Determination of the Fatty Acid Profile in the Skins of <em>Catla catla</em> and <em>Oreochromis spp</em>. Harvested from Sorabora and Mahakanadarawa Reservoirs, Sri Lanka

This study explores the untapped potential of freshwater fish skin, historically underutilized beyond animal feed, by investigating its fatty acid profiles. Focusing on catla (Catla catla) and tilapia (Oreochromis spp.) sourced from Sri Lankan reservoirs, this study aims to extract lipids and investigate variations in composition across species and locations, highlighting the potential for valuable byproducts such as fish oil. To assess the nutritional quality of the extracted oils, proximate composition, Gas-chromatography-mass spectrometry analysis, and physiochemical properties such as Iodine Value (IV), Peroxide Value (PV), and Thiobarbituric Acid Reactive Substances (TBARS) assay were conducted to evaluate the quality. Significant differences were observed in the fatty acid contents (p <0.05) in the skins of both species, with tilapia containing 9-16% and catla containing 22-26% of crude fat. A statistically significant contrast (p<0.05) in skin ash content was observed between the catla species examined from the two reservoirs, measuring 1.18% and 0.82%, respectively. However, there were no significant differences in the physiochemical properties between the two species (p >0.05). Predominant polyunsaturated fatty acids in both fish oils included Pentadecanoic acid, Hexadecanoic acid, Docosahexaenoic acid (DHA), Eicosapentaenoic acid (EPA), Arachidonic acid, and Octadecenoic acid. In conclusion, both fish species exhibit the presence of Omega-3 and Omega-6 fatty acids in their skins, making them potential industrial resources.