Packaged frozen food, method for thawing packaged frozen food, method for producing packaged frozen food, and package container

Abstract

Provided are: a packaged frozen food that is suitable for thawing of a frozen food by heating even when preferable heating degrees vary depending on parts of the frozen food; a method for thawing a packaged frozen food; a method for producing a packaged frozen food; and a package container.　A packaged frozen food according to the present invention is intended to be thawed by heating upon eating, and comprises: a frozen food which has a first part that requires heating during thawing by heating and a second part that requires heating at a lower degree compared with the first part or does not require heating; and a cold storage agent which is disposed corresponding to the second part, can absorb and / or reflect microwaves, and is obtained by cooling a liquid composition and / or a gel-like composition.

Description

Packaged frozen foods, thawing method for packaged frozen foods, manufacturing method for packaged frozen foods, and packaging containers Cross-reference to related applications 【0001】 This application claims priority based on Japanese Patent Application: Japanese Patent Application No. 2024-217365 filed in Japan on December 12, 2024, and incorporates the entire content thereof by reference. 【0002】 The present invention relates to packaged frozen foods, a thawing method for packaged frozen foods, a manufacturing method for packaged frozen foods, and packaging containers. 【0003】 Frozen foods that are frozen, distributed in a frozen state, and thawed and served at consumption locations such as homes and restaurants are generally widely distributed. Such frozen foods are convenient for cooking at the consumption location and in some cases do not require cooking, can be stored for a long time, and can be thawed and served when needed. 【0004】 As thawing methods for frozen foods, in addition to natural thawing and running water thawing, heat thawing using a microwave oven or the like is common. Among these, heat thawing is widely used because the thawing time can be significantly shortened compared to natural thawing and running water thawing. 【0005】 On the other hand, heat thawing generally heats the entire frozen food, but since heat rapidly flows into the frozen food from its surface, uneven thawing is likely to occur in the thawed food, and it is also difficult to select the thawed part of the food when it is sufficiently heated. Therefore, there are many frozen foods that are not suitable for heat thawing. 【0006】 For example, in frozen sushi, the ingredients (sushi toppings) and rice are frozen simultaneously. While the rice requires sufficient heating, excessive heating of the raw sushi toppings causes deterioration of the sushi toppings, resulting in loss of the flavor and texture of the resulting sushi. Therefore, frozen foods such as frozen sushi, where the preferred thawing degree varies by part, are generally not suitable for heat thawing using a microwave oven or the like, and it is common to use running water thawing or the like as the thawing method. 【0007】Patent Document 1 proposes a packaging container for frozen foods that allows for quick thawing of frozen sushi, characterized by forming an electromagnetic wave shielding layer on the inner wall surface of the packaging container around the ingredients, and forming an electromagnetic induction heating layer on the inner wall surface of the packaging container around the molded rice portion. 【0008】 Japanese Patent Publication No. 2010-126181 【0009】 The frozen food packaging container described in Patent Document 1 employs an electromagnetic shielding layer to suppress heating of the contents, but aluminum is used for the electromagnetic shielding layer. When using microwaves such as those used in microwave ovens, the use of large amounts of metal is undesirable. Furthermore, the frozen food packaging container described in Patent Document 1 cannot be used for heating and thawing by methods other than microwaves, such as heating and thawing by steam. 【0010】 Therefore, the object of the present invention is to provide packaged frozen foods suitable for heating and thawing, even for frozen foods where the preferred degree of heating differs depending on the part of the food, a method for thawing packaged frozen foods, a method for manufacturing packaged frozen foods, and a packaging container. 【0011】 As a result of diligent research to achieve the above objective, the inventors of the present invention have discovered that by arranging a cooling agent of a liquid composition and / or gel composition capable of absorbing and / or reflecting microwaves in a location corresponding to a portion of the frozen food that requires a lower degree of heating or does not require heating at all, it is possible to appropriately heat and thaw frozen food even if the preferred degree of heating differs depending on the part of the food, leading to the present invention. 【0012】The gist of the present invention is as follows: (1) A packaged frozen food that is heated and thawed for consumption, comprising: a frozen food having a first portion that requires heating during heating and thawing and a second portion that requires heating to a lower degree than the first portion or does not require heating; and a refrigerant provided in correspondence with the second portion, capable of absorbing and / or reflecting microwaves, and comprising a cooled liquid composition and / or gel composition. (2) The packaged frozen food according to (1), wherein the refrigerant is solidified. (3) The packaged frozen food according to (1) or (2), wherein the refrigerant contains water. (4) The packaged frozen food according to (1), further comprising a food carrier that supports the frozen food, wherein the frozen food is arranged such that the second portion is in contact with a part of the food carrier, and the refrigerant is arranged in contact with the opposite side of the portion of the food carrier to which the second portion is in contact. (5) The packaged frozen food according to (4), further comprising a cold agent carrier for supporting the cold agent, wherein the cold agent is disposed between the food carrier and the cold agent carrier. (6) The packaged frozen food according to (4) or (5), wherein the food carrier has a food carrying portion that forms a recess capable of supporting the frozen food and a convex portion that forms in the direction opposite to the frozen food. (7) The packaged frozen food according to (6), further comprising a cold agent carrier for supporting the cold agent, wherein the cold agent carrier has a recess in a portion corresponding to the convex portion of the food carrier. (8) The packaged frozen food according to any one of (1) to (7), wherein the frozen food is frozen sushi. (9) A method for thawing a packaged frozen food, comprising heating the packaged frozen food according to any one of (1) to (8). (10) A method for producing a packaged frozen food, comprising simultaneously cooling a pre-frozen food having a first portion that requires heating when frozen and a second portion that requires heating to a lower degree than the first portion or does not require heating, and a refrigerant of a liquid composition and / or gel composition installed corresponding to the second portion and capable of absorbing and / or reflecting microwaves.