Characterisation of the lipid component of seafood products based on chromatography-mass spectrometry techniques has been reported as a promising approach to differentiate farmed from wild-type products. In this study, Italian researchers used a fast method based on Direct Analysis in Real Time (DART) coupled to High Resolution Mass Spectrometry (HRMS) based on a single stage Orbitrap mass analyser, integrated by Principal Component Analysis (PCA), to discriminate wild-type from farmed salmon of Salmo salar species. Obtaining the 30 most intense signals (all referred to fatty acids, FA) detected in negative ion DART-HRMS spectra of the lipid extracts of salmon fillets [26 wild-type from Canada, 74 farmed from Canada (25), Norway (25) and Chile (24)] were considered as the variables for PCA. In agreement with other studies, three saturated (14:0, 16:0 and 18:0) FA, along with unsaturated ones having 20 or 22 carbon atoms, were found as the main discriminating variables for wild-type salmons, whereas FA with compositions 18:1, 18:2, 18:3 and several oxidised forms arising from them were found to have a significantly higher incidence in farmed salmon. The methodology was tested against 6 samples of farmed Norwegian salmon, which were all correctly classified.
Read the abstract here