DNA Barcoding Identification Exposes Mislabeled Salted Cod (Gadus spp.) Products Retailedat Porto Alegre, Brazil

Abstract

Fish fraud is a worldwide problem, mainly due to the characteristics of the production chain, which includes prior processing of fish on the ship, in addition to the morphological similarities between species. Salted cod, an important commodity imported into Brazil, is one example in which the fish ends up being morphologically mischaracterized due to both salting processes used for its conservation, and, later, due to handling by retailers. Thus, the aim of the present study was to evaluate legal aspects related to commercialization of salted cod, through the evaluation of sale presentation, label information and species involved. Collected samples were handled by retailers previously to sale. DNA barcode sequencing was used as a molecular tool in order to identify species traded under the name "cod". The target was the mitochondrial cytochrome c oxidase gene (COI). Labeling problems were observed in 91% of the analyzed products and species substitution was present in 13% of collected samples. Continuous inspection actions on products sold by retailers are important to reduce the occurrence of fraud in salted fish products.