JP2017192382A - Blood removal method of yellowtail, manufacturing method of blood removed yellowtail, manufacturing method of yellowtail processed article, blood removal treatment method of tuna, manufacturing method of blood removed tuna and manufacturing method of tuna processed article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blood removal method of yellowtail or tuna using practically feasible quality control method by preventing burned meat generated in yellowtail or the like which is major cultured fish, and indirectly digitalizing removal level of blood which is major causative agent thereof.SOLUTION: A blood removal treatment by introducing a perfusion liquid into a blood vessel of yellowtail and replacing from the blood is conducted so that L* value in L*a*b* color system of white meat of dorsal upper part or fatty upper part of yellowtail is 50 or more.SELECTED DRAWING: None

Description

  The present invention relates to a blood removal treatment method for a yellowtail, a method for producing a blood removal yellowtail, a method for producing a yellowtail product, a blood removal treatment method for a tuna, a method for producing a blood removal tuna, and a method for producing a processed tuna product.

  Yellowtail and red sea bream occupy over 80% of Japan's aquaculture production. In 2010, the production by fish type (percentage of fish culture) was 139 thousand tons (55.7%) for yellowtails, 68,000 tons (27.5%) for red sea bream, and 15,000 tons (6.0%) for coho salmon. %). The value of production (ratio of fish farming) is 117.6 billion yen (53.8%) for yellowtail, 50.6 billion yen (23.1%) for red sea bream, and 6.5 billion yen (3.0%) for coho salmon.

  Cultured yellowtail is the collective name for yellowtail, amberjack, and hiramasa (there are few in industrial statistics), while yellowtail and hiramasa capture natural seedlings that flow and flow with algae in the sea near Japan, while aquaculture begins. The difference is that most of the seedlings are spawning places near Vietnam and Hainan Island in China and imported seedlings from China. In other words, yellowtail is a temperate fish, but amberjack is a tropical fish.

  Cultured yellowtail is the largest aquaculture fish in Japan (100,000 tons), and its swimming range is different from other migratory fish, and it is known that a large group of fish migrate around the sea near Japan. It is a so-called national fish that is limited. Therefore, it is necessary to enumerate the problems of handling yellowtail throughout the year and to take solutions for long-term preservation of freshness as much as possible, as well as domestic species, because there are no competing fish species when promoting overseas exports. In recent years, increasing sales overseas from Japan toward the sixth-order industry is also a national policy, and yellowtail is an important fish species leading to the activation of the primary industry.

  As a characteristic of yellowtail, the season when the meat quality of both natural products and cultured products is substantial is from early winter to early spring (November to April), and shipping consumption is concentrated during that period. Since the beginning of spring, natural fish are scattered by parasites taken from the food intake from the natural environment and grow after the end of spawning, so nematodes and yellowtails become conspicuous when they are cut and consumed. As a raw ingredient (sashimi), he is shunned. Even in the case of farmed fish using mixed feed that is free of the risk of parasite infection, the spawning season in early spring (May-July) causes a sharp change in fish composition, resulting in a decrease in lipid content and an increase in water, resulting in a watery fish body. As a result, Japanese yellowtail was firmly consumed mainly in winter.

  Recently, since the shipping time is limited to the seasonal time, a system is in place that can be sold all year round by artificial spawning in the fall, which has shifted the natural spawning time with the public and private sectors. With this technology, summer shipment (July to October) was added during the winter season (November to April), and it became possible to supply and ship fresh fish almost all year round except for one season after spawning.

  In other words, as mentioned above, the season of yellowtail has been from November to March (4), but in recent years, the use of new seedling technology that makes full use of control of sunshine hours and breeding water temperature, induction hormone, etc. Techniques to lay eggs in the fall have come to be performed, and shipping aquaculture for the summer season has been increasing in line with the market size in the summer due to improvements in the feed feed.

  The yellowtail has been aquacultured since around 1965, and production exceeded the natural catch in 1960. It reached 160,000 tons in 1981 and has been maintained so far. As a result, some of them have been replaced with amberjack aquaculture for tropical sales. In recent years, frozen storage of yellowtail has been established and increased as a processed product by the applicant's application (Patent Document 1), but there have been many cases of failure in fresh frozen processing, and no processing in the industry. It is also because the recognition that the freezing of yellowtail is impossible has taken root, and has not yet spread in the country. Therefore, as a means to increase distribution consumption, it is necessary to provide a stable supply of summer yellowtail that matches the current distribution pattern of fresh products. In addition, the burnt meat problem in the shipping of fresh fish in summer yellowtail, which is expected to increase in the future, is still an unsolved theme at the time of filing.

  Although the mechanism of the burnt meat phenomenon of the general yellowtail is being elucidated by each research institution, there are no definitive measures to deal with it, and it remains a uniform response.

  Here, burnt meat means that when cultured yellowtail and tuna are shipped during the high water temperature period in summer July to August, blood clotted meat and white meat become cloudy in a short time in the early storage period and become tofu. Say that it will be. The tissue that has become burnt meat becomes soft, and the commercial value is completely lost due to the off-flavor. Such a phenomenon is commonly called “Yakiniku” in yellowtail tuna and causes the loss of commercial value, but the mechanism is not clearly understood. Watson et al. Hypothesize that the cause of burns cannot be explained only by high temperature and low pH, and advocates the following hypothesis about the burn generation mechanism (Non-patent Document 1).

  In other words, “In excessive tissue, oxygen and ATP deficient tissues cause metabolic disruption of the cell membrane, and the increase of Ca 2+ in the cell activates a type of enzyme, CANP (Calcium-activated neutral protease). “The stress at the time of fishing secretes neurotransmitters such as adrenaline and activates CANP.”

  The yellowtail (seriola quinqueradiata) has the largest blood volume among the yellowtails (yellowtail, amberjack, hiramasa), and it is difficult to completely remove it by normal blood removal treatment. Reflected in white color. The blood remaining in this fish meat has a unique flavor (bloody odor, iron taste) and is a place where palatability is reflected, but in general, it tends to be unfavorable, and the rate of change in meat quality thereafter Influencing has been known for some time. In this section, we will discuss the characteristics of Hb and Mb because we will describe post-mortem fish meat.

  Non-Patent Document 2 shows the percentage of Mb in normal muscle (Hb + Mb) without blood removal and after blood removal, but it is difficult to calculate whole blood because of the large fluctuation range. (47-100%) The average is about 80% -90%, and there is a rough description of 91% or more for horses, dolphins and whales.

  The color tone of the chromoprotein (Hb, Mb) is reduced (R-Hb, Mb dark red) and oxygenated (O2-Hb, Mb bright red) in that state, but then methified (H2O-Hb, Mb) Brown color). In the living body, Hb that has been methetinated by the carbonic reductase group returns to reduced Hb, but Hb remains in the methed state as a result of inactivation of the carbonic reductase after death. After that, with the progress of methonation and decay of porphyrin, deterioration-promoting substances (non-protein substances essential for enzyme activity are usually strongly bound to the protein part by covalent bonds and cannot be removed by dialysis etc. , Lipids, sugars, metal ions, phosphates, coenzymes, pigments, etc.), and various odorous gas components are emitted simultaneously.

