Frozen sushi thawing method and thawing appliance set

Abstract

This appliance for thawing frozen sushi is characterized in that the appliance has a tray on which frozen sushi can be set with the frozen rice facing downwards, steam, water vapor, or vapor can be brought into contact with the bottom of the rice from a hole provided in the tray when thawing the frozen sushi, and the periphery of the tray is opened to outside air when thawing the frozen sushi.

Description

How to thaw frozen sushi and thawing equipment

[0001] The present disclosure relates to at least one of an apparatus for thawing frozen sushi, a food product with an apparatus, a device for thawing frozen sushi, and a method for thawing frozen sushi.

[0002] Frozen sushi (hereinafter simply referred to as "frozen sushi") mainly consists of two parts: rice and sushi toppings (hereinafter simply referred to as "sushi toppings" or "toppings"). For example, frozen Edomae sushi generally consists of frozen rice topped with frozen toppings. It is known that when frozen rice is thawed slowly, such as by natural thawing, a phenomenon known as "white waxing" occurs. White waxing refers to the phenomenon in which rice loses moisture and becomes crumbly like wax, and rice that has undergone white waxing has a significantly reduced taste. The white waxing phenomenon is thought to be caused by the combined action of starch aggregation when rice is thawed and starch retrogradation when rice is left at low temperatures.

[0003] To eliminate this white waxing phenomenon, a method for thawing frozen sushi is known in which the frozen sushi, which consists of a rice section and a topping section, is heated using electromagnetic waves so that the temperature of the rice section is 60 to 95°C and the temperature of the topping section is -2 to 20°C, and then this heating is stopped (claims 1 and 2 of Patent Document 1).

[0004] Patent Document 2 also discloses a technology for packaging rice (the part referred to as "shari ball" in Patent Document 2, also called "rice ball") and sushi topping separately in order to thaw them separately. In Patent Document 2, the rice is thawed in a microwave oven, and the sushi topping is thawed under running water (paragraph

[0033] of Patent Document 2). Furthermore, Patent Document 3 discloses a technology relating to a double-layered container for storing frozen nigiri sushi that can be heated by pouring hot water over it, and a frozen nigiri sushi storage item using the same (paragraph

[0001] of Patent Document 3).

[0005] JP 2017-23145 A JP 2007-82471 A JP 2016-84151 A

[0006] However, when using a microwave oven as in Patent Documents 1 and 2, there is a problem in that frozen sushi cannot be thawed without a microwave oven and a power source. Also, when using a microwave oven to thaw frozen sushi, microwaves are generally applied to the entire sushi, making it difficult to control the temperatures of the rice and the sushi topping separately.

[0007] In addition, in Patent Document 2, the rice and sushi toppings are packaged and thawed separately, which increases packaging costs and the effort required for thawing. In particular, thawing sushi toppings under running water not only takes time and effort, but also requires a large amount of water, which places a heavy burden on the environment. Furthermore, the method in Patent Document 2 requires the sushi toppings to be placed on top of the rice after thawing, which not only increases the effort but also requires the sushi provider or eater to have the skill to make sushi.

[0008] On the other hand, the thawing method of pouring hot water described in Patent Document 3 takes time to thaw frozen sushi, or there is a risk that the frozen sushi may not be thawed sufficiently. In particular, the thawing method described in Patent Document 3, which does not have a heat source and the water temperature drops over time, takes time to thaw frozen sushi, or there is a high risk that the frozen sushi may not be thawed sufficiently. Furthermore, Patent Document 3 requires preparing hot water for the hot water bath and draining the water after thawing, which increases the effort and requires equipment to prepare and discard the hot water.

[0009] When thawing frozen sushi, it is desirable to thaw the rice by heating it quickly and thoroughly, while it is desirable to thaw the sushi topping by heating it slowly. For example, if the sushi topping is heated too quickly, the topping, which should be raw, will be overheated, causing the topping to be cooked or burned, making it impossible to reproduce the original taste, flavor, or texture of the sushi topping. Thus, when thawing frozen sushi, it is important to adopt a thawing method that is incompatible with the rice and the sushi topping, in other words, a thawing method that does not impair the texture of either the rice or the sushi topping. Furthermore, it is important to develop a thawing method that can thaw frozen sushi easily and quickly.

[0010] Therefore, at least one object of the present disclosure is to solve the above-mentioned problems.

[0011] In order to achieve the above-mentioned object, the present disclosure provides, as one embodiment, an appliance for thawing frozen sushi, the appliance having a tray on which the frozen sushi can be placed with the frozen rice facing downwards, and when thawing the frozen sushi, steam, vapor or steam can be directed onto the underside through holes provided in the tray, and when thawing the frozen sushi, the periphery of the tray is open to the outside air.

