Lipid classes and fatty acid composition of Diplodus vulgaris and Conger conger originating from the Adriatic Sea

Lipid classes and fatty acid composition of polar (phosphatidylethanolamine, phosphatidylcholine, phosphatidylinositol, phosphatidylserine) and neutral (triglycerides) lipid fractions of common two-banded seabream (Diplodus vulgaris, L.) and sea eel (Conger conger, L.) originating from the Adriatic Sea (the Sibenik basin) were determined. Total lipid content in C. conger (3.7 +/- 0.2%) was almost three times higher than in D. vulgaris (1.3 +/- 0.2%). Polar lipids in D. vulgaris were almost twice as high (28.1 +/- 4.2%) as in C. conger (15.5 +/- 0.2%). Neutral lipids were present in higher proportions (71.9 +/- 4.2%) in D. vulgaris and (84.5 +/- 0.2%) in C. conger. The fatty acid composition of triglycerides was much more complex than those of polar lipid, fractions. There were 25 identified fatty acids in Diplodus vulgaris and 23 identified fatty acids in Conger conger muscle tissue samples. Palmitic (16:0, 20.3-63.9%), stearic (18:0, 5.5-58.7%) and oleic (18:1 n-9c, 3.8-23.1%) acid were the most abundant fatty acids in both analysed fish species, but their amounts differed significantly. Appreciable quantities of docosahexaenoic acid (DHA 22:6 n-3, 0.5-15.4%), eicosapentaenoic acid (EPA 20:5 n-3, 1.2-5.3%), arachidonic acid (20:4 n-6, 0.7-7.8%) and tetracosaeonic acid (24:1 n-9, 0.7-4.8%) were also found. EPA + DHA values were much higher in the Conger conger lipid fractions in comparison with Diplodus vulgaris lipid fractions, except for phosphatidylethanolamine. Our study points out that both fish species contain appreciable levels of n-3 polyunsaturated fatty acids and would therefore be suitable for highly unsaturated low-fat diets.