Cooking utensil and multi-stage cooking method using same

Abstract

The invention provides a cooking utensil and a multi-stage cooking method applying the same. The cooking utensil comprises an inner pot (104) and a steaming basket (102) detachably arranged in the inner pot (104), and the bottom of the steaming basket (102) is provided with a closed bottom face (1002) facing a heat source. The cooking utensil further comprises a heat insulation layer (108) arranged between the bottom of the food materials in the steaming basket and the heat source, and the heat insulation layer (108) is made of non-metal materials with the heat conductivity coefficient lower than that of the steaming basket (102).

Description

Technical Field

[0001] The present invention relates to the field of kitchen appliances, and more particularly, to a cooking appliance and a multi-stage cooking method performed by the cooking appliance. Background Art

[0002] Cooking utensils are one of the important kitchen appliances. When using cooking utensils to steam food, heat energy can be transferred to the food in the steam basket through the surface of the steam basket. The efficiency of heat energy transfer through the surface of the steam basket is affected by the thermal conductivity of the steam basket material, the surface area in contact with the steam basket, and the direction exposed to high-temperature steam. Steam baskets are usually made of materials such as stainless steel, which generally have high thermal conductivity (for example, the thermal conductivity is reported to be about 17 W·m -1 ·K -1 ). Since the transfer of heat energy will gradually decrease along the path of its movement, CN 101406359B discloses an inner pot of an electric rice cooker, in which an outer layer with low thermal conductivity is added outside the inner layer with high thermal conductivity, thereby suppressing the heat release of the pot and storing the heat in the pot.

[0003] However, in a typical food steaming configuration, since a large area of ​​the bottom of the steaming basket is directly exposed to the high-temperature steam, the bottom layer of the food will obtain the maximum heat output during the cooking process, resulting in the upper layer of food receiving much less heat energy than the bottom layer of food in general. Therefore, in a typical steaming configuration, the temperature of the food cooked by steaming will show a large difference between the vertical layers, and this difference will be further amplified when a large amount of food is cooked. For this reason, some steaming baskets are designed with a gap at the top to allow high-temperature steam to enter and transfer heat energy to the food, but the amount of high-temperature steam that enters the steaming basket and then contacts the food to release heat energy is limited, so this problem has not been well solved. Summary of the invention

[0004] This disclosure is provided to introduce some concepts in a simplified form that will be further described in the following detailed description. This disclosure is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0005] One of the purposes of the present disclosure is to provide a cooking utensil and a multi-stage cooking method performed by the cooking utensil. The cooking utensil changes its heat transfer efficiency by adding a material with a different thermal conductivity from the material of the steam basket at the bottom of the steam basket, so that the food in the steam basket is heated more evenly in the vertical direction. On the other hand, by using the cooking utensil with more even heating and cooperating with the multi-stage cooking method, the temperature of the food is controlled within different temperature ranges in different time periods for cooking, and more resistant starch (RS) can be obtained when steaming rice.

[0006] According to one aspect of the present disclosure, a cooking utensil is provided, the cooking utensil comprising an inner pot and a steaming basket detachably disposed in the inner pot, the bottom of the steaming basket having a closed bottom surface facing a heat source. The cooking utensil further comprises a heat insulating layer disposed between the bottom of the food in the steaming basket and the heat source, the heat insulating layer being made of a non-metallic material having a lower thermal conductivity than that of the steaming basket. The solution makes the vertical heating in the steaming basket more uniform by adding a layer with a lower thermal conductivity between the steaming basket and the heat source.

[0007] In one embodiment of the present disclosure, the heat insulation layer is arranged on the outer side of the bottom surface of the steam basket. The solution has a simple structure, and the heat insulation layer is added on the outer side of the bottom surface of the existing steam basket, which is easy to manufacture and has low cost.

[0008] In another embodiment of the present disclosure, the heat insulation layer is arranged on the inner side of the bottom surface of the steam basket, and the heat insulation layer is made of food grade material. The solution has a simple structure, and the heat insulation layer is added on the inner side of the bottom surface of the existing steam basket, which is easy to manufacture and has low cost.

[0009] In another embodiment of the present disclosure, the ratio of the thermal conductivity of the heat insulating layer to the thermal conductivity of the steam basket is less than or equal to 20%. Under this relative relationship between the thermal conductivity of the heat insulating layer and the steam basket, a good uniform heating effect can be achieved.

