Extraction, Refining and Purification of ω-3 PUFA through Different Techniques – A Review

Poly unsaturated fatty acids (PUFA) are the important nutritional constituents of human diet and also used to characterize the quality of oils. The purified omega-3 fatty acids can be produced in the free fatty acid, simple alkyl ester and triacylglycerol forms. To achieve this, physical, chemical and enzymatic techniques may be employed. Supercritical fluid extraction, urea adduction, chromatography, enzymatic splitting and others. Traditionally, fatty acids have been analyzed by means of GC. The main problem in the GC separation of free fatty acids (FFAs), is their low volatility (especially those of high-molecular weight) and their high polarity (mainly hydroxy fatty acids). These causes peak tailing and it’s necessary to use high temperatures, which leads to the thermal degradation of certain polyunsaturated FAAs. Competent and economical techniques of enriching the level of omega-3 fatty acids will continue to be needed in order to reduce the cost and to meet the future demand for highly purified omega-products. HPLC, Supercritical fluid chromatography and other chromatographic techniques avoid the problems of thermal degradation but the main drawback sometimes is poor resolution for complex mixtures and low sensitivity. The purpose of this review is to clarify different techniques for extraction, refining and purification of ω-3 PUFA from raw oil to up to final ω-3PUFA.