Cooking and pressing is an effective and eco-friendly technique for obtaining high quality oil from Sardinella longiceps

The conventional Bligh and Dyer method of extracting oil from the edible tissues of Sardinella longiceps was compared with different eco-friendly methodologies using 40% ethanol, 95% ethanol, distilled water, and cooking followed by pressing, as well as cooking followed by the Bligh and Dyer method. Among the different methods studied, cooking followed by pressing showed a beneficial effect on the quality of the oil as evidenced by reduced saponification (209.8 mg KOH/g), peroxide (11.88 meqO­2/kg), para-anisidine (16.2), total oxidation (39.96), and TBARS (6.18 MDAEQ/kg) values. A comparable lipid yield (8.3%) with that of the Bligh and Dyer method was attained through the cooking and pressing method. The greater induction time (0.13 h) indicated better oxidative stability of cooked and pressed oil as compared to the oil obtained using other methods. The fish oil obtained by cooking followed by pressing has been demonstrated to yield comparable amounts of eicosapentaenoic acid, docosahexaenoic acid, and total polyunsaturated fatty acid contents when compared to the Bligh and Dyer method. These results demonstrated the effectiveness of the cooking and pressing technique for obtaining the best quality oil from Sardinella longiceps. The oil obtained by the cooking and pressing mode was characterized by FTIR and NMR experiments