WO2003059075A1

WO2003059075A1 - Process for producing highly fresh frozen tuna meat and highly fresh frozen tuna meat

Info

Publication number: WO2003059075A1
Application number: PCT/JP2001/011614
Authority: WO
Inventors: Nobuhiko Hatakeyama
Original assignee: Hoyo Fisheries Co., Ltd
Priority date: 2000-07-04
Filing date: 2001-12-28
Publication date: 2003-07-24
Also published as: JP2002017243A

Abstract

It is intended to provide tuna meat showing a high freshness comparable to fresh raw tuna meat even in case of thawing after preserving over a long time. A process for producing highly fresh frozen tuna meat characterized by comprising selecting alive fish from among tuna fish immediately after catching; sacrificing and bleeding the alive fish; ceasing the vital reactions by grinding medulla and marrow; immediately removing bowel, gills, fins, tail, head and bones from the fish while sufficiently bleeding to thereby process the fish into dresses, loins, fillets or blocks; freezing the fish meat at an ultra-low temperature so as to lower the temperature of the whole meat to the eutectic point or lower (about -60°C) within 10 hours, preferably within 8 hours; and preserving the meat while maintaining at the eutectic point or lower. Highly fresh frozen tuna meat characterized in that the meat has been preserved at a center temperature of -50°C or lower so as to prevent the meat from denaturation and, after thawing, rigor mortis is induced.

Description

Harm

Production method of high freshness frozen tuna meat and high freshness frozen tuna meat

The present invention utilizes a living tuna that has been caught and has a life response stopped so that the cells are still alive and dressed or mouthed or filed. Alternatively, the meat is processed into block-style meat, and the whole meat is frozen at a very low temperature while the cells of the meat are alive, and the meat is frozen and stored so as not to deteriorate. Also, the present invention relates to providing tuna meat with high freshness, such as freshly baked meat, even after thawing for a long time. Background art

There are two types of tuna fishing: pelagic fisheries, inshore fisheries, and aquaculture (breeding) fisheries. When tuna are distributed, they are distributed as frozen tuna through cold chains (cold distribution) and as raw tuna. There is a distribution through the chill zone (refrigerated distribution). However, it is practically difficult to distribute the tuna as it is, because the tuna body is large and heavy, and it is dangerous if it goes wild. Therefore, there is almost no distribution of live tuna fish. Moreover, in terms of quantity, most of the fishing grounds for migratory tuna that travel in the world's oceans are mostly distributed in the cold-sea, as frozen tuna that can be stored for a long period of time because they are mostly pelagic fisheries. At present, fish caught in the coastal waters are rarely distributed in the chill zone as raw tuna. Traditionally, in the case of seafood, live fish that have been kept alive and live are more fresh and delicious than fresh and chilled raw fish sashimi. The high commercial value is well known to Japanese people with a “sashimi food culture”. This is no exception for tuna. Therefore, the tuna sashimi that has been used up to now is longing Is difficult. Therefore, fresh tuna was evaluated to be higher in quality than frozen tuna because fresh tuna had better day keeping and freshness than frozen tuna in many cases. In other words, the freshness of tuna is also important, but fishermen, distributors such as wholesalers and retailers, producers of cooks and abalone shops, freshness of tuna meat I don't think it is possible to get something fresh, such as a lively one. Therefore, in the case of frozen tuna, whether it is a live tuna or a wild tuna (tuna with dead fish), the difference in freshness between the two is not noticed, and it is necessary to treat them differently. There was no one.

For this reason, the processing of frozen tuna on board in the conventional pelagic fishery was as follows. Tuna is usually caught by the tuna fishing method, but when fish caught in the fishing line are fried on board, there are a mixture of tuna caught alive and tuna caught dead. However, without discriminating this, all the fish are drained, then the intestines, gills, fins, and tail are removed, and the GG (Gi 11 and Gutless) style (With gills and internal organs removed, or with a semi-dressed tail). After that, arrange them on the GG style tuna quick-frozen shelf and freeze for about 36 hours to a core temperature of less than 55 ° C. Then move to Uogura and store frozen. After unloading, cut it with a large band saw into the mouth and the filet style, remove the blood with a grinder, and perform other processing before selling. . As a result, the characteristics of the product have been commercialized by mixing those with and without blood clots, and those that have rigidity after death and those that do not have a mixture are also commercialized. . Therefore, there is unevenness in freshness and color preservation, and most of them discolor about 2 days after thawing. In addition, since work management during freezing is not sufficient, it takes too much time to freeze, or some cannot be completely frozen. In the factory, there are many variations in quality, such as those that deteriorate and those that have many drops.

