JP2007061051A - Freezing method and apparatus for live fish - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a freezing method for keeping freshness of immediately killed fish by achieving more effect of removing blood than by a conventional method, when immediately killing live fish, and to provide an apparatus for the same. <P>SOLUTION: This freezing method for live fish comprises capturing live fish followed by immediately killing and removing blood, and freezing the fish. In more details, the method comprises an immediately killing step of capturing live fish, cutting the medulla oblongata of the live fish and performing immediate killing in a condition of preventing the cardiopulmonary function of the live fish from stopping, a blood removing step of charging the immediately killed fish into a cooling water tank kept at 7-15°C followed by holding in the tank for at least 1 min, a brine treatment step of charging the live fish subjected to blood removing treatment into a brine freezing tank set at brine concentration to be frozen at -20 to -17°C and holding the fish in the brine freezing tank for at least 6 h, and a storing step of freezing the fish in an air-cooling tank kept at -50 to -40°C. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method and an apparatus for keeping a live fish inside a fishing boat and freezing and storing it in a frozen state.By completely removing blood from the conventional method, the freshness of the fish body is maintained, the smell of fish meat is eliminated, the meat color and The added value can be enhanced by improving the taste, and it is particularly suitable for application to large fishes having a spindle-shaped body shape such as tuna, bonito, yellowtail, and amberjack.

  A conventional bonito freezing method called B1 freezing (brine freezing first grade product) will be described. FIG. 15 is a schematic view showing the conventional skipjack refrigeration method. In FIG. 15, for example, skipjack 01 lifted by a single skipjack fishing boat or the like bounces back to tent 011, falls on toy 012, and passes through toy 012 to hold a brine maintained at a temperature of −17 ° C. to −20 ° C. The stored brine fish hold 013a is loaded from the lid 015. The brine is cooled to the temperature by a brine cooler (not shown) provided in the fishing boat. 014 is a cooling coil provided on the inner wall of the brine fishhouse 013a, which is not used at the time of the brine freezing process, but used at the time of air-cooled freezing storage (-50 ° C to -40 ° C) in the subsequent step.

  Skipjack 01 is subjected to a brine freezing process in the brine fishhouse 013a. After the brine freeze, as shown in FIG. 15B, the brine is transferred from the fishhouse 013a to the fishhouse 013b by the provided brine pump 016. The bonito 01 is also manually moved to another fishhouse, and a refrigerant is passed through the cooling coil 014 to store the bonito 01 in an air-cooled and frozen state in a temperature range of −50 ° C. to −40 ° C. There are about 20 warehouses for Uokura 013.

In order to maintain the freshness of fish caught in recent years, it is indispensable to revitalize and remove blood.
Bonito is particularly easily discolored compared to tuna, and this is thought to be due to the fact that myoglobin is more rapidly metabolized than tuna, the pH of bonito is low, and the enzymatic reducing power of meth-type pigments is weak. It is done.
Conventionally, squeezing and blood removal processing have been performed by skilled workers, but there is a problem in that it is inefficient and requires skill because it is manual work.

  In order to solve such a problem, Patent Document 1 (Japanese Patent Laid-Open No. 2000-228941) discloses a method for automating the blood removal process. In the method disclosed in Patent Document 1, sandwiching plates are arranged on both sides of a support base inclined downward, a stopper member is provided on the back side of the support base, and live fish is thrown into the support base from the head side. Then, after the pinching operation of pressing and holding the pinch plate against the body side of the live fish is repeatedly fixed several times, the medulla and gills are reached from the live fish brain by an excavation drill and pulled out.

  Further, Patent Document 2 (Japanese Patent Laid-Open No. 2003-38091) discloses a table supplied with fish lying on its side as a device for automating livestock, and a fish supplied on the table. And two blades that are advanced and retracted simultaneously with respect to the fish. One of the two blades has a blade edge positioned on the head from the fish's buttocks positioned on the table. The other one discloses a fish squeezing device in which the blade tip is located on the throat side from the fish buttocks positioned on the table.

JP 2000-228941 A JP 2003-38091 A

However, both of the devices disclosed in Patent Document 1 and Patent Document 2 cut the fish brain, medulla and gills at the same time, and perform vitalization and blood removal at the same time. However, because the cutting location of the fish body is different, while both Patent Documents 1 and 2 handle the aliveness and blood removal in the same row, the blood removal effect is not yet sufficient, and about 3% of the weight of the fish body (3 minutes of the whole blood) Only about 1).
In addition, it is not easy to accurately cut into the target location of a moving live fish, and thus there is a problem that there is a large variation in the blood removal effect for each individual fish body.

