Tuna

Useful properties of a tuna and unusual taste of its meat made this fish extremely popular on all globe.

Description

Tuna – fish from Skumbriyev' family. Fish this quite large and some copies in length reach three meters, and weigh to 500 kg. The biggest tuna known to history weighed 1355 kg. Fish has slightly extended, spindle-shaped body, and on a tail stalk leathery Kiel is in parallel located. On spin there is a crescent fin.

The tuna preferential is found in warm waters of the tropical and subtropical seas, it is often possible to meet it in Quiet, Indian and Atlantic oceans. In Ukraine the tuna is found in the Black Sea. Fish prefers to keep small packs and to float at big depths. Jambs float from place to place in search of cephalopod mollusks, pelagic Crustacea and a small small fish. A tuna – fish bystry and for a short time can overcome quite long distance. It can gather speed to 77 km/h thanks to powerful circulatory system and the perfect structure of a body suitable for the constant movement. Energy which the tuna spends at the movement does its blood several degrees higher than temperature of surrounding water.

Species of a tuna

Six species of a tuna are most widespread:

• Avoador which also sometimes call a dlinnopery tuna. This look practically is found in all waters of the World Ocean. An exception make unless polar areas. In length the avoador can reach 1,5 meters and, thanks to very qualitative meat, it is valuable subject to industrial fishing. Especially meat of an avoador is widespread in America.
• The big-eyed tuna which in length can reach 2,5 meters and weighs to 400 kg. Distinctive feature of this look is the wide fin which has up to 14 back thorns. During migration the big-eyed tuna falls to cold deep waters that for other types it is unusual. There he is plentifully fed, and his heart functions more actively. But the tuna cannot reside in cold water and periodically it needs to come up on a surface to be warmed.
• The Chernopery tuna, the least representative of family, in length does not exceed one meter, and no more than 20 kg weigh, as a rule. Fish only at coast of Brazil, in the west of the Atlantic Ocean lives. Unlike other types, the chernopery tuna eats squids and crabs, small larvae and shrimps. Sometimes, of course, eats also a small small fish, but in much smaller volumes. This look has small life expectancy, 5-year-old fish is already considered old.
• Blue tuna – one of the most bystry and large fishes of family. Fish generally eats a mackerel, a herring and squids whom other species of a tuna cannot usually catch.
• The Atlantic blue tuna living in Atlantic. Earlier the blue tuna lived also in the Black Sea, but recently the Black Sea population disappeared. Visually it is similar on tikhookeanichesky blue therefore they can be confused easily. Among other types the blue tuna is the most valuable. Cases when its hulk was bought more than for 100 thousand dollars are known. Generally such money for fish is given by Japanese who use it for preparation of national dishes.
• The southern blue tuna which it is possible to meet in waters of the southern hemisphere. This look at the moment is under the threat of disappearance as from 50th years it is a trade basis therefore its population decreased by 90%. Therefore now catch of this look is possible only within accurately designated quotas.

Use of a tuna

In general, the tuna has important trade value, and numerous properties of a tuna allowed it to take the second place in the world among seafood in popularity (the first belongs to shrimps). The largest consumer of a tuna is Japan which annually consumes about 43 thousand tons.

On taste meat of a tuna very gentle and refined. Besides, because of quite high caloric content of a tuna, and also contents in it a large amount of protein and hemoglobin, he is considered a nutritious product. In France, for example, because of advantage of a tuna and uncharacteristic taste for fish, it is compared to pair veal.

The tuna is widely used for preparation of various dishes: salads, soups, hot vegetable dishes. It is fried, baked, salted, steamed, smoked, extinguished. From a tuna Japanese prefer to cook the well-known sushi as it is considered that this fish is not exposed to infection with parasites.

Around the world the tinned tuna enjoys wide popularity. It is preserved in own juice or in any vegetable oil. Such canned food represents independent snack in which unless, it is possible to add a droplet of lemon juice and to decorate with greens, vegetables and olives. In addition, such canned food can be added to various salads or to use for preparation of pizza or pies.

Structure and caloric content of a tuna

In 100 g of a tuna 68,09 g of water, 23,33 g of proteins, 4,9 g of fats, 1,18 g of ashes contain; vitamins: And, B1, B2, B3, B6, B9, B12, B4, E, D; macrocells: phosphorus, sodium, magnesium, calcium, potassium; microelements: selenium, zinc, copper, manganese, iron.

Caloric content of a tuna on 100 g of a product makes about 145 kcal.

Useful properties of a tuna

The Dutch scientists conducted a number of experiments as a result of which it was proved that the daily use of 30 g of a tuna reduces risk of cardiovascular diseases twice. The main, but not only, advantage of a tuna consists in the high content of the fatty Omega-3 complex.

High content of microelements, vitamins, necessary for an organism, and irreplaceable acids also belongs to useful properties of a tuna. The regular use of a tuna reduces risk of emergence of allergic reactions, promotes development of antibodies, struggles with inflammatory diseases, it is useful for prevention of oncological diseases, saves from a depression, kills pains at arthroses and arthritises.

The advantage of a tuna consists stimulations of a metabolism and normalization of level of sugar in blood. Besides, it promotes a conclusion from a cholesterol organism therefore doctors, despite the high caloric content of a tuna, recommend it to use to the people having obesity and a hypertension. The tuna is especially useful to improvement and recovery of properties of skin and mucous membranes of the person, in particular at eczema.

Contraindications

Despite huge advantage, a tuna it is contraindicated at individual intolerance and a renal failure. Also pregnant women and the feeding women and small children as meat of a tuna has property to accumulate mercury are not recommended to use it. Content of mercury in meat cannot do any harm to the adult, but can negatively affect development of nervous functions in small children.