  For example, yellowtail sashimi dishes arranged at a room temperature table change color in about 1 to 2 hours, causing a unique raw odor and stickiness, which is inconvenient for eating. Although it is still possible to extend the time with freshness with a feeling of crispy, the sashimi of yellowtails lined up in the sashimi all day and night from the production area is very short as the sashimi assortment of sashimi in this way. In the case of fresh fish (round), this phenomenon is a short time after death, and the fish meat almost consumes oxygen in the body and is in anoxic state, so the red blood clot portion is in the reduced (R-Hb, Mb) state (pO2 is less than 3 mmHg) ) And changes to a dark red color and stabilizes. However, contact with air after disassembly causes a coordinate bond with oxygen, resulting in blooming (coloring phenomenon) and a visually desirable bright red color. In addition, the change of food is promoted at room temperature, causing browning (metolation) in a short time, and Hb and Mb remaining in the fish body also become methanodized and cause a strange odor (bloody odor, raw odor) and unique stickiness It becomes.

  Therefore, yellowtail is a fish species that can be handled taking into consideration temperature and time as a food that requires preparation time in advance for a large number of meals. This is due to the generation of various off-flavor gas components in association with the transformation of Hb and Mb and the induction of changes, especially in the yellowtail in summer.

  Problems that occur in yellowtail at high water temperatures are as follows.

  The amount of dissolved oxygen (DO) in normal breeding seawater (10-25 ° C) is 8.75-6.59 mg / L, but due to some change in situation, yellowtail starts to roll over and rollover starts, and death occurs at 1.7 mg / L The individual to begin to appear. For example, when the dissolved oxygen amount decreases (6.39-6.19 mg / L) at high water temperature (27-29 ° C), even in a net ginger installed at sea, Excited, a large amount of oxygen consumption progresses, and many accidents in which the dissolved oxygen in the environmental water causes drowning at a relatively high concentration are found in the net cage, and burnt meat is likely to occur.

  In other words, in high-temperature seawater, the metabolic level (α) of the fish body (the oxygen demand of yellowtail obtained from energy conversion) has increased, and the oxygen demand of yellowtail has increased rapidly due to excitement during pick-up. Synergistically with the decrease in the amount of oxygen in the sea water (DO) at the time, the balance range of the oxygen balance becomes narrower than at low temperatures, and the oxygen supply to the fish body is not in time. As a result, the fish body rapidly becomes anaerobic, so creatine phosphate (Cr-P), which is an energy source of ATP, is consumed at a different rate than usual, and eventually the production of ATP is suppressed after consumption of creatine phosphate. When the body falls into an anaerobic state, glucose is taken into the cells from the blood and ATP supplementation continues by glucose degradation, but the production of pyruvic acid and the accumulation of lactic acid are rapidly promoted, and a specific protease is reduced by lowering the pH. The activity of (proteolytic enzyme) is promoted abnormally, resulting in irreversible burnt meat peculiar to high temperatures and loss of commercial value. In other words, the burnt meat part is watery when cut into fillets, and the hardness is extremely lowered and becomes a cloudy (tofu-like) grayish color, the taste is extremely bad, and the commercial value of the yellowtail where the burnt meat is produced is It will be completely lost. This burnt meat cannot be discriminated by appearance, and since it cannot be judged unless it is cut after distribution, it will become a serious problem if the handling of summer yellowtail increases in the future.

JP 2010-104356 A

Watson C, Bourke RE, and Brill RW, Acomprehensive theory on the etiology of burnt fish.Bul 1988; 86: 367-372. White and red fish 3 chromoprotein Shuhisa Hashimoto Fisheries Science Series 13

  The inventors of the present invention have made various studies in view of the current situation as described above, and have obtained the following knowledge and completed the present invention.

  That is, commercial size yellowtail is about 2.5 times the oxygen consumption compared to other farmed fish species (red snapper, troughfish), and the metabolic level (α) is normal at the breeding water temperature (10 ° C). (α) 100 vs. (α) 420 at 29 ° C, it changes by a factor of about 4 times, but the metabolic level at the time of excitement is only from 10 ° C to 25 ° C even in light of the conventional shipping time. As a result of adding an approximate line (extrapolated line) and calculating the metabolic level at the time of excitement at 29 ° C, it becomes a value of about 900 to 1000 (α) or more, and the oxygen demand at the time of excitement around 29 ° C is 10 ° C Since the oxygen demand is 10 times higher than that during normal breeding, it was assumed that the fish had a major obstacle in terms of oxygen balance necessary for energy acquisition (Fig. 1).

  In addition, although there is almost no burnt meat in the yellowtail that is usually shipped in winter, the difference in temperature and the difference in meat quality of the yellowtail in summer due to the occurrence of burnt meat only in summer yellowtail (July to August) Focused on. The inventors have measured the pH of the head and shoulder meat when tightening yellowtails for several years in the past, and the method of transporting live fish (with a cooler) and the transport density were measured at the same time in winter. There is a difference in pH value depending on the transport time, transport temperature, transport density, handling becomes a stressor for the fish body, and the pH is already lowered in the state of live fish, and the seasonal change of fish meat in the winter season after the processing The pH tended to decrease more, and it was assumed that the amount of lactic acid produced was due to the decrease in pH due to the difference in meat composition (glucose content) due to seasonal changes.

  Furthermore, although it is said in the general theory that the fish pH at rest is around 7.4, immediately after live fish transportation at the site, it decreased to 6.8 to 6.6 after instant killing, and to 6.4 or less in the bitter fish. After that, as a countermeasure, after maintaining a comfortable state for a whole day and night, the oxygen concentration at the pick-up location was immediately killed with saturation, and as a result, the pH rose to 7 or higher.

  In other words, it was speculated that it would become a stressor at the moment when a resting fish is scooped up by a net. It takes several seconds to several tens of seconds to change in the fish body due to flapping when picking up, and a large physiological change occurs in the fish body. Therefore, the fish that have been stressed at the time of distribution and sales have fallen to a pH of 6 or less due to the reasons mentioned above, although they have not reached the level of burnt meat immediately after transporting live fish or in the winter season. Selling fillets on trays reduces the water retention capacity, moves Mb (bleeds red pigment to the white), and the drip flows out and feels a strange odor.

  In addition, it is recommended to immediately kill the medulla and perform medullary treatment at the stage when it is transferred to cooling water and the metabolism is reduced, but control of environmental water is not possible when shipping from marine net cages raised outdoors in summer. It is possible to control the temperature of a large livestock aquarium with indoor half-flow water that can be adjusted indoor temperature, and it is extremely burdensome to control the water temperature all day in summer.

  Therefore, at the site, the bait is stopped as a handling at high temperatures, and the measures can only be taken to cool quickly, from the pond raising to the dredging process (blood removal) with a sufficiently low metabolic level (α). There may be no actual situation. However, these methods are not specially used in the summer, but the same thing is done at the time of shipment in the winter when the temperature is low, so there is a need for a special handling method at high water temperatures in the summer. .

  In addition, the importance of the blood removal treatment is introduced in each presentation document, booklet, etc., but since the specific confirmation method is unknown, the countermeasure and the effect are not clear. Each organ inside the fish body is maintained by a large number of enzyme groups, but as a technique that can be done in the field, removal of proteases and degenerated substances in a broad sense of blood by immediate killing and blood removal is possible. In livestock farming, this process is legalized by the slaughtering law, but for fish, these regulations have not been legislated because the fish species and fishing location differ greatly.

