JP2939239B1 - Large fish thawing method and device - Google Patents

Abstract

[PROBLEMS] To defrost a large fish as it is without discoloration or deterioration. SOLUTION: A frozen large fish is immersed in water of a predetermined temperature to defrost from the surface of the fish body, and a heat release part is installed so as to pass through the vertebrae of the fish, and thawed from inside the fish body by heat from the heat release part. A method comprising the steps of: The heat radiating section is supplied with heat by hot water. Before installing the heat releasing part, the method includes a step of immersing the heat radiating part in water at a predetermined temperature to allow the thawing from the fish body surface to proceed halfway. The portion where the heat release section is placed is the nerve cavity in the vertebra. A high voltage superimposed wave potential is applied to the fish during thawing. A defrosting water tank 2 having a water temperature adjusting means 10 and a size large enough to accommodate a large frozen fish, a heat emitting portion 3 provided to penetrate the vertebrae of the fish to be thawed, and a heat source for supplying heat to the heat emitting portion. A supply device. The heat release section is formed by a heat conductive pipe 16, and the heat supply means is a hot water circulation device. A superimposed wave potential applying means was provided in the thawing water tank.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for thawing edible frozen large fish, such as tuna and ara, and an apparatus used for the method.

[0002]

2. Description of the Related Art Conventionally, tuna is often frozen and stored almost in a round shape by cutting off the head and caudal fins, and is shipped in a frozen state in a round shape as required, and commercial transactions are carried out.
After that, it is dismantled with a saw blade while frozen, thawed, cooked with a kitchen knife, and served for food. Commerce is basically conducted at a price that depends on the quality.However, in the frozen state, it is generally difficult to judge the quality, for example, it is difficult to judge the degree of oil paste, etc. It often happens. In addition, cutting with saw blades can easily cut the fish body including large bones and disassemble it efficiently, but on the other hand, it causes a decrease in yield because it is cut roughly and there is a loss part equivalent to sawdust. Has become. Judging from such a situation, the thawed tuna,
Since it is easy to determine the quality, it can be expected to be traded at a more appropriate price than a frozen one and does not require thawing, so it can be traded at a higher price. Further, since it is not necessary to use saw blades for disassembly and disassembly with a kitchen knife is possible, the yield is improved.

[0003] For this reason, it is desired that frozen tuna be thawed as a whole before being shipped to the market. However, the thawing is not always good. That is, conventionally, frozen whole fish is thawed as it is by immersing it in an appropriate temperature, a temperature at which meat quality is not so affected, for example, about 15 ° C. water. When this thawing method is applied, when it becomes a large fish like a tuna, it is difficult for the central part to be thawed,
Even if it is immersed in water for a long time (1 day to 1.5 days), a part that is not thawed remains. This is because the size from the surface to the center is large, the meat has a lot of moisture, and the temperature is about -40 ° C up to the center before thawing. To thaw so that the unthawed portion does not remain in the center, it is necessary to immerse in water for a longer time or raise the water temperature. However, if it is immersed in water for an excessively long time, the freshness of the quickly thawed portion may deteriorate. In an experiment conducted by the applicant, a frozen tuna whose head and tail were cut off and weighed about 35 kg (body length 75 c
m, the longest diameter of the largest cross section is 36 cm, and the shortest diameter is 27 cm).
After being immersed in a water tank maintained at 0 ° C. for 20 hours and then disassembled, as shown in FIG.
The undecompressed portion 30 remains, and a portion 31 where the meat is clearly degraded near the tail, a portion 32 where the meat is discolored near the epidermis, and the like are observed. Therefore, raising the temperature of the water to be immersed greatly reduces the quality and does not become a commercial product, and the thawing time cannot be reduced so much.

Another method for thawing relatively small edible marine products is described in Japanese Patent Application Laid-Open No. 9-131158. The outline is a method of applying a high-pressure superimposed wave potential to a material to be thawed and taking a shower of water.
A water shower can contact the flowing water with the material to be thawed and effectively transfer the heat from the water to speed up thawing. It acts to adjust the molecular structure of water, proteins, fats, carbohydrates, etc. that compose it, preventing the collapse of the structure of water after thawing, preventing the outflow of water, and suppressing the deterioration of freshness. It stabilizes the quality of marine products after thawing.

[0005]

SUMMARY OF THE INVENTION The present invention provides a thawing method and an apparatus used for thawing a large fish stored in a frozen state as it is without discoloration or deterioration. The purpose is to do.

