Determination of the fatty acid composition of the liver oil from sting ray fish (Dasyatis sephen) captured from west cost of Jaffna peninsula in Sri Lanka

Abstract

Liver of cartilaginous chondrichthian fish comprises of poly-unsaturated fatty acids. The extraction of oil from liver of such fish remains affordable. The current study was conducted to analyse the proximate lipid profile and the chemistry of the Dasyatis sephen liver oil. Gas- Liquid Chromatography (GLC) was utilized to determine the fatty acid profiles. The lipid level of Dasyatis sephen liver oil was found to be 69.54 % (w/w) which was higher than the same from the Dasyatis pastinaca (58.27%) and Dasyatis violacea (57.33%). The total saturated fatty acid percentage was 44.2 among which palmitic acid (C16) was predominant (35.0%). Notably, unsaturated fatty acid levels of eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3) were at 0.5 % and 0.6 % respectively. Physio-chemical properties like moisture content, colour, specific gravity, peroxide value, and carboxylic acid composition were below the tolerable commonplace. Results show that Dasyatis sephen liver which is locally-available and currently wasted resource, has the potential to be used in pharmaceutical and nutraceutical industries.