In addition, if blood remains in the blood vessels of live fish, adenosine triphosphate (ATP) continues to be consumed, and lactic acid increases, causing self-digestion leading to a decrease in pH value. Therefore, it is necessary to ensure blood removal in order to prevent a decrease in freshness.
Lower vertebrates such as fish cannot process blood in capillaries that are stretched around the body even if the blood vessels in the aorta are removed simply by cutting the spinal cord, greatly increasing the self-digestion of live fish Can not be suppressed.

  In view of the problems of the prior art, the present invention increases blood removal effect when alive live fish than before, thereby greatly reducing the consumption of adenosine triphosphate after thawing, thereby reducing the self-digestion of live fish. The purpose is to realize a method for increasing the added value by improving the color, taste, etc., and a device for carrying out the method, while maintaining the freshness of the fish that has been greatly suppressed and consequently alive, over a long period of time. And

In order to achieve the above object, the method for freezing live fish of the present invention comprises:
In the method of freezing live fish, after catching live fish, alive the live fish, drain the blood, and then store it frozen.
After catching live fish, a lively step that cuts the medulla of the live fish and keeps it live without stopping the cardiopulmonary function of the live fish,
A blood draining step in which the live fish is put into a cooling water tank maintained at a temperature of 7 ° C. to 15 ° C. and held in the cooling water water tank for 1 minute or more;
A brine treatment step in which the blood-bleached fish is put into a brine freezing tank set at a brine concentration so as to be frozen at a temperature of −20 ° C. to −17 ° C. and held in the brine freezing tank for 6 hours or more;
The storage step is then stored in an air-cooled tank kept at a temperature of -50 ° C to -40 ° C.

In the method of the present invention, first, the fish is alive without stopping the cardiopulmonary function of the live fish. That is, by cutting the medulla of live fish, the movement of the fish is stopped, and while the cardiopulmonary function of live fish is working, it is put into a cooling water tank maintained at a temperature of 7 ° C. to 15 ° C. and held in the water tank for 1 minute or longer. To do.
Thus, when the fish is put into the cooling water tank with the cardiopulmonary function alive, blood is discharged out of the body by the pumping action of the heart. In this case, the cooling water tank stores seawater or water having a lower salt concentration than seawater.
When the temperature is lower than 7 ° C., fish that die due to the low temperature is generated. Therefore, by keeping the temperature of the cooling water at 7 ° C. or higher and maintaining the temperature of the cooling water at 15 ° C. or lower, As shown, the blood removal effect can be increased, the freshness of the fish after thawing can be maintained for a long time, the color saturation after thawing can be improved, and the fish-like odor can be eliminated.

Even if the lower vertebrates like fish cut the aorta and remove blood from the aorta, the blood in the capillaries stretched around the body cannot be processed, and the blood remains in the blood vessels. Then, since auto-digestion in which adenosine triphosphate continues to be consumed proceeds, the meat quality is softened and the freshness is lowered.
In the present invention, after thawing after thawing, the fish is put into a cooling water tank maintained at a temperature of 7 ° C. to 15 ° C. and kept in the water tank for 1 minute or longer after being alive. The freshness of the meat quality of the fish can be maintained for a long time.
The holding time in the cooling water tank needs to be at least 1 minute, preferably 1 to 6 minutes. Usually it is not necessary to hold any more.

Thereafter, the blood-bleeded fish is put into a brine freezing tank set at a brine concentration so as to be frozen at a temperature of −20 ° C. to −17 ° C. and held in the brine freezing tank for 4 hours or more.
The larger the water crystals in the cells when frozen, the more meat changes. The bigger the water crystal, the more meat juice called drip comes out. In order to solve this, it is necessary to freeze the water in the cell as fine crystals as possible. This is rapid freezing that allows the cooling temperature (-5 ° C to -1 ° C) of the ice crystal maximum formation zone to pass through in a short time. Solved by. That is, the lower the freezing temperature of the brine, the faster freezing is performed, the ice crystals generated in the frozen tissue cells become finer, the cells are less broken, and the quality is improved.

For this reason, in the present invention, the blood-depleted fish is put into a brine freezing tank set at -20 ° C to -17 ° C. As a result, rapid freezing through a temperature range of −5 ° C. to −1 ° C. in a short time becomes possible. If inexpensive saturated water of salt is used as the brine, a large amount of fish can be frozen at a low temperature within the above temperature range. The immersion time of the fish in the brine freezing tank requires 4-12 hours.
In the present invention, it is then stored frozen in an air-cooled tank maintained at a temperature of −50 ° C. to −40 ° C. By maintaining in such a temperature range, it is possible to maintain the quality and quality of fish.
In this air cooling tank, for example, a hairpin coil and a grid coil are provided on the wall surface of the air cooling tank, and the refrigerant is cooled therethrough. In the present invention, the brine freezing process and the frozen storage by air cooling may be performed in the same tank. That is, after the completion of the brine freezing, the brine is removed from the brine freezing tank and then frozen and stored in the same tank by air cooling.

