DNA barcoding reveals mislabeling and commercial fraud in the marketing of fillets of the genus

摘要

The substitution and mislabeling is facilitated by the processing of fish products. We employed a DNA barcoding to authenticate fillets labeled as “dourada” (Brachyplatystoma rousseauxii), and “piramutaba” (Brachyplatystoma vaillantii) marketed in the Brazil. A 615 bp of the Cytochrome oxidase subunit I (COI) was sequenced from 305 fillets and subsequently identified to species level by querying public databases and sequences of reference species. The results revealed a global mean substitution rate of 17%. The highest substitution rate was detected in “dourada” (26%), the most valuable species, followed by “piramutaba” (9%). The most cases of substitutions were by species of lower commercial value, suggesting fraud aimed at increased profits. Therefore, we suggest the improvement of food-labeling regulation, continued inspection, as well as the adoption of the DNA barcode for the molecular authentication of processed fish to prevent substitution of these products in Brazil.