Determination of fatty acid composition, cholesterol and fat-soluble vitamin levels of Capoeta trutta, Luciobarbus mystaceus and Luciobarbus esocinus procured from Keban dam lake Aydincik (Elaziğ) region

In this master's thesis, fatty acid composition, n-3/n-6 fatty acid ratio, cholesterol and fat-soluble vitamin levels in the muscle tissue of commercially important freshwater fish Luciobarbus esocinus, Capoeta trutta and Luciobarbus mystaceus, which live in the region of Aydıncık, Keban Dam Lake were investigated. Fatty acid methyl esters were analyzed by gas chromatography, and cholesterol and fat-soluble vitamin levels were analyzed by high-performance liquid chromatography (HPLC). Six of each fish species were used for analysis. Among the saturated fatty acids (SFA), palmitic acid (C16:0) was determined to be the highest amount, while palmitic acid (C16:0) was determined as 18.07% and 19.39%, respectively, in C. trutta and L. mystaceus, and the difference between them was not statistically significant (P>0.05). Among the monounsaturated fatty acids (MUFA), oleic acid (C18:1 n-9) and palmitoleic acid (C16:1 n-7) were found to have the highest amounts. Total MUFA amount (%) was determined as 33.93, 24.57 and 31.75 in L. esocinus, C. trutta and L. mystaceus, respectively. Among polyunsaturated fatty acids (PUFA), eicosapentaenoic acid (EPA, C20:5n-3) was found to be statistically significantly higher (P<0.05) in C. trutta compared to the other fish species (14.84%), while the highest amount of docosahexanoic acid (DHA, C22:6n-3) was determined in L. mystaceus (20.43%). While the highest level of total n-3/n-6 PUFA ratio was determined for C. trutta with 4.64%, it was determined that the sum of EPA and DHA from n-3 series fatty acids was statistically significantly higher in C. trutta with 31.74%. (P<0.05). On the other hand, there was no statistical difference between species in terms of arachidonic acid (P>0.05). When the fat-soluble vitamin and cholesterol levels of the species were compared, it was seen that the difference between the amounts of δ-tocopherol, α-tocopherol, D3, K1, K2 and cholesterol did not differ statistically between the species (P>0.05). Vitamin D2 and retinol levels (5.22μg/g and 3.66 μg/g, respectively) were observed to be higher in L. mystaceus than in other species. The thesis study carried out showed that these fish species in Keban Dam Lake are a valuable food source in terms of fatty acids, n-3/n-6 PUFA, PUFA/SFA ratio, vitamin amounts and cholesterol. In conclusion, this thesis showed that L. esocinus, C. trutta ve L. mystaceus living in Aydıncık region of Keban Dam Lake are a valuable food source in terms of fatty acids, n-3/n-6 PUFA, PUFA/SFA ratio, vitamin amounts and cholesterol.