Tuna is a very interesting fish, it swims fast, travel range of up to thousands of kilometers, can make the trans-oceanic circumnavigation. The tuna is uniquely adapted to its environment and its growth potential is enormous. In recent decades, many scientists on the tuna "mark exile" test, they caught the tuna, marked and then put back to the sea, to observe their migratory routes, the results of fisheries workers from the return of the tuna found that there is a kind of tuna from the United States of America's California coast to the Japanese offshore, the whole process of up to 8500 kilometers, an average of 26 kilometers a day; another tuna across the 7770 kilometers wide Atlantic Ocean only 119 days, every day the distance swam by more than 65 kilometers; there is a tuna is able to cross the Indian Ocean from the Gulf of Australia, and ultimately arrived at the other side of the Atlantic Ocean, its long-distance migratory stamina is really admirable! Therefore, the tuna is worthy of the fish in the swimmer. Tuna in the whole world's oceans east and west, there is no fixed habitat, so some people call it "no national boundaries of the fish", is a certain reason. Tuna belly and back different
In the sea, tuna in order to adapt to the environment, it is different colors of the belly and back, which is a method of self-protection tuna. Tuna belly color is lighter than the back, so, from the sea face up to see it when it talks about the color of the body with the sea surface is almost the same; face down from the sky to see when it is almost the same color with the ocean depths of the water, so that the tuna rely on the upper and lower body color difference not only to be able to avoid the air and the sea's natural enemies, but also able to skillfully confuse the other organisms to prey on. The tuna's main food is a variety of fish and crustaceans and other animals, because the tuna is a carnivorous marine fish. Streamlined body
The tuna's shape is also peculiar, its entire body is streamlined, and the breastplate that extends along its head seems to be a unique balance plate capable of adjusting the water current, which reduces the resistance it creates while swimming. In addition, the tuna's tail is in the shape of a half-moon, enabling it to sprint forward very quickly in the ocean. It has been recorded that the tuna is able to swim an average of 20 nautical miles per hour. Unique Respiratory and Circulatory Systems
The tuna's respiratory and circulatory systems are also unique among fish. Its circulatory system, which consists of a blood-supplying heart and a network of blood vessels, stores heat or burns it according to its needs, storing it when the tuna is less active and burning it when activity intensifies. Tuna's body temperature changes are also very special, different from most fish, it is not only related to its own size and the size of the activity, but also with the surrounding water temperature is also related to the tuna's body temperature is always kept higher than the water temperature of their own activity place. Scientists believe that the tuna's high body temperature speeds up the breakdown of sugar in its muscles, thus meeting its need for this chemical energy rush during sudden movements. The tuna is capable of reaching speeds of up to 75 kilometers per hour during sudden movements.
Body temperature is higher than the water temperature
Why is the tuna's temperature higher than the surrounding water temperature? It turns out that it has a skin-muscle-vessel network plexus on both sides of the body, and after thorough research by scientists, the tuna's body temperature is 9 degrees Celsius higher than the surrounding water temperature. This tireless fast swimmers, muscle contraction force is the main reason for their body temperature. Along the tuna spine on both sides of the powerful muscles and skin on a large number of blood vessel network plexus, indicating that these parts of the metabolism is particularly vigorous, and thus the tuna's flesh resembles beef, is purplish red. It has a high content of hemoglobin and is low in fat but high in strong protein, so it has a high nutritional value. Tuna tuna has nutrition
Because the tuna must always keep swimming fast to maintain the body supply, plus only in the depths of the sea activities, so the meat is tender and fresh, and is not subject to environmental pollution, is the modern people can not be missed healthy food. The protein content is as high as 20%, but the fat content is very low, commonly known as submarine chicken, with high nutritional value. Most of the fatty acids in the fish are unsaturated fatty acids, and it contains a full range of amino acids, all of which are required by the human body in 8 kinds of amino acids. It also contains microbiotics, rich iron, potassium, calcium, iodine and other minerals and trace elements. Tuna in the unsaturated fatty acids DHA docosahexaenoic acid and EPA eicosapentaenoic acid, the content of all kinds of food in the first place.DHA is called brain gold, is the human brain and central nervous system development of essential nutrients.EPA, also known as OMEGA3, tuna is unique to the nutrients, can inhibit the increase of cholesterol and to prevent hardening of the arteries, for the prevention and treatment of cardiovascular and cerebrovascular diseases has a special role. special role. Tuna taste good