[0010] In a further embodiment of the present disclosure, the non-metallic material is silicon dioxide hydrogel. Silica hydrogel has low thermal conductivity and is a safe material that can be in contact with food, which can play a good effect of reducing heat transfer at the bottom of the steaming basket.

[0011] In another embodiment of the present disclosure, one or more vents are provided above the side wall of the steam basket for allowing steam to enter the steam basket from above the food in the steam basket. By adding vents above the steam basket, high-temperature steam is allowed to enter the steam basket through these vents and transfer heat energy to the food, thereby increasing the temperature of the upper layer of food and further reducing the temperature difference between the upper and lower layers of food.

[0012] In another embodiment of the present disclosure, the upper edge of the steam basket has a protrusion, which cooperates with the upper edge of the inner pot to place the steam basket on the side wall of the inner pot. The method of placing the steam basket directly on the inner pot is simple in structure, thereby allowing the steam basket to be used without a bracket.

[0013] In another embodiment of the present disclosure, the cooking device further comprises a steam basket support, which is detachably arranged in the inner pot and used to place the steam basket on the storage surface thereof. The method of using the support to place the steam basket makes the steam basket simple in appearance and easy to manufacture.

[0014] In a further embodiment of the present disclosure, the heat insulation layer is arranged on the side of the storage surface of the steam basket support facing the steam basket. In the case of using a steam basket support, this method can be used to add a heat insulation layer to reduce the heat exposure of the lower layer of food.

[0015] In a further embodiment of the present disclosure, the heat insulation layer is arranged on the side of the storage surface of the steam basket support facing away from the steam basket. In the case of using a steam basket support, this method can be used to add a heat insulation layer to reduce the heat exposure of the lower layer of food.

[0016] According to another aspect of the present disclosure, a multi-stage cooking method is provided, which is performed by the cooking apparatus described in the present disclosure, including: in the first stage, heating the water at the bottom of the inner pot to generate steam, thereby heating the food in the steam basket, so that the temperature of the food rises and is maintained within a first preset temperature range; and in the second stage, the steam heats the food in the steam basket so that the temperature of the food rises and is maintained within a second preset temperature range, and the second preset temperature range is higher than the first preset temperature range. The heat and moisture treatment (HMT) stage is omitted, which saves cooking time. In addition, by applying the cooking apparatus described in the present disclosure to the multi-stage cooking method, a good temperature control effect can be achieved.

[0017] In one embodiment of the present disclosure, the first stage is 20-45 minutes, and the first preset temperature range is 60° C.-70° C. This duration and temperature range can allow the food to rise and maintain the desired annealing temperature during this stage, thereby achieving annealing of the food, which is beneficial to the production of resistant starch.

[0018] In another embodiment of the present disclosure, the second stage is 10-20 minutes, and the second preset temperature range is 85° C.-95° C. This duration and temperature range can make the food rise and maintain at the desired cooking temperature in this stage, which is conducive to the production of resistant starch.

[0019] In another embodiment of the present disclosure, in the first stage, the food in the steam basket is heated with a first power so that the temperature of the food rises and is maintained within a first preset temperature range, further comprising: heating the food in the steam basket with the first power; in response to the temperature of the food reaching the lower limit of the first preset temperature range, stopping heating for a first time; continuing to heat the food with the first power; and in response to the temperature of the food reaching the median value in the first preset temperature range, stopping heating until the first stage ends. During heating, the temperature of the steam in the pot changes very quickly, and it is usually difficult to accurately control the temperature. Through this solution, the temperature in the pot can be controlled within the desired temperature range only by a specific power output and time.

[0020] In a further embodiment of the present disclosure, in the second stage, the food in the steam basket is heated with a second power so that the temperature of the food rises and is maintained within a second preset temperature range, wherein the second power is greater than the first power, further comprising: heating the food in the steam basket with the second power; and in response to the temperature of the food reaching the median value of the second preset temperature range, heating the food with the second power and at a non-full duty cycle so as to maintain the temperature of the food within the second preset temperature range. This solution conveniently achieves temperature control by controlling the duty cycle of the power output after the temperature in the pot rises to the desired temperature range.

