Rice cooking method using rice cooker and rice cooker

Abstract

The present application discloses a rice cooker and a rice cooking method thereof, comprising: a soaking and absorbing stage, wherein a heating device heats water in a water storage chamber to a first preset temperature; a cooking chamber pressure is reduced to the first preset pressure, and some of the water in the water storage chamber flows from the water storage chamber to the cooking chamber; a draining and heating stage, wherein the air pressures in the cooking chamber and the water storage chamber tend to be balanced, the water flows back into the water storage chamber, and is heated to a second preset temperature by the heating device; a pre-gelatinization stage, wherein the air pressure in the cooking chamber is reduced to the second preset pressure, and some of the water in the water storage chamber flows from the water storage chamber to the cooking chamber; and a steam cooking stage, wherein the air pressures in the cooking chamber and the water storage chamber tend to be balanced, the water flows back into the water storage chamber, and is heated to a third preset temperature by the heating device, steam-cooking the food in the cooking chamber. The pre-gelatinization stage gelatinizes the surface of the rice grains to form a starch film, thereby enabling the cooking of rice with different textures, facilitating user operation, reducing operational errors, and improving user experience.

Description

Technical Field

[0001] The present application belongs to the technical field of kitchen appliances, and in particular relates to a rice cooking method using a rice cooker and a rice cooker. Background Art

[0002] As people's quality of life continues to improve, people's requirements for the quality of rice are getting higher and higher, and consumers are paying more and more attention to the aroma, taste, appearance and flavor of rice.

[0003] Existing methods for making rice generally use electromagnetic heating or heating plates to heat the inner pot of a rice cooker. When cooking rice, rice and water with an appropriate rice-water ratio are usually placed directly into the inner pot. During heating, the inner pot is heated and the heat is transferred to the rice and water inside. Due to the limited heating area, the overall heating uniformity of the rice is poor, and the upper and lower layers of rice are uneven, with the bottom layer being wet and sticky and the upper layer being dry and hard.

[0004] Existing rice cooking methods require a high rice-water ratio, requiring users to precisely control the amount of water added during cooking. Otherwise, the rice can easily become too soft or too hard, placing high demands on the user. Furthermore, the type of rice and the air pressure in the pot also affect the texture of the rice, making it prone to being undercooked.

[0005] Not only that, the taste of rice is completely determined by the amount of water, which further increases the requirements for the rice-water ratio, making it difficult for users to obtain rice with their ideal taste by accurately controlling the amount of water added, resulting in a poor user experience. Summary of the Invention

[0006] The present application provides a rice cooking method using a rice cooker and a rice cooker to solve at least one of the above technical problems.

[0007] The technical solutions adopted in this application are:

[0008] A rice cooking method using a rice cooker, the rice cooker comprising a pot body, a water storage cavity and a cooking cavity provided in the pot body, and a heating device for heating the water storage cavity, a flow passage being provided between the water storage cavity and the cooking cavity to connect the water storage cavity and the cooking cavity, the rice cooker further comprising a vacuum pump connected to the cooking cavity, during the rice cooking process, rice is placed in the cooking cavity, and water is contained in the water storage cavity, the method comprising the following steps: in a soaking and water absorption stage, the heating device heats the water in the water storage cavity to a first preset temperature T1; the vacuum pump reduces the air pressure in the cooking cavity to a first preset air pressure P1, and part of the water in the water storage cavity is heated under the action of the pressure difference The water in the cooking cavity flows from the water storage cavity to the cooking cavity; in the draining and heating stage, the air pressure in the cooking cavity and the water storage cavity tends to be balanced, the water in the cooking cavity flows back into the water storage cavity, and is heated to a second preset temperature T2 by the heating device; in the pre-gelatinization stage, the vacuum pump reduces the air pressure in the cooking cavity to the second preset air pressure P2, and part of the water in the water storage cavity flows from the water storage cavity to the cooking cavity under the action of the pressure difference; in the steam cooking stage, the air pressure in the cooking cavity and the water storage cavity tends to be balanced, the water in the cooking cavity flows back into the water storage cavity, and is heated to a third preset temperature T3 by the heating device, thereby steam cooking the food in the cooking cavity.

[0009] In the pre-gelatinization stage, the second preset temperature T2 satisfies 90° C. ≤ T2 ≤ 98° C., and water soaks the rice in the cooking chamber for a second preset time t2, and the second preset time t2 satisfies 1 min ≤ t2 ≤ 15 min.

[0010] In the soaking and water absorption stage, water soaks the rice in the cooking cavity for a first preset time t1, and the second preset time t1 satisfies 10 min≤t1≤40 min.

[0011] During the cooking process, the pressure in the cooking cavity is detected in real time, and the start or stop of the vacuum pump is controlled to maintain the first preset pressure P1 in the soaking and water absorption stage and the second preset pressure P2 in the pre-gelatinization stage.