[0012] The above-mentioned device has the advantage that by using steam or the like to thaw frozen sushi, the texture of the rice and sushi toppings is not compromised and the frozen sushi can be thawed easily and quickly.

[0013] Furthermore, the present disclosure provides, as one embodiment, an apparatus, characterized in that the tray is provided with a guide that indicates a position where the frozen sushi should be placed.

[0014] The device described above provides guidance on the placement position of the frozen sushi, making it easy to place the frozen sushi on the tray, for example.

[0015] Furthermore, the present disclosure provides, as one embodiment, an appliance characterized in that the tray has an uneven portion on the portion on which the frozen sushi is placed. Furthermore, the present disclosure provides, as one embodiment, an appliance characterized in that the tray has a mesh portion on the portion on which the frozen sushi is placed that allows steam, water vapor, or vapor to pass through.

[0016] These above-mentioned devices have the effect of preventing thawed rice from sticking to the tray 11, or making it easier to apply steam or the like relatively evenly to the rice in frozen sushi SS, for example.

[0017] Furthermore, the present disclosure provides, as one embodiment, a food product with a tool, comprising the tool disclosed herein and frozen sushi placed on the tray of the tool.

[0018] Furthermore, the present disclosure provides, as one embodiment, a device for thawing frozen sushi, characterized by comprising the device disclosed herein and a device for generating steam, water vapor, or steam. Furthermore, the present disclosure provides, as one embodiment, a device for thawing frozen sushi, characterized in that the device for generating steam, water vapor, or steam comprises a reaction vessel for generating the steam, water vapor, or steam by reacting a heat-generating material with water.

[0019] Furthermore, the present disclosure provides a method for thawing frozen sushi, characterized in that the method includes applying steam, water vapor or vapor to the underside of frozen sushi placed on a tray of a device for thawing frozen sushi, with the frozen sushi placed with the frozen rice on the underside, through holes in the tray, with the periphery of the tray open to the outside air.

[0020] According to the above method, by using steam or the like to thaw frozen sushi, it is possible to thaw frozen sushi easily and quickly without compromising the texture of the rice and sushi topping.

[0021] 1 is a perspective view showing a tool for thawing frozen sushi and a thawing device including the tool according to an embodiment of the present disclosure; FIG. 2 is a top view of a tray according to an embodiment of the present disclosure; FIG. 3 is a top view of a tray including a guide that indicates where frozen sushi should be placed according to an embodiment of the present disclosure; FIG. 4 is a cross-sectional view of the tray of FIG. 3 taken along the line A-A; FIG. 5 is a cross-sectional view of a tray including a concave-convex portion according to an embodiment of the present disclosure; FIG. 6 is a cross-sectional view of a tray including a mesh portion according to an embodiment of the present disclosure; FIG. 7 is a diagram showing experimental results of thawing frozen sushi; FIG. 8 is a diagram showing experimental results of thawing frozen sushi; FIG. 9 is a diagram showing experimental results of thawing frozen sushi; FIG. 10 is a diagram showing experimental results of thawing frozen sushi; FIG. 11 is a diagram showing experimental results of thawing frozen sushi;

[0022] The present disclosure relates to a device for thawing frozen sushi, the device having a tray on which the frozen sushi can be placed with the frozen rice facing downwards, and when thawing the frozen sushi, steam, water vapor or vapor can be directed onto the underside through through holes (hereinafter simply referred to as holes) provided in the tray, and when thawing the frozen sushi, the periphery of the tray is open to the outside air.

[0023] As mentioned above, when thawing frozen sushi, there is a demand for rapid heating of the rice, while there is a demand for slow thawing of the sushi topping on top of the rice, or for thawing at a temperature lower than the thawing temperature of the rice. The difficulty in developing a thawing method that satisfactorily thaws frozen sushi, i.e., that enables the production of sushi with excellent taste and texture, lies in the fact that, for frozen sushi in which the frozen topping is placed on (in contact with) the frozen rice, the frozen rice at the bottom must be thawed by rapid heating (or thawed at a high temperature), while the topping on top must be thawed slowly (or thawed at a low temperature). While conventional technology has been unable or difficult to achieve these contradictory thawing methods at the same time, the present inventors conducted extensive research to achieve this contradictory thawing method.

[0024] During the course of the above-mentioned investigations, the inventors discovered that, instead of using a conventional microwave oven (electromagnetic waves), they use steam, water vapor, or steam (hereinafter, "steam, water vapor, or steam" may be collectively referred to as "steam, etc.") to apply (expose) steam, etc. to the underside of frozen sushi, i.e., the underside of the frozen rice (i.e., the side opposite the side on which the sushi topping is placed). This applies a constant amount of heat to the frozen rice, rapidly thawing it, while opening the frozen sushi to the outside air during thawing allows the heat generated by thawing the frozen rice to escape to the surroundings, thereby slowing the thawing of the sushi toppings. In this thawing method, steam, etc., serves as a heat source for the frozen sushi. Because frozen rice has gaps between the rice grains, steam, etc., passes through these gaps to thaw the frozen rice, while also allowing the heat generated by thawing to escape to the surroundings through these gaps. Therefore, opening the surroundings during thawing of frozen sushi allows the steam heat to escape more easily, facilitating thawing without damaging the sushi topping.

