Positional distribution of DHA and EPA in triacyl-sn-glycerols (TAG) of Artemia franciscana nauplii enriched with fish oils ethyl esters and TAG

This paper reports the positional distribution of fatty acids in triacyl-sn-glycerols (TAG) of Artemia franciscana nauplii. The nauplii were enriched for 4 to 24 h with fatty acid ethyl esters (EE) and TAG prepared from two fish oils, bonito head oil and cod liver/mackerel oil. TAG isolated from the enriched Artemia nauplii were subjected to stereospecific analysis in order to determine the content of each fatty acid in the sn-1, sn-2 and sn-3 positions. In TAG of the enriched Artemia nauplii (24 h), docosahexaenoic acid (DHA) was esterified in the sn-3 position (5.0-35.0 mol%) in preference to the sn-1 position (0.7-7.3 mol%) and sn-2 position (1.0-10.4 mol%). Eicosapentaenoic acid (EPA) was preferentially esterified in the sn-2 position (10.2-12.8 mol%) followed in sequence by the sn-3 position (6.4-8.8 mol%) and sn-1 position (2.5-5.8 mol%). The Artemia nauplii tended to attract 18:1 and 18:0 fatty acids to the sn-1 position, EPA and 16:0 to the sn-2 position, and DHA, 22: 1, and 20:1 to the sn-3 position of their TAG. The positional distribution of fatty acids in the dietary fish oils TAG was not held in the Artemia nauplii. Once fatty acids are released from dietary fish oils EE and TAG, these fatty acids seem to be incorporated into Artemia TAG in a consistent manner independent of their origin, fish oils EE or TAG. (C) 2004 Elsevier B.V. All rights reserved.