In the method of the present invention, preferably, as the alive step, the medulla of the live fish is cut, the tail of the live fish is cut, or the blood vessel of the tail of the live fish is cut. When the blood vessel in the tail is cut and the blood vessel communicates with the outside air, no negative pressure is generated in the blood vessel even by the pumping action of the heart, and blood can be continuously drawn by the pumping action of the heart.
In the case where only the blood vessel of the tail is cut and the tail is not cut, it is possible to perform conveyance and other processing by gripping the tail in the subsequent processing, and handling becomes easy.

In the method of the present invention, it is preferable that an electric shock is applied to the live fish to temporarily faint before performing the alive step. When live fish are blown out in a fishing boat after catching live fish, there is a problem that internal bleeding occurs due to bruising, and therefore the quality of the meat deteriorates. In addition, when alive with the alive device, the fish may be blown and the medulla of the fish may not be cut accurately.
Therefore, an electric shock is applied to the live fish to temporarily faint before performing the live-up treatment so that the live-up treatment can be performed accurately.

  When the live fish is a skipjack, it is desirable that the cutting position is between the second and third from the tail among a plurality of protrusions arranged in a row from the tail of the skipjack toward the front and back. This is because in the case of skipjack, a relatively large blood vessel passes from the tail of the protrusion to the second and third, and by cutting this part, the blood vessel can be cut, thereby causing the pumping action of the heart. It can make blood draining active.

The device of the present invention
In the live fish refrigeration equipment that keeps live fish inside the fish boat, drains blood, and then freezes and stores it.
A device that cuts the medulla of the captured live fish and keeps it in a state that does not stop the cardiopulmonary function of the live fish,
A blood-cooling cooling water tank for storing cooling water maintained at a temperature of 7 to 15 ° C .;
A brine freezing tank for freezing blood-bleed fish set to a brine concentration that freezes to a temperature between -20 ° C and -17 ° C;
And a freezing tank for storing fish frozen at the temperature of −50 ° C. to −40 ° C. and frozen in the brine freezing tank.

The apparatus of the present invention is provided with a dedicated cooling water tank for performing the squeezing device and the blood draining process inside the fishing boat in order to revitalize the live fish captured inside the fishing boat, perform blood bleeding and freezing treatment, As a result, the above-described method of the present invention can be carried out in the fishing boat. In addition, the cooling water tank for blood removal stores seawater held at 7 ° C. to 15 ° C. or cooling water having a lower salt concentration than seawater.
The cooling means for cooling water in the cooling water tank may be cooled by a refrigerator attached to a fishing boat, or it may be brought into the temperature range by introducing seawater cooled for food such as sardine. Good.

In the device of the present invention, preferably, the above-mentioned squeezing device is
An introduction port through which live fish is introduced from the head, connected to the live fish conveyance path,
A base plate disposed to be inclined downward from the introduction port;
Holding means for holding live fish from above the base plate;
A cutter that cuts the head of a live fish provided above the base plate so as to be close to or away from the base plate;
A stop plate provided on the base plate for stopping live fish at a position where the medulla is cut by the head cutting cutter;
A sensor that is provided on the stop plate and senses that the live fish hits the stop plate, lowers the presser means, and makes the head cutting cutter approach the base plate to the medullary cutting position of the live fish; and
Means for discharging the lived fish from the base plate.

In the live-fishing device having the above-described configuration, live fish is introduced into the base plate from the live fish transport path through the introduction port. The introduction port may be provided with a shutter so that the introduction port is closed at the same time as live fish is introduced into the base plate.
Live fish introduced into the squeezing device from the introduction port slides on the base plate and stops by hitting the stop plate. Simultaneously with the stop, the sensor senses it, and the presser means descends from above the base plate to press the fish, and the head cutting cutter approaches the live fish to cut the medulla of the live fish. The stop plate is provided at a position where the head cutting cutter can cut the medulla of the live fish at a position where the live fish hit the stop plate and stopped.
The fish body whose medulla has been cut is discharged from the base plate by the discharging means.

In the device of the present invention, more preferably, in addition to the above-described configuration, a cutter that cuts a tail of the live fish or a blood vessel of the tail in response to a signal of the sensor that senses that the live fish hits the stop plate is provided.
By cutting not only the medulla of the live fish but also the blood vessel of the tail, the blood vessel communicates with the outside air, so that the inside of the blood vessel does not become a negative pressure even by the pumping action of the heart, and the blood removal is performed more actively.
In the device of the present invention, preferably, a region for applying an electric shock to the live fish is provided in a passage for transporting the captured live fish to the live device, whereby the live fish is temporarily stunned, and the live device is processed by the live device. Can be made easier.

