Friday, June 26, 2009

Tuna


Tuna are several species of ocean-dwelling carnivorous fish in the family Scombridae, mostly in the genus Thunnus. Tunas are very fast swimmers—they have been clocked at 70 km/h (45 mph)—and include several species that are warm-blooded.


Unlike most fish species, which have white flesh, tuna have flesh that is pink to dark red. The red coloring comes from tuna muscle tissue's greater quantities of myoglobin, an oxygen-binding molecule. Some of the larger tuna species, such as the bluefin tuna, can raise their blood temperature above that of the water through muscular activity. This ability enables them to live in cooler waters and to survive in a wide range of ocean environments.


Nutrition and health

Canned tuna is a prominent component in many weight trainers' diets, as it is very high in protein and is easily prepared.

Tuna is an oily fish, and therefore contains a high amount of Vitamin D. A can of tuna in oil contains about the Adequate Intake (AI) of the US Dietary Reference Intake of vitamin D for infants, children, men, and women aged 19–50 - 200 UI.

Canned tuna can also be a good source of omega-3 fatty acids, of which it sometimes contains over 300 mg per serving.

Thursday, May 28, 2009

Tilapia


Tilapia' is the common name for nearly a hundred species of cichlid fish from the tilapiine cichlid tribe. Tilapia inhabit a variety of fresh water habitats including shallow streams, ponds, rivers, lakes, and estuaries. Most tilapia are omnivorous with a preference for soft aquatic vegetation and detritus. Historically they have been of major importance in artisanal fishing in Africa and the Levant, and are of increasing importance in aquaculture (see tilapia in aquaculture). Tilapia often become problematic invasive species in new habitats, whether deliberately or accidentally introduced.


Nutrition

Tilapia have very low levels of mercury because it is a fast growing and short lived fish that mostly eats a vegetarian diet and therefore does not concentrate mercury found in prey. Farm-raised tilapia has very low levels of omega-3, the primary fatty-acid nutrient doctors look for in fish. Farmed tilapia also have high levels of omega-6 fatty acids. A diet with a high ratio of omega-6 to omega-3 is suspected to cause inflammation. It is not clear if this poor ratio of omega-6 to omega-3 is due to the corn and/or soy based diets typically fed to farm raised Tilapia, natural fatty acid levels, or a combination of the two.





Wednesday, May 20, 2009

Salmon- popular food



Salmon is the common name for several species of fish of the family Salmonidae. Several other fish in the family are called trout; the difference is often attributed to the migratory life of the salmon as compared to the residential behaviour of trout, a distinction that holds true for the Salmo genus. Salmon live in both the Atlantic (one migratory species Salmo salar) and Pacific Oceans, as well as the Great Lakes (approximately a dozen species of the genus Oncorhynchus).


Typically, salmon are anadromous: they are born in fresh water, migrate to the ocean, then return to fresh water to reproduce. However, there are rare species that can only survive in fresh water habitats. This is most likely due to the domestication of these certain species of Salmon. Folklore has it that the fish return to the exact spot where they were born to spawn, tracking studies have shown this to be true but the nature of how this memory works has long been debated.

Salmon as food

Salmon is a popular food. Consuming salmon is considered to be healthy due to the fish's high protein, high Omega-3 fatty acids, and high vitamin D content. Salmon is also a source of cholesterol, ranging 23–214 mg/100g depending on the species. According to reports in the journal Science, however, farmed salmon may contain high levels of dioxins. PCB (polychlorinated biphenyl) levels may be up to eight times higher in farmed salmon than in wild salmon. Omega-3 content may also be lower than in wild caught specimens, and in a different proportion to what is found naturally. Omega 3 comes in three types, ALA, DHA and EPA; wild salmon has traditionally been an important source of DHA and EPA, which are important for brain function and structure, among other things. This means that if the farmed salmon is fed on a meal which is partially grain then the amount of Omega 3 it contains will be present as ALA (alpha-linolenic acid). The body can itself convert ALA Omega 3 into DHA and EPA, but at a very inefficient rate (2–15%). Nonetheless, according to a 2006 study published in the Journal of the American Medical Association, the benefits of eating even farmed salmon still outweigh any risks imposed by contaminants . Type of Omega 3 present may not be a factor for other important health functions. A simple rule of thumb is that the vast majority of Atlantic salmon available on the world market are farmed (greater than 99%), whereas the majority of Pacific salmon are wild-caught (greater than 80%). Farmed Atlantic salmon outnumber wild Atlantic salmon 85 to 1.


Vitamin D is naturally produced by the human body when exposed to direct sunlight. Season, geographic latitude, time of day, cloud cover, smog, and sunscreen affect UV ray exposure and vitamin D synthesis in the skin, and it is important for individuals with limited sun exposure to include good sources of vitamin D in their diet.



Salmon flesh is generally orange to red in colour, although there are some examples of white fleshed wild salmon. The natural colour of salmon results from carotenoid pigments, largely astaxanthin but also canthaxanthin, in the flesh. Wild salmon get these carotenoids from eating krill and other tiny shellfish. Because consumers have shown a reluctance to purchase white fleshed salmon, astaxanthin (E161j), and very minutely canthaxanthin (E161g), are added as artificial colorants to the feed of farmed salmon because prepared diets do not naturally contain these pigments. In most cases the astaxanthin is made chemically; alternatively it is extracted from shrimp flour. Another possibility is the use of dried red yeast, which provides the same pigment.