Usually in edible fish
Barbara ---- Natural agony death (no blood removal)
Killing with a mallet, etc .--- Concussion Concentration of medulla by stabbing with a handcuff and spontaneous bleeding by cutting the tail aorta (promoting) ---- Promoting bleeding by cutting the medullary dorsal artery and spinal column Bleeding ---- Heart hemorrhage by cutting a sputum into the aquarium (assuming blood loss)
Perfusion treatment ---- Infusion of isotonic saline into the arterial system to derive blood, etc., is well known from non-bleeding treatment to high-level blood removal treatment. However, in each case, only a method for blood removal is described, and a method for confirming the degree of blood removal, which is the effect, has not been established.

  In terms of improving the storage stability of fish, the goal is achieved if blood-derived proteases (proteolytic enzymes), which are factors of postmortem changes, are ideally completely eliminated and the temperature of the fish body can be cooled quickly. Although it can, blood removal treatment is the only means. Therefore, it is expected that the improvement of these drought methods and the extension of the quality retention period will progress by establishing a method capable of measuring the degree of blood removal.

  The present invention prevents burnt meat that occurs when the main cultured fish such as yellowtail is shipped not only in the winter but also in the summer when the water temperature is high, and also removes the causative substance blood. Yellowtail blood removal method, blood removal yellowtail manufacturing method, yellowtail processed product manufacturing method, tuna blood removal treatment method, blood removal tuna An object of the present invention is to provide a method for producing a tuna processed product and a method for producing a tuna processed product.

  The gist of the present invention will be described.

  Blood removal by introducing perfusate into the blood vessels of the yellowtail to replace the blood so that the L * value in the L * a * b * color system of the white meat on the back or upper body of the yellowtail is 50 or more The present invention relates to a yellowtail blood removal method characterized in that the treatment is performed.

  In addition, the yellowtail that has been cured in seawater below the saturated oxygen concentration is taken from the picked-up water area that is separated from the seawater area below the saturated oxygen concentration and made into a supersaturated oxygen seawater area and subjected to blood removal treatment. The present invention relates to a blood removal treatment method.

  In addition, the perfusate is introduced into the blood vessels of the yellowtail to replace the blood so that the L * value in the L * a * b * color system of the white meat on the back or upper body of the yellowtail is 50 or more. The blood removal treatment method according to claim 2, wherein blood removal treatment is performed.

  Moreover, immediately after destroying the spinal cord of a yellowtail, the blood perfusion solution is introduced into the blood vessel of the yellowtail and subjected to a blood removal treatment for replacing the blood with the yellowtail. This relates to the blood removal treatment method.

  5. The method according to claim 4, wherein the oxygen supersaturated liquid is used as the perfusate after passing through a filter having an average pore diameter of 10 μm or less at a pressure higher than normal pressure.

  5. The yellowtail blood removal method according to claim 4, wherein the perfusate is electrolytic cathodic water in electrolytic water.

7. The yellowtail blood removal method according to claim 4, wherein the perfusate contains NaHCO ₃ .

  In addition, the present invention relates to a method for producing a blood-bleeding yellowtail, which comprises producing a blood-bleeded blood yellow blood using the blood-bleaching blood removal method according to any one of claims 1 to 7.

  A chilled processed product of yellowtail or a frozen processed product of yellowtail is produced using the blood-bleeded blood removed by using the yellowtail blood removal method according to any one of claims 1 to 7. This relates to a method for manufacturing a yellowish processed product.

  Further, the tuna cured in seawater having a saturated oxygen concentration or less is taken from a picking water area that is partitioned from the seawater region having the saturated oxygen concentration or less to be a supersaturated oxygen seawater region, and is subjected to a blood removal treatment. The present invention relates to a blood removal treatment method.

  The tuna blood removal method according to claim 10, wherein a blood removal treatment is performed immediately after destroying a tuna spinal cord to introduce a cooling perfusate into a blood vessel of the tuna to replace the blood. Is.

  The tuna blood removal method according to claim 11, wherein the oxygen supersaturated liquid is used as the perfusate after passing through a filter having an average pore size of 10 μm or less and a pressure higher than normal pressure.

  12. The tuna blood removal treatment method according to claim 11, wherein the perfusate is electrolytic cathodic water in electrolyzed water.

The irrigated blood treatment method according to any one of claims 11 to 13, wherein the perfusate contains NaHCO ₃ .

  In addition, the present invention relates to a method for producing blood-removed tuna, which comprises producing blood-removed tuna that has been blood-removed using the method for removing blood of tuna according to any one of claims 10 to 14.

  Further, a tuna chilled processed product or a tuna frozen processed product is manufactured using the blood-removed tuna blood that has been removed using the tuna blood removal method according to any one of claims 10 to 14. It relates to a method for manufacturing processed tuna products.

  Since the present invention is as described above, the main cultured fish, yellowtail, etc., not only in winter but also in the winter, it prevents burnt meat that occurs when shipping at high water temperatures, and its causative substance The blood removal level of blood is indirectly quantified, and the blood removal treatment method of the yellowtail using the quality control method that can be implemented practically, the method of manufacturing the blood removal yellowtail, the method of manufacturing the processed yellowtail, the blood removal of tuna It becomes a processing method, the manufacturing method of a blood removal tuna, and the manufacturing method of a tuna processed product.

It is a graph regarding the influence of the state of fish and water temperature on oxygen consumption. It is a schematic explanatory drawing which shows a measurement site | part. It is a table | surface and a graph which show a test result. It is a table | surface and a graph which show a test result. It is a table | surface and a graph which show a test result. It is a table | surface which shows a test result. It is a graph which shows a test result. It is a comparative photograph of the savage yellowtail and the perfusion treated yellowtail. It is a graph which shows a test result. It is the table | surface which put together the result of the taste test.

  An embodiment of the present invention which is considered to be suitable will be briefly described with reference to the drawings showing the operation of the present invention.

  Blood removal by introducing perfusate into the blood vessels of the yellowtail to replace the blood so that the L * value in the L * a * b * color system of the white meat on the back or upper body of the yellowtail is 50 or more Apply processing. Alternatively, when the yellowtail that has been cured in seawater with a saturated oxygen concentration or less is taken from a picked water area that is partitioned from a seawater region with a saturated oxygen concentration or less and is a supersaturated oxygen seawater region, Blood removal is performed so that the L * value in the L * a * b * color system of the white meat on the back or upper belly of the picked yellowtail is 50 or more.

  As a result, the occurrence of burnt meat can be prevented even in the summer, and it becomes possible to supply (cultured) yellowtail stably in the summer. The present invention can also be applied to winter yellowtail, which is a normal shipping time.

  Specific embodiments of the present invention will be described with reference to the drawings.

  In this example, perfusion treatment was performed on the yellowtail so that the L * value in the L * a * b * color system of the white meat at the upper back (shoulder) and upper abdomen (shoulder) of the yellowtail was 50 or more. This is a blood removal method for yellowtail that is subjected to (blood removal treatment).

  Before blood removal treatment, yellowtail is seawater below the saturated oxygen concentration in which oxygen stored in ginger (aquarium) etc. is dissolved by about 6-8mg / L (specifically, general seawater that is not particularly treated) And the oxygen concentration is 75-100%). In addition, the ginger (water tank) or the like is provided with a pick-up water area that is separated from a seawater area below the saturated oxygen concentration and is composed of supersaturated oxygen seawater. Seawater in the picked water area is supersaturated oxygen seawater in which oxygen is dissolved at a concentration of 30 mg / L or more by dissolving 93% oxygen in the seawater using an oxygen generator (PSA). That is, a ginger (water tank) is divided into a curing water area that is a seawater area below saturated oxygen concentration and a picking water area that is a supersaturated oxygen seawater area (for example, equipment that does not contain external seawater such as a Zuk water tank in a large water tank) Then, when picking up yellowtail that has been cured for a certain period of time (about 24 hours) in the curing water area, move it to the picking water area and then pick it up in the picking water area.