[0006]

According to the method of the present invention, a large frozen fish is immersed in water at a predetermined temperature to defrost from the surface of the fish body, and a heat releasing portion is provided so as to pass through the vertebrae of the fish. And defrosting from the inside of the fish body by the heat released from the heat release portion , wherein the heat release portion has warm water inside.
Characterized that you supplied heat by flowing of (claim 1).

[0007] By thawing from both the surface and the inside of the fish body, there is no portion that remains unthawed along the center for a long time, unlike the conventional method of simply immersing in water,
The whole thawing becomes possible in a relatively short time. This short thawing reduces the freshness deterioration of the meat quality. Thawing from the inside of the fish body requires that the surface temperature of the heat emitting part is slightly higher than the temperature of the water to be immersed because the heat from the heat emitting part installed in the vertebrae is transmitted through the vertebrae and transmitted to the meat. Becomes possible. This effectively acts on thawing without deteriorating the meat quality around the vertebrae.

Further, prior Symbol heat emitting portion, since a configuration supplied heat by flowing hot water through the inside, appropriate decompressor temperature of the heat-emitting part by controlling the temperature of the hot water to pass through the flow Can be maintained.

In the method of the present invention, it is preferable that the method further includes a step of immersing in a water of a predetermined temperature and thawing from the surface of the fish partway before installing the heat releasing part (claim). Item 2 ). As thawing progresses from the surface of the fish, the temperature of the vertebrae in the center increases, although it is lower than in other parts. When the temperature of the vertebra exceeds -3 ° C., a wire or rod can be pushed into the nerve cavity or vascular cavity in the vertebra from one end and pierced to form a through hole. The heat emitting portion can be easily inserted into the hole and installed, or the heat emitting portion can be directly inserted and installed.

[0010] In the method of the present invention, the portion of installing the heat release portion is preferably set to configure a neurological cavity in said vertebrae (claim 3). The flesh of the fish is slightly thicker than the vertebra passing through the center of the fish, and the nerve cavity is located along the upper part of the vertebra. Therefore, the heat from the heat emitting portion provided in the nerve cavity is easily transmitted to the thick portion of the meat above the fish body. That is, heat is easily transmitted to the thickest part. Thereby, thawing from the inside of the fish body is performed more effectively.

[0011] In the method of the present invention, it is preferable to a structure for applying a high voltage of the superimposed wave potential to the fish in the decompression (claim 4). Applying a high-voltage superimposed wave potential to a fish or the like during thawing to suppress freshness degradation and stabilize the meat quality of the fish or the like after thawing is a known technique as described above. However, not only the quality after thawing is stabilized, but also the following operational effects can be obtained. That is,
In a long-time thawing of a large fish, the part that was initially thawed will be placed in the thawing environment as it is,
It is expected that the freshness of the initial decompressed portion is degraded at the stage where the entire decompression is completed, compared to the portion decompressed at the end. By applying a high-voltage superimposed wave potential during thawing, the remaining thawing is continued while suppressing the freshness deterioration of the initial thawing portion, so that the entire fish body can be partially thawed with little difference in freshness.

[0012] The apparatus of the present invention comprises a defrosting water tank having a water temperature adjusting means for maintaining the stored water at a desired temperature and having a size capable of storing a large frozen fish, and a vertebrae of a slender fish body to be thawed. a heat discharging part that is provided so as to penetrate the inner, and a heat supply means for supplying heat to the heat sink
Wherein said heat emitting portion is formed of a heat conductive pipe,
The heat supply means supplies hot water adjusted to a predetermined temperature to the pipe.
Characterized in that it is a hot-water flow device for flowing (claim 5). By thawing from both the surface and the inside of the fish body, there is no portion that remains unthawed along the center for a long time unlike the conventional method of simply immersing in water, and the entire thawing can be done in a relatively short time. It becomes possible. This short thawing reduces the freshness deterioration of the meat quality. Thawing from the inside of the fish body requires that the surface temperature of the heat emitting part is slightly higher than the temperature of the water to be immersed because the heat from the heat emitting part installed in the vertebrae is transmitted through the vertebrae and transmitted to the meat. Becomes possible. This effectively acts on thawing without deteriorating the meat quality around the vertebrae.

Further, the pipe inserted through the spinal vertebrae, by circulating the hot water of the desired temperature, through a vertebra can be extracted from the center of the fish at the desired temperature, adjusting water temperature of supply of the thawing temperature Because it is adjustment, it is easy.

