PREPARATION OF OILS, ENHANCED IN HIGHLY UNSATURATED FATTY-ACID (HUFA) CONTENT, BY LOW-TEMPERATURE CRYSTALLIZATION SEPARATION, FOR ROTIFER (BRACHIONUS-PLICATILIS) ENRICHMENT

The use of enrichment emulsions to increase the (n-3) HUFA content of rotifers before feeding to marine culture organisms has been shown to increase growth and survival. These emulsions require (n-3) HUFA-rich oils which are not always available. A technique for the low temperature separation of unsaturated from saturated fatty acids is described, which can be used to enrich oils otherwise poor in (n-3) HUFA. Capelin fish oil that underwent low temperature crystallization separation at -70°C for 8 h produced an enriched fraction containing 50% less saturated fatty acids and 50% more polyunsaturates (2-6 double bonds). Emulsions containing this enriched fraction were fed to rotifers and resulted in a three-fold increase in the polyunsaturates of the rotifers. © 1990.