Method for sterilizing eel processed product

Abstract

To provide a method for sterilizing an eel processed product that may suppress generation of meat crumbling.SOLUTION: A method for sterilizing an eel processed product includes the steps of: placing a heat-cooked eel 1 on a tray 2 and vacuum-drawing and packing the eel while covering the eel with a non-gas-permeable packing material 3; and then sterilizing the eel with heat at a constant temperature within a range of 50-95°C.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a method for sterilizing processed eel products. [Background technology]

[0002] 2. Description of the Related Art Processed eel products in which cooked eels are vacuum-packed have been known. For example, Patent Document 1 below discloses a method for preserving grilled eel, in which grilled eel is placed in a non-breathable packaging material, vacuumed, sealed, and retort sterilized in a sterilization kettle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 5-123098 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the preservation method of grilled eel described in Patent Document 1, there is a concern that the eel meat will fall apart inside the bag-shaped non-breathable packaging material during vacuuming, retort sterilization, transportation, etc.

[0005] The present disclosure has been made in consideration of the above-mentioned circumstances, and aims to provide a method for sterilizing processed eel products that can suppress the occurrence of the flesh falling apart. [Means for solving the problem]

[0006] In order to achieve the above-mentioned objective, configuration 1 of the method for sterilizing eel processed products according to the present disclosure is characterized in that cooked eels are placed on a tray and covered with a non-breathable packaging material, vacuum-packaged, and then sterilized by heating at a constant temperature within the range of 50°C to 95°C, and then cooled.

[0007] The following description of the embodiments discloses that the sterilization method for eel products according to the present disclosure may include the following subsidiary configurations. <Configuration 2> In configuration 1, the heat sterilization may be carried out by using far infrared rays. <Configuration 3> In the configuration 1 or 2, the heat sterilization may be carried out for 5 minutes to 60 minutes. <Configuration 4> In any one of Configurations 1 to 3, the product may be cooled to a temperature within a range of -35°C to 5°C after the heat sterilization. Effect of the Invention

[0008] The sterilization method for processed eel products according to the present disclosure has the above-mentioned configuration, which makes it possible to prevent the flesh from falling apart. [Brief description of the drawings]

[0009] [Figure 1] 1 is a flowchart illustrating a schematic diagram of an example of a method for sterilizing eel processed products according to an embodiment of the present disclosure. [Diagram 2] 1(a) to (c) are schematic views of an example of an eel processed product, where (a) is a schematic plan view, and (b) and (c) are schematic longitudinal sectional views. [Diagram 3] FIG. 2 is a schematic front view showing an example of an apparatus used in the sterilization method. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an example of the sterilization method for processed eel products according to this embodiment will be described with reference to the drawings. Note that in some of the drawings, some of the detailed reference numerals are omitted. 1 and 2 are diagrams showing an example of a method for sterilizing processed eel products according to this embodiment.

[0011] In the sterilization method for eel products according to the present embodiment, as shown in Figs. 1 and 2, cooked eels 1 are placed on a tray 2 and covered with a non-breathable packaging material 3, and then vacuumed and packaged, followed by heat sterilization at a constant temperature within the range of 50°C to 95°C, and cooling. With this configuration, eels 1 can be packaged, heat sterilized, and cooled while placed on the tray 2, so that the meat of the eels 1 is less likely to fall apart or become unevenly distributed when vacuuming, heat sterilization, cooling, transporting to each process, and transporting thereafter. In addition, even if the shelf life of the eels is generally about 3 to 5 days when vacuum packed, the heat sterilization is performed, so that the shelf life can be extended, for example, to about 10 to 45 days when refrigerated. Furthermore, heat sterilization at a constant temperature within the range of 50°C to 95°C can reduce loss of flavor, etc., compared to a configuration in which heat sterilization is performed at a high temperature of, for example, 100°C or higher. In addition, since the food is cooled after heat sterilization, it can be stored in a refrigerator or freezer as is, and even if bacteria remain after heat sterilization, bacterial growth can be suppressed.

[0012] Specifically, as shown in FIG. 1, the sterilization method for eel products may first carry out a cooking step (step S101) in which eel is cooked by heating. In this cooking step, for example, raw eel that has been cut open from the back or belly may be lightly grilled, or may be further seasoned with seasonings such as sauce and kabayaki. In other words, eel 1 as an eel processed product sterilized by the sterilization method may be lightly grilled or kabayaki. Also, eel 1 may have a head to tail fin, or both or either of the head and tail fin may be removed. Also, eel 1 may be fillets cut into appropriate sizes. In the example of FIG. 2(a), eel 1 is illustrated as about half the body on the tail fin side, but this is not limited to such an example. Also, eel 1 placed on tray 2 described later is not limited to one tail or one piece, and may be multiple tails or multiple pieces. It is not necessary to have a cooking step in the sterilization method. In this case, it is sufficient to purchase eels 1 that have been appropriately cooked. Also, if the purchased cooked eels 1 are frozen, they may be thawed before the coating process described below.