(11) A packaging container for packaging a frozen food that is to be heated and thawed before consumption and has a first portion that requires heating and a second portion that requires heating to a lower degree than the first portion or does not require heating, comprising: a food carrier having a food carrier portion for carrying the frozen food; and a cold agent carrier for carrying a cold agent which is a cooled liquid composition and / or gel composition, wherein the food carrier is configured such that the second portion of the frozen food is in contact with the food carrier portion, and the cold agent carrier is configured such that the cold agent is in contact with the food carrier portion from the side opposite to the frozen food. (12) The packaging container according to (11), wherein the food carrier has a recess so as to be able to carry the frozen food and a convex portion in the direction opposite to the frozen food. (13) The packaging container according to (12), wherein the cold agent carrier has a recess as a cold agent carrier portion in a portion corresponding to the convex portion of the food carrier. 【0013】 As described above, the present invention provides packaged frozen foods suitable for heating and thawing, even for frozen foods where the preferred degree of heating differs depending on the part of the food, a method for thawing packaged frozen foods, a method for manufacturing packaged frozen foods, and a packaging container. 【0014】 Figure 1 is an exploded perspective view of a packaged frozen food according to the first embodiment of the present invention. Figure 2 is a longitudinal cross-sectional view of the packaged frozen food shown in Figure 1. Figure 3 is a schematic cross-sectional view showing an example of how to remove the food from the packaged frozen food shown in Figure 1 after heating and thawing. Figure 4 is a schematic diagram illustrating the vicinity of the longitudinal end of the packaging container of the packaged frozen food shown in Figure 1. Figure 5 is a schematic diagram showing an example of how to manufacture the packaged frozen food shown in Figure 1. Figure 6 is a longitudinal cross-sectional view showing an example of a modified example of the packaged frozen food according to the first embodiment of the present invention. Figure 7 is a longitudinal cross-sectional view showing another example of a modified example of the packaged frozen food according to the first embodiment of the present invention. Figure 8 is a longitudinal cross-sectional view of a packaged frozen food according to the second embodiment of the present invention. Figure 9 is an exploded perspective view of a packaged frozen food according to the second embodiment of the present invention. Figure 10 is a cross-sectional view of the packaged frozen food shown in Figure 9. Figure 11 is a cross-sectional view of a packaged frozen food according to the fourth embodiment of the present invention. 【0015】Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. <1. First Embodiment> First, a first embodiment of the present invention will be described. Figure 1 is an exploded perspective view of a packaged frozen food according to the first embodiment of the present invention, Figure 2 is a longitudinal cross-sectional view of the packaged frozen food shown in Figure 1, Figure 3 is a schematic cross-sectional view showing an example of how to remove the food after heating and thawing the packaged frozen food shown in Figure 1, Figure 4 is a schematic diagram illustrating the vicinity of the longitudinal end of the packaging container of the packaged frozen food shown in Figure 1, and Figure 5 is a schematic diagram showing an example of how to manufacture the packaged frozen food shown in Figure 1. 【0016】 (1.1. Packaged Frozen Food and Packaging Container) First, a packaged frozen food and packaging container according to the first embodiment of the present invention will be described. The packaged frozen food 1 shown in Figures 1 and 2 is a packaged food in which frozen food 40 is packaged in a packaging container 100. The packaged frozen food 1 comprises a packaging container 100 having a lid member 10, a food carrier 20 and a cold storage agent carrier 30, frozen food 40 and a cold storage agent 50. 【0017】 As shown in Figures 1 and 2, in the packaged frozen food 1, the lid member 10, the frozen food 40, the food carrier 20, the cold storage agent 50, and the cold storage agent carrier 30 are stacked in this order. The packaged frozen food 1 is also further packaged with a plastic bag or shrink film, etc., as needed (not shown). 【0018】 In this embodiment, the frozen food 40 is a so-called temari sushi, in which the rice-formed portion (first part) 41 and the topping (second part) 43 are integrated to form a spherical shape, and it is thawed before consumption. When heating and thawing such a frozen food 40, the rice-formed portion 41 needs to be sufficiently heated to a suitable temperature, while the topping 43, which is often raw such as sashimi, needs to be thawed at a low temperature with reduced heating. In other words, when heating and thawing, the topping 43 is a part that requires heating at a lower level than the rice-formed portion 41, or does not require heating at all. In this embodiment, the frozen food 40 is arranged in two rows of four in each of the packaging containers 100. The topping 43 of each frozen food 40 may be the same or different. 【0019】The lid member 10, food carrier 20, and cold agent carrier 30 that constitute the packaging container 100 are each components obtained by sheet molding of a sheet of microwave-permeable resin material (for example, polystyrene, polypropylene, or a material mainly composed of silicone). In plan view, the lid member 10, food carrier 20, and cold agent carrier 30 each have a roughly rectangular shape of approximately the same size as their basic form. 【0020】 The lid member 10 is a lid for sealing the food carrier 20 of the packaging container 100 from above. The lid member 10 has a flat base plate 11, a protrusion 13, and ribs 15 formed around the base plate 11. The protrusion 13 protrudes upward, that is, on the opposite side from the food carrier 20, at a position corresponding to where the frozen food 40 is placed on the base plate 11, forming a curved (spherical) convex portion. Therefore, the lid member 10 has a total of eight protrusions 13, four in each of two rows along the longitudinal direction. Furthermore, the shape of the protrusion 13 on the food carrier 20 side corresponds to the shape of the frozen food 40. Therefore, as shown in Figure 3, after heating and thawing, it is possible to invert the food carrier 20 together with the lid member 10 and carry the thawed food 40' on the protrusion 13. 