Why is hairtail frozen?
Introduction of hairtail
Hairtail is one of the common fish in life because of its high yield, also called nepotism or hairtail, etc. It is also called fish in Qingdao, Rizhao and other cities. Its body is silvery gray, and its biggest feature is that its body is slender and flat, and even its internal organs are flat. Hairtail, together with large yellow croaker, small yellow croaker and squid, is called the four major seafood in China.
Hairtail is a migratory fish, which is mainly distributed in the warm zone waters of the world. It usually lives in the water depth of 60- 100 meters, and migrates to shallow water when spawning. Hairtail looks weak, but it is actually a very fierce carnivorous fish. When it is at rest, its body is vertical, its head is up, and it keeps its balance by swinging its dorsal fin and pectoral fin. When it finds prey, hairtail bends, its dorsal fin swings rapidly and pounces on its prey. Its main foods include krill, bamboo pod fish, etc., and there are also cases of cannibalism.
Nutritional value of hairtail
Hairtail has a very high nutritional value, containing protein, fat, phosphorus, iron, calcium, vitamin B 1, B2 and other nutrients. Although hairtail has a high fat content, it is mostly unsaturated fatty acids, including DHA and EPA. DHA, commonly known as brain gold, is helpful for strengthening the brain and improving intelligence. EPA is a blood vessel scavenger, which helps to prevent the accumulation of fat in blood vessels, thus preventing cardiovascular diseases such as hypertension.
About the delicacies of hairtail.
Hairtail is not only fresh and tender, but also has a variety of practices, such as steaming, braising, frying, dry frying, stewing and so on, which has created special foods in different places, such as pie-rolled hairtail in Beijing, dry-fried hairtail in Shanghai, hairtail in chili pepper in Sichuan, steamed hairtail in Zhoushan, and hairtail in iron pot in Northeast China.
Why are hairtail frozen?
Why is it difficult to buy live hairtail in the market? This is because hairtail generally lives in the sea area with a water depth of about 60 meters, where hairtail is used to the high pressure of sea water. When hairtail is caught quickly, the external pressure will decrease, and the swim bladder in the body will expand sharply due to the pressure change (the diver's decompression sickness is also a similar principle), so that hairtail will die within 2 hours after coming out of the water.
If you want to avoid this situation, you need to put hairtail in a professional pressure box, which will lead to high transportation costs; Therefore, hairtail is usually frozen after being salvaged, which can not only reduce the cost but also basically retain the taste and nutrition.
Why is sashimi called sashimi? And hairtail can be made into sashimi?
The saying of sashimi comes from Japan. Because the peeled fish fillets are not easy to tell what kind of fish they are, bamboo sticks will be stabbed on the fish fillets. Therefore, the sashimi hairtail can also be made sashimi, but the conditions are very harsh. First, it is generally necessary to wait until the hairtail is brought to shallow water to catch it slowly, and then put it in professional equipment for storage. It is recommended that it take no more than 5 hours from fishing to the table.
How to choose fresh hairtail
First, look at the gills. The gills of fresh fish are generally red, and the gills will gradually turn black as time goes on, so don't buy fish with black gills.
The second is to look at the fish eyes. The fish eyes of fresh hairtail are generally full and convex, and the whites are white, clean and bright, while the fish eyes of fresh hairtail will sink and look fuzzy and turbid.
The third is to look at the fish body and scales. The fish body of fresh hairtail is silvery white and has a relatively complete silver film, so the scales will not fall off easily, while the surface of stale hairtail will not only be yellow due to oil oxidation, but also the scales will fall off at the touch.
Yellow-eyed hairtail VS black-eyed hairtail
Hairtail in the market has yellow eyes and black eyes, which are actually mainly related to the origin of hairtail. Hairtail with black eyes mainly comes from northern China, such as Zhoushan, Zhejiang, Dalian, Liaoning and other places, while hairtail with yellow eyes mainly comes from southern China, such as the South China Sea, and imported hairtail from the Philippines and other places are mostly yellow eyes. In terms of taste, the head of hairtail with black eyes is smaller than that of hairtail with yellow eyes, but the meat is more fishy and lighter, which is suitable for steaming, while the skin of hairtail with yellow eyes is thicker, which is more suitable for braising or frying.
Will hairtail decrease?
Among the four major marine products in China, the catch of Pseudosciaena crocea, Pseudosciaena crocea and cuttlefish is decreasing day by day, but the distribution of hairtail has been very firm, ranking first in the catch of marine fish all the year round, and the annual catch is around one million tons, which is due to the breeding habits and strong adaptability of hairtail. Hairtail spawns twice a year, with a single spawning time of 2.5 to 35,000, and hairtail has few natural enemies due to its fierce character in the growth process, which is also the reason for its high yield.
However, in recent years, it has been found that the catch of hairtail has a downward trend, from1186,800 tons in 20 19 to 908,500 tons in 2019; Now scientists are studying whether hairtail can be farmed artificially. Because hairtail has the habit of migrating from deep sea to shallow sea, coupled with cannibalism, it is very difficult to create a suitable habitat for hairtail. In 20 17, Zhoushan Fisheries Research Institute successfully put hairtail in artificial environment to feed for more than two months, which laid a good foundation for future exploration.