Effect of Deodorization Methods on Physico-Chemical and Fatty Acids Properties of Refined Milkfish (Channos Channos) By-Product Oil

Milkfish oil possesses beneficial properties for human health due to its composition of omega-3 fatty acids, which are essential fatty acids, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). EPA and DHA are long-chain unsaturated fatty acids susceptible to oxidation and produce compounds that cause odors from oil degradation. Ultrasound-assisted extraction was performed for 68 min at 84 °C with a solvent-to-sample ratio of 3:1 mL/g using d-limonene as a bio-solvent to extract milkfish by-product oil. One of the crucial stages in the oil refining process is deodorization. In this study, several deodorization techniques were used, including liquid-liquid extraction (LLE), steam distillation (SD), and solid-phase adsorption using activated carbon (AC), zeolite (ZT), bentonite (BT), and diatomite (DT). Refined milkfish by-product oil during refining with the deodorization method showed significant differences in physical-chemical characteristics, nutrition, and saturation levels compared with crude oil. The LLE method can significantly reduce the acid and peroxide values and maintain the composition of omega-3 fatty acids. The low temperature used in LLE can prevent the oxidation and degradation of oil. The LLE and solid-phase adsorption method is beneficial because it is low-cost, efficient, and easy to use in milkfish oil deodorization.