[0012] During the draining and heating stage and the steam cooking stage, the heating device continuously heats the water storage cavity to generate steam, so that the air pressure in the cooking cavity and the water storage cavity is balanced.

[0013] During the soaking and water absorption stage and the pre-gelatinization stage, the heating device heats the water storage chamber in an intermittent heating manner, so that during the soaking and water washing stage, the temperature of the water in the cooking chamber is maintained at the first preset temperature T1, and during the pre-gelatinization stage, the temperature of the water in the cooking chamber is maintained at the first preset temperature T2.

[0014] The first preset air pressure P1 and the second preset air pressure P2 satisfy P1 = P2.

[0015] The present application also discloses a rice cooker, comprising a pot body and a heating device, wherein the pot body has a water storage cavity and a cooking cavity, the cooking cavity is located above the water storage cavity, the heating device is used to heat the water storage cavity, the pot body is also provided with a flow channel connecting the water storage cavity and the cooking cavity, the rice cooker is also provided with a vacuum pump, the air inlet of the vacuum pump is connected to the cooking cavity, and the air outlet of the vacuum pump is connected to the outside of the rice cooker, so that the rice cooker has a negative pressure state in which the air pressure in the cooking cavity is lower than the air pressure in the water storage cavity; the rice cooker also includes a control unit, which controls the rice cooker to implement the above-mentioned rice cooking method.

[0016] A heat collecting cover is provided in the water storage cavity, and the heat collecting cover surrounds the flow channel. The water storage cavity also includes a water collecting cavity located outside the heat collecting cover. The heat collecting cover is provided with a water outlet connecting the water collecting cavity and the flow channel, and a first flow outlet connecting the flow channel and the cooking cavity.

[0017] The rice cooker further comprises a steaming rack placed in the cooking cavity, and a second flow opening communicating with the first flow opening is formed on the bottom wall of the steaming rack.

[0018] Due to the adoption of the above technical solution, the beneficial effects achieved by this application are as follows:

[0019] 1. The present invention realizes separate cooking of rice and water by placing rice and water in two chambers respectively, thereby eliminating the influence of the rice-water ratio on the taste of rice, and facilitating the operation of the user. Only a certain amount of water needs to be added to the water storage chamber to cook rice of any weight within the product range.

[0020] The vacuum pump regulates the air pressure within the cooking chamber, allowing water to flow between the cooking chamber and the water storage chamber under the influence of a pressure differential during different cooking stages. This allows the rice cooker to have two soaking stages during the rice cooking process. During the soaking and water absorption stage, water at the first preset temperature soaks the rice within the cooking chamber, evenly entering the rice grains and allowing them to fully absorb water, thus preventing the rice from becoming undercooked or unevenly soft or hard. During the pre-gelatinization stage, water at the second preset temperature soaks the rice, causing gelatinization on the rice surface and forming a starch film. This reduces the rate at which the rice grains absorb further water, resulting in a desired hardness and a desired texture. Furthermore, users can choose the soaking time of the rice in this stage according to their personal preference to achieve rice with varying textures (the longer the soaking time, the more soggy the rice). This eliminates the need for strict manual control of the rice-to-water ratio, reducing operational errors, facilitating user experience, and improving user experience.

[0021] Not only that, when rice is soaked in water, the starch and sugar inside it dissolve into the water and are separated from the rice during the subsequent steaming process, thereby reducing the sugar content of the cooked rice, meeting the needs of some users for eating low-sugar rice, and further improving the user experience.

[0022] 2. As a preferred embodiment of the present application, during the pre-gelatinization stage, the second preset temperature T2 satisfies 90°C ≤ T2 ≤ 98°C, and the water soaks the rice in the cooking chamber for a second preset time t2, wherein the second preset time t2 satisfies 1 min ≤ t2 ≤ 15 min. When the rice is soaked in water at a temperature of 90°C-98°C for 1-15 minutes, sufficient and uniform contact between the rice and the water is achieved, which helps form a uniform and complete starch film on the surface of the rice grains, thereby enhancing the gelatinization effect.

[0023] Furthermore, users can choose the soaking time of rice in the pre-gelatinization stage according to personal preference to form starch films of different thicknesses on the surface of the rice grains to obtain rice with different soft and hard textures. That is, the longer the soaking time, the higher the gelatinization degree of the rice grains, the higher the gelatinization degree of the rice after cooking, the higher the moisture content of the rice, and the softer the rice produced. On the contrary, the shorter the soaking time, the harder the rice tastes.