[0013] In this sterilization method, a covering step (step S102) is carried out in which eels 1 are placed on a tray 2 and covered with packaging material 3. In this placing step before the covering step, the eels 1 may be placed directly against the bottom 2a of the tray 2, or may be placed via an appropriate sheet material (for example, various functional sheet materials such as antibacterial sheets or drip-resistant sheets). If the eels 1 have just been cooked, they may be cooled to about room temperature before being placed on the tray 2, or they may be placed on the tray 2 immediately after cooking. In addition to the eels 1, seasonings such as sauce may also be placed on the tray 2. The tray 2 is in the form of a thin container that opens upward. There are no particular limitations on the shape of the tray 2, so long as it can accommodate the eel 1. For example, the tray 2 may be substantially rectangular in plan view, as shown in Fig. 2(a), or, instead of such a shape, it may be shaped such that the width of both ends in the longitudinal direction decreases toward both ends in accordance with the shape of the eel 1, or it may be substantially elliptical in plan view, or may be of various other shapes.

[0014] The tray 2 may have a flat bottom 2a on which the eels 1 are placed, and a side wall 2b that rises upward from the outer periphery of the bottom 2a and surrounds the entire circumference of the bottom 2a. The side wall 2b may be shaped to rise almost vertically from the bottom 2a, or, as shown in FIG. 2(b), may be formed in an inclined shape that inclines from the bottom 2a upward so as to increase the opening area of ​​the tray 2. The corner between the bottom 2a and the side wall 2b may be formed into a concave curved surface shape. With this configuration, the packaging material 3 is more likely to adhere to the corner when the vacuum is drawn than when the corner is a right angle.

[0015] The size (inner dimensions) of the tray 2 in a plan view, that is, the size of the bottom 2a, may be appropriately determined depending on the size and number of the eels 1 to be accommodated. The size of the bottom 2c of the tray 2 may preferably be such that at least the outer peripheral edge of the bottom 2a is exposed around the eel 1 placed on the bottom 2a, as shown in Fig. 2(a). With this configuration, the packaging material 3 can easily get between the eel 1 and the side wall 2b when vacuuming, and the packaging material 3 can easily adhere to almost the entire surface, including the side of the eel 1, and almost the entire inner surface of the part of the tray 2 other than where the eel 1 is placed (the upper surface of the bottom 2a and the inner peripheral surface of the side wall 2b). The dimension where the outer peripheral edge of the bottom 2a is exposed around the eel 1 placed on the bottom 2a (the dimension between the eel 1 and the side wall 2b (the lower end of the side wall 2b if it is inclined as in the example)) may be 0.5 mm or more, 1 mm or more, or 2 mm or more. As shown in Fig. 2(b), the depth of the tray 2 may preferably be equal to or greater than the thickness of the eels 1. With this configuration, the flesh of the eels 1 placed on the tray 2 can be more effectively prevented from falling apart.

[0016] As long as the inner dimensions of the tray 2 are substantially rectangular in plan view as described above, the inner dimensions of the long sides may be approximately 100 mm to 400 mm, and the inner dimensions of the short sides may be approximately 50 mm to 200 mm. The depth of the tray 2 may be approximately 3 mm to 15 mm. The thickness of the tray 2 (thickness of the bottom 2a and side wall 2b) may be approximately 0.5 mm to 3 mm, depending on the material constituting the tray 2, etc. Tray 2 only needs to have a suitable rigidity to resist deformation due to the weight of the eels 1 placed on it, during vacuuming, and during transportation, and can withstand the temperatures of heat sterilization and cooling, and may be made of paper, synthetic resin, foamed resin, etc. If tray 2 is made of paper, a coating layer that is water-resistant, oil-resistant, etc. may be provided to cover the inner surface or the entire tray 2.

[0017] The packaging material 3 may be a bag capable of containing the entire tray 2 on which the eels 1 are placed, or may be a sheet or the like that covers at least the open side of the tray 2 on which the eels 1 are placed. In the illustrated example, the dimensions of the bag-shaped packaging material 3 along the longitudinal direction of the tray correspond to the length of the tray 2, but this is not limited to this example. For example, the packaging material 3 may be provided with appropriate heat-sealed parts or excess parts, etc., so as to surround the periphery of the tray 2 (or on both longitudinal ends of the tray 2, etc.). The packaging material 3 may be non-breathable, strong enough to withstand damage during vacuuming or transportation, and able to withstand the temperatures of heat sterilization and cooling. The packaging material 3 may be made of synthetic resin such as polypropylene, polyester, or polyethylene, or may be a film laminated with aluminum foil.