[0025] In order to achieve the above-mentioned contradictory thawing methods, the device for thawing frozen sushi in the present disclosure has a tray on which the frozen rice of the frozen sushi can be placed with the frozen rice facing downwards, and when thawing the frozen sushi, steam, water vapor or vapor can be directed onto the underside through holes in the tray, so that when thawing the frozen sushi, the area around the tray is open to the outside air.

[0026] The following describes an apparatus for thawing frozen sushi, a food product with an apparatus, a device for thawing frozen sushi, or a method for thawing frozen sushi according to one embodiment of the present disclosure. Fig. 1 is a perspective view showing an apparatus for thawing frozen sushi and a thawing device including the apparatus according to one embodiment of the present disclosure.

[0027] The frozen sushi thawing device 1 of this embodiment includes an appliance 2 for thawing frozen sushi (hereinafter also referred to as the "thawing appliance 2") and an appliance 3 for generating steam, water vapor, or steam (hereinafter also referred to as the "steam, water vapor, or steam generating appliance 3"). Here, the term "apparatus" is a concept that includes not only dish- or plate-shaped members, but also container-shaped members.

[0028] In this embodiment, the thawing device 2 is disposed above the steam-generating device 3. However, the positional relationship between the thawing device 2 and the steam-generating device 3 is not limited as long as the steam, etc. generated from the steam-generating device 3 can pass through the hole 111 from the bottom to the top of the hole 111. For example, a configuration can be adopted in which the steam, etc. generated from the steam-generating device 3 installed at an arbitrary location is guided to the bottom of the hole 111 by a pipe.

[0029] The thawing device 2 has a tray 11. Frozen sushi SS is placed on the tray 11. Specifically, the frozen sushi SS can be placed on the tray 11 with the frozen rice facing down. Suitable types of frozen sushi SS include, but are not limited to, nigiri sushi and gunkan sushi (gunkan rolls with seaweed wrapped around the outside). The shape and size of the rice and the toppings are not important, but it is preferable that at least a portion of the rice be in contact with the tray 11 when the frozen sushi SS is placed on the tray 11. It is also preferable that the frozen sushi SS be quick-frozen.

[0030] Holes 111 are provided in the tray 11. Specifically, the holes 111 are provided in the portion of the tray 11 where the frozen sushi SS will be placed. The holes 111 allow steam, etc. generated by the steam-generating device 3 to pass at least from the bottom to the top of the hole 111. The steam, etc. that passes through the hole 111 from the bottom to the top of the hole 111 hits the underside of the frozen rice in the frozen sushi SS placed on the tray 11. In other words, when thawing the frozen sushi SS, the thawing device 2 can apply steam, etc., from the holes 111 provided in the tray 11 to the underside of the frozen rice in the frozen sushi SS.

[0031] The periphery of the tray 11 is open to the outside air. More specifically, the periphery of the tray 11 is open to the outside air, at least when thawing the frozen sushi SS. Here, "the periphery of the tray 11 is open to the outside air" refers to a configuration in which heat from a heat source such as steam does not accumulate near the area on the tray 11 where the frozen sushi SS is placed. For example, "the periphery of the tray 11 is open to the outside air" may include a configuration in which steam generated from the steam-generating device 3 (described below) and passing through the hole 111 does not stagnate in the area on the tray 11 where the frozen sushi SS is placed. However, even with the above description, this disclosure does not exclude configurations in which condensed steam or other water droplets adhere to the surface of the tray 11. As described below, having the periphery of the tray 11 open to the outside air has the advantage of preventing undesirable phenomena such as "cooked" or "burned" sushi toppings.

[0032] On the other hand, as described above, other configurations may be employed, such as a configuration with a lid formed on top of the tray 11, as long as they are configured to prevent heat from being trapped, such as steam. Examples of other configurations include a configuration with a lid capable of heat exchange or heat recovery, a configuration with a lid made of a material that allows steam to pass through but not other substances (such as frozen sushi SS and water 15, described below), and a configuration with a lid equipped with a vent. Additionally, regardless of whether a lid is provided or whether the thawing device 1 or thawing tool 2 is open to the outside air, a configuration in which a cooling system (which may be a mechanical heat exchange system or simply a system in which a cooling material is placed) is also employable. The example of FIG. 1 has the advantage of not requiring large-scale equipment, while an example equipped with a cooling system has the advantage of making it easier to control heat.