【0021】 The ribs 15 are formed around the base material 11, projecting downward, that is, toward the food carrier 20. By forming these ribs 15 three-dimensionally around the lid member 10, the mechanical strength of the lid member 10 as a whole is increased. Furthermore, by projecting downward from the base material 11, the ribs 15 come into contact with the ribs 25 of the food carrier 20, thereby preventing contact between the base material 11 of the lid member 10 and the base material 21 of the food carrier 20. This reduces the contact area between the lid member 10 and the food carrier 20, preventing the lid member 10 and the food carrier 20 from sticking together due to static electricity or water generated during thawing, which would make it difficult to remove the lid member 10. 【0022】The food carrier 20 is a tray for carrying frozen food 40. The food carrier 20 has a flat base material 21, food carrying sections 23, and ribs 25. The food carrying sections 23 are the parts for carrying frozen food 40. Therefore, eight food carrying sections 23 are provided on the food carrier 20, in two rows of four along the longitudinal direction. 【0023】 The food-carrying portion 23 is circular in shape when viewed from above, corresponding to the shape of the frozen food 40. The food-carrying portion 23 protrudes downward from the base material 21, that is, in the direction opposite to the frozen food 40 and the lid member 10, thereby forming a recess and a convex portion in the direction opposite to the frozen food 40 and the lid member 10. As a result, the food-carrying portion 23 forms a recess such that the tip of the cylinder forms a curved surface. The food-carrying portion 23 is capable of carrying the frozen food 40 through the formed recess. In such a food-carrying portion 23, the frozen food 40 is carried such that its contents 43 are positioned below the recess of the food-carrying portion 23. Thus, the frozen food 40 is positioned so that its contents 43 are in contact with the lower part of the recess of the food-carrying portion 23. 【0024】 Furthermore, near the base material 21 of the food-carrying portion 23, there are protrusions 231 that project in the planar and depth directions of the base material 21. The protrusions 231 contact the base material 31 of the cold-storage agent carrier 30 or the protrusions 331 together with the ribs 25 to support the food-carrying portion 23, so that the base material 21 of the food-carrying portion 23 and the base material 31 of the cold-storage agent carrier 30 are separated. This assists the function of the ribs 25, which will be described later. 【0025】The rib 25 shown in Figure 1 is formed around the base material 21, projecting upward, that is, toward the lid member 10. By forming such a rib 25 three-dimensionally around the food carrier 20, it increases the overall mechanical strength of the food carrier 20. Also, as shown in Figure 2, in relation to the lid member 10, the rib 25 abuts against the rib 15 as described above, making it easier to remove the lid member 10. Furthermore, in relation to the cold storage agent carrier 30, which will be described later, the rib 25 engages with the rib 35 of the cold storage agent carrier 30, making slight contact and supporting the food carrier 20 with the cold storage agent carrier 30. In this case, the food carrier 20 is supported by the cold storage agent carrier 30 via the ribs 25 and 35, so that the base material 21 is positioned spaced apart from the base material 31 of the cold storage agent carrier 30. This reduces the contact area between the food carrier 20 and the cold pack carrier 30, preventing them from sticking together due to static electricity or water generated during thawing, and making it easier to remove the food carrier 20 from the cold pack carrier 30 after heating and thawing. 【0026】 The cold storage agent carrier 30 shown in Figure 1 is a tray for carrying the cold storage agent 50. The cold storage agent carrier 30 has a flat base plate 31, a cold storage agent carrying portion 33, and ribs 35. The cold storage agent carrying portion 33 is the part for carrying the cold storage agent 50, which will be described later. Since the cold storage agent 50 is placed in a position corresponding to the frozen food 40, eight cold storage agent carrying portions 33 are provided in total, four in two rows corresponding to the positions of the food carrying portion 23 of the food carrier 20. 【0027】The cold storage agent carrying portion 33 is circular in shape when viewed from above, corresponding to the shape of the food carrying portion 23. The cold storage agent carrying portion 33 protrudes downward from the base material 31, that is, in the direction opposite to the food carrying portion 23, forming a recess where the tip of the cylinder forms a curved surface. As shown in Figure 2, the cold storage agent carrying portion 33 covers the area below the protrusion formed by the food carrying portion 23 via a gap, which is a space 331, and the cold storage agent 50 can be filled into the space 331. This makes it possible to efficiently obtain the heating reduction effect of the cold storage agent 50 while reducing the amount of cold storage agent 50 used, as described later. Furthermore, because the cold storage agent carrying portion 33 is provided in correspondence with the food carrying portion 23, each cold storage agent carrying portion 33 can individually carry the cold storage agent 50, as described later. This prevents the liquid and / or gel-like refrigerant 50 from flowing freely during the manufacturing of the packaged frozen food 1, and makes it possible to distribute a uniform amount of refrigerant 50 to each frozen food 40. This makes it possible to more reliably suppress uneven thawing among the frozen foods 40 during thawing. 【0028】 As described above, the space 331 of the cold storage agent carrying section 33 can be filled with a cold storage agent 50. Therefore, by changing the volume of the space 331, the amount of cold storage agent 50 can be changed, and the heating reduction effect of the cold storage agent 50 can be adjusted. The volume of the space 331 can be adjusted by adjusting the distance d between the bottom of the cold storage agent carrying section 33 and the tip of the protrusion of the food carrying section 23. This distance d is not particularly limited and can be set appropriately depending on the type of frozen food 40, but for example, it is 1.0 mm to 30 mm, preferably 3.0 mm to 20 mm, and more preferably 5.0 mm to 10 mm. 