Detection of fish species substitution frauds in Italy: A targeted National Monitoring Plan

Abstract Fighting food frauds is a ceaseless challenge because of the constant evolution of fraudulent practices and for the consequences both on consumers’ and on globalized trade. In Italy fish is a vulnerable commodity for frauds thanks to the high national production, importation and consumption and it is important to monitor the entire food chain in order to detect and prevent fraudulent actions, such as species substitutions, which is considered the most common fraud in seafood. Aim of this study was to realise a targeted Monitoring Plan to estimate the prevalence of fish species substitutions in Italy. As a first step, Italian fish supply chain, from production to selling, was analysed, in order to identify products and chain points at risk, by reviewing literature and by involving, in two focus groups, food inspectors and representatives of the large scale food distribution system. Then a monitoring plan was designed by sampling three fish species considered at major risk for their economic value and/or large consumption, i.e. tuna, grouper and flat fishes, at different selling points (wholesale markets, retail markets, fish shops and supermarkets). From February to March 2017, 242 samples from fresh, frozen or transformed whole fishes or fillets were sampled in 13 Italian cities (5 in Northern Italy, 2 in Central Italy, 3 in Southern Italy and 3 in the main Islands). Samples were analysed by “FINS” (Forensically Informative Nucleotide Sequencing), using two markers: cytochrome oxidase subunit I gene ( COI ) as first option and then mitochondrial cytochrome B gene ( cytb ), if necessary to identify uncertain or unassigned samples. Species substitutions were uncovered in 8.7% of analysed samples, principally related to grouper (prevalence of 14.71%). Supermarkets resulted the selling points with a major number of frauds (prevalence of 12.79%). Substituted species were taxonomically related to those declared on the label and no species harmful for consumers were detected. Results obtained can give to National Authorities a detailed frame of trends in fish substitution frauds in Italy, providing also relevant information to put into effect control measures.