[0033] Specifically, in this embodiment, at least the top surface of the tray 11 is open to the outside air. Steam and other contaminants that pass through the holes 111 are expected to move further up the tray 11. Therefore, by opening the top surface of the tray 11 to the outside air, steam and other contaminants can be prevented from accumulating in the area where the frozen sushi SS is placed. Furthermore, by opening at least a portion of the side surface of the tray 11 to the outside air, steam and other contaminants can be prevented from accumulating in the area where the frozen sushi SS is placed. Furthermore, it is preferable that the tray 11 be configured so that at least a portion of the side surface of the rice portion of the frozen sushi SS is open to the outside air. This configuration prevents steam and other contaminants from accumulating inside the frozen sushi SS or in the surrounding space adjacent to the frozen sushi SS.

[0034] The steam-generating device 3 in this embodiment includes an outer case 12 and a reaction vessel 14. Preferably, the steam-generating device 3 (in one embodiment, the outer case 12 of the steam-generating device 3) is connected to the thawing device 2 (in one embodiment, the tray 11 of the thawing device 2) and defines a sealed space between it and the tray 11 except for the hole 111. The outer case 12 and the reaction vessel 14 may be integrally configured or may be separate components. For example, a configuration in which a part of the outer case 12 functions as the reaction vessel 14 may be employed.

[0035] Here, in this disclosure, "a space sealed except for the hole 111" refers to a space sealed to the extent that most of the steam etc. generated in the steam etc. generating device 3 can pass through the hole 111. In other words, in this disclosure, "a space sealed except for the hole 111" includes, but is not limited to, a space that does not allow any steam etc. to pass through except for the hole 111. By sealing the space with the steam etc. generating device 3 and the thawing device 2, much of the thermal energy of the steam etc. can be used to thaw the frozen sushi.

[0036] Furthermore, it is not always necessary to seal the space between the steam generating device 3 (or the outer box 12 of the steam generating device 3) and the tray 11. For example, in cases such as (1) when the amount of steam generated from the steam generating device 3 is sufficient, or (2) when the steam generated from the steam generating device 3 has a directional flow toward the hole 111, the space between the steam generating device 3 and the thawing device 2 does not need to be sealed.

[0037] In this embodiment, the reaction vessel 14 is a vessel for reacting the heat-generating material 13 with the water 15. The heat-generating material 13 generates heat by reacting with the water 15, providing thermal energy to the water 15. The reaction vessel 14 is configured so that the heat-generating material 13 can be placed therein and water 15 can be poured into it. The water 15 that has been provided with thermal energy by the heat-generating material 13 boils (evaporates) into steam, which moves upward from the reaction vessel 14 and passes through the holes 111. The steam (or steam generated by condensed steam) that passes through the holes 111 hits the underside of the frozen rice in the frozen sushi SS, thawing the frozen sushi SS.

[0038] At least a portion of the water 15 that has evaporated into steam may condense before reaching the frozen sushi SS, forming tiny droplets of steam. Furthermore, if the heat-generating material 13 does not generate much heat, the water 15 may not boil, and only steam, not steam, may be generated from the reaction vessel 14. However, even steam may contain sufficient thermal energy to thaw the frozen sushi SS. Furthermore, even steam can pass through the hole 111. Therefore, in this disclosure, what is generated by the steam-generating device 3 or what passes through the hole 111 may not be limited to steam, but may be steam.

[0039] Furthermore, when other drinkable liquid is used instead of water 15, the steam generating device 3 may generate steam instead of water vapor.

[0040] In this embodiment, when the thawing device 2 is placed above the steam-generating device 3, the reaction vessel 14 is configured to be located below at least a portion of the hole 111. By positioning the reaction vessel 14 below the hole 111, the steam and other vapors generated from the reaction vessel 14 are naturally directed toward the hole 111. Therefore, in this embodiment, frozen sushi can be easily thawed.

[0041] The steam generating device 3 is not limited to the configuration disclosed above. For example, the steam generating device 3 may be a device that generates steam by heating water with an electric heating wire, gas heating, or other means. One exemplary advantage of using the heat generating material 13 is that no large-scale equipment is required. On the other hand, an exemplary advantage of using a device that uses an electric heating wire or the like is that it does not require disposable components (or only a few disposable components), making it easy to reuse or to defrost a large number of frozen sushi at once.

[0042] The heat generating material 13 and water 15 may be sold separately from the frozen sushi thawing device 1, or may be prepared by the user of the frozen sushi thawing device 1. The thawing tool 2 and the steam generating tool 3 may also be sold separately. Both the thawing tool 2 and the steam generating tool 3 may be disposable, or at least one of them may be reusable. The frozen sushi SS may also be sold separately from the frozen sushi thawing device 1, or may be sold as a food product with tools together with at least a part of the frozen sushi thawing device 1 (for example, the thawing tool 2).