Taste fresh tuna has always been Japan, Taiwan's favorite seafood cuisine, especially tuna sashimi is known as sashimi among the best, not only the old diners deep into the taste, even the less eaten sashimi people will choose tuna sashimi chunks of a taste. From the tuna species, the quality of sashimi from high to low are bluefin tuna, masu tuna, bigeye tuna and yellowfin tuna. Bluefin tuna and masu tuna have low production and very high prices, and common tuna fillets are made from bigeye tuna and yellowfin tuna. Raw food is the best, cooked food is also rich and delicious, made of canned tuna in oil is very tasty, not only by the people around Southeast Asia, even Europe and the United States also like to use to prepare sandwiches, loved by consumers, the market and its broad, Japan, Western Europe and the United States is the three major markets for tuna products. It can be said that in these countries tuna is a household name, just like our people are familiar with the yellowtail, yellowtail and scallop. In some countries in Europe and the United States, people compare tuna meat to "chicken meat" or "veal". Canned tuna in oil made in the U.S.A. is popular all over the world and is one of the best-selling foods internationally. Japan's demand for tuna is very large, the general annual consumption of 800,000-900,000 tons, accounting for about one-third of the world demand, especially fresh tuna is more popular, the consumption is 60% of the demand, annual imports of about 1 billion U.S. dollars. In the reform and opening up today, our people are living better and better, more and more will eat, but also more and more attention to diet and health care, to high-grade seafood such as lobster, mussels, salmon and other seafood, has lost the sense of freshness. Therefore, I am now developing the domestic market, part of the tuna shipped to the Japanese market directly back to the domestic sales, so that people can enjoy this delicious and nutritious treasures of the sea at any time.
Other features
The tuna has a strong sense of population. If you look down from the airplane, you will find schools of tuna swimming forward in a neat line. Small body in the front, large body in the back, the foremost is a "leader". Therefore, when catching tuna, attracting the "leader" is a key. The tuna also has some habits that it does not like bright light, so it is not easy to trap it at night by using a spotlight. In addition, the tuna's sense of smell is not sensitive, but the eyesight is quite good, if you throw some small fish into the sea, it will quickly find and come to catch food. According to these habits of tuna, people have created three main methods of catching tuna: pole fishing, netting and longlining. Species Biologically speaking, tuna in the broadest sense refers to about 30 species of fish in the families Scombroid, Swordfish and Swordfish***. The species with greater economic value include six species, including bluefin tuna, masu tuna, bigeye tuna, yellowfin tuna, albacore tuna, and skipjack tuna. Among them, bluefin tuna, masu tuna, bigeye tuna, and yellowfin tuna are the raw material fish for sashimi, and albacore tuna and skipjack tuna are mainly used to make raw material for canned tuna; however, recently, albacore tuna has been used for sashimi as well. Yellowfin, bigeye, and albacore tuna are the main targets for longline fishing, and skipjack tuna[/url is the main target for pole fishing. There are more than 50 species of tuna, most of which varieties of "a child" is relatively large, the largest body length of 3.5 meters, weighing six or seven hundred kilograms, and the smallest species of only three kilograms of weight, the size of the visible difference is very different. Tuna's reproductive capacity is relatively strong, a 50 kilograms of female fish, about 5 million eggs per year, if these eggs are able to fertilize and hatch young fish, and grow into 500 kilograms of big fish, then, a female and a male fish will be able to produce 2.5 million tons of tuna, which is equivalent to the world's total catch of tuna. In fact, this is impossible. Because the vast majority of the eggs do not live to maturity, and only a few are able to hatch out young fish, and even if they do, most of them fall victim to other adult fish, seabirds and other marine animals, and tuna also have the nasty habit of killing each other with the same kind of fish, so the survival rate of the young fish is extremely low, and it is estimated that only two parts in a million of the small life will grow up to be a big fish. However, in addition to natural enemies, tuna in the sea also has its protectors, whales and shark whales are its good friends, they often swim together, tuna if the natural enemy, will rush close to the whale or shark whale, with the help of friends of the huge body to cover themselves. Tuna 1, yellowfin tuna (Yellowfin Tuna): the fish body is fusiform, slightly flattened, head small, tail long and thin, flesh pink. The back of the body is blue-green, the side of the body light gray, with a little yellow, a little transverse band, the adult fish of the two dorsal fins and anal fins and the back of the small fins, are bright yellow. The first dorsal and ventral fins are tinged with yellow. The length of the body is 1-3 meters, which varies from one sea area to another, and the weight is generally 40-60 kilograms. Yellowfin tuna has a wide diet, dominated by squid, surface