  Specifically, seawater at the time of aquaculture has an oxygen concentration of 75 to 100% as described above. However, the net ginger at the time of conventional shipping narrows the net, so that the fish becomes excited and oxygen consumption increases. The oxygen concentration in the net ginger is greatly reduced to 50% or less.

  As a result, the fish body becomes oxygen deficient after a short time shift, which greatly affects the quality thereafter (burning and death occur at high temperatures).

  In the case of yellowtail, the current method of shipping at the aquaculture site is at sea, live fish carriers (oxygen replenishment will be replenished from the hull intake as the ship progresses. (Supply oxygen by air blower, etc.) Or slowly tow aquaculture ginger (3km / h), pick it up on a work table with a crane tammo net for each seawater from a live fish boat or a net ginger, and perform medullary cutting (live tightening treatment) After cooling, it goes through the steps of weighing, packing, and shipping, but for example, it is cured overnight in an onshore water tank to eliminate carry-in stress, and supplied with pure oxygen partitioned in this onshore water tank, It is preferable to take out from the picked-up water area and perform processing.

  The same is true for tuna, but tuna is more delicate than the yellowtail and runs away with a slight stimulus until it gets used to the net and hits the net and dies due to a wound. In addition, yellowtail can be used as a transport ship, but in the case of tuna, it is subjected to live-end treatment with an aquaculture net ginger.

  Tuna can be transported slowly (1km / h or less) for juvenile fish (Yokowa) if it is a young fish, but when it becomes an adult fish, it is difficult to move because it is a large deep bottom. Therefore, for example, a picking water area separately provided in the net ginger at the time of shipment is provided, and this portion is set as a supersaturated oxygen seawater area.

  In this example, immediately after breaking the spinal cord (not left for more than 5 minutes), the yellowtail taken up from the ginger and the like immediately introduces (perfuses) the perfusate into the blood vessels of the yellowtail to replace the blood (the blood (Derived) Perform blood removal treatment. The perfusion treatment is performed by introducing the perfusate into the blood vessel at a flow rate that does not rupture the heart tissue (approximately 0.25 to 0.3 L / min · kg depending on the fish size).

  Specifically, only the ventricle is drilled from the head with an air drill, and a stainless steel rod is inserted from the perforated part to the tail to destroy the medulla oblongata and spinal cord. Can be.) Thereafter, when the perfusate is injected into the whole body from the heart, the perfusate is derived from the fragile tissues (liver, kidney digestive organ, etc.) of the internal organs while expanding the capillaries.

The perfusate is electrolytic cathodic water in electrolytic water. Further, an oxygen supersaturated liquid (supersaturated oxygen solution) may be used as a perfusate after passing through a filter having an average pore size of 10 μm or less and a normal pressure or higher. In addition, electrolytic cathode water or the like containing NaHCO ₃ may be used. In addition, the perfusate is cooled to 20 ° C. or lower (a temperature lower by about 8 ° C. to 10 ° C. than the seawater temperature, for example, a temperature 9 ° C lower than the seawater temperature).

  In addition, for example, as the perfusate, in the initial stage of the perfusion process (a state in which blood is still largely remaining, 1 to 2 minutes from the start of the perfusion process), a solution obtained by passing the oxygen supersaturated liquid through a filter is used. Can be used after a certain amount of is derived).

  According to the above method, the blood-removed bloodlet is produced and refrigerated and distributed as it is (fresh fish), or processed into a chilled processed product of a yellowtail or a frozen processed product of a yellowtail and distributed.

  In addition, with respect to tuna, burnt meat can be prevented by performing the same treatment as the above-described curing, blood removal treatment, and the like on the yellowtail.

  The specific reason for adopting the above method will be described below.

  鰓 If the body's breathing is interrupted and the body falls into an anaerobic state in a short time, ATP, which is the energy of activity, is supplied by the degradation of glucose taken into the cells from the blood, but on the other hand, glucose is lost in an anaerobic environment. Lactic acid accumulation proceeds via pyruvic acid. Its precursor, pyruvic acid, has lower cell membrane permeability than lactic acid, so it remains in the cells, indicating that it can be a source of lactic acid for a long time after cessation of movement. These reductions in pH indicate activation of various proteases present in fish meat, but various proteases in blood have been discussed in recent published papers. Collagen (extracellular matrix) which is an index of feeling is greatly related to freshness (goodness of life). The cathepsin group is classified according to differences in optimum pH, interaction with inhibitors, substrate specificity and molecular weight. Among them, cathepsin L (EC 3.4.22.15) has a strong endoprotease activity. In vivo, the enzyme acts as a function of regulating glucose uptake into cells, but is considered to be most important as a proteolytic enzyme after death. Especially in fish, muscle proteins are known to self-digest much faster than livestock meat, and the functions and expression regulation mechanisms of these lysosomal cysteine proteases differ from mammals. Seem. Examples of proteases that further act include collagenase and gelatinolytic enzymes (G1, G2, G3, G4, etc.). Collagen itself is a stable protein, but also contains proteases such as cathepsin L, so complete separation from the fish meat is impossible.

  It is well known that collagen is transformed into gelatin by heat treatment. If conditions such as temperature and pH are met, a gelatin structure is obtained. The gelatin denaturation temperature of this fish meat is low, and the structure is generated by thermal denaturation of general collagen tissue, but it seems to have a large relationship with the weakening of fish muscle. The fact that marbles of beef are stable, but the marbles of yellowtail and tuna disappear over time, the changes in lipid and collagen tissue may be visually observed, but details are unknown . It is known that blood has a unique bloody odor, odor and other gas components (odor) in the process of the enzyme group before the start of rot by bacteria, the main cause of which is the activity of protease (cathepsin L) in the blood It is thought that the main reason is that the muscles are weakened by collagenase and gelatinolytic enzyme, and odor is also generated.

  In the case of yellowfin tuna as an example, the cross-section of the tuna that suffered from the seine fishing method in the hot water area below the equator was observed. It has been confirmed that burnt meat spreads to the skeletal muscle beyond the bloody part. From a viewpoint, it is not a change in color that first changes with the passage of time, but a rainbow-colored film is formed on the surface of the fish meat. Judgment of burnt meat has long been done in the production area market by inserting a straw-like stab stick into the spinal column from the dorsal fin and collecting muscle tissue near the spine to judge burnt meat.

  When looking at the surface of commercially available tuna, there may be a iridescent film, which is called a “rainbow” among traders and is a leaking liquid film containing lactic acid. When eating, you may feel a little sour, but when the pH drops below 6 due to lactic acid formation, the water holding capacity decreases sharply and the drip flows out, and it is not evaluated as good quality because it is watery. In the local market, there are places where pH 6.3 or higher is traded as “SA”, 5.9 to 6.2 as “A” and 5.8 or lower as “B”. This is a quality confirmation method that is performed because the tuna contains a large amount of glucose and thus the pH fluctuates greatly.