  According to the method for freezing live fish of the present invention, after capturing the live fish, the live fish step is performed by cutting the medulla of the live fish so as not to stop the cardiopulmonary function of the live fish, and the live fish is 7 to 15 ° C. A blood removal step of charging the cooling water tank maintained at a temperature of 1 ° C. and holding it in the water tank for 1 minute or more, and a brine concentration set to freeze the blood that has been subjected to blood removal treatment at a temperature of −20 ° C. to −17 ° C. It consists of a brine treatment step that is put into a freezing tank and held in the brine freezing tank for 6 hours or more, and then a storage step that is frozen and stored in an air-cooled tank kept at a temperature of -50 ° C to -40 ° C. As a step, the blood removal effect can be improved by putting the live fish into a cooling water tank maintained at a temperature of 7 ° C. to 15 ° C. and holding it in the water tank for 1 minute or longer. By combining brine freezing treatment and air-cooled frozen storage having the above-mentioned temperature range, the freshness of the fish body after thawing can be maintained for a long time, the saturation of the meat is improved, and the fish-like raw odor is also found in the taste This eliminates the need to maintain good meat quality and color.

Further preferably, as the alive step, the blood draining effect can be further improved by cutting the medulla of the live fish, cutting the tail of the live fish, or cutting the blood vessel of the tail of the live fish. Before the revitalization step is performed, the live fish is electrically shocked and temporarily stunned, facilitating the treatment at the time of revitalization and accurately cutting the medulla of the fish, thus eliminating the variation in the blood removal effect. be able to.
In addition, if only the blood vessel of the tail is cut and the tail is left, the transportation of the fish and other handling becomes easy.

Also, when the live fish is a skipjack, it is located at the tail by cutting between the second and third from the tail among a plurality of protrusions arranged in a row from the tail to the front side of the skipjack. The main blood vessels can be cut reliably, and the blood removal effect can be improved reliably.
Further, since the accurate cutting position of the tail can be easily confirmed using the projection as a guide, the installation position of the tail cutting cutter can be easily set.

  Preferably, the squeezing device includes an introduction port through which a live fish is introduced from a head connected to a live fish conveyance path, a base plate disposed to be inclined downward from the introduction port, and a live fish from above the base plate. A holding means for holding the head, a cutter provided above the base plate so as to be close to or separated from the base plate and cutting a head of the live fish, and a medulla is cut on the live fish provided on the base plate by the head cutting cutter A stop plate to be stopped at a position to be moved, and detecting the live fish abutting against the stop plate provided on the stop plate to lower the presser means and moving the head cutting cutter toward the base plate By providing a sensor for approaching the cutting position and means for discharging the lived fish from the base plate The IKE tighten process automated, can shorten dramatically the time required per one animal, can be more accurately cut the bulbar live fish.

In the device of the present invention, it is preferable that the apparatus includes a cutter that cuts the tail of the live fish or a blood vessel of the tail by receiving a signal from the sensor that senses that the live fish hits the stop plate, so that not only the medulla of the live fish but also the tail When the blood vessel is cut and the blood vessel communicates with the outside air, the inside of the blood vessel does not become negative pressure even by the pumping action of the heart, and blood can be continuously removed.
In the device of the present invention, preferably, a region for applying an electric shock to the live fish is provided in a passage for transporting the captured live fish to the live device, whereby the live fish is temporarily stunned, and the live device is processed by the live device. Can be made easier.

Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this example are not intended to limit the scope of the present invention only to specific examples unless otherwise specified. Only.
FIG. 1A is a schematic view of the apparatus of the present invention as viewed from above, FIG. 1B is a schematic view of the apparatus as viewed from the front, and FIG. FIG. 3 is a sectional side view taken along line III-III in FIG. 1, FIG. 4 is a sectional side view taken along line IV-IV in FIG. 1, and FIG. 5 is an explanatory view showing a fish body of skipjack 6 is a diagram showing the fat values of the first embodiment and the comparative example, FIG. 7 is a diagram showing the fat values of the comparative example, and FIG. 8 shows the saturation of the first embodiment and the comparative example. FIG. 9 is a diagram showing the saturation of the comparative example, FIG. 10 is a diagram showing the hardness of the fish meat of the first embodiment and the comparative example, and FIG. 11 is the hardness of the fish meat of the comparative example. FIG. 12 is a chart showing the sensory test results of the first example and the conventional example, and FIGS. 13A and 13B are color photographs of the fish meat of the first example and the comparative example. Figure 4 is a diagram showing a functional test results of the first embodiment and comparative examples.

