Stability of omega-3 fatty acids - deep fat frying mackerel

Stability of polyunsaturated omega-3 fatty acids during deep fat frying of Atlantic mackerel (Scomber scombrus L.)
 

J.L. Sebedio^a, W.M.N. Ratnayake^{, b, *}, R.G. Ackman^b and J. Prevost^a

INRA, Station de Recherches sur la Qualité des Aliments de l'Homme, Unité de Nutrition Lipidique, 17 rue Sully, BV 1540, 21034 Dijon, France
Technical University of Nova Scotia, CIFT, PO Box 1000, Halifax, Nova Scotia, Canada B3J 2X4

Received 24 July 1992; 

Accepted 2 November 1992. 

Available online 22 September 2003.

Abstract

Fall-caught Atlantic mackerel (Scomber scomburus L.) were cut transversely into steak sections and deep fat fried for 7 min in canola oil at 180°C. A total of 20 batches, each consisting of 10 randomized steak sections with approximately 12%, total fat, was fried over 10 days.

The longer-chain omega-3 polyunsaturated fatty acid content of the mackerel was not affected by deep frying. Only small quantities of polar components, polymers and geometrical fatty acid isomers of the long chain highly polyunsaturated fatty acids were formed during deep frying.

Examination of the fatty acid composition of the frying medium, the fish skin, and the meat showed extensive lipid exchanges between the fish and the frying medium. Of the major isomers of eicosapentaenoic acid formed by thermal action 20:5Δ5c,8t,11c,14t, 17c was less then 0·1% of the total 20:5 recovered from the used canola oil.

Keywords: heated fat; omega-3 fatty acids; polymers; polar components; gas liquid chromatography; eicosapentaenoic acid; eicosapentaenoic acid geometrical isomers

The work was executed at both INRA and CIFT.