Cod Liver Oil

COD LIVER OIL

Biological Source

It is processed from fresh liver of cod fish, Gadus morrhua and other species of Gadus, belonging to family Gadidae.

Geographical Source

It is mainly found in Scotland, Norway, Germany, Iceland, and Denmark.

Preparation

The liver is cleaned and minced into small pieces and heated to 80°C in a vat by admitting steam for half an hour. The enzyme lipase is destroyed at temperature above 70°C. The oil is removed and put in tin drums which are encased with wooden barrels. The barrels are kept inside the snow and the oil is cooled to -2 to -5°C, the slow cooling process precipitates the palmitin, which is separated by filtration. The oil obtained is medicinal oil. The residual cake formed after the medicinal oil is subjected to heating at higher temperature to obtain oil with inferior quality and brown colour.

Characteristics

The oil is pale yellow in colour; it has fishy odour and taste. Cod liver oil is slightly soluble in alcohol and fully soluble in chloroform, ether, carbon disulphide and petroleum ether. Specific gravity: 0.922–0.929, Refractive index: 1.475–1.4745, Acid value is less than 2, Iodine value 155–173. The oil should be stored in well-filled airtight containers, protected from light, and kept in a cool place.

                         Cod fish (Gadus morrhua)

Chemical Constituents

The cod liver oil contains glycerides esters of saturated acids of linoleic, oleic, myristic, gadoleic, palmitic, and other acids. The oil has vitamin A and vitamin D. Cod liver oil also contains about 1% unsaponifiable matter; like cholesterol, fatty alcohol, squalene, α-glyceryl esters, etc.

Uses

Oil is used as source of vitamins, in treatment of rickets, tuberculosis, and also as a nutritive.