  In addition, when you look at the fillets of natural yellowtail that have been caught by the purse seine method, where the catch has been increasing in recent years, this “rainbow” may be seen. In the case of burnt meat, these states are considered to have further advanced, and if the cause is the same such as yellowtail meat and tuna burnt meat, the cause is an abnormal state of energy metabolism (ATP, glucose decomposition, It can be easily estimated that changes that do not occur in the natural body and occur suddenly with the excitement of the fish at high body temperature. Cathepsin L, B, E, and D have been described as promoting fish change in the previous literature, but cathepsin L, which is activated by weak acidification due to lactic acid accumulation after death, causes the most metamorphosis due to its activity. Is known.

  The deterioration of quality of summer yellowtail is due to seasonality of meat quality, excitement state at high temperature, decrease in dissolved oxygen amount, etc., pH decrease due to proton generation by rapid dephosphorylation of ATP, and oxygen deficiency in the body progressing simultaneously Due to the rapid degradation of glucose in the anaerobic state caused by the transfer and storage of pyruvic acid, followed by the weak acidification of pH by the production of lactic acid outflow from the cell membrane.

  Due to the rapid disintegration of the collagen tissue and the high temperature due to the activation of the proteolytic enzyme, the present inventors partially change to gelatin, but the gelatinolytic enzyme further acts to promote softening and denaturation of fish meat, which is irreversible. It was assumed that it showed the possibility of producing burnt meat.

  When observing briachake meat, it is considered that the red color of Hb, which is a chromoprotein that remains in the white part even after blood removal, disappears completely, resulting in a tofu-like color tone and rapid softening. It was considered that the red blood cells contained in the sample were not disappeared, but Hb was denatured by an abnormal pH or enzymatic reaction, and the release and oxidation of the porphyrin ring was promoted to make it yellow and transparent. Therefore, the enzyme activity continues in the burnt meat state, and the range is expanded through body fluids and blood by the strongly activated enzyme group.

  Therefore, since the change in the color tone of the white after processing changes in conjunction with the change in the color tone of the blood, the L * value indicating the brightness of the white color tone after blood removal after the perfusion treatment and the color tone of the remaining blood is As the time elapses, there is a slight decrease within the best-tasting time (approximately 15 hours), but if blood remains after general blood removal, it rises in a complex 2-6 hours after treatment, and then begins to decline. The L * value is <50 at maximum. However, when burnt meat is generated, the L * value is 40-45 immediately after cooking, and it becomes tofu in 2-6 hours, and the L * value exceeds 60.

  The following are the items that can be actually executed in high-temperature sea water as handling methods at high temperatures. As a precondition, even during the summer high water temperature period (28-29 ° C), although the amount of food intake decreases, it operates normally, so the metabolic system is within the appropriate range at rest, but at the time of picking up It was presumed that the excitement of the body would cause an abnormal metabolic state in the body. Therefore, excluding the reduction of water temperature, which is difficult at sea work, the countermeasures satisfy the following conditions.

1) Partially divide the hot high-temperature seawater area where (α) of the fish body is excited and excite it, and make it into fine oxygen seawater with a pure oxygen, and a supersaturated oxygen water concentration state.
2) After picking up, destroy the spinal cord in the shortest possible time and make it asphyxia (immobility).
3) Immediately cool the blood vessels at the temperature of the seawater with a supersaturated oxygen-dissolved cooling perfusate (degree difference of about 9 ° C) to cool down the blood at the same time.
4) Cathodic electrolyzed water, pH adjuster (NaH) for treatment of exudate lactic acid outside the cells after perfusion treatment
CO ₃ ) is used to suppress the pH drop.
5) As a confirmation of treatment, white meat of yellowtail (upper) and belly (upper) is roughly 5cm from the decapitation.
Measure the L * a * b * value of the part (Figure 2) that does not contain the front and rear red meat (Mb), and standardize the degree of blood removal as the L * value.
6) Since tuna is a whole body red fish (Hb, Mb), it cannot be judged by L * value as simple as yellowtail. Considering the weight of the fish and the amount of perfusate per minute, it is considered that the indirect blood removal rate can be converted by the amount of perfusate. However, natural tuna has various types such as yellowfin, bigeye, bluefin tuna, and Indian tuna. Therefore, individual differences must be considered.

  The following describes how to determine the specific blood removal degree of yellowtail.

  In this example, including practical aspects, Hb in the perfusion derivation solution is spectroscopically measured at predetermined time intervals, the degree of absorption band (ABS) reduction is determined, and fish white meat (including red meat Mb) is scattered. No) A correlation table with the (L * value) in the color difference degree (L * a * b *) of the part is created, and the degree of blood removal is converted.

・ Speciation of Hb by spectrometer and selection of on-site measurement method Erythrocytes have a slight difference in absorption band for each fish species, but fish and mammals with ligands coordinated to the 6th coordination site of Mb are fresh. In such a state, it is known to form peaks of two bands of 536 to 540 nm and 568 to 582 nm. Further, it is known that in the case of the reduced form (R-Hb) from which the ligand is detached, a peak of one band is observed in the intermediate band 555 to 557 nm. However, as time passes, this band shows irreversible changes in both Hb and Mb outside the body, and the coloration changes in the same way as metation progresses. It is known that over time, Hb is an Mb tatami mat, the central core is Fe ++, and when it undergoes methation (browning), it becomes Fe +++ (the ligand is H ₂ O). When fresh Hb and Mb release the ligand and become reduced Mb, there is one peak in the middle of the two bands, so the coordination state can be grasped regardless of the presence or absence of the ligands of Mb and Hb. (Known ligands of Hb and Mb are O ₂ , CO, NO, CN, H ₂ S, etc.) However, H ₂ S has a different color of green.

  Since the presence of Hb in the fish meat differs depending on the fish species, the peak wavelength of the absorbance (ABS) of the perfusion derivation solution was used here for the yellowtail.

  Hb and Mb can be separated by HPLC (High Performance Liquid Chromatography) with a difference in the time axis, but a simple spectrometer has the same absorption band, so it does not overlap with Mb for many quality controls in the field. By limiting the white meat without Mb chromoprotein and measuring the L * a * b * value with a color difference meter by direct or indirect image processing so that it can be compared with the (ABS) value, rapid blood removal can be achieved. I can understand the degree.

  In this case, it includes the case of the liquid treatment, so oxygen is not the only coordinated molecule, so the conventional method has been adopted.

・ Significance and range of quantification of degree of blood removal Estimating whole blood including arteries and veins and capillaries in mammals and fish meat is based on the perfusion method using physiological water (infusion method), pigment (infusion method), and monoxide. Methods such as carbon (inhalation method) and isotope method (radioisotope method) exist, but a method for completely collecting whole blood has not yet been established. Methods other than the direct method are methods for estimating the whole blood volume based on the dilution of a specific marker in the fish. In the case of a perfusion method using physiological water containing a blood coagulation inhibitor as a perfusion experiment, whole blood is collected with a perfusate 10 to 30 times the weight of the fish. In addition, since the treatment site is a technique in which the lower ventricular membrane is punched with a syringe and injected from the heart ball, the treatment time is considered to require a long time. The blood volume varies greatly depending on the fish species, but it is said to be about 1/20 to 1/30 of the fish body.

  The purpose of the derived blood measurement by this perfusion method is to discharge the wastes such as protease in the blood and lactic acid released from the cell tissue within the practical range, and confirm the effectiveness of maintaining the quality and preservation of the fish meat A possible range is assumed. Therefore, the above-mentioned whole blood volume measurement method and the whole blood derivation amount by perfusion processing are different in meaning.