[0024] 3. As a preferred embodiment of the present application, during the draining and heating stage and the steam cooking stage, the heating device continuously heats the water storage chamber to generate steam, so that the air pressure in the cooking chamber and the water storage chamber are balanced. When the soaking and water absorption stage and the pre-gelatinization stage are completed, in order to allow the water in the cooking chamber to flow back into the water storage chamber, it is necessary to make the air pressure in the cooking chamber and the water storage chamber substantially the same. However, the present application heats the water in the water storage chamber by a heating device to generate a large amount of steam, and the steam flows into the cooking chamber, so that the air pressure in the cooking chamber and the water storage chamber tends to be balanced, without the need for an additional pressure relief device. This simplifies the structure of the rice cooker and avoids the problem of reduced sealing of the cooking chamber due to the provision of a large number of ventilation holes.

[0025] 4. As a preferred embodiment of the present application, the heating device intermittently heats the water storage chamber during the soaking and absorbing water stage and the pre-gelatinization stage, so that the temperature of the water in the cooking chamber is maintained at the first preset temperature T1 during the soaking and rinsing stage, and the temperature of the water in the cooking chamber is maintained at the first preset temperature T2 during the pre-gelatinization stage. Because it takes a certain amount of time for water to flow from the water storage chamber to the cooking chamber and completely immerse the rice, if the heating device continues heating, the temperature of the water flowing into the cooking chamber will differ, affecting the water absorption and pre-gelatinization of the rice. The intermittent heating of the heating device ensures that the temperature of the water in the rice cooker remains constant during the soaking and absorbing water stage and the pre-gelatinization stage, thereby improving the water absorption and pre-gelatinization of the rice.

[0026] 5. This application also discloses a rice cooker. By providing upper and lower chambers, rice is placed in the upper cooking chamber and water is placed in the lower water storage chamber, which are separated from each other, and steam is used to heat the rice. During the cooking process, a vacuum pump draws air from the cooking chamber, reducing the air pressure therein, allowing water from the water storage chamber to flow into the cooking chamber one or more times, soaking the rice multiple times to achieve water absorption and pre-gelatinization. This improves the taste of the cooked rice, facilitates user operation, reduces operational requirements, reduces operational errors, and provides a pleasant user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0028] Figure 1 This is a cross-sectional view of the rice cooker according to one embodiment of the present application;

[0029] Figure 2 This is a cross-sectional view of the rice cooker according to another embodiment of the present application;

[0030] Figure 3 This is a schematic structural diagram of the heat collecting cover in one embodiment of the present application;

[0031] Figure 4 This is a structural schematic diagram of the steaming rack according to one embodiment of the present application;

[0032] Figure 5 for Figure 1 An enlarged view of area A, wherein the one-way exhaust valve is in the first position;

[0033] Figure 6for Figure 1 An enlarged view of area B in the middle, wherein the pressure relief valve is in a position opening the intake passage;

[0034] Figure 7 This is a schematic flow chart of the rice cooking method according to one embodiment of the present application;

[0035] Figure 8 This is a schematic diagram of temperature changes in the rice cooking method according to one embodiment of the present application.

[0036] in:

[0037] 1 pot body; 11 upper shell; 111 cooking cavity; 12 lower shell; 121 water storage cavity; 122 water collection cavity;

[0038] 2. Heating device;

[0039] 3 heat collecting cover; 31 flow passage; 32 water outlet; 33 first flow outlet; 34 flow guide protrusion;

[0040] 4 vacuum pumps;

[0041] 5 steaming rack; 51 second flow outlet; 511 inner opening; 512 outer opening;

[0042] 6 pot cover; 61 one-way exhaust valve; 62 exhaust channel; 63 pressure relief valve; 64 air intake channel. DETAILED DESCRIPTION

[0043] In order to more clearly illustrate the overall concept of the present application, a detailed description is given below in an illustrative manner in conjunction with the accompanying drawings.

[0044] In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present application is not limited to the specific embodiments disclosed below.

[0045] In addition, in the description of the present application, it should be understood that the terms "top", "bottom", "inside", "outside", "circumferential", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0046] In this application, unless otherwise expressly specified or limited, terms such as "installed," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0047] In this application, unless otherwise expressly specified and limited, a first feature "above" or "below" a second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. In the description of this specification, the reference terms "implementation method", "embodiment", "one embodiment", "example" or "specific example" and the like mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in an appropriate manner in any one or more embodiments or examples.

[0048] like Figure 1-6 As shown, a rice cooker includes a pot body 1 and a heating device 2, the pot body 1 has a water storage cavity 121 and a cooking cavity 111, the cooking cavity 111 is located above the water storage cavity 121, the heating device 2 is used to heat the water storage cavity 121, the pot body 1 is further provided with a flow channel 31 connecting the water storage cavity 121 and the cooking cavity 111, the rice cooker is further provided with a vacuum pump 4, the air inlet of the vacuum pump 4 is connected to the cooking cavity 111, and the air outlet of the vacuum pump 4 is connected to the outside of the rice cooker, so that the rice cooker has a negative pressure state in which the air pressure in the cooking cavity 111 is lower than the air pressure in the water storage cavity 121; the rice cooker also includes a control unit.