[0021] These and other features and advantages will become apparent by reading the following detailed description and by reference to the associated drawings.It is to be understood that the foregoing general description and the following detailed description are illustrative only and are not restrictive of the aspects of what is claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to understand in detail the manner in which the above features of the present disclosure are used, the above briefly summarized contents may be described in more detail with reference to various embodiments, some of which are shown in the accompanying drawings. However, it should be noted that the accompanying drawings only show certain typical aspects of the present disclosure and should not be considered to limit its scope, as the description may allow for other equally effective aspects.

[0023] Figure 1 A schematic diagram of a cooking appliance according to an embodiment of the present invention is shown.

[0024] Figure 2a A schematic diagram of a steaming basket according to an embodiment of the present invention is shown.

[0025] Figure 2b A schematic diagram of a steaming basket according to another embodiment of the present invention is shown.

[0026] Figure 3 A schematic diagram of a cooking appliance according to another embodiment of the present invention is shown.

[0027] Figure 4 A schematic diagram of a cooking appliance according to another embodiment of the present invention is shown.

[0028] Figure 5 It shows that according to the present invention Figure 4 An enlarged view of a portion of the cooking appliance shown.

[0029] Figure 6 is a flow chart of a multi-stage cooking method performed by the cooking appliance of the present disclosure according to one embodiment of the present invention.

[0030] Figure 7 A curve diagram showing the change of food temperature and time according to an embodiment of the present invention is shown.

[0031] Figure 8a The hardness measurement results according to one embodiment of the present invention are shown.

[0032] Figure 8b The RS measurement result according to one embodiment of the present invention is shown.

[0033] Fig. 9 A schematic diagram of a steaming basket according to an embodiment of the present invention is shown.

[0034] Description of reference numerals:

[0035] 102 steaming basket; 104 inner pot; 106 steaming basket support; 108 heat insulation layer; 110 vent hole; 112 fixing piece; 114 protrusion; 116 upper edge; 118 buckle.

[0036] 1002 closed bottom surface; 1004 storage surface. DETAILED DESCRIPTION

[0037] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be construed as being limited to the embodiments described herein, which are instead provided for a more thorough and complete understanding of the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are only for exemplary purposes and are not intended to limit the scope of protection of the present disclosure.

[0038] In the description of the present disclosure, it should be noted that, unless otherwise specified, "multiple" means more than two; the terms "upper", "lower", "left", "right", "inside", "outside", etc. indicate positions or positional relationships only for the convenience of describing the present disclosure 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, and therefore cannot be understood as a limitation on the present disclosure. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not strictly vertical, but is within the allowable error range. "Parallel" is not strictly parallel, but is within the allowable error range.

[0039] The directional words appearing in the following description are all directions shown in the figures, and do not limit the specific structure of the present disclosure. In the description of the present disclosure, it should also be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present disclosure can be understood according to the specific circumstances.

[0040] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present disclosure. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0041] In the description of the embodiments of the present disclosure, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0042] Figure 1 A schematic diagram of a cooking utensil according to an embodiment of the present invention is shown. The cooking utensil includes an inner pot 104 and a steaming basket 102 detachably disposed in the inner pot 104. The bottom of the steaming basket 102 has a closed bottom surface 1002 facing a heat source (not shown). When cooking is required, water can be put into the inner pot 104, and food can be put into the steaming basket 102. During the cooking process, the water in the inner pot 104 is heated to form high-temperature steam, which transfers heat to the closed bottom surface 1002 at the bottom of the steaming basket 104, thereby steaming the food in the steaming basket 104. In order to make the food in the steaming basket 102 more evenly heated in the vertical direction, the cooking utensil may further include a heat insulating layer disposed between the bottom of the food in the steaming basket 102 and the heat source, and the heat insulating layer may be made of a non-metallic material with a lower thermal conductivity than the thermal conductivity of the steaming basket 102.

[0043] As a non-limiting embodiment, the ratio of the thermal conductivity of the thermal insulation layer to the thermal conductivity of the steam basket 102 may be less than or equal to 20%. Experimental studies have shown that when the ratio of the thermal conductivity of the added thermal insulation layer to the thermal conductivity of the steam basket 102 is less than or equal to 20%, the cooking utensil can better adjust the temperature difference between the upper and lower layers of the food during cooking, so that the food is heated evenly in the vertical direction.

