title: Fatty acids in liver, muscle and gonad of three tropical rays including non-methylene-interrupted dienoic fatty acids.
abstract: Scientific investigation of lipids in Elasmobranchs has been conducted mainly on shark species. Because rays seem to be neglected, this study was performed to examine the complete fatty acid (FA) composition with a particular interest for long-chain polyunsaturated FA (PUFA) content in different tissues of three ray species including parts usually discarded. The total FA and PUFA profiles of total lipids were determined in muscle, liver, and gonad of Rhinobatos cemiculus, Rhinoptera marginata, and Dasyatis marmorata, the most often caught ray species from the East Tropical Atlantic Ocean. Fifty FA were characterized as methyl esters and N-acyl pyrrolidides by gas chromatography/mass spectrometry, showing significant levels of 20:5n-3 (EPA) (up to 5.3%) and 22:5n-3 (DPA) (up to 7.3%), high levels of 20:4n-6 arachidonic (ARA) (4.8-8.6% of total FA) and 22:6n-3 (DHA) (up to 20.0%). The results show that muscle, liver and gonad of rays can provide high amounts of essential PUFA, specially DHA, for direct human nutrition or the food processing industry. High proportions of DHA were particularly found in all samples of R. cemiculus (11.6-20.0%), and in muscle and liver of D. marmorata (11.1-16.1%). Regarding the high amounts of (n-3) PUFA, this study shows that these rays deserve a better up-grading, including the normally discarded parts, and describes the occurrence of unusual NMID FA in all tissues studied. Five non-methylene-interrupted dienoic fatty acids (NMID FA) (0-3.4%) were reported, including previously known isomers, namely 20:2 Delta7,13, 20:2 Delta7,15, 22:2 Delta7,13, 22:2 Delta7,15, and new 22:2 Delta6,14. These acids are quite unusual in fish and unprecedented in rays. The 22:2 Delta6,14 acid occurred in gonads of male specimens of R. cemiculus at 2.9%.
authors.affiliation: Laboratoire de Phytochimie de Marseille, UMR CNRS 6171, Faculté des Sciences et Techniques de Saint-Jérôme, Université Paul Cézanne, Case 531, Avenue Escadrille Normandie-Niémen, 13397 Marseille Cedex 20, France.
authors.forename: Mohamed Vall Ould El
authors.initials: MV
authors.lastname: Kebir
authors.forename: Gilles
authors.initials: G
authors.lastname: Barnathan
authors.forename: Emile M
authors.initials: EM
authors.lastname: Gaydou
authors.forename: Yves
authors.initials: Y
authors.lastname: Siau
authors.forename: Joseph
authors.initials: J
authors.lastname: Miralles
mesh_terms: D000818:Animals; D004042:Dietary Fats, Unsaturated / Q000032:analysis; D004281:Docosahexaenoic Acids / Q000032:analysis; D005227:Fatty Acids / Q000032:analysis*; D015525:Fatty Acids, Omega-3 / Q000032:analysis; D043371:Fatty Acids, Omega-6 / Q000032:analysis; D005231:Fatty Acids, Unsaturated / Q000032:analysis; D005260:Female; D005395:Fish Oils / Q000032:analysis; D005504:Food Analysis; D008401:Gas Chromatography-Mass Spectrometry; D006066:Gonads / Q000737:chemistry*; D008099:Liver / Q000737:chemistry*; D008297:Male; D008435:Mauritania; D009132:Muscles / Q000737:chemistry*; D009792:Oceans and Seas; D010743:Phospholipids / Q000032:analysis; D012860:Skates, Fish; D013045:Species Specificity; D014329:Tropical Climate
chemical_list: D004042:Dietary Fats, Unsaturated; D005227:Fatty Acids; D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D005231:Fatty Acids, Unsaturated; D005395:Fish Oils; D010743:Phospholipids; D004281:Docosahexaenoic Acids