【0029】 Furthermore, protrusions 333 are provided near the base material 31 of the cold storage agent carrying portion 33, projecting in the planar and depth directions of the base material 31. The protrusions 333 are formed at positions corresponding to the protrusions 231 of the food carrying portion 23, making it possible to reduce the contact area between the protrusions 231 and the base material 31 of the cold storage agent carrying portion 33. This assists the function of the ribs 35, which will be described later. 【0030】The ribs 35 shown in Figure 1 are formed around the base material 31, projecting upward, that is, towards the food carrier 20. By forming these ribs 35 three-dimensionally around the cold agent carrier 30, the mechanical strength of the cold agent carrier 30 as a whole is increased. Furthermore, as shown in Figure 2, the ribs 35 engage with the ribs 25 of the food carrier 20, making slight contact and supporting the food carrier 20 with the cold agent carrier 30. As described above, the contact area between the food carrier 20 and the cold agent carrier 30 is reduced, preventing the food carrier 20 and the cold agent carrier 30 from sticking together due to static electricity or water generated during thawing, and making it easier to remove the food carrier 20 from the cold agent carrier 30 after heating and thawing. 【0031】 Furthermore, as shown in Figures 1 and 4, at the longitudinal end of the base material 31, the rib 35 is recessed toward the base material 31, forming a recessed portion 37. As shown in Figure 4, when the food carrier 20 and the cold agent carrier 30 are superimposed and viewed from above, the cold agent carrier 30 is absent at the location where this recessed portion 37 is formed, and only the food carrier 20 is present. Therefore, when removing the food carrier 20 from the cold agent carrier 30 together with the thawed food 40' after heating and thawing, it is possible to lift the food carrier 20 with a finger 200 in the recessed portion 37. 【0032】 The cold pack 50 is supported on the cold pack carrier 30 and placed in the space 331 between the cold pack carrier 30 and the food carrier 20. The cold pack 50 is positioned in a location corresponding to the topping 43 of the frozen food 40. In this embodiment, the cold pack 50 is positioned to cover the topping 43 of the frozen food 40 via the food carrying portion 23 of the food carrier 20. 【0033】The cold storage agent 50 is a cooled cold storage agent of a liquid composition and / or gel composition capable of absorbing and / or reflecting microwaves. That is, the cold storage agent 50 is cooled together with the packaged frozen food 1 before heating and thawing. This allows the ingredients 43 to be cooled during heating and thawing. The cold storage agent 50 may be solidified, liquid, or gel-like in the packaged frozen food 1 before heating and thawing. If the cold storage agent 50 is solidified in the packaged frozen food 1 before heating and thawing, handling such as transporting the packaged frozen food 1 becomes easier. 【0034】 Furthermore, because the cold storage agent 50 is capable of absorbing and / or reflecting microwaves, when heating and thawing using microwaves, for example when using a microwave oven, it is possible to suppress the microwaves from reaching the topping 43 of the frozen food 40, thereby allowing the topping 43 to be heated more gently. 【0035】 Furthermore, the cold storage agent 50 is a liquid composition and / or gel composition before cooling, that is, under a general temperature environment such as room temperature (5 to 40°C). This allows the cold storage agent 50 to be placed in a fluid state during the manufacturing of the packaged frozen food 1, and makes it possible to place it in close contact with the food carrying portion 23 regardless of the shape of the food carrying portion 23. In this embodiment in particular, by placing the cold storage agent carrier 30 below the food carrying portion 20 and placing the cold storage agent 50 below the food carrying portion 20, it is possible to make the cold storage agent 50 adhere closely to the food carrying portion 23. 【0036】The liquid and / or gel-like compositions constituting such a cold storage agent 50 are not limited as long as they are liquid or gel-like in a general temperature environment (5 to 40°C) such as room temperature and capable of absorbing and / or reflecting microwaves; for example, water can be used. Furthermore, these may be gelled with any gelling agent as needed. Examples of gelling agents include natural and synthetic gelling agents, which can be used individually or in combination of two or more. Examples of natural gelling agents include alginates such as sodium alginate, guar gum (unmodified), modified guar gum, xanthan gum, thickening polysaccharides such as caranagin, and gelatin. Examples of synthetic gelling agents include carboxymethylcellulose, sodium polyacrylate, polyvinyl alcohol, and acrylamide. Among the above, the cold storage agent 50 preferably contains water, and more preferably consists of water. Water can suitably absorb microwaves, has very little impact on the human body, and is easy to handle. Furthermore, when using a gelling agent, it is preferable to use a natural gelling agent. The configuration of the packaged frozen food 1 according to this embodiment has been described above. 【0037】 (1.2. Method for Thawing Packaged Frozen Food) Next, a method for thawing the packaged frozen food 1 according to this embodiment will be described, along with an explanation of the effects of the packaged frozen food 1 according to this embodiment. The method for thawing the packaged frozen food 1 according to this embodiment includes heating (heat thawing) the packaged frozen food 1. 【0038】 Such heating and thawing methods include microwave heating and thawing using a microwave oven, hot water thawing, and steam thawing, and one of these can be used alone or in combination of two or more. Among these, microwave heating and thawing is preferred because it allows for rapid thawing of the frozen food 40, and the cold storage agent 50 absorbs and / or reflects the microwaves, protecting the ingredients 43 from excessive heating and enabling gentle thawing of the ingredients. 【0039】During heating and thawing, the packaged frozen food 1 is generally heated throughout. In the frozen food 40, the rice portion 41 is heated in the same way as the other parts, while the topping 43 is cooled by a cooling agent 50 placed in the corresponding position, which blocks heat. Furthermore, since heat flows into the topping 43 via the cooling agent 50, the rate at which heat flows into the topping 43 is reduced. As a result, the topping 43 is heated and thawed gently, preventing it from being overheated. The topping 43 is often raw, and if it is overheated, the proteins will denature, resulting in a loss of texture and flavor. In this embodiment, heating and thawing the packaged frozen food 1 prevents this from happening. 