Mislabeling assessment and species identification by PCR-RFLP of mussel-based products (Mytilus spp.) sold on the Italian market

The labelling compliance with EU and national legislation of market products composed of Mytilus spp. sold in Italy was evaluated. Then, a PCR-RFLP technique analyzing a region of the Polyphenolic Adhesive Protein (PAP) nuclear gene was used to support the label assessment. The technique allows to discriminate the species most commercialized in EU (M. chilensis, M. edulis, M. galloprovincialis and their hybrids). The labelling of all the products was compliant with labelling legislation (mislabeling rate 0%). The PCR-RFLP identified 17 products (47.22%) as M. chilensis, 13 (36.1%) as M. galloprovincialis, 3 (8.3%) as a mix of pure species and hybrids and 3 (8.3%) as hybrids. Hybrids were represented by M. chilensis x M. edulis, M. chilensis x M. galloprovincialis, M. edulis x M. galloprovincialis. No cases of discrepancy respect to the information reported on the labels were found in products containing pure species; in those composed by mix of pure species and hybrids or hybrids, the pure species or at least one parental species of the hybrid corresponded to that declared. Some consideration emerged: the RFLP electrophoretic pattern should be deepened in M. edulis and in other Mytilus spp.; the possibility to extend the scope of the Regulation (EU) No 1379/2013 to pre-cooked and cooked products should be evaluated; since no disposition on hybrids labelling exist, a revision of the EU lists of commercial designations is recommended, also in the light to support official laboratories in interpretating the results and issuing analysis reports.