[0049] It should be noted that the present application does not specifically limit the structure of the pot body. In a specific embodiment, Figure 1-2 As shown, the pot body 1 includes an upper shell 11 and a lower shell 12, the cooking cavity 111 is arranged in the upper shell 11, and the water storage cavity 121 is arranged in the lower shell 12, and the upper shell 11 and the lower shell 12 are detachably connected.

[0050] In another specific embodiment, the pot body 1 includes a lower shell and an inner pot placed above the lower shell, the water storage cavity 121 is provided in the lower shell, and the inner pot surrounds the cooking cavity 111.

[0051] In another specific embodiment, the pot body 1 is an integrally formed structure, so as to omit the assembly process before cooking and improve cooking efficiency.

[0052] It can be understood that when cooking, the water storage chamber 121 contains liquid (such as water, etc.), and the food is placed in the cooking chamber 111. The air in the cooking chamber 111 is sucked by the vacuum pump 4, so that when the rice cooker is in the negative pressure state, the water in the water storage chamber 121 flows from the area with higher air pressure to the area with lower air pressure under the action of the pressure difference between the two places, that is, it flows from the water storage chamber 121 to the cooking chamber 111 through the flow channel 31.

[0053] Preferably, the rice cooker also has a normal pressure state in which the air pressure in the cooking cavity 111 is basically balanced with the air pressure in the water storage cavity 121. In this state, the water in the cooking cavity 111 flows back into the water storage cavity 121 under the action of its own gravity and is separated from the food in the cooking cavity 111.

[0054] The present application realizes the separation of rice and water in the rice cooker by the cooking cavity 111 and the water storage cavity 121 arranged above and below, and realizes multiple soaking of rice in water before the steam cooking stage by the change of the air pressure in the cooking cavity 111 by the vacuum pump 4, so that the rice can fully absorb water and achieve surface pre-gelatinization before cooking. The prepared rice is more delicious, has lower operation difficulty, and provides a good user experience.

[0055] In the present application, the rice grains in the cooking cavity 111 are first placed in a negative pressure environment in a waterless soaking state. On the one hand, the negative pressure environment can isolate oxygen, prevent the reproduction of microorganisms, and promote the preservation of rice grains. On the other hand, the air between the rice grains will be sucked away, and the rice grains will be easier to absorb water after being soaked in water. Since the cooking cavity 111 is at negative pressure, there is an air pressure difference between the water storage cavity 121 and the cooking cavity 111. The water in the water storage cavity 121 enters the cooking cavity 111 to soak the rice grains, which can promote the water absorption of the rice grains and increase the moisture content of the rice grains. The cooked rice will finally be fuller.

[0056] As a preferred embodiment of the present application, Figure 1-3 As shown, a heat collecting cover 3 is provided in the water storage cavity 121, and the heat collecting cover 3 surrounds the flow channel 31. The water storage cavity 121 also includes a water collecting cavity 122 located outside the heat collecting cover 3, and the heat collecting cover 3 is provided with a water outlet 32 ​​connecting the water collecting cavity 122 and the flow channel 31, and a first flow outlet 33 connecting the flow channel 31 and the cooking cavity 111.

[0057] The water and steam in the water storage chamber 121 enter the cooking chamber 111 through the flow channel 31. Since the volume of the flow channel 31 is small, the water and steam can generate a large pressure in the flow channel 31, thereby increasing the flow speed of the steam and water, thereby shortening the time for the steam and water to enter the cooking chamber and improving the cooking efficiency.

[0058] As a preference, Figure 1-3 As shown, the water outlet 32 ​​is opened at the bottom of the side wall of the heat collecting cover 3, so that no matter how much water is in the water collecting chamber 122, it can be connected with the flow channel 31, and the liquid levels of the water in the water collecting chamber 122 and the flow channel 31 are basically flush.

[0059] Further, if Figure 3 As shown, the diameter of the upper end of the heat collecting cover 3 is smaller than the diameter of the lower end of the heat collecting cover 3.

[0060] The heat-collecting hood 3 has a smaller top and larger bottom structure, further increasing the pressure at the first flow opening 33 and guiding the flow of steam and water, thereby increasing their flow rates. Furthermore, the heat-collecting hood 3's tapering design facilitates the bursting of bubbles as steam carries them upward. Because these bubbles contain a certain amount of water, the bursting water falls into the flow passage 31 and is not sprayed into the cooking chamber 111 through the first flow opening 33. This prevents water from surging into the rice during the steam cooking phase, potentially affecting its texture.

[0061] In a preferred embodiment, Figure 3 As shown, the top of the heat collecting cover 3 is provided with a guide protrusion 34 extending into the cooking cavity 111 , the top of the guide protrusion 34 is closed, and the first flow opening 33 is opened on the side wall of the guide protrusion 34 .

