CONCENTRATION AND STABILIZATION OF N-3 POLYUNSATURATED FATTY-ACIDS FROM SARDINE OIL

A simple and relatively inexpensive procedure to obtain 90% eicosapent aenoic acid + docosahexaenoic acid concentrates from sardine oil invol ved a two-step winterization of the oil (10 and 4 degrees C), followed by saponification and selective precipitation of saturated and less u nsaturated free fatty acids by an ethanolic solution of urea. Antioxid ant effects of butylated hydroxytoluene, dl-alpha-tocopherol and two n atural antioxidants, quercetin and boldine, added to the concentrate ( 0.5% wt/vol), were compared in the Rancimat at 60 degrees C. dl-alpha- Tocopherol was unable to inhibit concentrate oxidation. Butylated hydr oxyanisole and butylated hydroxytoluene had induction periods of 1.7-1 .8 h compared to the control (1.0 h). A mixture of quercetin + boldine (2:1 w/w) significantly increased the induction period to 4.5 h.