Discrimination of Cod Liver Oil According to Wild/Farmed and Geographical Origins by GC and ¹³C NMR

Abstract

Abstract The objective of this study was to test the possibility of using lipid profiles obtained by gas chromatography (GC) and 13 C nuclear magnetic resonance (NMR) in authentication of cod liver oils according to wild/farmed and geographical origin. GC and 13 C‐NMR data of cod liver oil from wild and farmed fish from different locations in Norway and Scotland were obtained, and analyzed by principal component analysis (PCA) and linear discriminant analysis (LDA) to test if it was possible to differentiate oil from wild and cultured cod ( Gadus morhua L.), and to further elucidate differences between fish from the different farms/catch area. Cod liver oils of wild and farmed origin were clearly separated in the PCA score plot both from GC and NMR data. From NMR data it was also possible to observe groupings based on geographical origin (farm/catch area) of the different samples. Using LDA with cross validation the wild/farmed classification rates were 97% for GC data and 100% for NMR data. In the classification of cod liver oils according to geographical origin (38 samples from six different farms/catch area), the correct classification rate was 63% for GC data and 95% for NMR data.