[0062] The first flow opening 33 of the present application is formed on the side wall of the guide protrusion 34, so that the upward flow direction of the fluid in the flow channel 31 and the direction of the fluid passing through the first flow opening 33 form a certain angle. As the boiling and rising water changes its flow direction, it collides with the top wall of the guide protrusion 34 and falls, flowing back into the flow channel 31. At the same time, the bubbles will burst due to the change in flow path, while the steam, being lighter, will enter the cooking cavity 111 through the first flow opening 33. This ensures that only steam can enter the cooking cavity 111 during the steam cooking stage, directly contacting and heating the rice, reducing the possibility of boiling water rising into the cooking cavity 111 and mixing with the rice, thus affecting the taste of the rice.

[0063] The present application does not specifically limit the location of the heating device 2. In a specific embodiment, Figure 1 As shown, the heating device 2 is provided at the bottom of the heat collecting cover 3, and the heating device 2 heats the flow passage 31. The heating device 2 heats the flow passage 31. Since the volume of the flow passage 31 is small, the temperature rises quickly and the heating effect is good.

[0064] In another specific embodiment, the heating device 2 includes a first heating part and a second heating part, the first heating part is arranged at the bottom of the heat collecting cover 3, and the second heating part is arranged at the bottom of the water collecting chamber 122, the first heating part heats the flow channel 31, and the second heating part heats the water collecting chamber 122.

[0065] The second heating part heats the water collecting chamber 122 to play a preheating role, reducing the temperature difference between the water in the flow channel 31 and the water collecting chamber 122, so that the water in the water collecting chamber 122 is closer to the preset temperature. As a result, the first heating part heats the water in the flow channel 31 to the preset temperature in a shorter time, shortening the heating time and improving the heating efficiency.

[0066] As a preferred embodiment of the present application, Figure 1-2 、 Figure 4 As shown, the rice cooker further includes a steaming rack 5 placed in the cooking cavity 111 , and a second flow opening 51 communicating with the first flow opening 33 is formed on the bottom wall of the steaming rack 5 .

[0067] The provision of the second flow port 51 facilitates, on the one hand, the water and steam in the water storage chamber 121 to enter the upper portion of the steaming rack 5 through the second flow port 33 to soak and heat the rice; on the other hand, when the air pressure in the cooking chamber 111 is balanced with the air pressure in the water storage chamber 121, the second flow port 51 serves as a drain, and the water above the steaming rack 5 flows back into the water storage chamber 121 through the second flow port 51, thereby separating the rice from the water and preventing water from accumulating in the rice and affecting the heating and taste of the rice.

[0068] Preferably, Figure 4 As shown, the second flow opening 51 includes an inner opening 511 and an outer opening 512 . The inner opening 511 is opened in the central area of ​​the bottom wall of the steaming rack 5 , and the outer opening 512 is opened on the outer periphery of the inner opening 511 .

[0069] Compared with the method in which the flow port is only opened in the circumference of the steaming rack 5, in the rice cooker of the present application, water and steam can flow up from the central area and the peripheral area of ​​the steaming rack 5 into the top of the steaming rack 5, thereby increasing the amount of steam and water entering the top of the steaming rack 5 per unit time, improving cooking efficiency, shortening cooking time, and the rice in the central area and the peripheral area of ​​the steaming rack 5 can be fully in contact with the steam, so the rice is heated evenly and has a balanced taste.

[0070] As a preferred embodiment of the present application, Figure 1 、 Figure 5 As shown, the rice cooker also includes a pot cover 6 covering the cooking cavity 111, the pot cover 6 is provided with an exhaust channel 62 connected to the cooking cavity 111, and a one-way exhaust valve 61 is provided at the exhaust channel 62, the one-way exhaust valve 61 has a first position abutting against the pot cover 6 to block the exhaust channel 62, and a second position disengaging from the pot cover 6 to open the exhaust channel 62, the one-way exhaust valve 61 switches between the first position and the second position under the push of the airflow on both sides of the exhaust channel 62.

[0071] When the rice cooker is in the negative pressure state, there is a certain pressure difference between the cooking chamber 111 and the outside. The one-way exhaust valve 61 moves under the influence of the external air pressure and blocks the exhaust passage 62, forming a closed environment within the cooking chamber 111. This maintains the negative pressure state and fully immerses the rice in water. When the rice cooker returns to normal pressure, a large amount of steam accumulates within the cooking chamber 111. The one-way exhaust valve 61 moves under the influence of the steam and opens the exhaust passage 62, allowing the steam in the cooking chamber 111 to be discharged, thus preventing the formation of a high-pressure environment within the cooking chamber 111.

[0072] Further, if Figure 1 、 Figure 6 As shown, the pot cover 6 is further provided with an air inlet passage 64 communicating with the cooking cavity 111 and the outside of the rice cooker, and a pressure relief valve 63 . The pressure relief valve 63 can move relative to the pot cover 6 to close or open the air inlet passage 64 .

