[Essential fatty acids of the n-6 and n-3 series supplied to human diet by edible fish from the Paraná river].

The fatty acid composition of muscle lipids from eadible fish from Paraná river such as Dorado (Salminus maxillosus), Boga (Leporinus affinis), Patí (Luciopimelodus pati) and Surubí (Pseudoplatistoma coruscans) was studied in order to determine their food value in relation to essential fatty acid n-3 and n-6 supply. Flesh from these fishes is relatively lean and its lipids only contain 35% to 38% saturated fatty acids. Significant amounts of n-6 polyethylenic acids, mainly linoleic, arachidonic and the n-3 acids, docosahexaenoic, docosapentaenoic, eicosapentaenoic and alpha-linolenic are found in these fishes. Patí flesh is the most abundant in n-6 acids with a value of 306 mg/100 g muscle, followed by Boga, Dorado and Surubí. A large proportion of n-3 acids is supplied by muscles of Dorado, 183 mg/100g muscle, followed by Patí, Boga and Surubí. More than 90% of the lipids that supply these acids are present in triacylglycerols in Dorado, Boga and Patí. In Surubí, triacylglycerols constitute 60% and the remaining lipids are phospholipids. Cholesterol content in flesh of fresh water fish was analyzed, and it did not exceed 4.7 micrograms/g muscle for Patí, being lower for the other species studied. Fish considered in this work represent a good dietary source of polyunsaturated fatty acids either n-6 or n-3 series for the mediterranean population in our country.