An investigation on the fatty acids, cholesterol and fat-soluble vitamin levels in the gonads of Salmo trutta macrostigma (Dumeril, 1858) caught from Munzur stream, Tunceli

In this study, the levels of fatty acids, cholesterol and fat-soluble vitamins (A, D, E and K) in the gonads of Salmo trutta macrostigma (Dumeril, 1858) caught in the Munzur Stream in Tunceli before spawning (September-October), during spawning (November-December) and post-spawning (January-February) were evaluated. The fish caught by cast net (200 fish with an average weight of 149.8 (89.35-429.0) g and average length of 23.39 (20.13-32.0) cm) were transported in ice to the Firat University Faculty of Fisheries, where their weights and lengths were measured. The gonads (ovaries and testes) were weighted to calculate the gonadosomatic index. Samples were taken for chemical analyses. The age of the fish were determined by counting the age rings in the vertebrae. Stearic acid had the highest level within the saturated fatty acids. The differences in the levels of stearic acid before, during, and after spawning periods was insignificant (P>0.05). Palmitoleic acid was the dominant mono unsaturated fatty acids. The differences in the levels of palmitoleic acid before and after spawning periods was insignificant (P>0.05). However before and during spawning there was a significant difference (P<0.05). The dominant poly unsaturated fatty acids were eicosapentaenoic and docosahexaenoic acids. The differences in the levels of eicosapentaenoic acid before, during and after spawning periods was insignificant (P>0.05). For docosahexaenoic acid, the differences in the levels before and during spawning was insignificant, however the levels during and after spawning there was a significant difference (P<0.05). The highest level among the fat-soluble vitamins was observed for ?-tocopherol, where the differences in levels before and during spawning were insignificant (P>0.05) while those during and after spawning were significant (P<0.05). Cholesterol levels showed insignificant differences during and after spawning (P>0.05), while those before and during spawning were significant (P<0.05).