fish and large crustaceans. It makes long-distance migrations, and its migrations are related to seasonal changes in sea currents; during the tropical rainy season, it moves away from lighter coastal waters and swims to sea areas with high salinity. Yellowfin tuna is widely distributed in the equatorial waters of the three oceans, and is a representative species of the tropical sea area. Yellowfin tuna is common in water depths up to 160 meters, water temperature up to 20-28 ℃, the maximum swimming speed of 90 kilometers / hour. Yellowfin tuna accounts for 35% of global tuna production. Most of it is used for canning, and raw and frozen products continue to grow. Yellowfin tuna is now in a state of reasonable exploitation. Tuna 2, Bluefin Tuna (Bluefin Tuna) is the largest species of tuna. The body is short and sturdy, tapered and elongated, and the caudal fins are cross-shaped; the bottom to the side of the body is brightly colored, while the upper body is dark blue, the fins are dark, the small fins are yellowish, and the tailstock ridge is black. The entire body is scaled, the mouth is quite large, the eyes are not large, and the pectoral fins are short, ending less than the center of the first dorsal fin, which is the most characteristic feature of this species. The body length is generally 1-3 meters, the larger one is more than 3 meters long, weighing more than 700 kilograms. Bluefin tuna are often found in schools of 50-60 fish, but there are also schools of more than 1,000 fish. The habitat ranges from the surface to 50 meters deep, with an optimal water temperature of 10-20 degrees Celsius, and the bait is mainly herring, sardines, mackerel, squid and crustaceans. Average size: 200-400 kilograms Tuna 3, Bigeye Tuna (Bigeye Tuna), also known as fat tuna and parrot tuna, the body length of about 1.5-2.0 meters, the weight of large in more than 100 kilograms, generally 16-35 kilograms. The back of the body is blue-green, and the sides and belly are silver-white. The flesh is pink and slightly soft. The pectoral fins are long, with their ends protruding well below the second dorsal fin, which is also narrower and of similar height to the first dorsal fin. The fish is gray in color, plump, with a short tail and a distinctly large head and eyes. Bigeye tuna live in deeper water, up to 200-300 meters, and sexually mature individuals live in the surface layer. It mainly feeds on deep-sea fish, mainly small fish, squid and large crustaceans. The maximum swimming speed can reach 100 kilometers per hour. At present, bigeye tuna catch production is low, but the price is high, very potential for development. Tuna 4, longfin tuna (Longfin Tuna) body back was dark blue, side and belly for the silver white, body color uniform. Body length 1-1.5 meters, weight about 15 kilograms. Large individuals can reach 45 kilograms. The pink flesh and the blade-shaped, extremely long pectoral fins, which are longer than the head, are the most distinctive features of this species. Albacore tuna are mainly found in 90-150 meters of water during the day, sometimes as deep as 150-200 meters, and near the surface in the evening. Albacore tuna have a moderate temperature range of 14-20°C. The bait is sardines and other fish. The bait is mainly sardines and crustaceans. Albacore tuna accounts for about 7% of the total tuna production and is mostly used for canning. Fishing Methods There are two fishing methods for tuna, one is longline fishing method, which mainly catches bluefin tuna, marsupial tuna, bigeye tuna, yellowfin tuna and albacore tuna inhabiting in deeper waters and weighing more than 20 kg; the other is surface fishing gear fishing method, including purse seine, pole-and-line and trolling, etc., which catches tuna inhabiting in the surface layer of the ocean, and catches mainly small individuals of yellowfin tuna, bigeye tuna, bigeye tuna, yellowfin tuna and albacore tuna, which are mainly used in canning. The main species caught are small yellowfin tuna, bigeye tuna and skipjack tuna, with a weight range of 5-10 kilograms. At present, there are more than 70 countries in the world engaged in fishing tuna fishery production, mainly Japan, the United States, the Philippines, Spain and Indonesia and other countries, the production accounted for 70% of the world's total tuna production. The main consumer of tuna is Japan and the United States, in recent years, the world's annual production of tuna to maintain the three million tons, in addition to the Indian Ocean, some of the ocean's tuna resources have been fully utilized, therefore, the protection of tuna resources, but also in front of the world's marine fisheries, an important task in front of the processing methods, a deck of processing 1, to avoid the fish jump: fish on the deck, after the fish, can not allow it to jump, so as not to After the fish is on the deck, it should not be allowed to jump, so as not to cause the body to bruise. After bruising, it will cause 5 times the area of muscle damage, especially in the abdomen, the processing method is: put it on the carpet, press the eyes of the fish with both hands, or hit the head of the fish with a hammer, but be careful not to break it, and then bleed it out immediately afterward. 