[0073] When cooking is finished, if the air pressure in the cooking cavity 111 is still lower than the external atmospheric pressure, the pot cover 6 will be adsorbed on the pot body 1, making it difficult for the user to open the pot cover 6. At this time, the air inlet channel 64 can be opened through the pressure relief valve 63 to allow the outside air to quickly enter the cooking cavity 111, balancing the air pressure in the cooking cavity 111 and the outside, so that the user can easily remove the pot cover 6 from the pot body 1, thereby improving the user experience.

[0074] The present application also provides a method for cooking rice using a rice cooker. In one embodiment, the rice cooker adopts the rice cooker of the above structure, and the method for cooking rice using the rice cooker includes: S1 soaking and water absorption stage, S2 draining and heating stage, S3 pre-gelatinization stage and S4 steam cooking stage.

[0075] Reference Figure 7 , the rice cooking method of the rice cooker in this application:

[0076] In the S1 soaking and water absorption stage, the heating device 2 heats the water in the water storage chamber 121 to a first preset temperature T1; the vacuum pump 4 reduces the air pressure in the cooking chamber 111 to a first preset air pressure P1, and part of the water in the water storage chamber 121 flows from the water storage chamber 121 to the cooking chamber 111 under the action of the pressure difference.

[0077] The upwelling water soaks the rice in the cooking cavity 111, and the water fully contacts the rice grains and evenly enters the rice grains so that they fully absorb water, thereby increasing the moisture content of the rice grains, making them softer and easier to cook, thereby avoiding the phenomenon of the rice being undercooked or uneven in hardness and softness from top to bottom.

[0078] Preferably, the first preset temperature T1 is between 30°C and 60°C. Soaking the rice in warm water can accelerate the rice grains' absorption of water, allowing them to quickly reach the ideal moisture content and hardness, thereby improving cooking efficiency. Furthermore, during this stage, the moisture content of the rice grains after soaking is between 30% and 50%, ensuring that the rice grains are plump and elastic, thereby enhancing the taste.

[0079] In the draining and heating stage S2, the air pressure in the cooking cavity 111 and the water storage cavity 121 tends to be balanced, the water in the cooking cavity 111 flows back into the water storage cavity 121, and is heated to the second preset temperature T2 by the heating device 2.

[0080] In this stage, the rice and water are separated. On the one hand, this prevents the rice from being soaked in water for too long, resulting in too high a moisture content, which makes the cooked rice too wet and soft, affecting the taste. On the other hand, the water flows back to the water storage chamber 121 for heating. It is close to the heating device 2, has high heating efficiency, accelerates the temperature rise of the water, and improves cooking efficiency.

[0081] In the pre-gelatinization stage S3, the vacuum pump 4 reduces the air pressure in the cooking cavity 111 to a second preset air pressure P2, and part of the water in the water storage cavity 121 flows from the water storage cavity 121 to the cooking cavity 111 under the action of the pressure difference.

[0082] During this stage, the higher water temperature causes the rice's surface to gelatinize, forming a starch film that slows the rice's ability to absorb more water, giving it a firm texture. The rice's surface is also nearly ripe, allowing it to cook more easily and shorten the cooking time.

[0083] In the S4 steam cooking stage, the air pressure in the cooking cavity 111 and the water storage cavity 121 tends to be balanced, the water in the cooking cavity 111 flows back into the water storage cavity 121, and is heated to the third preset temperature T3 by the heating device 2, and the food in the cooking cavity 111 is steam cooked.

[0084] The rice in the cooking cavity 111 is steamed by using steam. The rice and water are placed in two chambers respectively. The water in the water storage cavity 121 is heated to generate steam, and the rice in the cooking cavity 111 is steam-cooked, thereby reducing the influence of the water-rice ratio on the taste of the rice. The contact between the steam and the rice is more uniform, so that the rice is evenly heated and the taste is improved.

[0085] Before cooking, the user only needs to add enough water to the water storage chamber 121 to meet the needs of the entire cooking process without strictly controlling the ratio of rice to water. Preferably, the water storage chamber 121 is provided with a water level line to prompt the user to add the amount of water required for cooking.

[0086] In addition, before steam cooking, the rice is soaked in water, and the starch and sugar inside it dissolve into the water and are separated from the rice during the subsequent steaming process, thereby reducing the sugar content of the cooked rice, meeting the needs of some users for low-sugar rice, and further improving the user experience.

[0087] As a preferred embodiment of the present application, in the pre-gelatinization stage, the second preset temperature T2 satisfies 90°C ≤ T2 ≤ 98°C, and water soaks the rice in the cooking chamber for a second preset time t2, and the second preset time t2 satisfies 1min ≤ t2 ≤ 15min.

[0088] High-temperature water at 90℃-98℃ can gelatinize the surface of rice grains, forming a starch film with a certain thickness. Users can choose the soaking time of rice at this stage according to their personal preferences to obtain rice with different softness and hardness (the longer the soaking time, the softer the rice tastes), meeting the needs of different users and improving user experience.