As described above, in the distribution industry such as markets, the quality of landed tuna varies, so the price is set based on the quality evaluation of fish. Tuna quality evaluation methods there are determined mainly by the presence or absence of thrombus, color tone, and the degree of fat riding as follows.

First, fish clots include bruised clots (blood running), which can be produced when fish run wild, and burrow clots, which can be formed due to insufficient blood removal. If there is a blood clot in the meat, it will not be sold as sashimi and its commercial value will be greatly reduced.

Second, regarding the grain, there are ranks of “complete chichire”, “half chile”, “slight red”, and “peke”. The price that can be sold according to this rank is determined, and the consumer's use is also determined. It is different.

In the case of “Complete Chile”, rigidity begins after thawing after thawing, and a bright red color blows out. If thawed well and stored, it can last 2 to 4 days. This phenomenon indicates that the flesh cells are not yet completely dead. This rank is the highest grade of frozen color and is used in high-end restaurants, high-end sushi restaurants, high-end inns and hotels. The appraisal is high because it can be used even when it takes a long time between assembling sashimi and actually eating. It ranks higher than fresh tuna in terms of good color, good color preservation, and good freshness.

In the case of a “half-tied”, it is rated one rank lower than the fully-tied product. Color preservation can be kept for no more than two days a day. This half-pea was only from the same active tuna, but did not become a perfect one due to some freezing failure. However, it is good enough to make sashimi, so it is a good product.

In the case of "slight red", it is the lowest level of tuna rank for sashimi. Solution It has already developed color when it freezes and has a red eye color, but it has a color only on the day of thawing. This point is inferior to the raw tuna that is kept for a long time. In the case of the field, this class is for the most part. Therefore, it has to be sold cheaply, and the price is less than half of the full price.

In the case of “bokeh”, it is an inferior product without commercial value as sashimi tuna. Not only are they used as cuts for grilled food, processed miso pickles, processed tsukudani, and raw materials for canning, but their prices are also significantly lower.

Third, fish vary in meat quality among individuals. Depending on the species, the timing, the location where they are captured, and the way they are raised, there is a difference in quality. In the evaluation, the quality evaluation varies greatly depending on whether or not the fish has good fat riding, the fish with poor fat riding, or the part where the fat riding is good.

The inventor of the present invention has found that the difference between the market evaluation and the commodity price due to the difference in quality of tuna is very large and has a great effect on corporate management. If it is fresh and of good quality, even if the price is high, there is a strong need among consumers and it becomes a business. Therefore, the inventor has conducted intensive research on how to always provide frozen tuna with high freshness and high quality.

As a result, they noticed that the main cause of the deterioration in the quality of tuna products was apparently due to artificial treatment mistakes, and that the quality that tuna naturally possesses was reduced. In other words, specifically, how to eliminate thrombus, how to make thawing when thawing, and how to make the color better, and how to commercialize as a high-quality frozen tuna As a result of research, when the tuna caught is fried on board, it is determined that the distinction between live fish and dead fish and keeping the live fish alive will cause the thaw when thawing. No matter how fresh it is, it is important to know that if you go to a so-called field where you have a good point and that you eat fish that have died and fried, no matter how fresh you are, As a result, it turned out to be red. Therefore, it is necessary to clearly treat the two as having different qualities. Also, in order to prevent blood clots from occurring, it is necessary to prevent live fish from being rampaged so as not to be bruised, and to sufficiently remove blood from the meat. From a certain point, it is necessary to make sure that, when alive, they will not be killed immediately and suffered or moved, and that they will be able to drain blood from the capillaries of the flesh sufficiently. It is necessary to carry out the processing in consideration of the request. Furthermore, to prevent quality deterioration in the freezing process, it is necessary to freeze ultra-low-temperature to the core in as short a time as possible, and to freeze and store it at ultra-low temperature after freezing so that the meat does not deteriorate. It is necessary to overcome technical issues such as good thawing. For the first time, by overcoming the above technical issues, frozen tuna can maintain high freshness and high quality, and receive a higher quality evaluation than fresh tuna. Disclosure of the invention

According to the present invention, it is necessary to adopt the following production method as a means for solving the technical problem, and it is possible to realize highly fresh frozen tuna meat with high evaluation.