2. cut the tail: usually cut off the dorsal fins in the penultimate third between the sixth section with a sharp knife, and for the individual larger fish, in order to prevent cutting off the tail after the tail is too thin, it should be in the penultimate four between the section and the section of five. 3, Cut off the blood vessels at the back of the pectoral fins: usually there are two blood vessels in the back of the pectoral fins of the tuna, and the knowledge of their separation is cut off, the cut is 5 centimeters deep and 4 centimeters long, and the degree of cutting should be appropriate, such as the cut is cut too deep, the blood will invade into the internal meat, resulting in waste. Even if the fish has died in the water, must also be carried out the above super work. 4, cut off the heart before the cephalic artery: the heart before the cephalic artery cut off, with seawater rinse the fish body to prevent the fish body temperature rises, and then carry out bloodletting, operation. The gill lining of the fish is cut into a hole, and seawater is poured into it through a water pipe until there is basically no blood, and whether the blood is drained or not is based on the tail. 5. Pin insertion at the back of the head: Pin insertion is performed after the end of the snow removal treatment. This operation is aimed at destroying the cartilage in the brain of the fish, so that the fish is in a state of death,. The location of pin insertion is at the inner point or depression of the head or the top of the head above the eyes of the fish.6. Remove the viscera and gills: use a sharp knife to cut open the abdomen from the anus to the pectoral fins, take out the viscera of the fish, and rinse it with seawater, and it should be noted during the operation that a layer of the membrane affixed to the inner wall of the abdominal cavity should be taken out as well, and the abdominal cavity should be rinsed with seawater to cut gills by cutting the gill ossicles along the edges of the gills to remove part of the gills, and when gill removal is done, the block of the back of gill cutting When removing the gills, the back of the gills is cut as large as possible, preferably with the knife pushed flat along the inside of the gills until it touches the bone, and then the gills are cut straight off from the top of the gills so that the product has a good feel to it. After removing the gills, use a small spoon to chop off the miscellaneous meat attached to the bones inside the gills, but not to scrape the meat inside the gills.7. Washing: When brushing the fish body, it must be brushed from the tail to the head, and then seawater bathing, and then respectively from the preparation room to the freezing room to make the ice coat, keep cold, so that the commercial fish to meet the requirements of high-quality and high-priced. Second, the process of chilling 1, the bilge and bulkhead processing: the bilge and bulkhead to be 30 cm ice paving pads, put the fish away from the bulkhead 30 cm, and fill the gap with ice. 2, the ice from the mouth of the fish to the abdominal organs stuffed, stuffed and stuffed. 3, placed: the body of the fish is placed flat, the fish spacing of 30 cm, the middle of the ice to fill in. Each layer of fish should also maintain 30 cm of ice, layer and layer between the fish should be staggered, the formation of a triangle, and the head and tail inverted, set up after sealing the ice, covered with ice, so that the ice fish process is over. 4, knocking the ice and ice cover twice: generally in the next day before the ice fish, the ice fish the day before the ice ice overlaying the ice to be re-crushed, covered with a layer of ice, then ice fish. 5, the temperature of the chilled fish compartment, control at 0 The temperature of the iced fish compartment should be controlled at 0-2, and the maximum temperature should not exceed 56. The freshness period of iced fish is 12 days, and 14 days is the limit, and more than 14 days will gradually deteriorate. Cooking method Tuna tuna seems to be a lot of Western or Japanese cuisine, raw food is the classic method.
Tuna sushi
Ingredients:
Ultra-low temperature tuna ....................... 300 grams
White rice .................................. .3 cups
White vinegar ................................ .1/4 cup
Sugar .................................. .1 teaspoon
Salt, MSG ............................. A little of each
Cucumber, green onion ...............................
Sushi seaweed Method:
1. Thaw the tuna and cut it into long strips. Cucumber also cut into long strips, white rice while hot is mixed with white vinegar, sugar, salt and monosodium glutamate (MSG), mix well and blow cold standby.
2. Put seaweed on the sushi bamboo, spread four tablespoons of white rice, flatten the rice, put tuna and cucumber strips, roll it up and press the sushi into the desired shape with the bamboo, then take out the sushi bamboo sheet.
Note: There are many different types of sushi, but you can also put raw tuna on top of the rice or minced fish on top of the rice ball. Tuna Tuna sashimi two ways
Ingredients:
Ultra-low-temperature tuna
Japanese toppings: Chinese toppings:
Yamabi powder: 2 tablespoons
Shredded white radish, shredded carrot, shredded green onion,
Water: 1 tablespoon
Shredded ginger, cilantro, crumbled fried peanuts,
shredded white radish as desired, Deep-fried crispy flakes, seasoning mix Directions:
1. Thaw the tuna in ultra-low temperature.
2. Thaw the tuna until it is soft around the meat but still hard in the center, then slice it. Serve ten minutes after slicing for best flavor.