・ Measurement instruments Temperature measuring instrument Body surface temperature measurement: Infrared thermometer with laser pointer Raytek-minTempFS
Fish center temperature measurement and intraperitoneal temperature: stab stick thermometer DRETEC
Spectrometer: SIMADZU UV1240mini
Optical microscope: OLIMPUS BH-2
Color difference meter: MINOLUTA CR-13

・ Blood removal index using blood component as an indicator Blood components are plasma (55-60%, including water 90, protein 8, lipid 1, saccharide 0.1 and other 0.9), blood cells (40-45%, breakdown) As for red blood cells 96, leukocytes 3, and platelets 1), the spectroscopic measurement was carried out by separately collecting the derived perfusate-perfused blood in advance, and the derived initial stock solution and diluted solution (the initial derived solution with high blood concentration was 10% Na citrate solution). As a result of measuring the spectrum from 190 to 1100 nm in advance with a spectrometer, the main peak is 536,569,418 nm and the erythrocyte Hb band to which the ligand is bound is 536,569 nm As a result of measuring the absorbance (ABS) of the perfusion derivation solution for another 60 minutes, the peak at 536,569 nm indicating the presence of red blood cells was not found. Within 10 minutes, the presence of red blood cells is insignificant compared to 60 minutes treatment. Based on minute processing. Furthermore, the upper and lower abdominal meats of the treated fish treated for the same time were diluted with 10-fold distilled water, homogenized, filtered through a 10 μm filter, and measured with a spectrometer. None of the blood-derived absorption bands were present.

・ Blood removal degree If the degree of blood removal can be quantified, it can be an effective management standard in terms of quality control, so we assumed blood removal degree as a new term. Measure perfusion treatment at regular intervals to a concentration that can be measured by perfusion treatment, measure the concentration of the solution with a spectrometer, measure the T2, T3, T4 to T10 ... T60 stages every minute after the initial concentration T1, and use the red blood cell spectrometer Measure to Tn where absorption band (536,569nm) cannot be detected, and add up to (T1 + T2 + T3 + ... Tn) as whole blood index (W), and total integrated value of absorbance (ABS) up to each stage The degree of blood removal was quantified as the degree of blood removal by dividing by the blood index (W).

Example Formula of blood removal degree at arbitrary T3 point Blood removal degree = (T1 + T2 + T3) / (T1 + T2 + T3 + T4 +… Tn) × 100 (Equation 1)
= (T1 + T2 + T3) / (W) × 100
T1 of the above-mentioned blood removal degree is original blood, and the absorbance is large (ABS) value shows 56.3, and thereafter the absorbance rapidly decreases and is an accumulation of numerical values that become insignificant in 10 minutes or more, (56.3 to 100 However, since the intercept of the correlation equation is not 0, the blood removal rate may be from 0 to 100% by performing numerical processing if necessary.

・ Test 1 (Relationship between cold water perfusion effect time, derived blood absorbance (ABS value), fish body temperature (° C), and white color at the time of blood removal (L * a * b * value))
Method:
The water temperature was changed from 22 ° C to 29 ° C (discolored meat) while dissolving 5 pieces of yellowtail (5.5 to 5.8 kg) 3 days after feeding stopped in a 500 L container overnight with pure air to maintain saturation or higher with air stone. The temperature was raised in the container until the temperature range of occurrence condition), one for fish temperature measurement and two for blood collection.

  Perfusion is the amount that can be perfused, and perfusion treatment is performed with a mixture of sea water and tap water adjusted to approximately 20 ° C with a plastic bag ice block, and the temperature of each part of the fish body for 0 to 10 minutes and the extracted perfused blood 90 cc The sample was mixed with 10 cc of a 10% Na citrate solution, stirred, stored at 3 ° C. and subjected to 418,536,569 nm absorbance (ABS) measurement.

  Moreover, on the premise of complete blood removal for each of the two tails, perform perfusion treatment for 60 minutes for a long time, measure the color tone L * a * b * value, collect the perfusion derivation solution at the end in a beaker, and observe visually through light did.

result:
1) Insert a catheter into the circulatory arterial system and inject 20 ° C perfusion cooling water at the perfusion treatment limit. Over the course of 10 minutes, the head and back of the body, the back and abdomen, and the back of the body Meat perforation and surface temperature measurement were conducted at the center of the buttocks, the shoulders of the back and shoulders (upper), the center of the back and stomach (middle), the center of the back of the hip (lower) and the abdominal cavity. The results are shown in FIG.

2) Derive fluid was collected every 10 minutes from the start of perfusion treatment for 10 minutes and a total of 11 samples of 536, 569 nm and 418 nm
The absorbance (ABS) of was measured. The results are shown in FIGS. As the degree of blood removal by perfusion treatment, the degree of blood removal shown in FIG.

3) Since the presence of red blood cells in the derived perfusate can be grasped by a spectrometer, a large amount of perfusion treatment (60 min / 120 L) was performed for a long time to induce the maximum blood removal state. No band (536,569 nm) indicating the presence was detected.

L * values in the L * a * b * measurement results at this time are the upper back 61.5-64.1, the upper abdomen 66.8-67.1, and the visual color of the derived liquid at the end is also shown along with other measurement results (Figs. 6 and 7).

Consideration:
1) In the same test, 5 fish were processed under the prescribed conditions, but no burnt meat was generated (however, after perfusion treatment, cooling in a normal 7 ° C cooling sterilization tank).

2) The difference between the temperature of the fish center and the perfusate is generally the temperature range that does not cause body shock (convulsions, etc.)
The perfusion treatment was performed without any problem (9 ° C difference).

3) The main body of the back and shoulders, including bloody meat that is the occurrence of burnt meat, the center of the back and belly is roughly
In 6 minutes, it was possible to reduce the temperature to the shipping time of about 23 ℃ in normal early winter and early spring. The center of the dorsal buttocks fell slightly later.

4) The inside of the abdominal cavity (liver) cooled most rapidly to 22 ° C, and after 3 minutes it became similar to the perfusate temperature and stabilized.

5) The flesh-colored L * value that seems to have been completely introduced by perfusion treatment is the upper back (61.5-64.1),
It seems to be in the upper abdomen (66.8-67.1) range.

・ Test 2 (color of fish white meat by short-time perfusion treatment)
Method:
Results of Test 1 (Because most of the blood was derived in 3 minutes with the absorbance of the perfusion solution (ABS) over time, perfusion treatment was performed every 1, 2, 3 and 6 minutes, and the upper body white The L * a * b * values of the meat and the white meat of the upper abdomen were measured, and the derived solution for each time was collected in a beaker and visually evaluated.

result:
The red difference (a *) can be clearly discerned visually by 1, 2, 3 minute treatment and 6 minute treatment, but the L * value was> 50 in the 1 min treatment area and above.

  Further, it was difficult to visually discriminate in the 6-minute treatment zone, the 10-minute treatment zone and the 60-minute treatment zone.

  The measured value of L * value and visual evaluation of the derived liquid are shown in FIGS.

・ Test 3 (L * a * b * distribution in multiple perfusion treatments)
Method:
Based on the results of Test 2, the perfusion time was 6 minutes or more, and white meat at the top of the back and white meat at the top of the abdomen (considering individual errors, measured 10 times for each back and abdomen for each 10 fishes, averaged L * a * b * values were counted four times with different producers and dates.

result:
In the case of perfusion treatment, the L * value was 52.4-65.7 for the upper back and 58.4-72.1 for the upper abdomen when compared with the back burn index L *> 55. The L * value measurement results are shown in FIGS.