[0043] As explained above, the thawing device 1 or thawing tool 2 for frozen sushi SS of this embodiment allows steam and other vapors to pass through the holes 111 in the tray 11 and hit the underside of the rice in the frozen sushi SS. With this configuration, the thawing device 1 or thawing tool 2 for frozen sushi SS of this embodiment makes it possible to thaw frozen sushi SS using steam and other vapors.

[0044] The steam passing through the holes 111 is at a high temperature, so the rice in the frozen sushi SS is heated quickly and thoroughly. Therefore, the frozen sushi SS thawing device 1 or thawing tool 2 of this embodiment can eliminate the white wax phenomenon of the frozen sushi SS.

[0045] Here, the steam that passes through the holes 111 hits the underside of the rice in the frozen sushi SS. However, in this embodiment, it is not just the underside of the rice that is thawed, but the entire frozen sushi SS is thawed. The reason why the entire frozen sushi SS is thawed even though steam is hitting the underside of the rice is thought to be as follows.

[0046] The rice portion of a frozen sushi SS is an aggregate of cooked and frozen rice grains, and there are sufficient gaps between each grain for steam to pass through. Therefore, it is thought that the steam hitting the bottom of the frozen rice in a frozen sushi SS heats not only the bottom of the rice but the entire rice rapidly and sufficiently, thawing the entire rice.

[0047] However, the above description does not preclude the coexistence of other heat transfer methods in addition to those described above, such as the conduction of heat from an already heated grain of rice to another grain of rice.

[0048] Furthermore, steam that reaches the sushi topping in the frozen sushi service center through the gaps between the rice grains transfers heat energy to the already frozen rice. Therefore, it is thought that the steam that reaches the sushi topping in the frozen sushi service center has lower heat energy than when the steam was generated. Steam with relatively low heat energy heats the sushi topping slowly and at a low temperature. This slow, low-temperature heating prevents the sushi topping from being cooked or burned.

[0049] Furthermore, in this embodiment, when thawing frozen sushi, the area around the tray 11 is open to the outside air. This prevents steam and other contaminants from accumulating around the tray 11 and allows the steam and other contaminants to be expelled into the outside air. This prevents the accumulating steam, which still has high thermal energy, from applying excessive heat to the sushi topping. This further prevents the sushi topping from being cooked or burned.

[0050] As explained above, the thawing device 1 or thawing tool 2 for frozen sushi SS of this embodiment achieves separate temperature control for the rice and the sushi topping by applying steam or the like to the underside of the rice in the frozen sushi SS through holes 111 provided in the tray 11. This allows the thawing device 1 or thawing tool 2 for frozen sushi SS of this embodiment to prevent the rice from turning white and waxy while also preventing the sushi topping from being cooked or burned. Furthermore, because the thawing device 1 or thawing tool 2 for frozen sushi SS of this embodiment uses high-temperature steam or the like to thaw the frozen sushi SS, it can thaw the frozen sushi SS relatively quickly compared to the thawing method described in Patent Document 3, for example, in about 15 minutes.

[0051] In addition, when thawing frozen sushi SS using the thawing device 1 or thawing tool 2 for the frozen sushi SS of this embodiment, equipment such as a microwave oven is not required. Furthermore, with the thawing device 1 or thawing tool 2 for the frozen sushi SS of this embodiment, it is not necessary to thaw the rice and sushi topping separately, and there is no need to place the sushi topping on the rice after thawing.

[0052] Now that sushi is consumed worldwide, there is a demand for technology to thaw frozen sushi with minimal effort and cost, regardless of the eating location, the availability of cooking facilities, or the sushi-making skills of the eater (or the sushi provider). In particular, when frozen sushi is served in environments where open flames are strictly prohibited and facilities are limited, such as on airplanes or ships, there is a strong demand for thawing frozen sushi with minimal effort and cost, regardless of the eating location, the availability of cooking facilities, or the sushi eater (or the sushi provider)'s sushi-making skills. The thawing device 1 or thawing tool 2 for a frozen sushi SS of this embodiment provides technology to thaw frozen sushi extremely easily with minimal effort and cost, regardless of the eating location, the availability of cooking facilities, or the sushi eater (or the sushi provider)'s sushi-making skills.

[0053] Furthermore, the thawing device 1 or thawing tool 2 for frozen sushi SS in this embodiment uses steam or other methods to thaw the frozen sushi SS. Other thawing methods, such as placing frozen sushi on a hot plate, dry out the frozen sushi as it heats up, causing the sushi to lose its original taste, flavor, and texture. In this embodiment, using steam or other methods maintains the humidity around the frozen sushi SS, which has the advantage of preventing the frozen sushi from drying out when thawing.