3. Serve sashimi with wasabi powder, water and soy sauce with shredded white radish.
4. Chinese style: Shredded white radish is placed under the sashimi, surrounded by cilantro, fried peanut crumbs, and fried crispy flakes, and drizzled with a combination of seasonings and tossed to serve. Tuna Miso Tuna Steaks
Ingredients:
Tuna steaks: 2 slices
Miso: 3 tablespoons
Sake: 2 tablespoons
Sugar: 2 tablespoons
Water: 4 tablespoons Methods:
1. Wash and pat dry the tuna steaks.
2. Mix miso and other seasonings and water in a bowl, and add tuna to soak.
3. Line a baking sheet with aluminum foil, grease the sheet with a little salad oil, and place the tuna steaks on the sheet and transfer to the oven. Bake on high heat for 8 minutes, then turn the fillets over and bake for another 5 minutes, until the fillets are lightly browned.
Note: Remove miso seasoning from tuna steaks before grilling (but don't wash with water) to avoid scorching. Tuna Crispy Tuna Steaks
Ingredients:
Tuna Steaks ............... .4 slices
Oil ..................... .2 cups Method:
1. Frozen tuna steaks do not need to be thawed, and can be taken out and deep-fried directly.
2. Heat 2 cups of oil in a wok to 8 minutes, add the tuna steaks and deep fry over low heat. Do not turn the tuna steak over, but turn it over and deep-fry for about 3 minutes.
3. After 4 minutes of deep-frying, turn up the heat and deep-fry the tuna for another half minute.
4. Serve with ketchup. Tuna Tuna Sandwich
Materials:
Canned tuna .......... .1 can
Salsa .............. .2 tablespoons
Onion shavings .............. .1 tablespoon
Cucumber shavings ............ .1 tablespoon
Salt and pepper .......... .1/4 teaspoon
Cucumber ................ .1 strip
Lettuce, tomato ........... Feel free
Bread on toast ............. At will Directions:
1. Empty the tuna into a bowl, crush the fish with a fork, and season with the salsa, onion shavings, pickle shavings, salt and pepper.
2Cut the bread into various shapes and put the tuna into them to make a tuna sandwich. Tuna Balls
Materials:
Fresh tuna ........ .400g
Onion ............... Half
green pepper ............... One
Canned pineapple .......... .4 slices
Fish marinade:
Light soy sauce .......... .1 tablespoon
Taiyaki powder ............ .1 tablespoon
Egg ................ .1 piece
Oil ................ .1 tablespoon Combined seasonings:
Sugar ............ .3 tablespoons
Water .............. .5 tablespoons
Ketchup .......... .3 tablespoons
Salt .............. .1/4 tablespoon
Powdered rice .......... .1/4 tablespoon
Sesame oil ............ .1 teaspoon Method:
1. Use the back of a knife to loosen the fish and cut it into one-inch cubes, mix the fish marinade and marinate the fish for half an hour or more.
2. Pepper seeded and cut into small pieces, onion also cut into one-inch square pieces, pineapple each slice cut into six pieces, seasoned with a combination of seasonings and then standby.
3. Fish piece by piece with the white powder sticky coating, into the hot oil over high heat to fry for a minute and a half, fish ball, the oil will be hot and then over high heat to fry for half a minute.
4. Use 2 tablespoons of oil to sauté the onion, add green pepper and pineapple pieces, stir fry and pour in the comprehensive seasoning and fry, turn off the heat and pour down the fish ball a mix can be on the plate. Tuna in black bean sauce and lettuce
Ingredients:
Lettuce (wrapped): 1
Canned tuna in oil: 1 Seasoning:
Soy beans: 1 tablespoon
Garlic: 2
Soy sauce: 2 tablespoons
Sugar: 1/2 tablespoon
Salt: 1/2 teaspoon Directions:
1, black beans: 1 tablespoon
Soy beans: 1 tablespoon
Garlic: 2
Soy sauce: 2 tablespoons
Sugar: 1/2 tablespoon
Salt: 1/2 teaspoon >
1: Mince the black beans and garlic, put them in a small microwaveable bowl, add the soy sauce, sugar, and the oil from the can, mix well, set aside for 10 minutes, then microwave for 1 minute to make the black bean sauce.
2. Cut lettuce into slices. When the oil in the pan is hot, lettuce down, stir fry, add a little salt to taste. Be careful not to overcook. Remove from the pan and plate.
3. Crumble the tuna, arrange it on top of the lettuce, pour the black bean sauce over it, OK!