[0044] Furthermore, in order to reduce the heat output of steam to the bottom of the steam basket 102, silica hydrogel can be added to the bottom of the steam basket 102 as a heat insulating material between the bottom of the food and the heat source. Silica hydrogel is selected because of its low thermal conductivity (e.g., 0.175 W·m -1 ·K -1 ) and its common use as a food contact material. However, it can be appreciated that other materials can also be used to achieve similar effects.

[0045] In addition, as a non-limiting embodiment, one or more vents 110 may be further provided on the side wall of the steam basket 102 to allow steam to enter the steam basket 102 from above the food in the steam basket 102. In this way, during the cooking process, in addition to directly heating the bottom of the steam basket 102, the high-temperature steam may also enter the steam basket 102 through the vents 110 and transfer heat energy to the food, thereby increasing the temperature of the food above the steam basket 102 and further reducing the temperature difference between the upper and lower layers of the food.

[0046] As another non-limiting embodiment, a protrusion 114 may be provided on the upper edge of the steam basket 102, and the protrusion 114 cooperates with the upper edge 116 of the inner pot to place the steam basket 102 on the side wall of the inner pot 104. It can be appreciated that other methods may be used to place the steam basket 102 in the inner pot 104.

[0047] Furthermore, one or more fixing members 112 may be provided on the side wall of the steaming basket 102 , so that the steaming basket 102 can be better fixed in the inner pot 104 , thereby facilitating the positioning of the steaming basket 102 in the inner pot 104 .

[0048] for Figure 1 In the cooking device shown in FIG. 1 , a non-limiting way to set the heat insulation layer is to set the heat insulation layer 108 on the outer side of the bottom surface 1002 of the steam basket 102, such as Figure 2a As shown. Figure 2b Another non-limiting way of setting the heat insulating layer is shown, that is, the heat insulating layer 108 is set on the inner side of the bottom surface 1002 of the steam basket 102, and the heat insulating layer 108 can be made of food grade material. By using food grade material as the heat insulating layer 108, it can be in direct contact with the food, for example, silica hydrogel can be used as the heat insulating layer. The above two ways of setting the heat insulating layer can be improved on the basis of the existing steam basket, so the structure is simple, the cost is low, and a good effect of reducing the temperature of the bottom of the food can be achieved. Of course, it can be understood that the heat insulating layer can also be added in the middle of the bottom material of the steam basket, that is, as long as the heat insulating layer is set between the bottom of the food in the steam basket and the heat source, it can help the food to be heated evenly.

[0049] Figure 3FIG. 2 shows a schematic diagram of a cooking appliance according to another embodiment of the present invention. Figure 1 In the embodiment, a protrusion 114 is provided on the upper edge of the steaming basket 102 so as to place the steaming basket 102 in the inner pot 104. Figure 3 The cooking device shown further includes a steam basket support 106, which is detachably disposed in the inner pot 104 and is used to place the steam basket 102 on its storage surface 1004. However, it can be appreciated that the steam basket 102 can also be placed in the inner pot 104 by combining the protrusion 114 and the steam basket support 106 or other methods.

[0050] As a non-limiting example, Figure 4 and Figure 5 As shown, one or more buckles 118 may be provided on the outer edge of the storage surface 1004 of the steam basket support 106 to better fix the steam basket 102 on the steam basket support 106 .

[0051] for Figure 3 In the cooking device shown in FIG. 1 , in addition to arranging the heat insulating layer 108 on the outside, middle or inside of the bottom surface 1002 of the steam basket 102, the heat insulating layer 108 can also be arranged on the steam basket support 106. For example, as shown in FIG. Figure 4 and Figure 5 As shown, the heat insulation layer 108 can be disposed on the storage surface of the steam basket support 106 (ie, Figure 3 1004) on the side facing the steam basket 102, and / or the heat insulation layer 108 can be arranged on the storage surface of the steam basket bracket 106 (ie, Figure 3 1004) on the side facing away from the steaming basket 102.

[0052] It can be understood that the heat insulating layer 108 can be disposed at at least one of the following locations: the outside, middle or inside of the bottom surface 1002 of the steam basket 102, and / or the side of the storage surface 1004 of the steam basket support 106 facing toward or away from the steam basket 102. In other words, as long as the heat insulating layer 108 is disposed between the bottom of the food in the steam basket 102 and the heat source, it can help to heat the food evenly.

