Metabarcoding-based authentication of ethnic foods in the context of official control activities in Italy

Ethnic foods, increasingly consumed in Italy, often raise concerns regarding labelling compliance and traceability. A total of 62 pre-packed ethnic products (PPs), collected in the Latium and Tuscany regions in the context of official control activities and analysed by the Competent Authority using a validated and accredited method (DNA microarray), was re-analysed using a metabarcoding approach based on Next Generation Sequencing (NGS) technologies. The PPs included animal-based PPs (n = 37) and plant-based PPs (n = 25). Two primer pairs targeting the 16S rRNA region were selected after evaluating their taxonomic coverage based on literature data. A mislabelling rate (only assessed qualitatively) of 78.4 % was observed among animal-based PPs, with discrepancies due to undeclared species (MIS-A), missing declared species (MIS-B), or both, while DNA belonging to animal species was found in all plant-based PPs (100 %) (MIS-A). Notably, undeclared allergenic species were detected, namely fish in 18 PPs (29.0 %) and molluscs (squid or scallop) in 10 PPs (16.1 %). Although the results do not constitute official control data, they demonstrate the value of metabarcoding in strengthening surveillance efforts, particularly for the screening of complex food products. Integrating advanced molecular techniques, into official control frameworks could substantially enhance monitoring capacities, enabling more effective risk assessment and fraud prevention.