued to grow, it was about 15
Proliferates to the number of solids that produce an off-flavor in ~ 20 hours. Therefore, it is preferable to operate the heating means about 5 hours after opening and closing the lid.

In the present invention, it is not necessary to completely sterilize microorganisms in food by heating, and it is sufficient that the number of living bacteria can be reduced to stop the progress of spoilage. Therefore, the heating temperature of the food need only be a temperature at which some of the bacteria can be sterilized, and an effect can be expected if the food is heated to 80 ° C. or higher.

[0014] The heating time is also sufficient to reduce the number of viable bacteria, and the effect can be expected by keeping the food itself at the above temperature for several seconds to several minutes. The invention described in claim 2 of the present application is an application of the present invention to a rice cooker. The type of rice cooker is not particularly limited, and can be applied to a gas rice cooker, an electric rice cooker of a heater heating type, a rice cooker of an electromagnetic induction heating type, and the like.

As the control means for controlling the heating means and the heat retaining means, a control means incorporating a microcomputer can be employed. The heating means and the heat retaining means are not limited to one method, and may be configured by combining methods using gas, electricity, and the like. For example,
As in the third aspect of the present invention, while a gas heater is employed as the heating means, an electric heater can be employed as the heat retaining means.

Since the gas heater has a strong thermal power, the food in the container can be heated to the sterilization temperature in a short time. For this reason, it is possible to stop the progress of spoilage while minimizing the deterioration of the food due to heat.

[0017]

According to the present invention, after heating and cooking, about 7
While keeping the temperature at 0 ° C., the food is temporarily raised to a sterilization temperature of 80 ° C. about 5 hours after opening and closing the lid.
Proliferating vegetative cell-type microorganisms are killed by this heating or the number of surviving individuals is greatly reduced. Therefore, the microorganisms that enter when the lid is opened and closed cannot multiply to the number of individuals involved in the spoilage of the food, and the spoilage of the food can be stopped. As a result, it is possible to prevent the generation of a strange odor or the like for a long time.

Further, since the progress of spoilage can be effectively stopped only by temporarily heating the food, deterioration of the food due to the heating can be minimized. Therefore, it is possible to prevent the taste from decreasing for a long time, and it is possible to make full use of the heat retaining function of the heating cooker. In particular, in a rice cooker, cooked rice cooked in the evening can be kept warm for a long time until the next morning without substantially deteriorating the taste, and the heat keeping function of the rice cooker can be dramatically improved.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 shows an outline of a rice cooker according to the present embodiment. In the present embodiment, the present invention is applied to a rice cooker in which rice is cooked by a gas heater and heat is kept by an electric heater.

As shown in FIG. 1, a rice cooker 1 is a rice cooker 2 for storing and cooking rice and the like, an outer container 3 for containing the rice cooker 2, and an openable and closable attachment to the outer container 3. Cover 4, a gas heater 5 provided below the bottom of the rice cooker 2, and a burner 6 constituting the gas heater 5.
And a temperature sensor 8a provided so as to contact the bottom surface of the rice cooker 2.
And a temperature sensor 8 b provided on the inner surface of the lid 4. An ignition device 9 is arranged near the burner 6.

The operation of the gas heater 5 and the electric heater 7 is controlled by a control device 10 having a microcomputer. The operation of the gas heater 5 is controlled according to a set rice cooking pattern, so that ignition timing, Fire extinguisher,
Cook rice while controlling the heat power. on the other hand,
After the rice cooking is completed, the inside of the rice cooking container can be kept at a constant temperature by the electric heater 7 and the temperature sensor 8a.

In the present embodiment, after a predetermined rice cooking operation is completed, the electric heater 7 is energized to keep the inside of the rice cooking container at about 70 ° C. FIG.
Is a flowchart showing the flow of control after the start of heat retention. Although not shown, when performing the above-described rice cooking operation, the amount of cooked rice to be cooked is detected from the heating time when the inside of the rice cooker reaches a predetermined temperature and used as information on the heat retaining operation according to the present invention. .

After the rice cooking operation is completed, a warming operation is started.
In the warming operation, the electric heater is intermittently energized while the temperature of the bottom of the rice cooker is detected by the temperature sensor 7 to maintain the rice in the rice cooker at about 70 ° C. After the heat retaining operation is started, it is detected whether or not the lid 4 has been opened and closed (S10).
1). In the present embodiment, whether the lid 4 is opened or closed is detected by detecting a decrease in temperature when the lid 4 is opened by the temperature sensor 8b.

It is conceivable that the lid may be opened and closed several times in a short time.
After a lapse of minutes (S102), the timer is activated (S103). Then, after 5 hours (S104),
The warming operation according to the present invention is started. First, the heating time is determined according to the rice cooking amount detected during the rice cooking operation (S1).
05, S106). Thereafter, the heating means is activated (S
107, S108, S109), 1 when the amount of cooked rice is small
Heating is performed for one minute (S110), and when the amount of rice is being cooked, heating is performed for two minutes (S111), and when the amount of cooked rice is large, heating is performed for three minutes (S112).