[0018] Then, in this sterilization method, a sealing process (step S103) is carried out in which the eels 1 placed on the tray 2 are covered with packaging material 3 and then vacuum-packaged. The method for carrying out the sealing step is not particularly limited, and for example, if the packaging material 3 is a bag, the air inside the packaging material 3 may be sucked out using a suction machine or the like to draw a vacuum, and then the opening of the packaging material 3 may be heat-sealed or sealed. Also, if the packaging material 3 is a sheet body covering the opening of the tray 2, the air inside the tray 2 may be sucked out using a suction machine or the like to draw a vacuum, and then the edge of the opening of the tray 2 and the packaging material 3 may be heat-sealed or glued to seal them, depending on the materials of the tray 2 and the packaging material 3. In this sealing step, suction may be performed with an appropriate pressure so that the eels 1 are not excessively crushed. By carrying out the sealing process as described above, as shown in Figure 2(c), the eels 1 placed on the tray 2 are covered with packaging material 3 and sealed, that is, eel packaging body 9 is obtained in a vacuum-packed state with most of the air removed.

[0019] Next, in this sterilization method, a sterilization step (step S104) is carried out in which the eel packaging body 9 is heat sterilized at a constant temperature within a range of 50°C to 95°C. The method of heat sterilization is not particularly limited and may include heating with steam or heating in a hot water bath. This heat sterilization may be performed using far-infrared rays. With this configuration, compared to a configuration in which heat sterilization is performed using steam or hot water, the eel 1 can be heated to its core more quickly using far-infrared rays, and the adhesion of moisture to the eel packaging body 9 can be suppressed. Heating with far-infrared rays may be performed using a device such as a heater that radiates far-infrared rays. This heat sterilization may be performed at a preset constant temperature until a preset heat sterilization time has elapsed. This constant temperature may be 55°C or higher, or 63°C or higher. This constant temperature may be 90°C or lower, or 85°C or lower. The heat sterilization time may be 5 to 60 minutes. If the heat sterilization time is too short, it tends to be difficult to heat the core of the eel 1, and if it is too long, the flavor tends to be easily damaged, but with the above configuration, heat sterilization can be performed effectively. The heat sterilization time may be appropriately set depending on the heat sterilization temperature, the thickness dimension of the eel 1, the amount of eel 1, etc. The heat sterilization time may be 10 minutes or more, or 15 minutes or more. The heat sterilization time may be 55 minutes or less, or 50 minutes or less.

[0020] The temperature and time for heat sterilization may be set appropriately depending on the desired expiration date and the desired flavor of the eel 1. For example, if it is desired to extend the expiration date of the eel 1, heat sterilization may be performed at a relatively high temperature or for a relatively long time. On the other hand, if it is desired to reduce deterioration of the flavor of the eel 1, heat sterilization may be performed at a relatively low temperature or for a relatively short time. This heat sterilization may be performed so that the refrigerated shelf life of the eel 1 after heat sterilization is 10 days or more, or so that the refrigerated shelf life of the eel 1 after heat sterilization is 15 days or more, or even so that the refrigerated shelf life of the eel 1 after heat sterilization is 20 days or more.

[0021] Heat sterilization may be performed by a heating device 4 as shown in FIG. 3. The heating device 4 may have a storage chamber that stores multiple eel packages 9. The heating device 4 may also have a door that opens and closes the opening of the storage chamber that opens forward. The heating device 4 may also have a window that allows the state inside the storage chamber to be visually observed, an operation unit that sets heating conditions such as heating temperature and heating time, a sensor unit that measures the temperature inside the storage chamber, a display unit that displays information such as temperature, a control unit that controls a heating source such as a heater, etc. The heating device 4 may be capable of appropriate heating control to maintain the temperature inside the storage chamber at the constant temperature as described above. The heating method in this heating device 4 may be far infrared rays, hot air, steam, etc. as described above, or a combination of these.

[0022] The storage chamber of the heating device 4 may be capable of housing a rack-shaped holding member 7 that holds multiple eel packaging bodies 9. In this case, this holding member 7 may be capable of housing in the storage chamber of the cooling device 5 that performs the cooling step described below. With this configuration, multiple eel packaging bodies 9 can be moved from the heating device 4 to the cooling device 5 while being held by the holding member 7, improving workability after heat sterilization. In the illustrated example, the holding member 7 is provided with multiple upper and lower stages of support members 6, each supporting multiple eel packaging bodies 9. Such support members 6 may be plate-shaped members on whose upper surface multiple eel packaging bodies 9 can be placed, or rod-shaped members provided at appropriate intervals so as to support the eel packaging bodies 9 with multiple rods, or may even be members that support the eel packaging bodies 9 by suspending them. In the illustrated example, the holding member 7 includes a pair of frame portions 7a, 7a provided on both sides in the depth direction when housed in the housing chamber of the heating device 4, and a holding portion 7b that is provided so as to span between the frame portions 7a, 7a and holds the support member 6. The holding portions 7b are provided in a plurality of stages with a gap between them vertically. Such holding portions 7b may be grooved members having grooves that open to face each other and are configured to hold both ends of the support member 6 in the width direction.