【0040】 In particular, when heating and thawing is performed using microwaves such as in a microwave oven, the cold pack 50 blocks the microwaves, preventing direct heating of the filling 43. Then, heat from the rice-forming section 41 heated by the microwaves and heat from the cold pack 50 whose temperature has risen due to the microwaves flow into the filling 43, and the filling 43 is heated gently. Heating and thawing with microwaves allows for rapid thawing compared to other thawing methods, but on the other hand, because heat flows into the thawed food rapidly, it is not easy to adjust the degree of thawing, and it was especially difficult to adjust the degree of thawing for each part. However, in this embodiment, by using packaged frozen food 1, it is possible to appropriately heat and thaw frozen food 40 having a rice-forming section 41 and filling 43, that is, frozen food 40 where the preferred degree of heating differs depending on the part. 【0041】Incidentally, the frozen food 40 in the present embodiment is frozen sushi and includes a cooked rice forming section 41. The starch of the cooked rice that constitutes the cooked rice forming section 41 can take two forms: α-starch with a loosened (amorphous) crystal structure and β-starch with a crystal structure. Normally cooked rice is α-starch due to heating, but when cooled and frozen, it crystallizes and transforms into β-starch. β-starch is crumbly and has lost its chewy and delicious texture. Generally, in heating frozen sushi, how to convert it into α-starch is important. To convert β-starch in the rice of frozen sushi into α-starch, heating at 60°C or higher is required. 【0042】 In thawing by conventional natural thawing or running water thawing, while heating of the topping of frozen sushi is suppressed, it cannot be thawed at a temperature that can convert β-starch in the rice into α-starch. Furthermore, thawing by conventional natural thawing or running water thawing takes time. On the other hand, when heating and thawing conventional frozen sushi, problems such as denaturation of the protein of the topping due to heating as described above occur. 【0043】 In contrast, in the present embodiment, it is possible to directly heat and thaw the upper cooked rice forming section 41 while arranging the topping 43 below and protecting the topping 43 with the cold storage agent 50. Thereby, it becomes possible to raise the temperature of the cooked rice forming section 41 to an extent that enables α-starch formation, and the texture of the cooked rice forming section 41 can be improved. 【0044】 The food 40' thus heated and thawed is served for eating. In this case, first, as shown in FIG. 4, place the finger 200 in the recess 37 at the longitudinal end of the cold storage agent carrier 30, lift the food carrier 20, and the food carrier 20 can be removed from the cold storage agent carrier 30 together with the thawed food 40'. Then, as shown in FIG. 3, the food carrier 20 together with the lid member 10 can be turned upside down to carry the thawed frozen food 40 on the protruding portion 13 of the lid member 10. In this way, it is possible to directly eat the food 40' using the lid member 10 as a dish. Alternatively, the food 40' may be transferred from the lid member 10 to another dish and served for eating. 【0045】(1.3. Method for Producing Packaged Frozen Food) Next, a method for producing the packaged frozen food 1 according to the present embodiment will be described. The method for producing a packaged frozen food according to the present invention includes a pre-frozen food having a first portion that requires heating when frozen and a second portion that requires less heating or no heating than the first portion, and a liquid composition and / or a gel-like composition disposed corresponding to the second portion and capable of absorbing and / or reflecting microwaves. A cold storage agent, and cooling them simultaneously. In particular, in the method for producing the packaged frozen food 1 according to the present embodiment, the packaging container 100 in which the pre-frozen food 40'' and the cold storage agent 50 are arranged is cooled. 【0046】 First, as shown in FIG. 5(a), the pre-frozen food 40'' is placed on the food carrier portion 23 of the food carrier 20. Here, the pre-frozen food 40'' is arranged such that its ingredient 43 faces downward and contacts the bottom of the food carrier portion 23. On the other hand, the cold storage agent 50 is arranged in the cold storage agent carrier portion 33 of the cold storage agent carrier 30. 【0047】 Next, as shown in FIG. 5(b), the food carrier 20 carrying the pre-frozen food 40'' and the cold storage agent carrier 30 carrying the cold storage agent 50 are stacked such that the food carrier portion 23 contacts the cold storage agent 50. Here, since the cold storage agent 50 is in a gel-like or liquid state, it has fluidity. Therefore, when the food carrier portion 23 contacts the cold storage agent 50, the cold storage agent 50 is deformed and adheres closely to the bottom surface of the food carrier portion 23 from the opposite side of the pre-frozen food 40''. As a result, the cold storage agent 50 can adhere efficiently to the food carrier portion 23, and the cold storage agent 50 can efficiently cover the ingredient 43 of the pre-frozen food 40''. 【0048】 Next, as shown in FIG. 5(c), the lid member 10 is placed on the food carrier 20. Finally, the packaging container 100 including the lid member 10, the food carrier 20, and the cold storage agent carrier 30 is cooled in a state of carrying the pre-frozen food 40'' and the cold storage agent 50 as shown in FIG. 5(c). Thereby, the pre-frozen food 40'' and the cold storage agent 50 can be cooled simultaneously. 【0049】The cooling method is not particularly limited as long as it is a method that freezes the food 40'' before freezing. For example, rapid freezing methods such as air blast freezing, brine freezing, CAS (Cells Alive System) freezing, proton freezing, and 3D freezing may be used, or a slow freezing method in which the packaging container 100 is simply placed in a freezer may be used. 【0050】 As a result, the pre-freezing food 40'' freezes to become frozen food 40, and at the same time the cold storage agent 50 is cooled, resulting in packaged frozen food 1. The packaged frozen food 1 may be further packaged in a bag or shrink film, if necessary. This packaging with a bag or shrink film may be done before the cooling process described above. 【0051】 (1.4. Modified Examples) Next, some modified examples of this embodiment will be described. The following will mainly focus on the differences from the first embodiment described above, and similar configurations will not be described. Some of the components described in the first embodiment described above have been omitted from the following drawings for the sake of clarity. 