Differentiation of Fish Oils According to Species by ¹³C‐NMR Regiospecific Analyses of Triacyglycerols

Abstract

Abstract The aim of this study was to use 13 C‐nuclear magnetic resonance (NMR) regiospecific analyses of triacylglycerols to distinguish fish oils from different fish species for authentication purposes. 13 C‐NMR data of muscle lipids from Atlantic salmon ( Salmo salar L .) , mackerel ( Scomber scombrus ) and herring ( Clupea harengus ) were obtained, and the distribution of omega‐3 polyunsaturated fatty acids between the sn‐1,3 and sn‐2 glycerol chains calculated from the carbonyl region. The results show that there were significant differences in the sn‐2 position specificity of the fatty acids 22:6n‐3, 20:5n‐3 and 18:4n‐3 among the species investigated. The most pronounced difference was that herring had a higher proportion of its 22:6n‐3 in the sn‐2 position compared to the two other species. Principal component analysis of data points in the carbonyl‐region showed that there were also differences in the level and regiospecific distribution of monounsaturated/saturated fatty acids, which made it possible to distinguish oils of these three species solely from the carbonyl region of 13 C‐NMR spectra.