Fish: Rich source of protein

Fish and seafood products, have a high nutritional value regarding beneficial amounts of protein, lipids as well as essential micronutrients.

Aquatic animal foods are a rich source of protein and currently supplies 17% of all the protein consumed in the world. Fish is also a good source of easily digestible protein, and its amino acid profile usually contains most of the essential amino acids which is required to humans for balanced diet.

A 100 g cooked serving of most types of fish and shellfish provides approximately 18–20 g of protein, or about a third of the average daily recommended protein intake.

The amount of protein in fish muscle is usually between 16 and 21 %, but values lower than 16 % or as high as 28 % are occasionally found in some species. Proteins are important for growth and development of the body, maintenance and repairing of worn out tissues. Fish is known to be a source of protein rich in essential amino acids (lysine, methionine, cystine, threonine, and tryptophan). Eighteen amino acids were identified in tuna species, and glutamic acid was the most predominant.

Aquatic animal foods have a higher protein content than most terrestrial meats. In addition, aquatic protein is highly digestible and rich in several peptides and essential amino acids that are limited in terrestrial meat proteins, as for example methionine and lysine.

In addition to the high nutritional value, fish proteins also have good functional properties such as water-holding capacity, gelling, emulsification, and textural properties for the products such as fish mince and surimi, the water-holding capacity and the gelling properties which determine the textural attributes of the products are important quality parameters.
Fish: Rich source of protein

Omega-3 fatty acids in fish

There are a lot of benefits relating fish oil to human health, especially from omega 3 fatty acids content in fish oil.

Fish that containing omega-3 fatty acids include salmon, lake trout, tuna and herring. Omega-3 also present in vegetables oils, however these acids are less effective in relation to human health. This makes fish, especially marine fish become one of the richest sources of these vitally important fatty acids.

Researches in animals have found that omega-3 fatty acids found in fish may suppress cancer formation of hinder the progression of cancer.

Omega-3 fatty acids also may reduce the risk of coronary heart disease by reducing blood pressure cholesterol, and triglycerides in the blood.

Unlike saturated fat in dairy products and meats, the fatty acids in fish have been shown in epidemiological studies to be beneficial to health. The strongest evidence for the important of omega-3 fatty acids is reduction in risk of sudden death from cardiac arrest.

Not all fish are equal in omega-3 fatty acid content. Cold water fish contain more omega-3 fatty acids than leaner, warm water fish.

Fish do not make the omega-3 fatty acids they have themselves. Rather they obtain these fatty acids from the algae that the feed on.

Omega-3 fatty acids in fish

Moisture in fish

Water is the principle component (up to 80%) of the edible portions of seafood.

Usually the oil and water content together total about 80%.

The method of storage as well as further processing, such as freezing determines the final moisture content of the fish flesh.

Considerable moisture, as well as soluble nutrients, may be lost in thaw drip. Water retention is highest in fresh fish. Finfish moisture contents generally show an inverse relationship to the lipid content.

The average percentage of moisture in raw edible flesh, summarized from various sources, is 77.2 with a range of 64.3 – 82.8%.

Raw shellfish moisture contents fall in the same range as finfish, but average is slightly higher, 80.1%.

About one fourth of the moisture can be lost during cooking, which results in concentration of other components.
Moisture in fish