【0052】 Figure 6 is a longitudinal cross-sectional view showing an example of a modified example of the packaged frozen food according to the first embodiment of the present invention. The packaged frozen food 1A shown in Figure 6 differs from the packaged frozen food 1 according to the first embodiment mainly in that the shape of the cold storage agent carrier 30A of the packaged container 100A is different from the shape of the cold storage agent carrier 30 of the packaged frozen food 1 according to the first embodiment described above. 【0053】In the cold pack carrier 30A, the base material 31 is present only at the periphery along with the ribs 35, and a wall portion 38 is formed in the depth direction from the base material 31 so as to surround all the cold pack carrier portions 33, with a bottom plate 39 formed at the tip of the depth direction, forming a single tray. Accordingly, the cold pack 50A is integrated and covers each of the contents 43 of the multiple frozen foods 40. In this case, it may be necessary to use a larger amount of cold pack 50A compared to the packaged frozen food 1 according to the first embodiment described above. When a large amount of cold pack 50A is used, the heat and energy for thawing originating from microwaves or other means are consumed by the cold pack 50A, which takes time to thaw, but a stronger heating reduction effect can be obtained from the cold pack 50A. 【0054】 It should be noted that the embodiment is not limited to the illustrated one. For example, the cold agent carrier may have multiple cold agent carriers corresponding to multiple food carriers 33. For example, in a packaged frozen food having A x B frozen food items 40, B cold agent carriers can be provided, each corresponding to one of the A food carriers 33. This allows for some of the effect of uniformly distributing the cold agent 50 in the first embodiment, while also partially achieving the strong heating reduction effect shown in Figure 6. The number of A and B can be adjusted considering the balance between these effects. 【0055】 Figure 7 is a longitudinal cross-sectional view showing another example of a modified packaged frozen food according to the first embodiment of the present invention. In the packaged frozen food 1B shown in Figure 7, the shape of the frozen food 40B differs from that of the frozen food 40 described above, and correspondingly, the shapes of each component of the packaging container 100B are different. 【0056】 The frozen food 40B is a type of nigiri sushi, and is generally roughly rectangular in shape. In this modified example, four frozen food 40B are placed in a single row in the packaging container 100B, with their longitudinal directions perpendicular to the longitudinal direction of the packaging container 100B. 【0057】On the lid member 10B, the protrusions 13B project upward at a position corresponding to the position where the frozen food 40B on the base material 11 is placed, that is, on the side opposite to the food carrier 20B. Therefore, four protrusions 13B are provided in a single row along the longitudinal direction on the lid member 10B. Furthermore, in a plan view, the protrusions 13B have a shape corresponding to the frozen food 40B, that is, a roughly rectangular shape. 【0058】 The food carrier 20B has food carrying portions 23B positioned at locations corresponding to where the frozen food 40B on the base material 11 is placed. Therefore, four food carrying portions 23B are provided in a single row along the longitudinal direction on the food carrier 20B. In plan view, the food carrying portions 23 are roughly rectangular in shape, corresponding to the shape of the frozen food 40. 【0059】 The cold agent carrier 30B has four cold agent carrying sections 33B arranged in a single row, corresponding to the positions of the food carrying sections 23B on the food carrier 20B. In plan view, the cold agent carrying sections 33B are roughly rectangular in shape, corresponding to the shape of the food carrying sections 23B. 【0060】 Other aspects are the same as in the first embodiment described above. However, the embodiment is not limited to the illustrated form, and for example, the refrigerant carrier 30B may have a single bat-shaped refrigerant carrier portion, as shown in Figure 6, for example, the refrigerant carrier 30A. 【0061】 Other variations include, for example, the number and placement of the protrusions 13 provided on the lid member 10, the food carrying parts 23 provided on the food carrier 20, and the cold pack carrying parts 33 provided on the cold pack carrier 30, which can be appropriately changed according to the number and placement of the frozen foods 40. 【0062】 Furthermore, the cooling agent 50 only needs to be placed for at least one of the frozen foods 40, and it is not necessary to place a cooling agent 50 for all of the frozen foods 40. Depending on the type of ingredients 43 of the frozen foods 40, some may require sufficient heating, in which case it is not necessary to place a cooling agent 50. 【0063】 Furthermore, the packaging container 100 may be made of a material other than resin. Examples of such materials include glass, ceramics, and paper. 【0064】 <2. Second Embodiment> Next, a packaged frozen food according to the second embodiment of the present invention will be described. Figure 8 is a longitudinal cross-sectional view of the packaged frozen food according to the second embodiment of the present invention. Hereinafter, the differences between this embodiment and the first embodiment and its modified examples described above will be the main focus of the explanation, and similar configurations will not be described. 【0065】 In the packaged frozen food 1C shown in Figure 8, the frozen food 40C is a long-shaped seafood roll sushi. The frozen food 40C is formed by covering a long-shaped topping 44 with cooked rice 45 and seaweed 46. The topping 44 is usually raw, such as tuna or salmon, and if it is subjected to excessive heat during heating and thawing, proteins and other components will denature, impairing its flavor and texture. The topping 44 is surrounded by cooked rice 45, and is protected from excessive heat by the cooked rice 45 during heating and thawing. On the other hand, the ends 441 on both sides are exposed to the outside of the frozen food 40C and are parts that are easily heated during heating and thawing. Therefore, in the frozen food 40C, the area near the ends 441 of the topping 44 can be designated as the second part 43C, and the other parts as the first part 41C. 【0066】 The packaging container 100C is a rectangular box corresponding to the shape of the frozen food 40C, and its length is adjusted so that its longitudinal end is spaced apart from the frozen food 40C to the extent that the cold storage agent 50C, described later, can be inserted. The cold storage agent 50C is a liquid or gel composition similar to the cold storage agent 50 in the first embodiment described above, which is stored in a container such as a bag and then cooled. The cold storage agent 50C is positioned so as to be in contact with the end 441 of the topping 44 of the frozen food 40C, that is, corresponding to the second portion 43C of the frozen food 40C. 