[0014] In the apparatus of the present invention, it is preferable to a structure in which a superimposed wave potential applying means for applying a superimposed wave potential fish contained in the thawing water tank (claim 6). By applying a high-voltage superimposed wave potential during thawing, the remaining thawing is continued while suppressing the freshness deterioration of the initial thawing portion, so that the entire fish body can be partially thawed with little difference in freshness. The superimposed wave potential generator used in the apparatus of the present invention is disclosed in Japanese Patent Application Laid-Open No. 51-81939,
It is a known one as seen in JP-A-56-6673. For example, one of the superimposed wave potential generators is configured such that a commercial frequency power supply 100V is connected to the primary side, and an arbitrary waveform is charged by a transformer with the secondary side shunted,
Waveforms having different frequencies are partially stacked, and the voltage composed of the waveforms is boosted to 10 KV or more by the final transformer via the insulating transformer, and the winding start lead wire (output terminal) on the secondary side of the final transformer is transformed. This is one in which the inside is insulated and sealed, and only the end-of-winding lead wire is sent out to an external terminal (output terminal), without being output outside. One of the output terminals is formed by forming the thawing water tank with a conductive material and connected to the thawing water tank, or by being connected to an electrode immersed in the thawing water tank, thereby providing a high-voltage superimposed wave potential. Is applied to the fish to be thawed through the water. At this time, the ground voltage is equal to zero, and no current flows.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. Figure 1 shows a large fish thawing device 1
2 is a defrosting water tank, 3 is a heat release part, 4
Is a heat supply means, and 5 is a tuna being thawed. The thawing tank 2
It is formed of a stainless steel plate in a size large enough to accommodate a large fish to be thawed and has a temperature adjusting means 10 so that the temperature of the stored water can be maintained at a predetermined temperature, for example, about 15 ° C. I have. The temperature adjusting means 10 detects that the water temperature has dropped below a predetermined temperature, and provides a heating pipe 11 appropriately arranged over substantially the entire area at the bottom of the thawing water tank 2,
The configuration is such that heated oil is circulated to raise the water temperature, and when the temperature reaches a predetermined temperature, heating is stopped. A temperature sensor, an oil reservoir, a heater, a pump, a motor, and the like are provided on the lower surface portion 12 of the defrosting water tank 2. Further, the stirring means 13 is used so that the temperature of the water in the thawing water tank 2 becomes as uniform as possible as a whole.
Is provided. The stirring means 13 separates the pipe 14 provided with a large number of air ejection holes separately from the heating pipe 11
The air is supplied to the bottom of the thawing tank, and a blower, a motor and the like for supplying the air are installed on the lower surface 15 of the thawing tank 2. The water is agitated by blowing an appropriate amount of air from almost the entire bottom of the defrosting water tank 2,
The temperature becomes uniform. In addition, the temperature of the surface of the fish being thawed is deprived of water by heat, and the temperature decreases. However, the agitation rapidly replaces the water on the surface with water having a predetermined temperature, and the thawing is performed effectively.

The heat radiating section 3 is made of, for example, a stainless steel pipe 16 having a diameter of 4 mm, and is formed to be slightly longer than the length of the fish 5 to be thawed.
8 for connection. Heat supply means 4
Is a device for flowing hot water of a predetermined temperature through the pipe 16 of the heat release section 3 and is provided at an appropriate position close to the defrosting water tank 2, and controls the water temperature of the hoses 17, 18, fixed pipes 19 and 20, heaters and the like. It comprises a water receiving tank 21 with a device, a pump 22, a pressure tank 23 and the like. The hoses 17 and 18 have a joint 24 which is detachable from the pipe 16 at one end, and a fixed pipe 19 at the other end via an intermediate fixed joint 25 at the edge of the defrosting water tank 2.
Or 20. In the illustrated connection state, hot water adjusted to a predetermined temperature of the water receiving tank 21, for example, 55 ° C., is supplied to the pipe 16 via the pump 22, the pressure tank 23, the fixed pipe 19, and the hose 17 to release heat. Then, it returns to the water receiving tank 21 via the hose 18 and the fixed pipe 20. In addition, a flow control valve (not shown) is provided on the outlet side of the pressure tank 23 as necessary.

