Lipid content and fatty acid composition of freshwater eels Anguilla japonica caught in different seasons and locations in South Korea

The objective of this study is to determine the lipid content and fatty acid composition of Anguilla japonica caught in South Korea. Seventy-nine eels caught at four different locations in different seasons were analyzed. Lipid content (1.3-30.0% of muscle weight) was more affected by season than by the location where the fish were caught, being the highest among the eels caught in May. Lipid content was higher in cultured eels than in wild eels. The predominant fatty acids in the eels were C18:1n-9 (24.4-33.0% of the total detected peak areas), C16:0 (17.7-22.0%), C16:1n-7 (7.0-10.2%), C22:6n-3 (2.4-6.8%), C18:1n-7 (2.9-6.2%), C18:2n-6 (0.6-6.1%), C20:5n-3 (1.5-5.1%), C14:0 (2.4-5.1%), C18:0 (3.4-4.5%), and C20:4n-6 (1.0-2.9%). Most fatty acids showed significantly more difference by location than by season. Cultured eels had significantly more saturated fatty acids (31.6-32.9%) and less monounsaturated fatty acids (42.5-43.3%) than wild eels (26.4-28.1% and 44.5-48.0%, respectively). Among the wild eels, estuarine eels had more n-3 fatty acids (12.2 and 14.8%) than lake eels (8.7-12.1%). Principal component analysis showed that the fatty acid composition could be an effective variable to classify fish according to the location where they were caught.