  The color tone showing this value is clearly the color tone level of burnt meat that is not normally seen in yellowtail, but it can be clearly observed that it is a blood-bleeding effect, and at first glance it became a color tone different from conventional yellowtail meat However, although there is no unnaturalness in the color tone, it is extremely white at the visual level, but it became natural white while it turned out that the brightness felt by the visual sense and the L * value indicating the brightness of the burnt meat were different .

  A comparative photograph of the Nobi Ward and the perfusion treatment is shown in FIG.

Consideration:
The color difference between the L * value treated for a long time and the back, stomach and white of the same test showed a difference in both the L * value, a * value, and b * value. Although there was a difference in the values, there were some crossing measurements. This was estimated to be an individual difference due to a large number of measurement results rather than the degree of blood removal.

  In terms of the measured values, only the L * value was clearly different between the perfusion treatment group and the general blood removal group, and most of the samples had an L * value of 55 or more, which is called burnt meat. That is, although the L * value indicates burnt meat, the present invention intentionally sets the L * value by blood removal treatment, and the yellowtail that has been applied to the present invention is an index of burnt meat on the L * value. Even if it meets, it is not burnt meat.

・ Test 4 (Blood removal level measurement)
Method:
Since the degree of blood removal has not been shown in the past, the absorbance (ABS range 0 to 3) indicating the presence of red blood cells by perfusion and the color difference meter (L * a * b * value) which is a simple measurement method The correlation was examined.

result:
The 536,569nm peak, which is the Hb band of spectrometer absorbance (ABS) of blood drained perfusate drainage, suddenly decreased until 3 minutes of treatment, indicating that the blood in the fish body is drained out of the body and decreased. It was.

  The concentration of the blood-derived 418 nm peak band decreased after 5 minutes with a delay of about 2 minutes.

  As a confirmation, the white part of the upper part of the untreated area (Nosame) was homogenized by diluting 10 times with distilled water, and even if the 10 μm filter filtrate was measured with a spectrometer 400 to 650 nm, The band (536, 569 nm) indicating the presence and three bands of 418 nm derived from blood were detected with 418 nm as the maximum, whereas the white meat of the perfusion treatment group was diluted 10 times with distilled water and homogenized, and the 10 μm filter filtrate was added. Even when measured with a spectrometer of 400 to 650 nm, the band (536, 569 nm) showing the presence of Hb-ligand-bound erythrocytes and 3 bands of 418 nm derived from blood were not detected. The effect was confirmed.

  A similar sample changed the balance of the band over time (536,569 nm), which was consistent with the disruption of the blood cell membrane. Therefore, it is indispensable to use fresh perfusate and fish meat at the time of processing as an optical method and measurement by a spectrometer.

Consideration:
As an optical method, a piece of meat is squeezed (pressed) onto a slide glass, and the presence or absence of red blood cells after Giemsa staining was attempted. Therefore, it was judged that it was not suitable for quantification. As an optical method, blood in the derived perfusate was confirmed by Giemsa-stained smear until 3 minutes, but not after 5 minutes. Further, the sample solution was stored at 15 ° C., and the follow-up observation was continued. However, in each section, hemolysis progressed the next day and the erythrocyte membrane collapsed, making observation difficult.

  The specimen of homogenized and spontaneously precipitated back meat containing red Mb pigment in the upper part of the shoulder meat forms a slight peak at 536 nm, which is very different from the Hb band and is used to identify the measurement site. Although there is no effect, the same upper band (see Fig. 2) is essential for the back and abdomen because the same absorption band as Hb appears in the part containing many Mb protein pigments such as tail and blood.

・ Relationship between spectrometer absorbance (ABS) and color difference meter (L * a * b *) in each treatment zone Measurement of the derived perfusate is the average of the two Hb peak values from 0 min (at the start of discharge) to every 1 min Absorbance at the peak value of 536 nm, which was stable for 10 min and 60 min, was measured, and on the assumption that blood removal was completed completely in 60 minutes, the cumulative value of the ABS value for each minute was taken as the blood removal degree.

  Since blood removal is derived from each derived blood vessel through the spinal artery and each organ and capillary in the muscle, only the blood removal from the muscle does not match the degree of blood removal. Therefore, it is considered that the initial degree of blood removal may be derived from internal organs, and it is assumed that it takes time to remove blood from the muscles, and the perfusion treatment time is 1, 2, 3, 6, 10, 60 minutes. FIG. 6 shows the blood level, the corresponding L * value (both the back and the abdomen), and the visually derived perfusate color tone.

-Threshold of perfusion treatment and squeezing The degree of blood removal is the accumulated absorbance of the derived perfusate (ABS) from the beginning of the derivation. Therefore, it is possible to calculate the blood removal rate by substituting this value with 0. The results of this test are shown as Nobi Ward as 56.4 and 60 min treatment as 100.

  Perfusion treatment is extremely effective in deriving blood from the internal circulation system from the principle compared to other blood removal treatments. On the other hand, however, there is an opinion from consumers that the degree of blood removal should be reduced from the viewpoint of taste and color. Can be adjusted.

  Based on the L * value, which is said to be the standard for burnt meat, the Hb remaining in the fish meat in the derived perfusate in the sample is blood within the time (1 min to 10 min) shown in Fig. 4 It was shown that 82.9-99.17% of red blood cells in the components were removed from fish.

1) Nobuchi Ward Untreated Nosame Ward products gave back L * values of 32.4 to 35.3 and abdominal body L * values of 35.6 to 37.4.

2) Careful blood removal The medullary amputated blood squeezed section: Back L * value 40.1 ~ 44.6, Abdominal L * value 44.3 ~ 46.2
Suspension for 30 min after blood drainage: Back meat L * value 44.3-36.3 Belly meat L * 42.4-47.6
Got.

3) Perfusion treatment section (1-10min)
Back L * values 52.4-57.5 and abdominal L * values 58.4-72.1 were obtained.

  Hb, a chromoprotein, has a large effect on color tone, and the L * value exceeds 50 after a perfusion treatment of only 1 minute or more. At this time, the a * value (red green) decreases from 0 to 1, but after 2 minutes, the a * value is clearly lower than the change in the L * value, indicating roughly around -2. Become. Furthermore, after 6 minutes, the back L * value is 55-60, and the abdominal L * value is 60-65, and the blood removal effect becomes remarkable.

Figure 4 than described ratio of white portions L * value of de tides and 10 minutes treatment group obtained was corrected to 100% by (Equation 1) Semi-top R ² = 0.98732, a skirt steak upper R ² = .98761 A strong correlation was observed (Figure 9).

  The correlation equation is y = 0.6928X-6.0454 for the upper back and y = 0.7009x-3.2438 for the upper abdomen.

  In addition, L * exceeded the abdomen meat in all wards than the back meat.

Effect 1:
The method of cooling using the blood vessels that are the internal circulation system is an extremely effective means that can cool the fish body from the burnt meat generation site in a short time because it can be cooled from inside the fish body.

  The degree of blood removal means that the color tone of the blood in the muscles is lost, and if there is a large amount of protease (cathepsin L) that causes muscle softening in the erythrocyte membrane, blood removal is an indirect means for on-site management. For yellowtail, the L * value a * of the L * a * b * values of the white upper back and the upper abdomen is effective.

  Measurement of L * a * b * values can be indirectly analyzed, so if you define the measurement position, you can incorporate it into the production line and control the quality variation.