FIG. 3 shows a temperature change when the rice cooker is heated for 2 minutes. The solid line indicates the temperature change of the cooked rice in the rice cooker, and the chain line indicates the temperature change of the rice cooker bottom.
As shown in this figure, when the amount of cooked rice is medium, 2
It can be seen that the temperature of the cooked rice exceeds 80 ° C. by reheating for a minute. Although not shown, the rice cooker is configured so that the temperature of the cooked rice exceeds 80 ° C. depending on the respective heating times even when the amount of cooked rice is small and when the amount of cooked rice is large.

In order to reduce the number of living microorganisms and prolong the time for stopping putrefaction, it is preferable to set a longer heating time to increase the sterilization temperature and set a longer time for maintaining the sterilization temperature. However, the deterioration of cooked rice due to temperature is accelerated, and the taste is rather lowered. On the other hand, in order to stop the progress of spoilage, the number of living bacteria is set to 10 ⁷ to 10 ⁸ /
It is sufficient to reduce it to g or less. Therefore, it is preferable that the heating is performed in a short time. Further, if the temperature of cooked rice is raised to 80 ° C., the number of viable bacteria can be reduced to some extent, and the progress of spoilage can be stopped.

After the above heating operation, the gas burner is extinguished and the operation of the heating means 5 is terminated (S113), and the operation returns to the normal heat retaining operation. In the present embodiment, when the lid 4 is opened and closed after the operation of the heating means 5 is completed, the timer is operated again to perform the heating again. According to the present invention, even when microorganisms invade when opening and closing the lid,
While minimizing the deterioration of cooked rice by heating, it is possible to prevent the growth of microorganisms and stop the rot of cooked rice for a long time. In the present embodiment, it has been found that the growth of bacteria can be inhibited for 24 hours.

As a result, it is possible to prevent a decrease in taste over a long period of time, so that even if the rice cooked in the evening is kept warm until the next morning, no odor or the like is generated. Therefore, the heat retaining function of the rice cooker can be significantly improved. The present invention is not limited to the above embodiments. In the embodiment, when the lid is opened and closed, the heating means is repeatedly operated, but it may be configured to perform reheating once. Also,
The amount of cooked rice was divided into three stages, large, medium, and small, and the heating time was controlled so as to be selected. However, the present invention is not limited to this. can do.

Although the opening / closing of the lid is detected by the temperature sensor 8b provided on the inner surface of the lid, the opening / closing of the lid itself may be detected. Furthermore, although a hold time of 10 minutes is provided before the timer is activated, it may be changed according to the use condition of the rice cooker and the like. In the above-described embodiment, the reheating time is specified, but there is a case where the vicinity of the bottom of the pot is burnt due to the amount of cooked rice. As a means for solving this, if the set temperature (cooking rice extinguishing temperature or a temperature lower than the cooked rice extinguishing temperature, for example, 110 ° C.) is reached within the reheating time, the setting temperature may be given priority and the heating operation may be ended.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an outline of a configuration of a rice cooker.

FIG. 2 is a flowchart illustrating an example of control according to the present invention.

FIG. 3 is a diagram showing a change in temperature of a rice cooker and cooked rice stored therein.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Rice cooker 2 ... Rice cooker 5 ... Heating means 7 ... Electric heater 8a ... Temperature sensor 8b ... Temperature sensor 10 ... Control means

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Takashi Oya 2-26 Fukuzumicho, Nakagawa-ku, Nagoya-shi Examiner, Linto Co., Ltd. Masato Matsunawa (56) Reference JP-A-7-313355 (JP, A) JP-A-57-99925 (JP, A) JP-A-55-26814 (JP, A) JP-A-8-140814 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) A47J 27 / 00

Claims (3)

(57) [Claims] 1. A container for storing and cooking food by heating, a lid for opening and closing the opening of the container, a heating unit for heating the container, and a heat retaining unit for holding the container at a predetermined temperature. And a control means for controlling the operation of the heating means and the heat retaining means, wherein the control means heats the food stored in the container by the heat retaining means at about 70 ° C. On the other hand, about 5 hours after the lid is opened and closed, the temperature in the container is set to a sterilizable temperature 8 by the heating means.
A heating cooker characterized by controlling the temperature to be 0 ° C. or higher temporarily to prevent the growth of microorganisms. 2. The cooker according to claim 1, wherein the cooker is a rice cooker.
A heating cooker according to item 1. 3. The cooking device according to claim 1, wherein the heating means is a gas heater, and the heat retaining means is an electric heater.