[0053] Figure 6 FIG. 1 is a flow chart of a multi-stage cooking method performed by a cooking appliance according to an embodiment of the present invention. Figure 6 As shown, the method 600 starts at step 602. In the first stage, water at the bottom of the inner pot 104 is heated to generate steam, thereby heating the food in the steaming basket 102 so that the temperature of the food rises and is maintained within a first preset temperature range.

[0054] As a non-limiting example, the first stage can be set to 20-45 minutes, and the first preset temperature range can be set to 60° C.-70° C. Experimental studies have shown that when the first stage is set to 20-45 minutes and the first preset temperature range is set to 60° C.-70° C., better cooking results can be obtained.

[0055] As a further non-limiting example, the specific steps of the first stage may be as follows: heating the food in the steam basket 102 at a first power, for example 1000 W; in response to the temperature of the food reaching the lower limit of the first preset temperature range, stopping the heating for a first time period; then continuing to heat the food at the first power; and in response to the temperature of the food reaching the median value in the first preset temperature range, stopping the heating until the first stage ends.

[0056] In step 604, in the second stage, the steam may heat the food in the steam basket 102 so that the temperature of the food rises and is maintained within a second preset temperature range, wherein the second preset temperature range is higher than the first preset temperature range.

[0057] As a non-limiting example, the second stage can be set to 10-20 minutes, and the second preset temperature range can be set to 85° C.-95° C. Experimental studies have shown that when the second stage is set to 10-20 minutes and the second preset temperature range is set to 85° C.-95° C., better cooking results can be obtained.

[0058] As a further non-limiting example, the specific steps of the second stage may be as follows: heating the food in the steaming basket 102 with a second power greater than the first power, for example 1200 W; and in response to the temperature of the food reaching a median value of a second preset temperature range, heating the food with the second power and at a non-full duty cycle to maintain the temperature of the food within the second preset temperature range.

[0059] Figure 7 FIG. 1 shows a curve diagram of food temperature and time according to an embodiment of the present invention. It can be understood that Figure 7 The variation curves shown correspond to the simplified Figure 6 The multi-stage cooking method shown in Figure 7 In the process, the first stage can be called, for example, an annealing stage (Annealing, ANN), and the second stage can be called, for example, a cooking stage (COOKING).

[0060] In the first stage, Figure 6 The first preset temperature range is simplified to the target temperature T1, that is, the food is steamed under the preset conditions (the food temperature is controlled near T1, and the time of the first stage is controlled from t0 to t1).

[0061] In the second stage, Figure 6 The second preset temperature range is simplified to the target temperature T2, that is, the steam processing process is adjusted according to the preset conditions (the temperature of the food is controlled around T2, and the time of the first stage is controlled between t1 and t2).

[0062] As a non-limiting example, rice can be cooked by the multi-stage cooking method of the present invention. However, it should be noted that the example of rice as an ingredient is only for the convenience of description, and those skilled in the art will understand that the scheme and improvements of the present invention are not only applicable to rice, but can be applied to any ingredient that can be placed in an inner pot for cooking.

[0063] The multi-stage cooking method omits the heat-moisture treatment (HMT). Before cooking, the rice is cleaned and drained thoroughly, and then placed in the steaming basket 102. Next, a predetermined amount of water (for example, the required amount of water is predetermined based on a fixed weight ratio of water to rice of 1:1) is added to the rice in the steaming basket 102. The steaming process can consist of two stages: (1) a 30-minute ANN stage at a first temperature range (for example, 60°C-70°C); (2) a 10-20-minute COOKING stage. Specifically, for example, an exemplary setting of a 30-minute ANN stage plus a 10-minute COOKING stage is as follows:

[0064] State 0: ANN stage starts timing, 1000W full power and full duty cycle heating until the bottom temperature of the food reaches 60℃.

[0065] State 1: ANN stage continues timing and stops heating for 2 minutes and 20 seconds.

[0066] State 2: ANN stage continues timing, 1000W full power full duty cycle heating until the bottom temperature of the food reaches 65℃.