  In FIG. 1, reference numeral 11 denotes a tent that receives the bonito 01 that is lifted, and the bonito 01 bounces back at the tent 11 and falls onto the toy 12. Up to this point, it is the same as the conventional B1 brine freezing method shown in FIG. The toy 12 is inclined to one side, and the skipjack 01 reaches the region 13 by sliding on the inclined surface in the toy 12. In the area 13, for example, a terminal loaded with a voltage of 12 volts is installed, and when the skipjack 01 enters the area, an electric shock is received.

  The bonito 01 stunned by the electric shock slides on the toy 12 as it is and is put into the alive device 20. This electric shock makes it quiet before bonito is released, preventing the fish temperature from rising. In the alive device 20, the medulla of bonito is cut by the head cutting cutter 21, and at the same time, the tail cutting cutter 22 cuts only the blood vessels around the tail. In this case, the processing is not performed until the tail is cut in consideration of the subsequent processing.

Skipjack 01 cut off the blood vessels around the head (medulla oblongata) and the tail by the head cutting cutter 21 and the tail cutting cutter 22 enters the blood removal chamber 30 and is bleeded here. In the blood drainage 30, seawater maintained at a temperature of 7 ° C. to 15 ° C. or water having a lower salinity than seawater is stored, and the bonito 01 that has been alive is introduced here for 1 minute or longer.
Bonito is cut from the medulla oblongata, but cardiopulmonary function is not stopped, and blood pumping is promoted by the pumping action of the heart. Skipjack has a blood vessel cut at the tail, so even if the pumping action of the heart is performed frequently, the blood vessel does not become negative pressure, and the blood bleeding action is promoted.

By letting blood out in the blood drainage warehouse 30, it is possible to prevent the brine from becoming dirty when the skipjack is introduced into the next brine freezing warehouse. If the brine becomes dirty, the heat exchange function of the brine cooler will deteriorate, making it impossible to produce good-quality fish. This blood drainage 30 replaces the cooling water in each operation.
After completing the blood removal process in the blood removal chamber 30, the skipjack 01 is manually put into a brine freezing chamber maintained at a temperature of -20 ° C to -17 ° C. The subsequent processing is the same as the B1 brine freezing method described above.

Next, the configuration of the squeezing device 20 will be described with reference to FIGS. 2-4, 21 is a head (medullary) cutting cutter, 22 is a tail cutting cutter. Reference numeral 201 denotes a frame that forms the main body of the swaging device 20, and a moving caster is attached to the frame as necessary. 202 is an inclined base plate provided inside the apparatus main body, 203 is an opening to which the end of the toy 12 to which bonito is conveyed is connected, 204 is a shutter that opens and closes the opening 203, and 205 is a shutter 204. The piston rod 205 a is connected to the shutter 204 via the floating joint 206.
Reference numeral 230 denotes a stop plate protruding on the base plate 202, and the skipjack 01 that has slid onto the base plate 202 through the opening 203 from the toy 12 hits the stop plate 230 and stops.

The stop plate 230 is positioned on the base plate 202 so that when the head of the skipjack 01 hits the stop plate 230, the blade 211 of the head cutting cutter 21 comes to the medullary position of the skipjack head. 212 is an air cylinder that drives the blade 211 up and down, 221 is a blade of the tail cutting cutter 22, and 222 is an air cylinder that drives the blade 221 up and down. The tail cutting cutter 22 is configured such that the distance from the stop plate 230 can be adjusted by driving means (not shown).
Reference numeral 231 denotes a head guide for guiding the skipjack head so that it hits the stop plate 230, and 240 is a presser plate that descends from above and presses the fish body when the skipjack fish body 01 stops on the base plate 202. Yes, it has a curved surface that follows the contour of the bonito fish body.

Reference numeral 241 denotes an air cylinder that drives the presser plate 240 in the vertical direction. The piston rod 241a is attached with a tip plate 243 in the lateral direction via a floating joint 242, and is supported on the tip plate 243 in the vertical direction. A holding plate 240 is attached to the plate 244 so as to be tiltable in the front-rear direction of the fish body 01 in accordance with the fish body 01 that has entered the base plate 202. 240 a is an opening formed in the presser plate 240 for inserting the blade 221 of the tail cutting cutter 22, 245 is a shaft attached to both ends of the tip plate 246, and 246 slides on the shaft 245 It is a bush housing that supports it.