[0089] After experiments, the relationship between the second preset time t2 of rice soaking in the pre-gelatinization stage and the gelatinization degree of rice, the hardness of rice after cooking and the moisture content is shown in the following table.

[0090]

[0091] It can be concluded that compared with the traditional method of directly heating and cooking rice by contacting rice with water, the rice cooking method of the present application can achieve rice with different tastes and hardness by changing the soaking time of rice in the pre-gelatinization stage, without the need to control the rice-water ratio, thereby reducing the difficulty of operation and reducing operational errors.

[0092] As a preferred embodiment of the present application, in the soaking and water absorption stage, water soaks the rice in the cooking cavity for a first preset time t1, and the second preset time t1 satisfies 10min≤t1≤40min, so that the rice can fully absorb water, the rice grains become soft, and are convenient for steam heating, easier to mature, and the rice grains are fuller and elastic, thereby improving the taste.

[0093] In a preferred embodiment, during the cooking process, the rice cooker can detect the pressure in the cooking cavity 111 in real time and control the start or stop of the vacuum pump 4 so that the cooking cavity 111 maintains the first preset pressure P1 during the soaking and water absorption stage and maintains the second preset pressure P2 during the pre-gelatinization stage.

[0094] The rice cooker detects the air pressure environment in the cooking cavity 111 in real time and controls the start and stop of the vacuum pump 4, thereby maintaining the rice cooker in the negative pressure environment during the soaking and water absorption stage and the pre-gelatinization stage and maintaining the corresponding preset pressure, thereby ensuring that water can stably flow from the water storage cavity 121 into the cooking cavity 111, ensuring the effective progress of the cooking process.

[0095] For example, during the pre-gelatinization stage, after the air pressure in the cooking chamber reaches the second preset pressure P2, the vacuum pump 4 may stop operating. However, due to the high temperature of the heating device 2, some of the water in the water storage chamber 121 may be converted into water vapor. This water vapor, driven by the pressure difference, enters the cooking chamber 111 from the water storage chamber 121, causing the air pressure in the cooking chamber 111 to increase. If the pressure difference between the cooking chamber 111 and the water storage chamber 121 fails to meet the conditions for water to rise, the water in the water storage chamber 121 will no longer be able to rise into the cooking chamber 111. At this point, the rice cooker detects the change in air pressure in the cooking chamber 111 and controls the vacuum pump 4 to restart, restoring the air pressure in the cooking chamber 111 to the second preset pressure P2, ensuring normal cooking.

[0096] Furthermore, during the draining and heating stage and the steam cooking stage, the heating device 2 continuously heats the water storage cavity 121 to generate steam, so that the air pressure in the cooking cavity 111 and the water storage cavity 121 is balanced.

[0097] When the soaking and pre-gelatinization stages are complete, the air pressures in the cooking and water storage chambers 111 and 121 need to be substantially equal in order for the water in the cooking chamber 111 to flow back into the water storage chamber 121. However, the present invention utilizes a heating device 2 to heat the water in the water storage chamber to generate a large amount of steam, which flows into the cooking chamber 111, thereby balancing the air pressures in the cooking and water storage chambers 111 and 121. This eliminates the need for an additional pressure relief device, simplifies the structure of the rice cooker, and avoids the problem of increased sealing costs associated with the provision of numerous ventilation holes.

[0098] Of course, the rice cooker can also relieve the pressure of the cooking cavity 111 in other ways, such as setting a pressure relief valve, and controlling the movement of the pressure relief valve to connect the cooking cavity with the outside world, so that the outside air enters the cooking cavity 111, so that the cooking cavity 111 and the water storage cavity 121 are restored to the outside atmospheric pressure.

[0099] Furthermore, during the soaking and water absorption stage and the pre-gelatinization stage, the heating device 2 heats the water storage chamber 121 in an intermittent heating manner, so that during the soaking and washing stage, the temperature of the water in the cooking chamber 111 is maintained at the first preset temperature T1, and during the pre-gelatinization stage, the temperature of the water in the cooking chamber 111 is maintained at the first preset temperature T2.

[0100] Because it takes time for water to flow from the water storage chamber 121 to the cooking chamber 111 and completely immerse the rice, continuous heating by the heating device 2 can result in differences in the temperature of the water flowing into the cooking chamber 111, affecting the rice's water absorption and pre-gelatinization. Intermittent heating by the heating device 2 maintains a constant water temperature within the rice cooker during the immersion and pre-gelatinization stages, thereby improving the rice's water absorption and pre-gelatinization.

