Production of omega-3 concentrate from lemuru fish (Sardinella longiceps) oil by two-step urea complexation

Abstract

Lemuru fish (Sardinella longiceps) oil is a by-product containing polyunsaturated fatty acids (PUFA) that is important for the prevention of several diseases. For daily intake, saturated fatty acids should be removed from fish oil to obtain PUFA concentrates. Various methods have been observed in producing omega-3 concentrates. The objective of this study was to produce the omega-3 concentrate from lemuru fish oil using a two-step urea complexation method and to characterize the omega-3 product. Lemuru fish oil was saponified and purified to produce fatty acids and urea was added to the fatty acids to obtain crystal complexes. In this study, crystallization was carried out at -20 °C for 24 h with an oil-urea ratio of 1:0.625, 1:1.25, and 1:2.5. The results showed that the highest content of omega-3 (ALA, DHA, EPA) was reached at a ratio of fish oil-urea of 1:0.625. Based on the FTIR spectrum analysis, omega-3 concentrate contained the specific spectrum indicated by HC=CH trans, -C=O (ester), and -C-O (acid) groups. UV-Vis spectra analysis showed that light exposure affected the stability of omega-3 concentrate, as is evident by the hypsochromic shift of the resulting spectrum.