The blade 211 of the head cutting cutter 21 is connected to the piston rod 212a of the air cylinder 212 via a floating joint 213, a blade mounting plate 214, and a blade mounting boss 215. Both ends of the blade mounting plate 214 mounted in the lateral direction are connected to the shaft 216, and the shaft 216 is slidably supported by the bush housing 217. The air cylinder 212 is fixed to the cylinder mounting plate 218.
Further, the blade 221 of the tail cutting cutter 22 is connected to the piston rod 222 a of the air cylinder 222 via a floating joint 223, a blade mounting plate 224, and a blade mounting boss 225. The air cylinder 222 is fixed to the cylinder mounting plate 226.

232 detects that the fish body 01 has hit the stop plate 230 and gives an instruction to close the opening 203 to the air cylinder 205 of the shutter 204, and the air cylinder 212 of the head cutting cutter 21 and the air of the tail cutting cutter 22. This is a proximity switch that gives a cutting command to the cylinder 222. The head switch 233 is a switch for confirming that the fish has been inserted, and operates when the fish 01 comes into contact with the stop plate 230. Reference numeral 219 denotes a column for fixing the cylinder mounting plate 218, and reference numeral 247 denotes a column for fixing the cylinder mounting plate 226.
A part 202a of the base plate 202 is separated to form a payout chute 202a, and a piston rod 251a of the air cylinder 251 is connected to the lower surface of the chute 202a. It is configured to pay out.

  260 is an air cylinder for fixing the lower chute 202a. When the shaft 263 is attached to the piston rod via the floating joint 264, the lower chute 202a is fixed so as to be flush with the base plate 202. The shaft 263 is inserted into the bush 262 and the receiving block 261. Reference numeral 207 denotes a guide plate provided on the base plate 202 in the longitudinal direction of the base plate 202 to prevent the fish from dropping off from the base plate 202.

In the living device having such a configuration, the bonito 01 stunned by an electric shock in the region 13 of the toy 12 is placed on the flat plate provided in front of the opening 203 with the head of the operator first, and the head is moved forward from the opening 203. It is put on the base plate 202. When the skipjack enters the base plate 202 and its head hits the stop plate 230, the proximity switch 232 is actuated to lower the shutter 204 and close the opening 203, and the blade 211 and the blade 221 are lowered to lower the medulla of the fish body. Cut the blood vessels in the tail.
FIG. 5 is an explanatory view showing a bonito fish body. In FIG. 5, the medulla and brain 03 are cut with the blade 211, and the second protrusion and the third protrusion from the tail side of the skipjack-specific protrusion 011 near the tail portion of the skipjack with the blade 221 (in FIG. 5). The cutting position c) is cut. The reason is that the main blood vessels of the skipjack are arranged up to the second and third protrusions, and blood can be drained efficiently by cutting the cutting position c.
In the first embodiment, the tail is cut only by a blood vessel, and the tail fin 010 is not cut off. By not cutting off the tail fin 010, conveyance and other handling are facilitated.

  After the cutting process, the air cylinder 251 is operated, the lower chute 202a is lowered, the fish body 01 is paid down, and the blood is put into the blood removal chamber 30 as it is. Blood is drained by holding in the blood drain 30 for 1 minute or longer. At this time, since the cardiopulmonary function of the fish body 01 is not stopped, blood removal is performed by the pumping action of the heart. In particular, since the blood vessel of the tail is cut, the blood pressure does not become negative even by the pumping action of the heart, so that the blood removal action can be maintained for a long time.

  In the blood removal chamber 30, it is maintained for 1 to 6 minutes, and then it is put into a brine fishhouse 013a shown in FIG. . When the brine freezing is completed, the brine is extracted from the brine fishhouse 013a, and the fish body is transferred to another fishhouse and stored in an air-cooled and frozen state at a temperature of −50 ° C. to −40 ° C. Alternatively, the fish body may be stored in an air-cooled and frozen state without changing the fish body to another fishhouse.

2 to 4 was installed in the fishing boat, and after the live blood removal skipjack was processed on the boat, the same freezing method as the B-1 freezing method was performed, and then landed at the port . Five types of fishing boats:-A) Room temperature seawater blood removal (comparative example), B) 15 ° C seawater blood removal (present invention), C) 5 ° C seawater blood removal (comparative example), D) 5 ° C seawater blood removal Tail (tail cut) (comparative example), E) Conventional B-1 freeze-freeze treatment, randomly select 5 fish from each freeze treatment group, (1) Fat value, (2 The results of measuring the color difference, saturation, and (3) fish meat hardness (average of 5 fish) are shown in FIGS.
6 and 7 show fat values (fat content) (average of 5 for each treatment method), and it is clear that the fat value (fat content) of the skin, blood, and body is thin in any treatment method. .

