Monthly changes in fat composition of Kahla (Saddled bream)‎ ‎(Oblada melanura) Caught from western Libyan coast (Tripoli)‎

Abstract

This study was carried out to investigate monthly changes in lipid composition of Kahla (Saddled ‎bream) (Oblada melanura) from the Libyan coast. Samples of fresh Kahla were collected in the early ‎morning once every month at the end of the four studied months directly‏ ‏from fishing boats and from ‎wholesale stores in fish market at Tripoli Marine Fishing Port. Edible parts of Morgan tissues were ‎minced and used for lipid extraction using a mixture of chloroform methanol. Cholesterol content was ‎assessed and fatty acids were identified both quantitatively and qualitatively in a part of extracted lipid. ‎The remaining part was separated by chromatographic column into neutral lipids and phospholipids, ‎which their compositions of fatty acids were identified using gas – liquid chromatography technique. ‎The total lipid, neutral lipids, phospholipids and cholesterol contents ranged between 1.78–6.40% ‎‎(g/100g meat), 64.22–91.97% (g/100g lipid), 9.92–36.40% (g/100g lipid) and 109–262 (mg/ 100 g ‎meat) respectively. Statistical analysis indicated a significant difference at p< 1% between the contents of ‎total lipids, neutral lipids, phospholipids and cholesterol in the months of study. The results of this study ‎also showed a significant correlation between the total lipid content and cholesterol. Results of ‎cholesterol and results of polyunsaturated fatty acids indicated a monthly variation in their contents of ‎‎(w-3 PUFA). The percentage of Deccosahexanoic acid (C22:6) in all Kahla samples was higher than the ‎percentage of Ecosapentaenoic acid (C-20:5). Palmitic acid was dominant in saturated fatty acid group of ‎all lipid‏ ‏‎ classes .The average total percentages of W-3 PUFAs (C18:3, C20:5 and C22:6 ) in total lipids, ‎neutral lipids and phospholipids were 19.00%, 12.69%, and 8.65% as a percentage of total fatty acids ‎respectively.‎

Key words: phospholipids Kahla, neutral lipids, cholesterol, polyunsaturated fatty acids.‎