Some of the major fish product of India are as follows:
Fishes, besides being used as edible material, also gives some important substances in the form of fish products which are listed below:
Perhaps it is the most important fish product as it has an important medicinal value.
Oils can be extracted both from whole fish as body oil and from liver as liver oil. Body oil is used for both edible and industrial purposes whereas liver oil, being a rich source of vitamin A is exclusively of medicinal values, Fish oil contains cholesterol, other alcohols in the unsaponifiable matter include pigments, vitamin A and D, glycerol ethers and fatty alcohols. Vitamin E may be present in small form. Sardine, salmon, herring, mackerel, anchovy, white fish and cat fishes are important for fish oil.
Fish liver oil is very rich in Vitamin A and Vitamin D. The percentage of two main constituents of liver i.e., oil and Vitamin A varies in different fishes. For example cod, halibut and hammer-headed shark yield oil 60-75%; 4-28% and 25-75% respectively and vitamin A potencies varies from 500—20,000 iu/g; 25,000—6,00,000 iu/g and 3,00,000 iu/g respectively. Besides vitamin A and oil, Vitamin D, Vitamin E, hydrocarbons, cholesterol, pigments, fatty alcohols and glycerol ethers are found in liver.
For extraction of liver oil, healthy and undiseased liver is cut into small pieces and boiled with sufficient quantity of water. The oil which accumulates on the surface is decanted off. This oil is further boiled with water and filtered. The filtered material is dehydrated with anhydrous sodium sulphate. Later on, the pharmaceutical establishment puts them under refining and standardisation before they are brought to market. Besides this, several other techniques are also employed for the extraction.
For extraction of body oil from oil rich fishes, the flesh is crushed to a pulp and cooked with steam in a continuous vertical and cylindrical cooker. The cooked material is regularly pressed to extract the oil. The oil which along with other body materials comes to the surface is decanted and later on centrifuged to separate the oil.
The waste materials left after extraction of oil and the flesh of non-oily fishes are dried in sun or inflame driers at high temperature. This is used for feeding cattle, pigs, poultry birds and also used as manure in coffee, tea and tobacco plantation. Horse mackerels, mackerel and sardines which are unfit as food are good as fish meal.
It is similarly prepared as fish meal but here the fishes used are of high nutritive value and are fit for human consumption. Fish flour is rich in protein and easily digestible. It is to be used along with wheat or maize flour. Addition of more than 10% fish flour with other edible flour may not be acceptable to all due to its disagreeable taste, but a lesser amount does not bring any change to the taste.
By treating the flesh of fish with hydrochloric acid and fumic acid a semi-solid material is formed which is called fish silage. It is used as fish meal with better nutritional values as most of the vitamin constituents are retained here.
The residual part of the liquid which comes out during extraction process of fish oil is known as fish soluble and is used as animal diet. It is rich in protein and vitamin В complex.
In China and Philippines the sharks fin except the caudal one are used in soup.
Due to the presence of a large number of amino acids and Vitamin А, В, С etc., the roes of several fishes are used as food. They are also used in manufacturing of glue and synthetic fibres.
It is a water soluble strong, flexible, adhesive substance required for court plaster stamps, for book binding and for repairing of shoes. It is prepared by grinding the fish bone and skin and later on treating them in steam jackets for 6—12 hours along with certain amount of water and acetic acid. The liquid is separated out and changed to concentrated forms.
It is obtained from swim or air bladder of different fishes by scraping the outer portion and sun drying the inner part. Isinglass as a gelatinous substance is used for clarification of wine, beer and vinegar. It is also used for the preparation of special grade cement and plaster.
Skin of large sized fishes such as shark and rays, after tanning, are used for the manufacture of shoes, handbags etc.
India has an abundant marine and inland resource, perhaps one of the richest in the world. Japan tops the list of fish producing countries of the world, seconded by Peru. India stands between seventh and ninth position. India’s total annual production in 1950 was 0.817 million tones which reached the highest in 1970 at 1.845 million tones. Although it is difficult to estimate the inland fish production, the rough idea given by different states and by the reports on the marketing of fish in India shows that 1951 annual production of 218.0 thousand times had reached its height in 1969 with 693.2 thousand tones.
It, however, declined slightly as the annual production of 1972 was 665.8 thousand tones. State wise data shows that West Bengal is at the top of the list in both annual production and the average production of ten years followed by Tamil Nadu and Andhra Pradesh. Bihar is trailing at fifth-sixth position. The Indian Council of Agricultural Research has established the Central Inland Fisheries Research Institute (CIFRI) with several pilot projects in different parts of India.
India exports the preserved fish and fish products to several countries like U.K., U.S.A, Mauritius, West Germany, Ceylon, Singapore and Burma. The annual return in the form of foreign exchange exceeds six crores in term of rupees. Certain fish products especially cod liver oil has been imported from U.K, Norway, U.S.A, Italy and West Germany.