Türkiye Sularında Avlanan Engraulis Encrasicolus (Linnaeus, 1758)’Un Kas Dokusu Yağ Asidi Kompozisyonunun Lokasyona ve Mevsime Göre Değişimi
Özet
Within the scope of the presented thesis, seasonal and locational changes in the fatty acid content of the muscle tissue of European anchovy (Engraulis encrasicolus) captured from the Black Sea and Marmara Sea in Turkey were investigated. Fish muscle samples taken monthly from each location during the fishing season were analyzed by gas chromatography (GC). It is aimed to contribute to the nutritional value researches in terms of health in aquatic products by determining the changes in fatty acid composition of anchovy muscle depending on different locations and catching seasons. According to the results of gas chromatography, palmitic acid has the highest percentage of saturated fatty acid in muscle tissue during all fishing months for both the Marmara Sea and the Black Sea. Total saturated fatty acid ratio was highest in March with 29.89% in Marmara population, and lowest in December with 19.43%. In the Black Sea, these rates were 25.52% (December) and 16.22% (January). Statistically significant differences were observed in the total SFA (saturated fatty acid) ratio for both populations in monthly comparisons (p<0.05). The total MUFA (Monounsaturated fatty acid) percentages for the Marmara and Black Sea populations ranged between 23.78 - 24.93 and 16.06 - 23.57, respectively. In the Black Sea, C18:1 n-9 was dominant in ΣMUFA in December and May, while C16:1 was dominant in November, January, February and March. In Marmara population, C18:1 n-9 was dominant in ΣMUFA in November and March, while C16:1 was dominant in December. No statistically significant difference was observed between the catching months for both populations in the total MUFA ratio. It has been determined that European anchovy contains significant amounts of DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid) in all catching seasons and locations. DHA levels were higher than EPA in both Black Sea and Marmara anchovy during all fishing months. A statistical difference (p<0.05) was observed in ΣPUFA (polyunsaturated fatty acid) percentages in Black Sea anchovy in November, February and March, however the percentages were found to be statistically similar in December, January and May. In Marmara anchovy, on the other hand, no statistical difference was observed in ΣPUFA percentages during the catching season. Average ΣPUFA percentage differed for Black Sea and Marmara (p<0.05), and was found to be higher in anchovy caught in Marmara Sea. The percentages of ∑PUFA and ∑n-3 were directly proportional to the sea water temperature in both the Black Sea and the Marmara Sea in this study. In the Black Sea population, a directly proportional relationship was found between the Fulton’s condition factor and n-3 PUFA, and it was determined that the n-3 PUFA percentages were also high in the months when the Fulton’s condition factor was high. The n-3/n-6 ratio varied statistically throughout the entire fishing season in the Black Sea.
