Preparation of highly purified ω-3 docosapentaenoic acid from seal oil via urea complexation combined with preparative high performance liquid chromatography

Docosapentaenoic acid (DPA) derived from seal oil was concentrated by urea complexation and purified by preparative high performance liquid chromatography (pre-HPLC). A Box-Behnken Design (BBD) combined with response surface methodology (RSM) was applied to optimize urea complexation conditions. The maximum concentration of DPA (12.75%) with the yield of 48.54% were obtained at the FFA/Urea ratio of 1:3.7 (g/g) and crystallized at 1.3°C for 17.5 h. The concentrates were further fractionated by isocratic elution with the mixture of methanol and 0.1% aqueous phosphate on a C18 column, giving rise to a DPA purity to 93.12% with the yield of 38.37%. The present study could provide useful information and the highly purified products would contribute their beneficial effects for food and nutraceutical applications.