The comparison of some ecofriendly and conventional methods of extracting common kilka oil in terms of quantity and quality

The objective of the current study was to evaluate the effectiveness of various extraction techniques, namely supercritical carbon dioxide (SC-CO2), ultrasound, and enzymatic methods, in comparison to the conventional wet reduction method, in terms of oil yield, quality attributes, and fatty acid composition in common kilka oil.

Mentioned methods were used to extract fish oil. Then, their quality oxidation, including PV, TBA, FFA, and CD, and fatty acid composition were evaluated.

The study's findings revealed that the SC-CO2 extraction method exhibited the most favorable outcome in terms of extraction yield, achieving a remarkable rate of 89.6%. The lowest oxidation indexes including PV (1.78 ± 0.19 mmol.kg-1), TBA (0.54 ± 0.03 mg MA.kg-1), FFA (35.49 ± 0.52 mg FFA.g TAG-1), and CD (7.61 ± 0.34 %) was found in oil extracted with SC-CO2 method. The fatty acid profile of oil extracted by SC-CO2 exhibited higher polyunsaturated fatty acid (PUFA) (29.81 ± 0.27) and lower saturated fatty acid (SFA) (27.64 ± 0.20) and monounsaturated fatty acid (MUFA) (34.78 ± 0.67) than those obtained by the other extraction methods (p > 0.05). The n-3/n-6, PUFA/SFA, and EPA + DHA/C16 ratios were higher for oil extracted by SC-CO2 than the other three methods.

The common kilka oil, extracted through supercritical carbon dioxide (SC-CO2), can be regarded as an abundant source of crucial polyunsaturated fatty acids belonging to the n-3 series.