[0101] In a preferred embodiment, the first preset air pressure P1 and the second preset air pressure P2 satisfy P1 = P2. Furthermore, the first preset pressure P1 and the second preset pressure P2 are both vacuum, so that the power of the vacuum pump 4 is the same during the soaking and water absorption stage and the pre-gelatinization stage, simplifying the structure of the vacuum pump 4 and saving costs. Furthermore, water in the water storage chamber 121 is pumped into the cooking chamber 111 via vacuum siphoning. In a vacuum environment, the rice has better contact with the water, which facilitates the uniform incorporation of water into the rice grains, or the formation of a uniform starch film on their surface, thereby improving the water absorption and surface gelatinization of the rice grains.

[0102] Anything not described in this application can be achieved by adopting or drawing on existing technologies.

[0103] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments.

[0104] The foregoing is merely an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

Claims

1. A rice cooking method using a rice cooker, characterized in that: The rice cooker includes a pot body, a water storage cavity and a cooking cavity disposed within the pot body, and a heating device for heating the water storage cavity. A flow passage is provided between the water storage cavity and the cooking cavity, the flow passage being connected thereto. The rice cooker is further provided with a vacuum pump connected to the cooking cavity. During the cooking process of rice, rice is placed in the cooking cavity, and water is contained in the water storage cavity. The method includes the following steps: During the soaking and water absorption stage, the heating device heats the water in the water storage chamber to a first preset temperature T1; the vacuum pump reduces the air pressure in the cooking chamber to a first preset air pressure P1, and part of the water in the water storage chamber flows from the water storage chamber to the cooking chamber under the action of the pressure difference; During the draining and heating phase, the air pressure in the cooking cavity and the water storage cavity tends to be balanced, the water in the cooking cavity flows back into the water storage cavity, and is heated to a second preset temperature T2 by the heating device; During the pre-gelatinization stage, the vacuum pump reduces the air pressure in the cooking chamber to a second preset air pressure P2, and part of the water in the water storage chamber flows from the water storage chamber to the cooking chamber under the action of the pressure difference; the second preset temperature T2 satisfies 90°C ≤ T2 ≤ 98°C, and the water soaks the rice in the cooking chamber for a second preset time t2, and the second preset time t2 satisfies 1 minute ≤ t2 ≤ 15 minutes; During the steam cooking stage, the air pressure in the cooking cavity and the water storage cavity tends to be balanced, the water in the cooking cavity flows back into the water storage cavity, and is heated to a third preset temperature T3 by the heating device, and the food in the cooking cavity is steam cooked.

2. The rice cooking method of claim 1, wherein: In the soaking and water absorption stage, water soaks the rice in the cooking cavity for a first preset time t1, and the second preset time t1 satisfies 10 min≤t1≤40 min.

3. The rice cooking method of a rice cooker according to claim 1 or 2, characterized in that: During the cooking process, the pressure in the cooking cavity is detected in real time, and the start or stop of the vacuum pump is controlled to maintain the first preset pressure P1 in the soaking and water absorption stage and the second preset pressure P2 in the pre-gelatinization stage.

4. The rice cooking method of claim 3, wherein: During the draining and heating stage and the steam cooking stage, the heating device continuously heats the water storage cavity to generate steam, so that the air pressure in the cooking cavity and the water storage cavity is balanced.

5. The rice cooking method of a rice cooker according to claim 3, characterized in that: During the soaking and water absorption stage and the pre-gelatinization stage, the heating device heats the water storage chamber in an intermittent heating manner, so that during the soaking and water absorption stage, the temperature of the water in the cooking chamber is maintained at the first preset temperature T1, and during the pre-gelatinization stage, the temperature of the water in the cooking chamber is maintained at the first preset temperature T2.

6. The rice cooking method of a rice cooker according to claim 1, characterized in that: The first preset air pressure P1 and the second preset air pressure P2 satisfy P1 = P2.

7. A rice cooker comprising a pot body and a heating device, wherein the pot body has a water storage cavity and a cooking cavity, the cooking cavity is located above the water storage cavity, and the heating device is used to heat the water storage cavity, characterized in that: The pot body is further provided with a flow channel connecting the water storage cavity and the cooking cavity, and the rice cooker is further provided with a vacuum pump, the air inlet of the vacuum pump is connected to the cooking cavity, and the air outlet of the vacuum pump is connected to the outside of the rice cooker, so that the rice cooker has a negative pressure state in which the air pressure in the cooking cavity is lower than the air pressure in the water storage cavity; the rice cooker also includes a control unit, which controls the rice cooker to implement the rice cooking method according to any one of claims 1 to 6 above.

8. The rice cooker according to claim 7, characterized in that A heat collecting cover is provided in the water storage cavity, and the heat collecting cover surrounds the flow channel. The water storage cavity also includes a water collecting cavity located outside the heat collecting cover. The heat collecting cover is provided with a water outlet connecting the water collecting cavity and the flow channel, and a first flow outlet connecting the flow channel and the cooking cavity.

9. The rice cooker according to claim 8, characterized in that The rice cooker further comprises a steaming rack placed in the cooking cavity, and a second flow opening communicating with the first flow opening is formed on the bottom wall of the steaming rack.

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