Determination of the Seasonal Changes on Total Fatty Acid Composition of Rainbow Trout, Oncorhynchus Mykiss in Ivriz Dam Lake, Turkey

Total fatty acid compositions and seasonal variations of Oncorhynchus mykiss in Ivriz Dam Lake, Turkey were investigated using gas chromatographic method. A total of 38 different fatty acids were determined in the fatty acid composition of rainbow trout. Polyunsaturated fatty acids (PUFAs) were found to be higher than saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs) in all seasons. Oleic acid (C18:1 omega 9) is the major MUFA in all seasons. Palmitic acid (C16:0) was identified as the major SFA in four seasons. Docosahexaenoic acid (C22:6 omega 3), linoleic acid (C18:2 omega 6) and eicosapentaenoic acid (C20:5 omega 3) had the highest levels among the PUFAs. In the present study, omega 3 /omega 6 ratios were found to be 1.24, 1.68, 0.61 and 0.98 in spring, summer, autumn and winter, respectively.