Abstract

The composition and profile (%) of fatty acids stored in liver, muscle, and fat tissues of the fresh-water African lungfish Protopterus annectens were determined by gas chromatography. High content of total fatty acids (TFA) was found in fat (62.06 ± 3.4 g/100 g) followed by liver (50.68 ± 4.72 g/100 g) and muscle tissues (10.9 ± 0.81 g/100 g). Saturated fatty acids (SFA) formed 72.9% TFA in the liver and muscles and 53.3% in fat. Fat was rich in polyunsaturated fatty acids (PUFA), containing 31.1%, while muscle and liver contributed 12.9 and 10.6 % respectively. Fat and liver also contained, respectively, 9.59 ± 1.1 and 8.38 ± 1.9 g/100 g of monounsaturated acids (MUFA) compared to 1.56 ± 0.3 g/100 g in muscles. The major SFA were C16:0, C18:0 and C14:0. The MUFA were characterized by the Oleic (C18:1n9c) and Palmitoleic (C16:1) acids. The major PUFA in all three types of tissues was the Linoleic acid (C18:2n6c), while C20:3n6 was detected in fat only, and C18:3n3 was detected in muscles only. The n-3/n-6 ratio in the muscles was 0.5. The results of this study show that fatty acid composition in the African lungfish P. annectens can considerably vary, depending on the storage organ. According to the present results, P. annectens was considered a semi-fatty fish, storing its lipids in muscles, liver and fat tissues. These organs are potential source of essential fatty acids and may play an important role in human health. More focus on lipid extraction from P. annectens is recommended.

Key words: Fat, fatty acids, freshwater, liver, lungfish, muscle, P. annectens.