Evaluation of the chemical composition of fish oil: a by-product from fish processing plants
Bulletin of the Sea Fisheries Institute 1 (155) 2002, pp. 38-46

Zbigniew Dobrza�ski1, Piotr Bykowski2, Zbigniew Iwaniuk3,
Zygmunt Usydus2, Helena G�recka4 and Tadeusz Trziszka1

1Agricultural University of Wroc�aw, Marii Sk�odowskiej-Curie 42, 50-369 Wroc�aw, Poland
2Sea Fisheries Institute, Kołłątaja 1, 81-332 Gdynia, Poland
3"Agro-Fish" Ltd., 84-111 Karlikowo, Poland
4Wroc�aw University of Technology, Smoluchowskiego 25, 50-372 Wroc�aw, Poland

Key words: fish oil, chemical composition, organic-inorganic contamination.

Abstract.
This study evaluated the chemical properties of fish oil derived from the fish processing industry. Its manufacturing technology was jointly developed by the Sea Fisheries Institute in Gdynia and Big-Fish Ltd. in Gniewino. The acid contents of this oil are as follows: unsaturated fatty acids n 82.72%; polyunsaturated fatty acids n 35.59%; omega-3 - 17.04%; Cl - 0.23%; Ca - 0.047. The following are also present (in mg/kg): Mg - 24.6; Na - 37.57; P - 51.8; Zn - 220; Fe - 15.33; Al - 14.43; Se - 7.62. Twenty other trace elements are found in this product. Vitamins are present in the following concentrations (in IU/g): A - 458; D3 - 240; E - 1.21. The concentrations of organic chlorine pesticides, polychlorinated biphenyls and toxic metals (As, Cd, F, Hg, Pb) were within permissible ranges. This fish oil meets the general criteria for animal feed ingredients. It is, however, essential to determine its optimal nutritional rations.