The first invention, which seeks a patent, distinguishes the caught tuna into live fish and dead fish, draws blood using live tuna, and crushes the medulla and spinal cord. As a result, the intestines, gills, fins, tail, head, and bones were removed while immediately removing blood, and the dressing or mouth or fins were removed. Re-style or block-style fish meat is processed and then within 10 hours, preferably within 8 hours, the whole meat is below the Kyochang point (around-60 ° C). The frozen fresh tuna meat is characterized by being frozen at ultra-low temperature and kept frozen so that the meat remains below the Kyochang point. It is a manufacturing method.

The second invention, which seeks a patent, is to cut the tail and cardiac artery of all the tuna caught and fried on board, and to drain the blood. The tuna that lived died and caught fish that died and fried, and the living tuna further crushed the medulla and spinal cord and stopped living reactions. Remove and process into dressing or loin or fillet-style or block-style tuna meat with sufficient bleeding, preferably within 10 hours thereafter In a short period of 8 hours or less, the meat should be frozen at ultra-low temperature below the Kyochang point (around -60 ° C) and stored frozen at a center temperature of 150 ° C or less. This is a method for producing high-purity frozen tuna meat.

The third invention, which seeks to obtain a patent, is that the activity cuts the tail and heart artery of a living tuna, drains it in a standing state and puts it into a suspended state, and / or a living tuna. The fourth invention, which is intended to be patented, is a method for producing a high-purity frozen tuna meat as described in the first invention or the second invention, characterized in that the medulla oblongata and the spinal cord are crushed to stop living reactions. The living tuna were drawn to blood and put into a state of asphyxia, the medulla oblongata and the spinal cord were crushed, and life reactions stopped, and the intestines, gills, fins, tail, head, and bones were immediately removed. In a state where the cells are alive, they are processed into dress or loin or file style or block style meat, and the cells of the body are alive. The whole body is frozen at ultra-low temperature below Kyochang point (around 160 ° C) so that the meat does not deteriorate. Core temperature stored frozen below one 5 0 ° C, a high freshness frozen tuna flesh, wherein the lower child as flesh of the tuna upon thawing causes death after rigidity. The tuna according to the present invention includes: swordfish tuna, yellow-skinned tuna, true marlin, female marlin, long tuna, black tuna, southern tuna, cochinaga tuna, Atlantic tuna, Pacific marlin, Hanyu or marlin, Includes all swordfish and other swordfish and tuna fish You.

In the present invention, the ultra-rapid low-temperature freezing of meat so as to be below the Kyochang point means that the temperature at which the water content of food is 100% and the liquid is completely frozen from liquid to solid is called Kyochang point. In this case, around 60 ° C is the Kyochang point.

The high-purity frozen tuna meat of the present invention is such that, when thawed at least, it is of such a quality as to cause stiffness after dying (chile), is light-colored, has almost no thrombus, and has a dress. Means that the quality is such that the freezing time is short and the drip does not appear much because it is frozen in the mouth-in or file-style or pro-style. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is an explanatory diagram showing a method of processing tuna into a round, a GG style, a dress, a mouth, a fillet, and a block, and FIG. Samples of the frozen fresh tuna meat obtained by the manufacturing method and the frozen tuna prepared by the conventional method were taken out, and the freshness K values of both were measured and compared. is there. Similarly, FIG. 3 shows a test in which samples of the freshly-frozen tuna meat obtained by the production method of the present invention and a sample of the frozen tuna prepared by the conventional method were taken out, and the rotting degree VBN was measured. It is a test result showing a result. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail based on examples.

The fish caught lively and the yellow-skinned tuna caught and caught by the long-hauled fishery were discriminated between the fish caught alive and the fish caught dead, utilizing the former and leaving the latter in the field. Yes, use an identification tape to distinguish them. The activity cuts the tail and cardiac artery of a living tuna, bleeds it upright and puts it into asphyxia, crushes the medulla medulla and the spinal cord of the living tuna, and stops living reactions. On the other hand, the dead Cut the tail of the fried tuna and the heart artery and drain the blood in an upright position. At this stage, life as a living organism is dead, but cells are still alive.