【0067】In the packaged frozen food 1C described above, the cold storage agent 50C protects the second portion 43C near the end 441 of the filling 44 from excessive heating during heating and thawing, enabling thawing by gentle heating. In particular, when heating and thawing is performed by microwave, the cold storage agent 50C efficiently protects the second portion 43C from excessive heating. In addition, the first portion 41C, which is another part of the frozen food 40C, is heated as usual during heating and thawing. Thus, the packaged frozen food 1C according to the second embodiment can also appropriately heat and thaw the frozen food 40C, which has different preferred heating levels depending on the part. 【0068】 Furthermore, packaged frozen food 1C can also be manufactured by placing the rolled sushi and the cold pack 50C in a packaging container 100C and cooling the rolled sushi and the cold pack 50C simultaneously. 【0069】 <3. Third Embodiment> Next, a packaged frozen food according to the third embodiment of the present invention will be described. Figure 9 is an exploded perspective view of the packaged frozen food according to the second embodiment of the present invention, and Figure 10 is a cross-sectional view of the packaged frozen food shown in Figure 9. Hereinafter, the first embodiment and its modified forms, as well as the differences from the second embodiment described above, will be the focus of the explanation, and similar configurations will be omitted. 【0070】 In the packaged frozen food 1D shown in Figures 9 and 10, the frozen food 40D is a so-called seafood rice bowl 40D, and after thawing, seafood 43D is placed on top of rice 41D and served. In this embodiment, the rice 41D corresponds to the first part and the seafood 43D corresponds to the second part. The packaged frozen food 1D comprises a packaging container 100D, the frozen food 40D, and a cold storage agent 50D. 【0071】 The packaging container 100D has a bowl 60 and an inner lid 70. The bowl 60 holds cooked rice 41D. Meanwhile, seafood 43D is placed on the inner lid 70. The cold pack 50D is placed on top of the seafood 43D so as to cover it. The cold pack 50D is a liquid or gel composition similar to the cold pack 50 in the first embodiment described above, which is stored in a container such as a bag and then cooled. The cold pack 50D is stored in a flexible container and can be deformed to conform to the shape of the seafood 43D. 【0072】 Then, as shown in Figure 9, the bowl 60, cooked rice 41D, inner lid 70, seafood 43D, and cold pack 50D are stacked in this order, cooled, and integrated to form a packaged frozen food 1D. In the packaged frozen food 1D described above, the cold pack 50D protects the seafood 43D from excessive heating during heating and thawing, enabling thawing by gentle heating. In particular, when heating and thawing is performed by microwave, the cold pack 50D efficiently protects the second part, the seafood 43D, from excessive heating. In addition, the cooked rice 41D, which is the first part of the frozen food 40D, is heated as usual during heating and thawing. Thus, the packaged frozen food 1D according to the third embodiment can also appropriately heat and thaw the frozen food 40D, which has different preferred heating levels depending on the part. 【0073】 <4. Fourth Embodiment> Next, a packaged frozen food according to the fourth embodiment of the present invention will be described. Figure 11 is a cross-sectional view of the packaged frozen food according to the fourth embodiment of the present invention. Hereinafter, the first embodiment and its modified forms, as well as the differences from the second and third embodiments described above, will be the focus of the explanation, and similar configurations will be omitted. 【0074】 The packaged frozen food 1E shown in Figure 11 is a frozen bento box. The packaged frozen food 1E comprises a packaging container 100E, frozen food 40E, and a cold pack 50E. The frozen food 40E consists of cooked rice 411E, a main dish 413E, and a side dish 43E. In this embodiment, the main dish 413E is a grilled fish fillet or fried food, and the side dish 43E is a salad or pickles. Therefore, the cooked rice 411E and the main dish 413E are first parts 41E that are preferably heated thoroughly. On the other hand, the side dish 43E is a second part 43E that should be kept at a low temperature while thawing, as its flavor would be lost if it warmed up. 【0075】 The packaging container 100E is a bento box made of resin, and the box-shaped container body 81 is formed by a bottom plate 811 and side plates 813, with partitions 83 and 85 provided at intervals. In addition, an upper bottom plate 87 is positioned slightly higher than the bottom plate 811 in the space formed by the partition 85 and the side plate 813. 【0076】A cold storage agent 50E is placed between the upper bottom plate 87 and the bottom plate 811. The cold storage agent 50D is a liquid or gel-like composition similar to the cold storage agent 50 in the first embodiment described above, which has been cooled. 【0077】 Cooked rice 411E is placed between the side plate 813 and partition 83 of the packaging container 100E, the main side dish 413E is placed between partition 83 and partition 85, and the side dish 43E is placed on the top bottom plate 87. These are cooled and frozen together with the cooling agent 50E. 【0078】 In the packaged frozen food 1E described above, the cold storage agent 50E protects the side dish 43E from excessive heating during heating and thawing, enabling thawing by gentle heating. In particular, when heating and thawing is performed by microwave, the cold storage agent 50E efficiently protects the second part, the side dish 43E, from excessive heating. Furthermore, the first part 41E of the frozen food 40E, consisting of cooked rice 411E and the main dish 413E, is heated as usual during heating and thawing. Thus, the packaged frozen food 1E according to the fourth embodiment can also appropriately heat and thaw the frozen food 40E, which has different preferred heating levels depending on the part. 【0079】 Although the present invention has been described in detail above based on preferred embodiments, the present invention is not limited thereto, and each component can be replaced with any component that can perform a similar function, or any component can be added. 【0080】1, 1A, 1B, 1C, 1D, 1E Packaged frozen food 10, 10B Lid member 11 Base material 13 Protruding part 15 Rib 20, 20B Food carrier 21 Base material 23 Food carrier part 25 Rib 30, 30A, 30B Cold agent carrier 31 Base material 33 Cold agent carrier part 35 Rib 37 Recessed part 40, 40B, 40C, 40D, 40E Frozen food 41, 41B First part (rice molding part) 43, 43B Second part (filling) 50, 50B, 50C, 50D, 50E Cold agent 100, 100A, 100B, 100C, 100D, 100E Packaging container

