As heart diseases and diabetes continue to rise in the country in recent years owing to wealth and lifestyle change ( Al-Kaabi and Atherton 2015), promotion of healthy proteins and fats from seafood is of vital importance. For instance, although Qatar is surrounded by waters on three sides, historically seafood is not as favored as red meats and chicken by the residents. Relatively few studies are observed in other countries even where good aquatic resources are available, including North Africa and the Middle East. However, most of the current studies are concentrated in North America, Europe, and Pacific Asian countries. With DNA barcoding using the cytochrome c oxidase gene (COI) and the establishment of databases on DNA-based taxonomy (Barcode of Life Databases or BOLD) for fishes and other aquatic animals, seafood authentication has been a reality and has been adopted by researchers and regulatory agencies worldwide (e.g., Hanner et al. However, such techniques had limitations including the inability to distinguish among some species because of low specificity ( Carrera et al. In the past, immunological techniques, e.g., ELISAs, have been used for the identification of certain proteins in seafood products. Furthermore, mislabeling may encourage unlawful poaching of endangered species, which adds an environmental aspect to this issue. This may pose serious health risks if the substitutes are of banned species containing high levels of heavy metals or organic pollutants ( Focardi 2012) or with undisclosed allergens. Being a high value and high demand food type, seafood is rife with incidents of substitution (e.g., Golden and Warner 2014 Harris et al. Market substitution of processed food, herbal medicine, and fresh and frozen seafood have raised international awareness. Le faible taux d’erreur dans l’étiquetage des échantillons est peut-être dû à la forte réglementation locale des aliments, laquelle réglementation pourrait avoir entraîné une forte concordance entre les étiquettes des emballages et leur contenu. Deux des espèces substituées étaient de grande valeur, tandis que la troisième espèce avait été remplacée par une autre également de faible valeur. Parmi 62 emballages d’un seul type de poisson ayant produit des séquences connues, seuls trois étaient mal identifiés, soit un taux d’erreur de 5 %. Les séquences obtenues ont été comparées à celles contenues dans le système BOLD (« Barcode of Life Databases ») et analysées par une recherche BLAST sur les bases de données du NCBI. Un mélange de huit amorces, avec des extensions M13 et conçues pour l’identification des espèces de poissons, a été employé pour faciliter la PCR et le séquençage. La présente étude porte sur les poissons frais ou minimalement transformés (filets) disponibles dans huit grandes chaines de supermarchés au Qatar. Ailleurs, y compris les pays du Moyen-Orient et de l’Afrique du Nord, les études de ce genre sont rares. Dans l’identification des fruits de mer, les études ont surtout porté sur l’Amérique du Nord, l’Europe et l’Asie. Le codage à barres de l’ADN a permis d’authentifier diverses espèces employées en tant qu’aliments ou pour des fins médicinales. The relatively low rate of mislabeling in the samples is perhaps a result of strict local food safety regulations, which may have led to high consistency between the package labels and their contents. Two of the substituted species are high value items while the third species was replaced by another, equally low-cost species. Among the 62 unique fish packages with resolved sequences, only three are confirmed to be mislabeled, at a rate of about 5%. Sequences were compared with those available in the Barcode of Life Databases (BOLD Systems) and BLAST in NCBI databases. A cocktail of eight primers attached with M13 tails established for fish species identification was adopted to facilitate PCR and sequencing. This study focuses on packaged fresh or minimally processed fish fillet available at eight major supermarket chains in Qatar. Elsewhere, including countries in the Middle East and North Africa, studies of this sort are scarce. In the identification of seafood species, studies are concentrated in North America, Europe, and Asia. DNA barcoding technique has made it possible to authenticate various species used for food and medicinal purposes.
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