Then, the intestines, gills, fins, tails, heads, and bones of both the live and open tuna were removed, and the dress or mouth or file style or professional tuna was removed. Processed into meat of the style. This on-board processing ensures that sufficient fresh blood can be drawn, so that burrowing clots are almost eliminated. Compared to the conventional GG style tuna in which only the internal organs and tail were cut, sufficient fresh blood could not be drawn, and it was unavoidable that a partly sesame clot could be formed. The present invention in the form of a mouth or mouth or a file style or a block style provides a great quality improvement. In addition, dress or mouth-in or fillet style or proc- ess style reduced the meat, so that the desired frozen state (core up to (Ultra-low-temperature freezing to be less than) is shorter than 1/4 of the conventional GG style. This prevented the meat from deteriorating and allowed the cells to be frozen while still alive.

In addition, dress or mouth in, file style or proxy box will be explained based on Fig.1. The dress (headless) refers to a state in which the head and tail are cut off from the GG, and the fillet (three pieces) is a state in which the dress is reduced to three pieces and the spine is removed. Mouth-in means that the file is further divided into male and female segments, and block style is the cut of the file style vertically. Say what you did.

Next, tuna meat processed into a dress or mouth in or file style or block style is placed on a freezing shelf and placed in a frozen shelf for 8 hours to reach Kangchang Point (around 160). Freeze at very low temperature to below. In addition, the Kyochang point is the temperature at which the water content of food is 100% and the liquid is completely frozen from liquid to solid. In the case of tuna, the temperature is ideally around 60 ° C, but since meat also varies depending on the nature, the range around ± 5 ° C is included. This prevented the meat from deteriorating and ensured that the cells could be frozen while still alive. In other words, it became possible to freeze natural dishes on frozen dishes, and to keep natural red on pure red when frozen.

In the case of the conventional GG style, it takes an average of 36 hours for the core to be frozen at an ultra-low temperature below the Kyochang point (around 60 ° C). As a result, the core of the meat is slowly frozen, the quality of which deteriorates over time, the number of drippings increases, and the freshness of the meat, which is supposed to cause chilling when thawing, is reduced. It will be degraded to the extent that it does not occur.

As described above, the present invention has found a method for maintaining the freshness of cells in a state where the cells are alive, in which stiffness occurs after thawing when thawing, and has established a method that can always reproduce the frozen tuna. It is a breakthrough.

In this way, live and tuna are sorted on the ship, the meat is processed, and frozen at a low temperature until the temperature is below the Kyochang point in a short time. Maintain the freshness, separate the frozen meat into live and wild, and move it to Uonokura, and store it frozen at –50 ° C or less so that the high freshness quality does not deteriorate. Next, on land, the bloodline is removed with a grinder, and the small band is used to cut the block. Other processing for commercialization. Then, they are sold separately by activity, field, size, fat / lean, and other parts. The method of thawing frozen tuna can be any method such as natural thawing, microwave thawing, or running water thawing, but it is necessary to thaw well. To defrost particularly deliciously, the frozen tuna quickly passes through the temperature range (3 to 8 ° C) where deterioration is likely to occur. Therefore, salt water with a salt content of 3.5% is added to lukewarm water at 25 to 30 ° C. Allow 3-5 minutes. It is recommended that the tuna removed be wiped dry, left at room temperature for 20 to 30 minutes, wrapped in a cloth, placed in a refrigerator and cooled before eating. In the present invention, high-purity frozen tuna meat is thus produced. Next, a sample of the frozen fresh tuna meat obtained by the production method of the present invention and a sample of the frozen tuna frozen on board and processed by the conventional method are taken out, and the product characteristics of both are taken out. Were compared. The result is as follows.

<Presence / absence of thrombus> In the case of the high-purity frozen tuna meat of the present invention, blood was sufficiently removed by processing immediately after activation, so that no blood remained in the capillaries. Is hardly seen. In addition, since blood is drained while alive and the medulla and spinal cord are crushed and immobilized, the flesh is processed, so that the fish do not violate the suffering of death and make bruises. As a result, almost no bruising thrombus is seen.

On the other hand, frozen tuna manufactured by the conventional manufacturing method is mixed with fish that have been bruised because of the death of the fish, and the blood clots are not sufficiently formed. At present, some are mixed with some that are not.