[0054] 3 and 4, the tray 11 may be provided with a guide 300 that indicates the position where the frozen sushi SS should be placed. Since the frozen sushi SS is placed above the hole 111, the guide 300 should be positioned around the hole 111.

[0055] The guide 300 is provided to indicate the location where the frozen sushi SS should be placed. The specific shape of the guide 300 may be designed taking into consideration the thawing function and ease of handling after thawing. Since the shape of the guide 300 is thought to affect the flow of steam and other contaminants, in one example, the flow of steam and other contaminants (and thus the degree of thawing caused by steam and other contaminants) may be taken into consideration when determining the shape of the guide 300. Furthermore, since the shape of the guide 300 may make it difficult for eaters to grasp the sushi with their hands or chopsticks, in one example, the ease with which eaters can grasp the sushi may be taken into consideration when determining the shape of the guide 300. However, the above description does not in any way limit the shape of the guide 300.

[0056] Figure 3 is a top view of the tray 11 in an example where a guide 300 is provided on part of the tray 11. Figure 4 is a cross-sectional view taken along the line A-A in Figure 3. However, for the sake of convenience, some parts in Figure 4 have been simplified, and the dimensions of the components in Figure 4 may not be accurate. Also, in Figure 4, the frozen sushi SS is shown by imaginary lines (note that the points to note regarding Figure 4 also apply to Figures 5 and 6, which will be described later).

[0057] 3 and 4, the guide 300 may be formed by a physical or mechanical structure, such as a protrusion on the tray 11. If the guide 300 is formed by a protrusion on the tray 11, the tray 11 including the guide 300 is preferably configured so that at least a portion of the side of the rice in the frozen sushi SS is open to the outside air. This configuration prevents steam and other contaminants from accumulating inside the frozen sushi SS or in the space very close to the frozen sushi SS.

[0058] In addition to or instead of providing a protrusion on the tray 11, the guide 300 may guide the placement of the frozen sushi SS by visually indicating its placement position. For example, the guide 300 may be a line indicating the placement position of the frozen sushi.

[0059] The guide 300 may also indicate and guide the type of frozen sushi SS to be placed (e.g., the type of sushi topping). The type of frozen sushi SS to be placed may be indicated by text information, or by image information (such as a photo or illustration of each type of sushi topping). The guide 300 described above allows the frozen sushi SS to be placed on the tray 11 with the appropriate type of frozen sushi SS, or in the appropriate position.

[0060] The guide 300 may be provided for only some of the frozen sushi service stations, as in the example of Figure 3. Alternatively, the guide 300 may be provided for all of the frozen sushi service stations placed on the tray 11.

[0061] As yet another example, as shown in Figure 5, the portion of the tray 11 where the frozen sushi SS is placed may be provided with an uneven portion 500. The uneven portion 500 may be formed, for example, by embossing. Furthermore, as shown in Figure 6, the portion of the tray 11 where the frozen sushi SS is placed may be provided with a mesh portion 600 that allows steam and the like to pass through. The present disclosure also includes examples in which the tray 11 is provided with both the uneven portion 500 and the mesh portion 600.

[0062] The specific shape of the uneven portion 500 may be selected arbitrarily. In one example, the shape of the uneven portion 500 is a repeated uneven shape that is smaller than the size of a grain of rice in a frozen sushi SS.

[0063] Furthermore, the mesh size (mesh pitch), opening rate, wire diameter, thickness, and other parameters of the mesh portion 600 may be selected arbitrarily. In one example, the mesh portion 600 has mesh openings smaller than the size of rice grains in frozen sushi SS. In another example, the opening rate of the mesh of the mesh portion 600 may be approximately 70% (73.7%). In yet another example, the mesh pitch may be approximately 1 mm. In yet another example, the mesh thickness may be approximately 0.5 mm.

[0064] The uneven portion 500 or mesh portion 600 reduces the contact area between the tray 11 and the underside of the rice in the frozen sushi SS. In other words, the uneven portion 500 or mesh portion 600 creates a gap between the tray 11 and part of the underside of the rice in the frozen sushi SS. This is thought to prevent the thawed rice from sticking to the tray 11 and make it easier to apply steam or the like relatively evenly to the rice in the frozen sushi SS.

[0065] The reason why the mesh section 600 has the above-mentioned effect is thought to be that the frozen sushi SS (at least a part of it) does not come into direct contact with the tray 11, and steam, etc. (at least a part of it) is not sprayed directly onto the frozen sushi SS. In light of the above, the "mesh section" referred to in this disclosure is not limited to a simple net-like member, but also includes members that exhibit the above-mentioned effects, such as sheet-like nonwoven fabric.