A method for thawing tuna using the thawing apparatus 1 will be described below. The frozen tuna to be thawed has its head and caudal fin cut off, weighs 34.7 kg, 82 cm in length, the longest diameter of the largest section is 33.5 cm, the shortest diameter of the same section is 24.5 cm, and the meat temperature is -40 ° C Met. First, the temperature of the water in the thawing water tank 2 is adjusted to 15 ° C., the temperature adjusting means 10 is set so as to maintain the temperature, the operation is started, and the whole frozen fish is attached to a frame (not shown). And put it in the thawing tank 2
Thawed under water for 12 hours. When taken out of the thawing water tank 2 and examined, a considerable portion of the unthawed portion remains at the center in the thawing for 12 hours. At this time, the minimum temperature of the unthawed meat portion was -2.6 ° C. At this stage, the pipe 16 which is the heat release unit 3 is installed. From the results of several experiments, when the minimum temperature of the unthawed meat portion exceeds approximately −3 ° C., the pipe 16 is stabbed into the nerve cavity of the vertebra described below if it is a hard rod. Since it is possible to pass through the pipe, the pipe 16 is installed with an aim of exceeding -3 ° C.

The pipe 16 is to be inserted into the nerve cavity 27 of the vertebra 26 of the fish shown in an enlarged scale in FIG. In the figure, 28 is a blood vessel lumen, and 29 is a bone marrow. The pipe 16 is installed such that a stainless steel round bar having a diameter equivalent to that of the previously prepared pipe 4 mm in diameter is penetrated to the caudal side from the nerve cavity 27 of the vertebra 26 at the cut end side of the head of the fish body. After removing the round bar, the pipe 16 which is the heat releasing part 3 is inserted, the tuna 5 is again stored in the defrosting water tank 2, and the joints 24, 24 are connected to the end of the pipe 16. The thawing was performed by connecting the hoses 17 and 18 to each other, setting the heat supply means 4 at a water temperature of 55 ° C., and keeping the thawing water tank 2 at the same water temperature of 15 ° C. The flow rate of the water flowing through the pipe 16 is 1 liter / minute. The average value of the temperatures actually measured several times during thawing shows the inlet water temperature of the pipe 16 as 54.8.
° C and the outlet water temperature was 44.3 ° C. This pipe 16
In the thawing step using, at an appropriate time interval, the minimum temperature of the flesh, the thickness from the surface to the frozen part (thickness of the thawed part on the epidermis side), the thickness from the vertebra to the frozen part (thawed on the vertebral side) Table 1 shows the results of measuring the thickness of the frozen portion. At the end of the thawing process, the minimum temperature of the meat is 0
° C, and ended at + 0.6 ° C in this example.

[0019]

[Table 1]

When the tuna thus thawed was immediately dismantled, the whole meat portion was thawed, the meat color was good, there was no discolored portion, and no deteriorated portion was observed. The time required for thawing was 18 hours and 18 minutes in total: 11 hours and 40 minutes for thawing only from the outer surface of the fish, and 6 hours and 38 minutes for thawing from both the outer surface and the inside of the fish. Therefore, compared to the case of thawing only from the conventional fish outer surface,
Thawing time can be greatly reduced so that the overall meat quality after thawing is not impaired.

FIG. 3 shows a second embodiment of the apparatus of the present invention. This defrosting apparatus 1a differs from that of the first embodiment only in that a superimposed wave potential generator 7 is added, and the other parts are the same. Is omitted. The superimposed wave potential generator 7 has one output terminal connected to the thawing water tank 2 via a conducting wire 40,
The other output terminal is insulated and sealed. 3 in the figure
Reference numerals 7, 38, and 39 denote insulators for electrical insulation, each of which insulates and supports the defrosting water tank 2, the heat supply means 4, and the superposed wave potential generator 7 with respect to the floor surface.

In the case of the second embodiment, the superimposed wave potential generator 7 is always in operation during the thawing described in the first embodiment, and during the thawing through the water in the thawing tank 2. A high voltage superimposed wave potential is applied to the fish body. As a result, the meat portion at the portion where the thawing has been completed is prevented from deteriorating in freshness. In order to judge that the thawing state is good, one of the criteria is that the amount of drip after a predetermined time is small after disassembly and refrigeration after thawing. It is difficult to compare the whole thawing due to individual differences, but a dare comparison shows that the amount of drip is smaller in the second embodiment than in the first embodiment. Was.

In the above embodiment, the pipe 16 of the heat radiating section 3 is inserted into the nerve cavity 27. However, in some cases, the pipe 16 may be inserted into the blood vessel cavity 28 and thawed. Further, after the thawing from the outer surface of the fish was performed halfway, the pipe 16 was inserted, but in some cases, in a frozen state in which the fish had not been thawed at all, it was passed through the bone marrow 29 using a drill-shaped drilling tool. It may be perforated, and the radiator 3 may be installed in the hole.
This allows thawing from both inside and outside the fish from the beginning of thawing. The heat radiating section 3 may use an electric resistance heating element so that the temperature can be reliably controlled.