[0067] State 3: The ANN stage continues timing and heating is stopped. When the total time of the ANN stage (ie, state 0 to state 3) reaches 30 minutes, it jumps to the next stage (eg, COOKING stage).

[0068] State 4: COOKING phase begins, 1200W full power full duty cycle heating for 2 minutes.

[0069] State 5: The COOKING stage continues, with 1200W power on for 7 seconds and off for 3 seconds (i.e., non-full duty cycle heating), and ends after 8 minutes.

[0070] State 6: Cooking is finished and the process starts to keep warm.

[0071] It can be appreciated that in the above arrangement, the time of state 5 can be extended to perform a longer COOKING phase.

[0072] When the steam basket of the present disclosure is used, the temperature changes of each layer of the food in the steam basket corresponding to the above settings are shown in Table 1. It can be seen that after the ANN stage, the temperatures of the top layer, middle layer and bottom layer of the food are relatively close, that is, by performing the multi-stage cooking method through the cooker of the present disclosure, the temperature of the food can be made relatively uniform in the vertical direction.

[0073] Top floor Middle level Bottom Layer Initial temperature 15.9℃ 15.9℃ 15.9℃ ANN30 minutes later temperature 61.1℃ 58.5℃ 62.4℃

[0074] Table 1

[0075] Conversely, when cooking with an old style uninsulated steam basket, the rice will become less cooked from the bottom to the top due to the large difference in heat output at different positions of the basket. Figure 8a As shown, this difference can be reflected in the hardness measurement. For example, the texture profile of cooked rice was analyzed on a TA-XT plus texture analyzer (Stable MicroSystems, UK) equipped with a 25mm flat compression probe (SMSP / 25P). The analysis results are as follows: the rice sampled at the bottom layer showed a hardness of 716.475g*force, while the rice sampled at the top layer showed a hardness of 1241.34g*force, showing a 42.28% hardness difference between the bottom and top layers of rice.

[0076] In addition, if Figure 8b This difference in the upper and lower layers of rice after cooking can also be reflected in the resistant starch (RS) measurement, as shown in Figure 2. For example, when the rice was sampled only from the surface layer, the reported RS level was 1.1% of the total starch. However, when the rice was sampled after it was fully mixed, this value dropped to 0.78%, indicating that there is a difference in the cooking properties of the vertical layers.

[0077] As a non-limiting example, in order to further reduce the heat transfer at the bottom of the steam basket, multiple insulation layers 108 (e.g., multiple layers of silica hydrogel) can be added to the bottom of the steam basket 102 as insulation between the steam basket material (e.g., stainless steel) and the food (e.g., rice). Fig. 9 It can be appreciated that multiple insulation layers can also be added to the inner and / or outer sides of the bottom of the steam basket 102, or the upper and lower layers of the storage surface of the steam basket support (if any).

[0078] use Fig. 9 The cooking apparatus shown in the figure performs a multi-stage cooking method, and then the hardness of the cooked rice sampled from the bottom layer and the top layer of the steam basket 102 is evaluated respectively to indicate the thermal uniformity of the food in the vertical direction. The specific comparison values ​​are shown in Table 2.

[0079]

[0080] Table 2

[0081] The experiment shows that when the rice is cooked in the steaming basket 102 with the insulation layer, the hardness difference between the rice sampled at the top and bottom layers is greatly reduced, and it can be seen that the thermal uniformity of the vertical layer is improved. Further, compared with the addition of a single layer of silica hydrogel, when 4 layers of silica hydrogel are added, the hardness difference between the top and bottom layers of the rice is further reduced from 29.08% to 11.35%, and it can be seen that the thickness of the insulation layer further affects the thermal uniformity of the rice. This improved thermal uniformity further improves the RS performance using the multi-stage cooking method, and the RS value of cooked rice increases from 0.78% (using a steaming basket without an insulation layer) to 1.14% (steaming basket with an insulation layer).

[0082] It can be appreciated that the cooking utensil disclosed herein can be applied to rice cookers, pressure cookers, multi-function cookers, etc., and combined with the multi-stage cooking method disclosed herein, it can improve the thermal uniformity of the food in the cooking utensil and increase the resistant starch (RS) content in the food.

