Development of a method for the identification of scombroid and common substitute species in seafood products by FINS

In the present work, a method for the authentication of scombroid products was developed, by means of FINS (Forensically Informative Nucleotide Sequencing) technique (Polymerase Chain Reaction (PCR) followed by phylogenetic analysis). The methodology developed allows the identification of most important scombroid species using the mitochondrial cytochrome b as molecular marker. Due to the different commercial value of the species belonging to this family, substitutions between species in seafood products can take place. Several methodological strategies allow the authentication of scombroid species in all kind of products, from fresh fish to canned products, the more usual format for marketing such species. This analytical system was validated and subsequently applied to 20 commercial samples labelled as tuna, bonito, mackerel and frigate tuna, obtaining three that were incorrectly labelled (15%). Therefore, this technique can be used as a routine method to avoid the mislabelling in the marketing of scombroid species and it is also suitable to assess the correct seafood traceability of these products.