[0024]

According to the first aspect of the present invention, since the thawing is performed from both the surface and the inside of the fish body, the thawing time can be shortened, and at the same time, the time required for the part thawed in the initial stage of thawing to be placed in the thawing environment is reduced. The effect of shortening the thawing time can be shortened and the meat quality is hardly deteriorated . Also, there is an effect that it is easy to maintain an appropriate desired thawing temperature of the heat release section. The invention described in claim 2 has an effect of facilitating the work of installing the heat emitting portion on the vertebra. According to the third aspect of the present invention, since heat is easily transmitted to the thickest part, the effect of thawing from the inside of the fish more effectively can be obtained. According to the fourth aspect of the present invention, since the remaining thawing is continued while suppressing the freshness deterioration of the initial thawing portion, the whole fish body can be further thawed with less freshness deterioration and partially reduced in freshness difference. It works. According to the fifth aspect of the present invention, since the thawing is performed from both the surface and the inside of the fish body, the thawing time can be shortened, and at the same time, the thawing time of the portion thawed in the initial stage of thawing is reduced by shortening the time required for the thawing environment. It can be shortened by minutes and has the effect of preventing meat quality from deteriorating . Further, to decompress at the desired temperature from the center of the fish body, it achieves the regulation is easy effect of thawing temperature. The invention described in claim 6 has the effect that the whole fish body can be thawed to a state where freshness deterioration is further reduced and a difference in freshness is partially reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of an apparatus for describing a method and an apparatus according to a first embodiment of the present invention.

FIG. 2 shows a schematic structure of a vertebra of a large fish, (a) is a longitudinal front view perpendicular to the longitudinal direction, and (b) is a partial side view.

FIG. 3 is an explanatory diagram showing a schematic configuration of an apparatus for describing a method and an apparatus according to a second embodiment of the present invention.

FIG. 4 is an explanatory view showing a state of a longitudinally central side surface of a fish body thawed substantially according to a conventional thawing method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Thawing apparatus 1a Thawing apparatus 2 Thawing water tank 3 Heat release part 4 Heat supply means 5 Tuna 7 Superposed wave potential generator 10 Temperature adjusting means 11 Heating pipe 12 Lower surface part 13 Stirring means 14 Pipe 15 Lower surface part 16 Pipe 17 Hose 18 Hose 19 Fixed pipe 20 Fixed pipe 21 Water receiving tank 22 Pump 23 Pressure tank 24 Joint 25 Relay fixed joint 26 Spine vertebra 27 Nervous cavity 37 Insulator 38 Insulator 39 Insulator 40 Conductor

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yoshitaka Hataya 1-1-2, Ryudai, Suma-ku, Kobe-shi, Hyogo 30-301 (56) References JP-A-56-85694 (JP, A) JP-A-4- 349844 (JP, A) Japanese Utility Model 1-142684 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) A23B 4/00-4/32 A23L 3/36-3/365

Claims (6)

(57) [Claims] 1. A frozen large fish is immersed in water at a predetermined temperature and thawed from the surface of the fish body, and a heat radiating portion is provided so as to pass through the vertebrae of the fish, and heat radiated from the heat radiating portion is provided. Thawing from the inside of the fish body by the heat
Discharge unit supplies heat by circulating warm water inside
Thawing method of large fish which is characterized that you are. 2. The method for thawing a large fish according to claim 1 , further comprising a step of immersing the fish in a water of a predetermined temperature to advance thawing from the surface of the fish halfway before installing the heat releasing portion. A method for thawing large fish, characterized by the following. 3. The method for thawing a large fish according to claim 1 or 2 , wherein the portion on which the heat emitting portion is provided is a nerve cavity in the vertebra. 4. The method for thawing a large fish according to claim 1, 2 or 3, wherein a high voltage superimposed wave potential is applied to the fish being thawed. How to thaw fish. 5. A defrosting water tank having a water temperature adjusting means for maintaining the stored water at a desired temperature and having a size capable of storing a large frozen fish, and a slender, penetrating vertebra of a fish body to be thawed. And a heat supply means for supplying heat to the heat emitting portion.
Is formed of a heat conductive pipe, and the heat supply means,
Hot water for flowing hot water adjusted to a predetermined temperature through the pipe
A large fish thawing device characterized as a distribution device . 6. The large fish thawing apparatus according to claim 5 , further comprising a superimposed wave potential applying means for applying a superimposed wave potential to the fish contained in the thawing tank.