Shark Liver Oil
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Shark liver oil is the fixed oil obtained from the fresh and healthy livers of shark fish Hypoprion brevirostris, belonging to family Carcharhinidae.
SHARK LIVER OIL
Synonyms
Oleum selachoide.
Biological Source
Shark liver oil is the fixed oil obtained from the fresh and
healthy livers of shark fish Hypoprion
brevirostris, belonging to family Carcharhinidae.
Geographical Source
Shark is found on seacoasts of many European countries and
in India in Tamil Nadu, Maharashtra, and Kerala.
Preparation
Livers are removed from the fish, cleaned thoroughly, freed
from fatly substances, and attached tissues like gallbladders. Then the livers
are heated in water at about 80°C. The oil exudes, floats on the top, and is
separated, washed and water is removed. The dehydrated oil is cooled to separate
stearin. The suspended materials are removed by centrifugation. The oil is
supplemented with vitamins A and D in desired amount.
Characteristics
Shark liver oil is pale yellow to brownish yellow, viscous
liquid with fishy odour, and bland taste. It is insoluble in water, sparingly
soluble in alcohol and freely miscible in nonpolar solvents such as petroleum
ether, chloroform, and benzene. Its acid value is about 2, saponification value
150–200, and iodine value 160–350.
Chemical Constituents
The active principle of Shark liver oil is vitamin A which
varies from 15,000 to 30,000 I.U. per g of the oil. It contains glycerides of
saturated and unsaturated fatty acids.
Chemical Tests
A solution of shark liver oil (1 drop) in chloroform (1 ml)
is treated with sulphuric acid (1 drop). A violet colour changing to purple or
brown is formed due to the presence of vitamin A.
Shark liver oil (1 ml) is dissolved in chloroform (10 ml).
Few drops of saturated solution of antimony trichloride in chloroform are added
to the solution. A blue colour is formed due to the presence of vitamin A.
Uses
Shark liver oil is used to treat xerophthalmia (abnormal
dryness of the surface of conjunctiva) occurring due to deficiency of vitamin
A. The oil is nutritive and used as a tonic.
Marketed Products
It is one of the ingredients of the preparation known as
Shark liver oil softgels (Now Foods).