Claims

1. A packaged frozen food that is heated and thawed for consumption, comprising: a first portion that requires heating during heating and thawing, and a second portion that requires heating to a lower degree than the first portion or does not require heating; and a refrigerant installed corresponding to the second portion, capable of absorbing and / or reflecting microwaves, and containing a cooled liquid composition and / or gel composition.

2. The packaged frozen food according to claim 1, wherein the cold storage agent is solidified.

3. The packaged frozen food according to claim 1, wherein the cold storage agent contains water.

4. The packaged frozen food according to claim 1, further comprising a food carrier for supporting the frozen food, wherein the frozen food is arranged such that the second portion is in contact with a portion of the food carrier, and the refrigerant is arranged in contact with the opposite side of the portion of the food carrier to which the second portion is in contact.

5. The packaged frozen food according to claim 4, further comprising a cold agent carrier for supporting the cold agent, wherein the cold agent is disposed between the food carrier and the cold agent carrier.

6. The packaged frozen food according to claim 4, wherein the food carrier has a food carrier portion that has a recess capable of carrying the frozen food and a convex portion that is in the direction opposite to the frozen food.

7. The packaged frozen food according to claim 6, further comprising a cold storage agent carrier for supporting the cold storage agent, wherein the cold storage agent carrier has a recess in a portion corresponding to the convex portion of the food carrier.

8. The packaged frozen food according to claim 1, wherein the frozen food is frozen sushi.

9. A method for thawing a packaged frozen food, comprising heating the packaged frozen food according to any one of claims 1 to 8.

10. A method for producing packaged frozen food, comprising simultaneously cooling a pre-freezing food having a first portion that requires heating when frozen and a second portion that requires heating to a lower degree than the first portion or does not require heating, and a refrigerant, which is a liquid composition and / or gel composition installed corresponding to the second portion and capable of absorbing and / or reflecting microwaves.

11. A packaging container for packaging a frozen food that is to be heated and thawed before consumption and has a first portion that requires heating and a second portion that requires a lower degree of heating than the first portion or does not require heating, comprising: a food carrier having a food carrier portion for carrying the frozen food; and a cold agent carrier for carrying a cold agent in which a liquid composition and / or gel composition has been cooled, wherein the food carrier is configured such that the second portion of the frozen food is in contact with the food carrier portion, and the cold agent carrier is configured such that the cold agent is in contact with the food carrier portion from the side opposite to the frozen food.

12. The packaging container according to claim 11, wherein the food carrier has a food carrier portion that has a recess so as to be able to carry the frozen food, and a convex portion that is in the direction opposite to the frozen food.

13. The packaging container according to claim 12, wherein the cold storage agent carrier has a recess as a cold storage agent carrier portion in a portion corresponding to the protrusion of the food carrier.

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