8 and 9 show the coloring data (5 average values for each treatment method). FIG. 8 shows the case of storing in a 1 ° C. refrigerator after thawing, and FIG. 9 shows the case of storing in a 7 ° C. refrigerator after thawing. is there. Saturation is a method for evaluating the color of red meat, and the larger this value, the more brown the color becomes. 8 and 9, it can be seen that the change in saturation over time is less in the blood removal treatment than in the B-1 treatment, and has better color retention, and the blood removal treatment has an effect. In particular, in the case of 15 ° C. seawater blood removal according to the present invention, it has been found that the saturation is the best and the change in saturation over time is the smallest.
It can also be seen that 7 ° C storage has better color retention than 1 ° C storage. When stored at 7 ° C., the color persisted in the order of 5 ° C. seawater blood removal without tail (tail cutting), 5 ° C. seawater blood removal, and seawater free blood removal. Seawater-free blood removal has a low initial saturation and seems to have little blood removal effect.

10 and 11 show changes in meat hardness after thawing of bonito, FIG. 10 shows a case of storing in a 1 ° C. refrigerator after thawing, and FIG. 11 shows a case of storing in a 7 ° C. refrigerator after thawing. . 10 and 11, there was no significant difference between the case of alive blood removal and the B-1 treatment, but the hardness in the case of 5 ° C seawater blood removal when the storage temperature after thawing is 7 ° C. It turns out that there is little change.
From these results, it was found that the change in fish meat hardness over time was more influenced by the storage temperature after thawing than the presence or absence of blood removal. In FIG. 10, it can be seen that the change in hardness is the smallest in the case of 15 ° C. seawater blood removal according to the present invention.

Next, the skipjack bonito (A) that had been blood-removed according to the present invention and the PS freezing method (bonito caught by the seine net as a comparative example) were quickly frozen in brine. , And then stored in a refrigerator at −50 ° C. to −40 ° C. The freshness is good and it is used for raw food such as sashimi and tuna.) The sensory test results of bonito (B) stored by) are shown in FIG. . There are 25 participants (21 men and 4 women).
From FIG. 12, it can be seen that the blood removal treatment according to the present invention has more vivid colors, no bonito peculiar odor, has a crunchy taste, and is more delicious.
(A) of FIG. 13 shows the state of the fish meat of the skipjack (B) processed by the PS freezing method, and (b) is a color photograph showing the state of the fish meat of the skipjack (A) subjected to blood removal treatment according to the present invention. It is. In both cases, 6 examples passed after thawing. FIG. 13 shows that the fish meat of bonito (A) that has been subjected to blood removal treatment according to the present invention has a better saturation and a bright red hue than (B).

Next, the sensory test results (tasting) in the case where the blood removal treatment was performed according to the present invention (the blood removal treatment was performed in 15 ° C cold seawater) and the blood removal treatment was performed in normal temperature (30 ° C) seawater as a comparative example. The questionnaire results are shown in FIG. There were a total of 104 participants. In FIG. 113, 5 is a good evaluation, 2 is a bad evaluation, and 3 and 4 are intermediate evaluations.
From FIG. 14, it can be seen that there were more people who answered that the present invention (cold seawater blood removal) was better in color, taste, texture and no odor than the comparative example (room temperature blood removal).

According to the first embodiment, an electric shock is applied to the live fish to temporarily stun it before performing the slaughter process, thereby preventing the fish body temperature from rising and reducing the meat quality due to internal bleeding due to bruising. In addition, the medulla can be accurately cut and the tail can be cut when the alive device 20 is used.
In addition, by severing not only the medulla of the head but also the blood vessel of the tail when alive, the blood removal in the blood removal chamber 30 can be effectively performed, especially the second and third protrusions from the caudal side. By cutting the gap, there is an advantage that the main blood vessels in the tail can be accurately cut and positioning at the time of cutting becomes easy.
Moreover, there is an advantage that handling in a later process can be facilitated by leaving the tail portion.

Furthermore, as shown in the above-mentioned sensory test results, the color tone and taste are maintained by holding the blood in the cooling chamber 30 at a low temperature of 7 ° C. to 15 ° C. for 1 minute or more, preferably 1 to 6 minutes for blood removal. In addition, both the texture and odor are superior to the conventional treatment method or the comparative example, and it can be seen that the blood removal effect is remarkable.
In addition, after the blood removal treatment, the ice crystals generated in the tissue cells of the fish meat are made finer by rapidly freezing in a brine warehouse at -20 ° C to -17 ° C, thereby improving the quality and quality of the fish body. Can be maintained.

  According to the present invention, when the live fish is alive, the blood removal effect is improved as compared with the prior art, thereby greatly reducing the consumption of adenosine triphosphate after thawing and greatly suppressing the self-digestion of the alive fish. By maintaining the freshness of the alive fish over a long period of time, it is possible to provide the market with high added-value fish meat that has good color, taste and texture, and has no odor.