[0023] In the illustrated example, a carriage member 8 is provided below the holding member 7 to allow the holding member 7 to be freely inserted and removed from the storage chamber of the heating device 4. In the illustrated example, a leg member is provided at the lower end of the heating device 4 to separate the bottom wall of the housing that defines the storage chamber from the installation surface such as the floor. Therefore, in the illustrated example, the carriage member 8 is configured to have a receiving recess for receiving the bottom wall of the heating device 4 between the base 8b equipped with the wheels 8a and the pedestal 8c that supports the holding member 7. In this case, an appropriate recess or the like for receiving a connection portion 8d provided to connect the door side end of the base 8b and the door side end of the pedestal 8c may be provided at both or one of the opening side end of the bottom wall of the heating device 4. Instead of the embodiment in which the dolly member 8 arranged outside the accommodation chamber as described above is provided below the holding member 7, the dolly unit may also be configured to be accommodated in the accommodation chamber of the heating device 4. The holding member 7 is not limited to a configuration that is freely movable by a dolly unit or the like, and may be freely moved in and out of the accommodation chamber by a transport vehicle such as a forklift. The heating device 4 and the holding member 7 accommodated therein are not limited to the above configuration, and may have various other configurations.

[0024] Next, in this sterilization method, a cooling step (step S105) is carried out to cool the heat-sterilized eel package 9. The cooling step may be performed until the temperature of the core of the eel 1 is cooled to a set temperature. In the cooling step, the eel may be cooled to a temperature of 10°C or lower, preferably to a temperature within the range of -35°C to 5°C. With such a configuration, the eel can be refrigerated or frozen after heat sterilization, and bacterial growth can be effectively suppressed. If the eel is to be stored in a freezer or the like (frozen storage) after the cooling step, the eel may be cooled to a temperature suitable for freezing, for example, to -18°C or lower. If the eel is to be shipped refrigerated without being frozen after the cooling step, the eel may be cooled to a temperature at which the eel 1 does not freeze. The cooling time may be appropriately set depending on the cooling temperature, the thickness of the eel 1, the amount of the eel 1, etc. The cooling step may also be performed in multiple stages. For example, a mode in which pre-cooling before freezing and freezing are performed may be used.

[0025] The cooling method in the cooling step may be cooling water or cold air, or may be performed by a cooling device 5 as shown in FIG. 3. This cooling device 5 may have a configuration generally similar to that of the heating device 4 described above, and may have a storage chamber for storing multiple eel packaging bodies 9. Furthermore, the cooling device 5 may have a door, window, operation unit, sensor unit, display unit, a control unit for controlling a cooling source such as a chiller, and the like, generally similar to the heating device 4 described above. The cooling device 5 may be capable of appropriate cooling control to maintain the temperature in the storage chamber at the cooling temperature described above. Furthermore, the storage chamber of this cooling device 5 may be capable of storing a rack-shaped holding member 7 for holding multiple eel packaging bodies 9, as described above.

[0026] After the cooling step, inspection, labeling, etc. may be performed as appropriate. The above-mentioned method for sterilizing eel products is merely one example, and various other modifications are possible. For example, the eels 1 may be placed on the tray 2 by an appropriate robot arm or the like. The tray 2 on which the eels 1 are placed may be covered and sealed while being transported by an appropriate transport device such as a belt conveyor, and may further be subjected to heat sterilization, cooling, etc. The sterilization method for eel products may also include other steps than those mentioned above, such as a step of inspecting for the presence of foreign matter after the sealing step or cooling step. [Explanation of symbols]

[0027] 1. Eel 2 Tray 3 Packaging materials

Claims

1. This method for sterilizing processed eel products is characterized in that cooked eels are placed on a tray, covered with a non-breathable packaging material, vacuum packed, and then sterilized by heating at a constant temperature within the range of 50°C to 95°C, and then cooled.

2. In claim 1, A method for sterilizing eel processed products, characterized in that the heat sterilization is carried out using far infrared rays.

3. In claim 1 or 2, The method for sterilizing processed eel products is characterized in that the heat sterilization is carried out for 5 to 60 minutes.

4. In claim 1 or 2, A method for sterilizing eel processed products, characterized in that after the heat sterilization, the eel processed products are cooled at a temperature within the range of -35 ° C. to 5 ° C.

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