Authentication of canned fish packing oils by means of Fourier transform infrared spectroscopy

•ATR-FTIR to assess the genuineness of the packing media of canned fish.•PLS-DA can differentiate olive oil from seed oils regardless the type of fish canned.•Sunflower oil cannot be differentiate from oils labeled as “vegetable oil”.•No interfering effect from fish lipid transference has been observed. The authentication of packing oil from commercial canned tuna and other tuna-like fish species was examined by means of attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and chemometrics. Using partial least squares discriminant analysis (PLS-DA), it was possible to differentiate olive oil from seed oils. Discrimination of olive oil from high-oleic sunflower oil was possible, despite the latter having a degree of unsaturation more similar to olive oil than to sunflower oil. However, in the samples analyzed, sunflower oil could not be differentiated clearly from those labeled with the generic term “vegetable oil”. Furthermore, the authentication of extra virgin olive oil, although more difficult, could be achieved using ATR-FTIR spectroscopy. The method could be applied regardless of fish type, without interference from fish lipids.