Tuna is one of the strongest fish in the ocean, with three-quarters of its body covered in muscle tissue, so a large amount of myoglobin gives the flesh a red color. It is a swimmer in the ocean, with a general speed of 30 to 50 kilometers per hour and a maximum speed of 160 kilometers per hour. In general, tuna need to keep swimming and keep its mouth open so that it can get more oxygen with the help of water, and if it stops swimming, there is a risk of suffocation. Tuna is an outlier among fish, with a body temperature between 33 and 35 degrees, so the body metabolizes quickly and moves quickly. Tuna is a deep-sea active fish, rich in nutrients, tender flesh, and extremely delicious, and is recommended by the International Nutrition Association as a green, pollution-free and healthy food.
Tuna is more expensive, the price of different fish body parts is also different, ranging from 400 to 1200 yuan per kilogram, the most expensive part is the gills of bluefin tuna, and the price of each two is as high as 2800 yuan. However, countless tasters pursue tuna, which is only a matter of nearly a hundred years, the reason is that tuna is red meat, in the absence of frozen preservation conditions, it will quickly rot, so in the era of underdeveloped technology, tuna is almost no one eats. Until the modern freezing technology was available, tuna was in great demand for its nutrition and deliciousness, and the price was gradually more expensive.
There are three main types of tuna commonly found in the market that are suitable for sashimi.
Bluefin tuna, a large tuna, is a huge body, and it has been recorded that it has caught 4.3 meters long and weighs more than 800 kilograms. However, bluefin tuna is rarer and has better meat, so it is the most precious and the most expensive, and it is recorded that a bluefin in the Japanese market once sold for 11 million yuan.
Yellowfin tuna, a medium-sized tuna, can reach a maximum length of 3 meters and a weight of 225 kg. As the name suggests, the yellowfin tuna has a blue back, a silvery-white belly, and orange-yellow dorsal, and small fins. 、
Big-eyed tuna, about 2 meters long and weighing up to 150 kilograms, is similar in size to bluefin tuna, but has a pair of cute big eyes that are a significant sign. It has a bluish-blue back and a grayish-white abdomen.
Tuna is very strong, after being caught will struggle violently, at this time a large amount of lactic acid will be produced in the muscles, at the same time, the temperature of the fish will rise rapidly, this situation is called "tuna burning body", the disadvantage is that the fish meat will become pale, and the sour taste increases, greatly reducing the value of the tuna. Therefore, in commercial fishing, it is necessary to cut off the central nervous system at the first time, which is the key to the delicious meat of the marlin, and then release the blood of the fish body, remove the internal organs, and carry out fresh or frozen treatment, so as to guarantee the quality of the marlin fish.
Before making a delicacy, fine tuna needs to be drained and matured to achieve a rich meat flavor for optimal taste. Different parts of tuna have different meat and fat content, and the taste is also different. Can be divided into large belly (big fat), middle belly (middle fat), naked and gill meat several parts, the big belly part is the fattest abdomen, do sashimi entrance that melts, exceptionally delicious, the price is also more expensive; the belly meat is second, the color will be slightly darker, the price is cheaper than the big belly; the naked body is located on the back, the flesh color is bright red, less fat, but delicate and delicious, the price is the cheapest.
Tuna is a high-grade sashimi (sashimi) ingredient at a Japanese food shop. When processing sashimi, the knife and the fish meat texture should be cut at 90 degrees, so that the fish fillets are cut out with short tendons and have a better taste. The plate can be filled with ginger slices, washed radish shreds, mint leaves, cucumber flowers, etc. as ornaments to increase the beauty and enhance the sense of style. The condiment can be made with Japanese soy sauce and wasabi (green wasabi), which is generally sashimi thick, and the soy sauce can be thicker, and vice versa, it can be lighter.
To fry the tuna, sprinkle a small amount of salt, chili pepper and pepper on both sides of the tuna meat. Put vegetable oil in the pan, the temperature is not too high, fry the fish on both sides, the middle layer is best kept as raw fish, like steak, the taste will be better and more delicious, so it is also called tuna steak. After frying, slice and plate, if you like, supplemented with soy sauce, a plate of delicious pan-fried tuna is ready.
How to pick canned tuna? The canned tuna on the market is not necessarily made of tuna meat, because the generalized tuna genus, in addition to tuna, also includes bonito, tuna and other pelagic fish. In order to sell, manufacturers will make canned fish from other tuna species and label them as canned tuna. Generally ordinary canned tuna is made of bonito, high-end canned tuna will generally use yellowfin tuna, bluefin tuna is very expensive, canned too wasteful, mainly used to make sashimi or tuna steak.
Japan's tuna farming techniques are the best. There are three farming methods: one is short-term farming, the harvest of 10 to 60 kg of wild small tuna reared for 6 to 7 months, to grow up and then enter the market, the culture is generally mainly bluefin tuna. The second is wild tuna farming, which is raised with 100 to 500 grams of wild tuna fry or eggs, and then enters the market after 2-3 years, which is the main tuna farming method in Japan. The third is artificial breeding, that is, the entire stage from hatching to growing into large fish is cultured under artificial control conditions. In general, tuna farming techniques are not simple.