[0066] The uneven portion 500 or mesh portion 600 may be provided over the entire top surface of the tray 11 (the surface on which the frozen sushi SS is placed). Alternatively, the uneven portion 500 or mesh portion 600 may be provided only on a portion of the tray 11. The uneven portion 500 or mesh portion 600 is provided to prevent the rice in the frozen sushi SS from adhering to the tray 11 or to make it easier for steam and the like to be applied relatively evenly to the rice in the frozen sushi SS. Therefore, in one example, the uneven portion 500 or mesh portion 600 is provided around at least one hole 111.

[0067] The following describes the method for thawing frozen sushi according to this embodiment. The method involves applying steam or the like through holes 111 to the frozen sushi SS placed on the tray 11. The frozen sushi SS is placed on the tray 11 with the frozen rice facing downwards. When thawing the frozen sushi SS, the area around the tray 11 is open to the outside air.

[0068] The method for thawing frozen sushi of this embodiment may also include a step of placing the frozen sushi SS with the frozen rice facing down on the tray 11. The method for thawing frozen sushi of this embodiment may also include a step of generating steam or the like. The step of generating steam or the like may include a step of generating steam or the like using a steam generating device 3, for example. More specifically, the step of generating steam or the like may include a step of reacting a heat generating material 13 with water 15 in a predetermined location, for example, inside a reaction vessel 14.

[0069] The method for thawing frozen sushi of this embodiment may include a step of connecting the thawing appliance 2 and the steam generating appliance 3. The step of connecting the thawing appliance 2 and the steam generating appliance 3 may include a step of defining a sealed space between the thawing appliance 2 and the steam generating appliance 3.

[0070] The method for thawing frozen sushi of this embodiment, as explained above, does not require equipment such as a microwave oven, and allows for separate temperature control of the rice and topping of frozen sushi SS, preventing the rice from turning white and waxy while preventing the topping from being cooked or burnt. Furthermore, the method for thawing frozen sushi of this embodiment provides a technique for thawing frozen sushi with minimal effort and cost, regardless of the eating location, the presence or absence of cooking equipment, or the sushi-making skills of the eater (or the sushi provider). Furthermore, the method for thawing frozen sushi of this embodiment prevents the frozen sushi from drying out when thawing.

[0071] The details of this embodiment are explained below. For example, in FIG. 1 , a frozen sushi SS with 10 pieces of sushi is placed on a tray 11. In the example of FIG. 1 , a hole 111 is formed on the tray 11 in the location where one piece of frozen sushi will be placed. In the example of FIG. 1 , the number of holes 111 for each individual piece of frozen sushi, i.e., the number of holes 111 per piece of frozen sushi, is three. The number of holes 111 for each individual piece of frozen sushi is not limited to three, and any number is possible. However, from the perspective of uniformly heating the frozen sushi, the number of holes 111 for each individual piece of frozen sushi is preferably two or more, and more preferably three or more. Furthermore, in the example of FIG. 1 , since the frozen sushi SS has 10 pieces of sushi, the tray 11 has 10 locations where the 10 pieces of frozen sushi SS will be placed, with the holes 111 formed in groups of three.

[0072] The shape of each hole 111 may be, for example, circular. The size of each hole 111 may be, for example, between 2 mm and 5 mm in diameter. When multiple holes 111 are used for one piece of frozen sushi, the longest distance between the holes may be, for example, between 16 mm and 22 mm.

[0073] The shape and size of the holes 111 and the distance between the holes (hereinafter referred to as "the shape of the holes 111") may be determined depending on the size, type, freezing temperature, etc. of the frozen sushi SS (hereinafter referred to as "the size of the frozen sushi SS"). The temperature and amount of steam, etc. required to thaw the frozen sushi SS varies depending on the size, etc. of the frozen sushi SS. By changing the shape of the holes 111, it is possible to adjust the temperature and amount of steam, etc. passing through the holes 111. Furthermore, the shape of the holes 111 may be determined depending on the position of the holes 111 on the tray 11, the positional relationship between the holes 111 and the steam generating device 3 (more specifically, the source of steam, etc. (in the example of Figure 1, the reaction vessel 14)), the temperature and amount of steam, etc. generated by the steam generating device 3, etc. (hereinafter referred to as "the position of the holes 111 on the tray 11"). The temperature and amount of steam, etc. passing through each individual hole 111 varies depending on the position of the hole 111 on the tray 11, but by changing the shape of the hole 111, etc., it is possible to adjust the temperature and amount of steam, etc. passing through the hole 111.

[0074] Figure 2 is a top view of the tray 11. The tray 11 in Figure 2 has an outer periphery measuring 225 mm x 225 mm. The tray 11 is made of a heat-resistant material that is a composite of polypropylene and talc. The tray 11 also has an outer edge 112 and a sushi placement area 113.

[0075] The upper edge of the outer box 12 comes into contact with the underside of the outer edge portion 112 (the surface opposite to the surface (upper surface) shown in Figure 2), thereby connecting the thawing device 2 and the steam generating device 3, and the tray 11 is positioned above the opening of the outer box 12.