<Good or bad eye color> As the fresh frozen tuna meat according to the present invention, only the lively tuna meat was selected. It is a product that may cause chipping (rigor after death) when thawed. When stiffness begins after thawing after thawing in this way, a bright red color blows out and the color looks delicious. The resulting hues last for two to three days. This phenomenon indicates that the meat cells have not yet completely died, which is the original taste of fresh fish with a rich texture and flavor. The frozen color is also the highest grade. It is useful when it takes a long time from sashimi cutting to assembling to actually eat. It is ranked higher than raw tuna because of its good brilliant color, good color preservation, and good freshness.

If you don't do it, you won't see any blemishes, Each of the products is clearly inferior in quality and receives a distinct evaluation and treatment. On the other hand, frozen tuna produced by the conventional manufacturing method contains a mixture of those that cause seizure when thawed and those that do not, and a mixture of live and wild ones. The spots are bad and big.

<Color preservation> The high-purity frozen tuna meat according to the present invention is chipped, so that after thawing, a bright red color blows out, and its color does not change color for 4 days. On the other hand, frozen tuna prepared by the conventional manufacturing method has uneven spots in color preservation, and most of them change color about 2 days after thawing.

<Drip> The frozen fresh tuna meat according to the present invention freezes in a short time of 8 hours or less, so that dripping is very small. On the other hand, frozen tuna prepared by the conventional manufacturing method has a lot of dripping because it freezes slowly for as long as 36 hours.

Freshness K value measurement and putrefaction measurement (VBN measurement)> Take out a sample of the high freshness frozen tuna meat obtained by the production method of the present invention and the frozen tuna prepared by the conventional method, The freshness K value and decay degree VBN value of both were measured and compared. Figure 2 shows the test results (Japan Frozen Food Inspection Association) showing the results of the freshness K value measurement test. Here, the K value is defined as the value of adenosin triphosphate (ATP, a component that plays an important role in post-mortem stiffness and biochemistry) contained in fish muscle, after the death of the fish, by the use of muscle enzymes. It is sequentially degraded to syndinophosphate (ADP), adenosine monophosphate (AMP), inosine (HxR), and hypoxanthine (Hx). Therefore, the degree of degradation of adenosine peracid (ATP) is measured, and the freshness evaluation is quantified as the K value, which can be obtained by the following formula. [Equation 1]

HxR + Hx

k value (%) =

ATP + ADP + AMP + IMP + HxR + Hx Generally, in fresh tuna evaluation in the market, K value is 10% or less, high freshness, K value is 20% or less, freshness, K value is 50%. Before and after the edible limit freshness. As a result of the test, the K value of the high-purity frozen tuna meat of the present invention cannot be detected, and the K value is at least 3% or less. This indicates that the meat of the present invention has hardly changed in quality from a living state. The goodness of the freshness of the tuna according to the present invention is apparent even when compared with the K value of the frozen tuna prepared by the conventional production method of 16% and the K value of the raw tuna of 43%.

Figure 3 shows the results of the spoilage measurement. The test results show that the high freshness frozen tuna meat according to the present invention has an active VBN of 3 Nmg and a field / VBN of 3 Nmg. This indicates that the meat spoilage of the present invention is almost intact. On the other hand, the frozen tuna prepared by the conventional method, that is, the one frozen in GG soil, has a VBN of 10 N mg, and the frozen tuna on land has a VBN of 16 N mg. Thus, the present invention clearly indicates that the degree of decay is advanced.

From these measurement test results, it is understood that the present invention is clearly superior in quality including freshness. Industrial applicability

The present invention distinguishes caught tuna into living fish and dead fish, draws blood using living tuna, and crushes the medulla oblongata and spinal cord to stop living reactions. Intestine, gill, fin, tail, head, bone Four

13

And processed into dress or mouth-in or file-style or block-style fish meat, and then within 10 hours, preferably within 8 hours In a short time, the whole meat was ultra-low-temperature frozen so as to be below the Kyochang point (around -60 ° C) and stored frozen so that the central temperature of the meat was below 150 ° C. This is a method for producing a high-freshness frozen tuna meat. The high-purity frozen tuna meat according to the present invention has sufficiently removed blood, so that there is almost no burrow thrombus.

