South African pilchard oil. 2. Concentrates of highly unsaturated fatty acids and alcohols derived from South African pilchard oil

Abstract

The urea complex fractionation and lithium soap-acetone techniques were applied to the segregation of a concentrate of highly unsaturated fatty acids from the body oil of the South African pilchard. For comparison, the alcohols resulting from lithium aluminium hydride reduction of pilchard glycerides were also fractionated by the urea complex method. A comparison was made between the unsaturated concentrates prepared by each procedure. The urea complex method affords an excellent stepwise fractionation resulting in a concentrate of high average unsaturation rich in the shorter C16 and C18 chain lengths. The lithium soap-acetone procedure affords a concentrate of lower average unsaturation than does the urea method, but the segregate is relatively richer in the longer C20 and C22 chain lengths. Urea fractionation of total pilchard fatty alcohols affords a concentrate of high average unsaturation rich in the C18 and C20 chain lengths.