Effects of frying in various cooking oils on fatty acid content of farmed rainbow trout (Oncorhynchus mykiss)

Authors: FLASKERUD, KATRINA - University Of Minnesota; Picklo, Matthew; Bukowski, Michael; Raatz, Susan

Submitted to: Federation of American Societies for Experimental Biology Conference
Publication Type: Abstract Only
Publication Acceptance Date: 2/1/2016
Publication Date: 4/1/2016
Citation: Flaskerud, K., Picklo, M.J., Bukowski, M.R., Raatz, S.K. 2016. Effects of frying in various cooking oils on fatty acid content of farmed rainbow trout (Oncorhynchus mykiss) [abstract]. Federation of American Societies for Experimental Biology Conference. April 1-6, 2016, San Diego, California. 30:1163.7.

Interpretive Summary: Our goal was to describe the effects of frying with various oils on the fatty acid content of rainbow trout. Four different oils were evaluated (peanut oil, high oleic sunflower oil, corn oil, and canola oil). Farmed rainbow trout (Oncorhynchus mykiss) fillets were sliced into three portions and each section was trimmed to a 50 g piece for cooking and a 5g raw portion. Fillets were individually cooked with each of the oils (peanut oil, high oleic sunflower oil, corn oil, and canola oil) in an electric frying pan until the core temperature reached 63'C (145'F). The sample was set aside until cool to the touch and then re-weighed. After frying, both raw and fried samples were frozen at -80'C until processing for analysis. Frozen samples were pulverized, and lipids were extracted from the samples using a Folch extraction. The total fatty acids of the samples were determined by gas chromatography after the fatty acids were converted to fatty acid methyl esters. Frying in high oleic sunflower oil provided the greatest difference in fatty acid composition with a significantly decreased 14:0, 16:0, 18:0, 18:2 n-6, 18:3n-3, 20:5n-3, 22:5n-3, and 22:6n-3. 14:0 and 18:3n-3 were significantly lower in fish fried in peanut oil, when compared to raw fish. There was no significant difference between the fatty acid concentrations raw fish compared to fish fried in corn oil or canola oil. Peanut oil reduced the 14:0 and 18:3n-3 content of the fish. Frying in high oleic sunflower oil caused the greatest changes in fatty acid content of the fillets.

Technical Abstract: Our goal was to describe the effects of frying with various oils on the fatty acid content of rainbow trout. Four different oils were evaluated (peanut oil, high oleic sunflower oil, corn oil, and canola oil). Farmed rainbow trout (Oncorhynchus mykiss) fillets were sliced into three portions and each section was trimmed to a 50 g piece for cooking and a 5g raw portion. Fillets were individually cooked with each of the oils (peanut oil, high oleic sunflower oil, corn oil, and canola oil) in an electric frying pan until the core temperature reached 63'C (145'F). The sample was set aside until cool to the touch and then re-weighed. After frying, both raw and fried samples were frozen at -80'C until processing for analysis. Frozen samples were pulverized, and lipids were extracted from the samples using a Folch extraction. The total fatty acids of the samples were determined by gas chromatography after the fatty acids were converted to fatty acid methyl esters. Frying in high oleic sunflower oil provided the greatest difference in fatty acid composition with a significantly decreased 14:0, 16:0, 18:0, 18:2 n-6, 18:3n-3, 20:5n-3, 22:5n-3, and 22:6n-3. 14:0 and 18:3n-3 were significantly lower in fish fried in peanut oil, when compared to raw fish. There was no significant difference between the fatty acid concentrations raw fish compared to fish fried in corn oil or canola oil. Peanut oil reduced the 14:0 and 18:3n-3 content of the fish. Frying in high oleic sunflower oil caused the greatest changes in fatty acid content of the fillets.