Physicochemical Properties and Antioxidant Activity of Fish Oil From Indian Mackerel (Rastrelliger Kanagurta)

Fish oil is widely known for its beneficial polyunsaturated fatty acids content, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The Indian mackerel (Rastrelliger kanagurta) is an abundant marine fish living in Indonesian waters and offers excellent potential as a fish oil source. However, there have been limited studies on the specific profile of fish oil derived from this species. This study aimed to investigate the physicochemical properties and antioxidant activities of Indian mackerel fish oil. Fish oil was extracted using the wet rendering method, and oil characterization was done using proximate analysis, physicochemical analysis, and FTIR spectroscopy. The antioxidant activity was tested using the DPPH method. The Indian mackerel fish oil extracted had a lipid content of 95.93±0.042%, protein (1.285±0.177%), carbohydrate (1.986±0.143%), moisture (0.775±0.006%), and ash (0.016±0.003%). Physicochemically, this oil had FFA 1.4±0.02%, saponification value 227.46±0.71 mg KOH/g, PV 8.46±0.047 meq/kg, pAV 10.27±0.41, TOTOX 27.19±0.31. The heavy metals Cd and Pb were less than 0.01 ppm, and the Hg content was less than 0.025 ppm. FTIR spectra showed the presence of unsaturated functional groups (=C-H), alkane (-C-H), carbonyl (-C=O), and alkene (-C =C). The antioxidant activity fell into the "very strong" category, with an IC₅₀ value of 36.52±1.27 ppm. The overall results demonstrated the fish oil's favorable physicochemical characteristics and bioactivity, providing a foundation for further purification and potential applications.