[0076] The sushi placement area 113 is a flat area recessed from the outer edge 112, measuring 150 mm x 150 mm. The sushi placement area 113 has holes 111 formed in the areas where the frozen sushi SS will be placed (10 locations in this example).

[0077] The outer box 12 in Fig. 1 is a cardboard box having external dimensions of 195 mm x 195 mm x 70 mm high, and is open at the top (having an opening formed therein). The tray 11 is connected to the top of the outer box 12 by a portion of the underside of the outer edge 112 of the tray 11 contacting the edge of the top of the outer box 12 (the periphery of the opening).

[0078] In this embodiment, the heat generating material 13 is made primarily of aluminum powder and calcium oxide powder, and when it comes into contact with water 15, it causes a primary reaction of the following chemical formula (1) and a secondary reaction of the following chemical formula (2): CaO + H2O → Ca(OH)2 ... (1) 2Al + 3Ca(OH)2 → 3CaO.Al2O3 + 3H2 ... (2) The heat generating material 13 is not particularly limited to the above-mentioned materials used in this embodiment, and any material may be used as long as it undergoes an exothermic reaction when it comes into contact with water 15 and generates high-temperature steam or the like.

[0079] In this embodiment, the reaction vessel 14 is configured as a heat-resistant tray measuring 160 mm x 120 mm x 40 mm in height. However, the reaction vessel 14 is not limited to this, and any reaction vessel can be used as long as it is made of a material that can withstand the heat generated by the exothermic material 13 and has a material and size that prevents leakage or spillage of the water 15. The reaction vessel 14 may also be provided with a reference line indicating the appropriate amount of water.

[0080] 7A to 7I show the results of an experiment in which sushi with 10 different toppings was thawed under different conditions using the thawing device 1 shown in Fig. 1. The conditions relate to the shape of the holes 111, the amount of heat-generating agent, and the presence or absence of the mesh section 600. Specifically, the state of the sushi was recorded after adding water that releases steam when reacting with water and waiting for 15 minutes.

[0081] Although one embodiment of the present disclosure has been described above, the present disclosure is not limited to the above-described embodiment, and modifications, improvements, etc. within the scope of achieving the object of the present disclosure are included in the present disclosure. It should be noted that the advantages of the present embodiment described above are merely examples, and the scope of the present disclosure includes configurations that provide advantages other than the above advantages, as well as configurations that provide only some of the above advantages.

[0082] 1: Frozen sushi thawing device, 2: Device for thawing frozen sushi (thawing device), 3: Steam, water vapor or steam generating device (steam generating device), 11: Tray, 12: Outer box, 13: Heat generating material, 14: Reaction container, 15: Water, 111: Hole, 112: Outer edge, 113: Sushi placement section, 300: Guide, 500: Uneven section, 600: Mesh section, SS: Frozen sushi

Claims

1. A device for thawing frozen nigiri sushi or gunkanmaki, comprising: A tray on which the nigiri sushi or the gunkanmaki can be placed is provided, The tray has a plurality of holes, When the nigiri sushi or gunkanmaki is placed on a tray with the rice facing down, the device can thaw the nigiri sushi or gunkanmaki by applying steam, water vapor or steam from holes to the underside.

2. An apparatus as described in claim 1, wherein a hole is provided in the area of ​​the tray where the nigiri sushi or gunkanmaki is placed.

3. The apparatus described in claim 1, wherein the tray is provided with a guide indicating the position where the nigiri sushi or gunkanmaki is placed.

4. The device described in claim 3, wherein a hole is provided on the inside of the guide.

5. The tray has an uneven portion in the area where the nigiri sushi or gunkanmaki is placed, The device according to claim 1 , wherein the shape of the uneven portion is a repeating shape of unevenness smaller than the size of a grain of rice.

6. The apparatus described in claim 1, wherein the tray has a mesh portion in the area where the nigiri sushi or gunkanmaki is placed, which allows steam, water vapor or vapor to pass through.

7. An apparatus according to claim 1; Frozen nigiri sushi or gunkanmaki placed on a tray; Equipped with utensils, food.

8. An apparatus according to claim 1; A device for generating steam, water vapor or steam; A defrosting device comprising:

9. The steam, water vapor or steam generating device comprises a reaction vessel for reacting a heat generating material with water to generate the steam, water vapor or steam. The defrosting device of claim 8 .

10. A method for thawing frozen nigiri sushi or gunkanmaki, comprising the steps of: This thawing method includes a device having a tray on which the nigiri sushi or gunkanmaki can be placed, the tray being provided with a number of holes, and the nigiri sushi or gunkanmaki is placed on the tray with the rice facing downward, and the nigiri sushi or gunkanmaki is thawed by applying steam, water vapor or steam from the holes to the underside.