(A) is the schematic diagram which looked at 1st Example of this invention apparatus from the top, (b) is the schematic diagram similarly seen from the front. It is a cross-sectional elevation view of the swaging device 20 of the first embodiment. FIG. 3 is a cross-sectional side view taken along line III-III in FIG. 1. It is a cross-sectional side view which follows the IV-IV line of FIG. It is explanatory drawing of the fish body of a bonito. It is a diagram which shows the fat value of the said 1st Example and a comparative example. It is a diagram which shows the fat value of the fish meat of a comparative example. It is a diagram which shows the saturation of the fish meat of the said 1st Example and a comparative example. It is a diagram which shows the saturation of the fish meat of a comparative example. It is a diagram which shows the hardness of the fish meat of the said 1st Example and a comparative example. It is a diagram which shows the hardness of the fish meat of a comparative example. It is a graph which shows the sensory test result of the fish meat of the said 1st Example and a prior art example. (A) And (b) is a color photograph of the fish meat of the said 1st Example and a comparative example. It is a graph which shows the sensory test result of the fish meat of the said 1st Example and a comparative example. (A) And (b) is a schematic block diagram which shows the freezing method of the conventional bonito.

Explanation of symbols

01 Bonito fish body 011, 11 Tents 012, 12 Toys 013a, 013b Brine fishhouse 13 Electric shock region 014 Cooling coil 015 Lid 20 Vigorizer 30 Blood drain 21 Head cutting cutter 22 Tail cutting cutter 201 Frame 202 Base plate 202a Lower chute 203 Opening 204 Shutter 205, 212, 222, 241, 251 Air cylinder 207 Guide plate 211, 221 Blade 230 Stop plate 231 Head guide 233 Proximity switch 240 Presser plate 251 Air cylinder 260 Air cylinder for lower chute

Claims (8)

In the method of freezing live fish, after catching live fish, alive the live fish, drain the blood, and then store it frozen.
After catching live fish, a lively step that cuts the medulla of the live fish and keeps it live without stopping the cardiopulmonary function of the live fish,
A blood draining step in which the live fish is put into a cooling water tank maintained at a temperature of 7 ° C. to 15 ° C. and held in the cooling water tank for 1 minute or more;
A brine treatment step in which the blood-bleeded fish is put into a brine freezing tank set at a brine concentration so as to freeze at a temperature of −20 ° C. to −17 ° C. and held in the brine freezing tank for 4 hours or more;
And a storage step in which the product is stored frozen in an air-cooled tank maintained at a temperature of -50 ° C to -40 ° C.   2. The method for freezing live fish according to claim 1, wherein, in the alive step, the medulla of the live fish is cut and the tail of the live fish is cut or the blood vessel of the tail of the live fish is cut.   The method for freezing live fish according to claim 1, wherein the live fish is temporarily stunned by applying an electric shock to the live fish before performing the alive step.   The live fish is a skipjack, and the cutting position is between the second and third from the tail among a plurality of protrusions arranged in a row from the tail to the front side of the skipjack. The method for freezing live fish according to claim 2. In the live fish refrigeration equipment that keeps live fish inside the fish boat, drains blood, and then freezes and stores it.
A device that cuts and uses the medulla of the captured live fish,
A blood-cooling cooling water tank for storing cooling water maintained at a temperature of 7 to 15 ° C .;
A brine freezing tank for freezing blood-bleed fish set to a brine concentration that freezes to a temperature between -20 ° C and -17 ° C;
A fish freezing apparatus, comprising: a freezing tank for storing fish frozen at the temperature of −50 ° C. to −40 ° C. and frozen in the brine freezing tank.   6. The live fish freezing apparatus according to claim 5, wherein a region for applying an electric shock to the live fish is provided in a passage for transporting the captured live fish to the live device. The vitalizing device is
An introduction port through which live fish is introduced from the head, connected to the live fish conveyance path,
A base plate disposed to be inclined downward from the introduction port;
Holding means for holding live fish from above the base plate;
A cutter that cuts the head of a live fish provided above the base plate so as to be close to or away from the base plate;
A stop plate provided on the base plate for stopping live fish at a position where the medulla is cut by the head cutting cutter;
A sensor that is provided on the stop plate and senses that the live fish hits the stop plate, lowers the presser means, and makes the head cutting cutter approach the base plate to the medullary cutting position of the live fish; and
6. A live fish freezing apparatus according to claim 5, further comprising means for discharging the lived fish from the base plate.   8. The live fish freezing apparatus according to claim 7, further comprising a cutter that cuts a tail of a live fish or a blood vessel of a tail of a live fish in response to a signal from the sensor that senses that the live fish hits the stop plate.

Images