Tuesday, May 19, 2009

Algae/plant


Algae (Latin "seaweeds", singular Alga) are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms. The largest and most complex marine forms are called seaweeds. They are photosynthetic, like plants, and "simple" because they lack the many distinct organs found in land plants. For that reason they are currently excluded from being considered plants.


Nutrition

Naturally growing seaweeds are an important source of food, especially in Asia. They provide many vitamins including: A, B1, B2, B6, niacin and C, and are rich in iodine, potassium, iron, magnesium and calcium.[50] In addition commercially cultivated microalgae, including both Algae and Cyanobacteria, are marketed as nutritional supplements, such as Spirulina,[51] Chlorella and the Vitamin-C supplement, Dunaliella, high in beta-carotene.

Algae are national foods of many nations: China consumes more than 70 species, including fat choy, a cyanobacterium considered a vegetable; Japan, over 20 species; Ireland, dulse; Chile, cochayuyo. Laver is used to make "laver bread" in the British Isles; in Korea, gim; in Japan, nori and aonori. It is also used along the west coast of North America from California to British Columbia, in Hawaii and by the Maoris of New Zealand. Sea lettuce and badderlocks are a salad ingredient in Scotland, Ireland, Greenland and Iceland.


The oils from some Algae have high levels of unsaturated fatty acids. For example, Arachidonic acid is very high in Parietochloris incisa, where it reaches up to 47% of the triglyceride pool.[54] Some varieties of Algae favored by vegetarianism and veganism contain the long-chain, essential omega-3 fatty acids, Docosahexaenoic acid (DHA) and Eicosapentaenoic acid (EPA), in addition to vitamin B12. Fish oil contains the omega-3 fatty acids, but the original source is algae, which are eaten by marine life such as copepods and are passed up the food chain.


Pollution control

  • Sewage can be treated with algae, reducing the need for greater amounts of toxic chemicals than are already used.
  • Algae can be used to capture fertilizers in runoff from farms. When subsequently harvested, the enriched algae itself can be used as fertilizer.
  • Algae Bioreactors are used by some powerplants to reduce CO2 emissions.

Sunday, May 17, 2009

Anchovy


There are over 27,000 species of fish, making them the most diverse group of vertebrates. However, only a small number of the total species are considered food fish and are commonly eaten.

The anchovies are a family (Engraulidae) of small, common salt-water fish. There are about 140 species in 16 genera, found in the Atlantic, Indian, and Pacific Oceans.

Anchovies are small green fish with blue reflections due to a silver longitudinal stripe that runs from the base of the caudal fin. They range from 2 centimetres (0.79 in) to 40 centimetres (16 in) in adult length, and the body shape is variable with more slender fish in northern populations.

The snout is blunt with small, sharp teeth in both jaws. The snout contains a unique rostral organ, believed to be sensory in nature, although its exact function is unknown. The mouth is larger than that of herrings and silversides, two fish anchovies closely resemble in other respects. The anchovy eats plankton and fry (recently-hatched fish).


In South East Asian countries, anchovies are known as "ikan bilis", "setipinna taty", or in Indonesia "ikan teri", with "ikan" being the Malay word for fish, or "dilis" in the Philippines. In Indonesia, Malaysia, and to a certain extent Singapore, anchovies are used to make fish stock, sambal, or deep fried. Ikan Bilis is normally used in a similar way to dried shrimp in Malaysian cuisine. Anchovy is also used to produce budu, by a fermentation process. In Vietnam, anchovy is the main ingredient to make fish sauce- nước mắm- the unofficial national sauce of Vietnam. In other parts of Asia such as Korea and Japan sun-dried anchovies are used to produce a rich soup similar to "setipinna taty". These anchovy stocks are usually used as a base for noodle soups or traditional Korean soups. There are many other variations on how anchovy is used, especially in Korea.

In the United States, anchovies are most commonly known as a pizza topping.

Anchovies can concentrate domoic acid which causes amnesic shellfish poisoning in humans, sea mammals, and birds. If suspected, medical attention should be sought. Anchovies also contain a high level of uric acid, a build-up of which can cause the inflammatory condition known as gout.

*Gout is a disease hallmarked by elevated levels of uric acid in the bloodstream. In this condition, crystals of monosodium urate (MSU) or uric acid are deposited on the articular cartilage of joints, tendons and surrounding tissues.

introducing of SEA FOOD

Seafood is any sea animal or plant that is served as food and eaten by humans. Seafoods include seawater animals, such as fish and shellfish (including molluscs and crustaceans). By extension, in North America although not generally in the United Kingdom, the term seafood is also applied to similar animals from fresh water and all edible aquatic animals are collectively referred to as seafood.

Edible seaweeds are also seafood, and are widely eaten around the world. See the category of sea vegetables.

The harvesting of wild seafood is known as fishing and the cultivation and farming of seafood is known as aquaculture, mariculture, or in the case of fish, fish farming. Seafood is distinguished from meat, although it is still animal and many vegetarians consider it to be meat. Seafood is an important source of protein in many diets around the world, especially in coastal areas.