Further, in the method for producing frozen tuna meat of the present invention according to the present invention, after thawing, rigidity starts after death, and a bright red color is blown out to develop a color, which is likely to be delicious. Moreover, the hues that come out in this way can last for two to three days. In addition, this is the original taste of fresh fish with a rich texture and flavor, and its frozen color is also the highest grade. It ranks higher than raw tuna for its excellent color, good color preservation, and good freshness.

In addition, since the frozen fresh tuna meat according to the present invention is chopped, a fresh red color blows out after thawing, and its color does not change for four days.

Furthermore, since the frozen fresh tuna meat according to the present invention freezes in a short time of 8 hours or less, dripping is very small. On the other hand, the frozen tuna prepared by the conventional manufacturing method has a long drip of 36 hours, and thus has a large amount of dripping.

Furthermore, samples of the high freshness frozen tuna meat obtained by the production method of the present invention and a sample of the frozen tuna prepared by the conventional method were taken out, and the freshness K value and decay degree VBN value of both were taken. The results of the measurement and comparison prove that the present invention is clearly superior in quality including freshness.

Claims

The scope of the claims

1. The caught tuna is distinguished from living fish and dead fish, and the living tuna is used to draw blood, and the medulla and spinal cord are crushed to stop living reactions, and immediately Remove the intestines, gills, fins, tail, head, and bones with sufficient blood removal to process dress or mouth-in, or file-style or block-tile fish meat After that, within 10 hours, preferably within 8 hours, the whole meat is frozen at ultra-low temperature to be below the Kyochang point (around 60 ° C). A method for producing high-purity frozen tuna meat, which is stored frozen so as to maintain the temperature below Kyochang point.

2. For all the tuna caught and fried on the boat, their tails and cardiac arteries are cut off to draw blood, but the live fish that caught alive and the wild fish that ceased to die are caught. The active tuna further crushed the spinal cord and spinal cord to stop the life reaction, and immediately removed the intestines, gills, fins, tail, head, bones on the ship, and removed blood sufficiently to remove blood. Processed into loess or loin or fillet-style or block-style tuna meat and then share the meat within 10 hours, preferably within 8 hours. Manufacture of high freshness frozen tuna meat, characterized by ultra-low temperature freezing at a temperature below (about 160 ° C) and frozen storage at a center temperature of 150 ° C or less. Method.

3.Activity is to cut the tail and cardiac artery of a living tuna, draw blood in a standing state and put them into a state of asphyxia, and / or crush the medulla and spinal cord of a living tuna to respond to life. 3. The method for producing frozen fresh tuna meat according to claim 1 or 2, wherein the method is stopped.

4.Take the blood of the living tuna and make it alive and put into a state of asphyxia.Furthermore, the medulla and spinal cord are crushed to stop the life reaction, and the intestines, gills, fins, tail, head and bones are immediately destroyed. Removed and processed into dress or mouth-in or dress-style or pro-style fish meat while the cells are alive. While the cells of the meat are still alive, the whole body is frozen at a very low temperature below the Kyochang point (around -60 ° C), and the center temperature is kept at 150 ° C to prevent the meat from changing. A high-freshness frozen tuna meat, characterized in that the meat of the tuna is rigid after mortality when stored and frozen below.

Abstract

The present invention utilizes a living tuna that has been caught and alive, so that the life response is stopped, and the cells or cells are kept alive in a dress or a mouth or a filet. Alternatively, the meat can be processed into block-style meat, and the whole meat can be frozen at a very low temperature while the cells of the meat are still alive and stored frozen so that the meat does not deteriorate for a long time. The purpose is to provide tuna meat with a high degree of freshness as if it was thawed after the passage.

The composition consists of distinguishing the caught tuna into live fish and dead fish, using the live tuna to draw blood, crushing the medulla oblongata and spinal cord, and stopping the living reaction. Remove the intestines, gills, fins, tail, head, and bones immediately with sufficient blood removal, and process the meat into dress or mouth-in or fillet-style or pock-style fish. Then, within a short period of time, preferably 10 hours or less, preferably 8 hours or less, the whole of the meat is frozen at an ultra-low temperature to be below the Kyochang point (around 60 ° C). A method for producing frozen fresh frozen tuna meat, characterized by being frozen and stored so as to maintain the temperature at or below the point, and frozen and stored at a center temperature of 150 ° C or less so that the meat does not deteriorate. Characterized in that the meat of the tuna is rigid after thawing when thawed Freshness frozen tuna flesh.