  The white meat of yellowtail that had been perfused changed to a highly transparent blood-bleeded color that did not exist in the market (FIG. 8).

  In general blood removal (medullary amputation spinal cord destruction and phlebotomy swimming blood release), the degree of blood removal is unknown, but the degree of blood removal was estimated to be 68 to 71 from the L * value of white meat from the correlation equation (FIG. 7). ).

  Careful general blood removal as a means of blood removal has an initial L * value of 40 to 45, while perfusion treatment has a blood removal level of 80 min with treatment of 1 min, 2.2 L / min or more, and the upper back and abdomen. The L * value of the white part of the upper body was 50 or more, which led to the present invention.

・ Taste test Sample preparation procedure:
Except for specimens 1 and 2, the freezing process is the prescribed post-processing, fillet processing, and minus 35 ° C brine freezing treatment. After storage for 9 days in a minus 18 ° C freezer, each specimen is stored in a + 3 ° C incubator for 5, 6 and 3 , 4 were shifted for 8 hours and slowly thawed for 12 hours every vacuum pack for a tasting test. The following shows the handling after specimen processing.

1) 8 hours after freezing and thawing (Sample 5,6)
The specimens were 5 perfusion groups and 6 general blood-free sections. After freezing and thawing, the upper and middle parts of the back and abdomen were sliced, moisturized with wraps and stored at 6 ° C. (8 hours after freezing and thawing).

2) Immediately after freezing and thawing (Sample 3, 4)
The specimens were sampled approximately 30 minutes later, with thawed frozen upper and lower half of the back and belly in three perfusion and four general blood-free sections.

3) Live fish area (Sample 1, 2)
The specimens were sampled as 1 perfusion group and 2 general blood withdrawal groups immediately after the perfusion treatment of live fish and immediately after the medullary amputation blood removal treatment, and the upper and middle parts of the back and stomach were sliced.

The above 6 specimens have clear color difference, so prepare perfusion panel in the same table as perfusion group A column (1, 3, 5) and general blood removal group B column (2, 4, 6). Explain in advance that there are two types of special blood removal treatment and general blood removal, and indicate the following points to consider
1 Appearance (color tone)
2 Odor (raw odor, bloody odor)
3 Taste (taste, hardness)
Was evaluated in 5 stages (excellent 5, good 4, acceptable 3, acceptable 2, impossible 1) and requested their own comments.

  FIG. 10 shows the results (opinions by farmers, cooks who handle yellowtail, and processors).

From Fig. 10, the panelists' representative opinions are:
1 1,3,5 (perfusion product) is white as white as impossible for yellowtail.
2 1,3,5 (perfusion product) has no odor and no odor.
3 5 is slightly softer, but it is much harder than 6.
4 4,6 (general blood-free) is bad in color and does not want to eat.

On the other hand, as palatability
1 2 (unprocessed perishables) is a taste that is usually used to eating.
2 3 (perfused thawing product), the taste of fish is immediately understood when eaten. delicious.
3 1, 3, 5 (perfusion treatment) does not taste yellowtail (blood taste) or smell.
4 4 and 6 are too soft and the color is bad.
5 6 has a strong odor.

Rank as seen from the overall panel score of 10 people Rank Score Sample Details
1 (55 points) Fresh perfusion processed products
2,3 (49,49 points) After thawing perfusion frozen products and immediately after deflating fresh blood
4 (45 points) Perfused frozen product 8 hours after thawing
5 (24 points) Fresh general blood-free frozen product immediately after thawing
6 (19 points) Fresh and general blood-free frozen product thawed after 8 hours In addition, normal yellowtail produces a bloody odor with a few hours of normal temperature, whereas the yellowtail does not feel odor at all. Although it was a product, there was a negative opinion that "the taste of the yellowtail (the taste of blood) is not white, too white", but the panelists agreed that the color tone is difficult to change and the hardness is maintained. there were.

  This bloody smell is an area of palatability, but it seems that the response when the sample is given to women and children seems to be extremely sensitive, which makes the wild fish of wild samurai more disgusting than those who are accustomed to eating. The difference was as clear as it felt.

  Therefore, it was estimated that blood in the body was almost completely derived by perfusion treatment, and that the deterioration of quality occurred due to the removal of blood-derived enzyme groups, and the hardness was maintained.

Claims (16)

  Blood removal by introducing perfusate into the blood vessels of the yellowtail to replace the blood so that the L * value in the L * a * b * color system of the white meat on the back or upper body of the yellowtail is 50 or more A blood removal method for yellowtail characterized by performing the treatment.   The blood removal of the yellowtail characterized by picking up the yellowtail that has been cured in seawater below the saturated oxygen concentration from the picked-up water area that is partitioned from the seawater area below the saturated oxygen concentration and being supersaturated oxygen seawater, Processing method.   Blood removal by introducing perfusate into the blood vessels of the yellowtail to replace the blood so that the L * value in the L * a * b * color system of the white meat on the back or upper body of the yellowtail is 50 or more 3. The yellowtail blood removal method according to claim 2, wherein the treatment is performed.   The removal of a yellowtail according to any one of claims 1 to 3, wherein immediately after the spinal cord of the yellowtail is destroyed, a blood removal treatment is performed in which a cooled perfusate is introduced into the blood vessel of the yellowtail to replace the blood. Blood processing method.   5. The method for blood removal of yellowtail according to claim 4, wherein the oxygen supersaturated liquid is used as the perfusate after passing through a filter having an average pore size of 10 μm or less at a pressure higher than normal pressure.   5. The yellowtail blood removal method according to claim 4, wherein the perfusate is electrolytic cathodic water in electrolytic water. The blood removal treatment method for yellowtail according to any one of claims 4 to 6, wherein the perfusate contains NaHCO ₃ .   A method for producing a blood-bleeded yellowtail, comprising producing a blood-bleeded yellowtail that has been blood-removed using the method for blood-bleeding yellowtail according to claim 1.   A chilled processed product of a yellowtail or a frozen processed product of a yellowtail is manufactured using the blood-removed yellowtail which has been blood-removed using the blood removal method for yellowtail according to any one of claims 1 to 7. Manufacturing method for yellowtail processed products.   Tuna blood removal characterized in that tuna cured in seawater with a saturated oxygen concentration or less is taken up from a picked water area that is partitioned from the seawater area with a saturated oxygen concentration or less to be a supersaturated oxygen seawater region and subjected to blood removal treatment Processing method.   The blood removal treatment method for tuna according to claim 10, wherein a blood removal treatment is performed immediately after the tuna spinal cord is destroyed by introducing a cooling perfusate into a blood vessel of the tuna to replace the blood.   The method for blood removal treatment of tuna according to claim 11, wherein the oxygen supersaturated liquid is used as the perfusate after passing through a filter having an average pore size of 10 µm or less with a normal pressure or higher.   12. The tuna blood removal treatment method according to claim 11, wherein the perfusate is electrolytic cathodic water in electrolytic water. 14. The tuna blood removal treatment method according to claim 11, wherein the perfusate contains NaHCO ₃ .   A method for producing a blood-removed tuna, which comprises producing a blood-removed tuna that has been blood-removed using the method for blood-removing a tuna according to any one of claims 10 to 14.   A tuna chilled processed product or a tuna frozen processed product is produced using the blood-removed tuna blood that has been removed by using the tuna blood removal method according to any one of claims 10 to 14. Manufacturing method of tuna processed products.