[0083] What has been described above includes examples of various aspects of the claimed subject matter. Of course, it is not possible to describe every conceivable combination of components or methods for the purpose of describing the claimed subject matter, but one of ordinary skill in the art will recognize that many further combinations and permutations of the claimed subject matter are possible. Thus, the disclosed subject matter is intended to encompass all such alterations, modifications, and variations that fall within the spirit and scope of the appended claims.

Claims

1. A cooking appliance, comprising an inner pot (104), and a steaming basket (102) detachably arranged in the inner pot (104), wherein the bottom of the steaming basket (102) has a closed bottom surface (1002) facing a heat source, characterized in that: The cooking appliance further comprises a heat insulating layer (108) disposed between the bottom of the food in the steam basket (102) and the heat source, wherein the heat insulating layer (108) is made of a non-metallic material having a lower thermal conductivity than that of the steam basket (102).

2. The cooking device according to claim 1, characterized in that: The heat insulation layer (108) is arranged on the outer side of the bottom surface of the steam basket (102).

3. The cooking device according to claim 1, characterized in that: The heat insulation layer (108) is arranged on the inner side of the bottom surface of the steaming basket (102), and the heat insulation layer (108) is made of food-grade material.

4. The cooking device according to claim 1, characterized in that: The ratio of the thermal conductivity of the heat insulating layer (108) to the thermal conductivity of the steam basket (102) is less than or equal to 20%.

5. The cooking device according to claim 4, characterized in that: The non-metallic material is silica hydrogel.

6. The cooking device according to claim 1, characterized in that: One or more ventilation holes (110) are provided above the side wall of the steaming basket (102) for allowing steam to enter the steaming basket (102) from above the food in the steaming basket (102).

7. The cooking device according to claims 1 to 6, characterized in that: The upper edge of the steaming basket (102) is provided with a protrusion (114), and the protrusion (114) cooperates with the upper edge (116) of the inner pot (104) to place the steaming basket (102) on the side wall of the inner pot (104).

8. The cooking device according to claims 1 to 6, characterized in that: The cooking appliance further comprises a steam basket support (106), wherein the steam basket support (106) is detachably arranged in the inner pot (104) and is used for placing the steam basket (102) on its storage surface (1004).

9. The cooking device according to claim 8, characterized in that: The heat insulating layer (108) is arranged on a side of the storage surface (1004) of the steam basket support (106) that faces the steam basket (102).

10. The cooking device according to claim 8, characterized in that The heat insulation layer (108) is arranged on a side of the storage surface (1004) of the steam basket support (106) that is opposite to the steam basket (102).

11. A multi-stage cooking method, characterized in that: The multi-stage cooking method is performed by the cooking appliance according to any one of claims 1 to 10, comprising: In the first stage, water at the bottom of the inner pot (104) is heated to generate steam, thereby heating the food in the steaming basket (102) so that the temperature of the food rises and is maintained within a first preset temperature range; and In the second stage, the steam heats the food in the steaming basket (102) so that the temperature of the food rises and is maintained within a second preset temperature range, wherein the second preset temperature range is higher than the first preset temperature range.

12. The multi-stage cooking method according to claim 11, characterized in that: The first stage is 20-45 minutes, and the first preset temperature range is 60°C-70°C.

13. The multi-stage cooking method according to claim 11, characterized in that: The second stage is 10-20 minutes, and the second preset temperature range is 85°C-95°C.

14. The multi-stage cooking method according to claim 11, characterized in that: In the first stage, the food in the steaming basket (102) is heated at a first power so that the temperature of the food rises and is maintained within a first preset temperature range, further comprising: Heating the food in the steaming basket (102) at a first power; In response to the temperature of the food reaching the lower limit of the first preset temperature range, stopping heating for a first time period; Continue heating the food at the first power; and In response to the temperature of the food reaching a median value in the first preset temperature range, heating is stopped until the first stage ends.

15. The multi-stage cooking method according to claim 14, characterized in that: In the second stage, the food in the steaming basket (102) is heated at a second power so that the temperature of the food rises and is maintained within a second preset temperature range, wherein the second power is greater than the first power, further comprising: heating the food in the steaming basket (102) at a second power; and In response to the temperature of the food reaching a middle value of the second preset temperature range, the food is heated at the second power and at a non-full duty cycle to maintain the temperature of the food within the second preset temperature range.

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