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a b s t r a c tThe morphological similarity among Sparidae species, which are characterized by a different market price, represents a serious problem for their trade and for stock management, since it encourages frauds for substitution. The most accredited morphological method for their identification is based on the dental-plate, but this approach is not simple and cannot be used for prepared products. When molecular methods are used the DNA degradation induced by cooking is the main drawback. In this work, we collected 314 reference tissues belonging to 75 Sparidae species and we produced a dataset of full (FDB) and mini-barcode (MDB) reference sequences starting from DNA extracted from fresh and ethanolpreserved tissues using universal primes. Moreover, some fresh samples were cooked. The FDB was successfully amplified in 91% (fresh), 50% (cooked) and 81% (ethanol-preserved) samples, while the amplification rates of the MDB were considerably higher in case of cooked (100%) and ethanol-preserved (94%) samples. The same primers were used for the amplification of the DNA obtained from 58 market samples (MS). All the DNA barcodes were compared with BOLD and GenBank using IDs and BLAST analysis. FDB was able to provide unambiguous species-level identifications for 53 (78%) and 44 (64.7%) reference samples analyzed on BOLD and GenBank, respectively. The Mini-DNA barcode (MDB) showed a lower discriminating power with 32 (45.7%) and 29 (41.4%) sequences unambiguously matched to a species on BOLD and GenBank. However, the MDB allowed to identify all the reference sequences as belonging to the Sparidae family. FDB and MDB showed a similar performance in analyzing the MS, allowing to highlight 21 (38%) mislabeled MS. Our study, while confirming the FDB as a reliable tool for fish authentication, proposes the MDB as a promising tool to recover molecular information in case of cooked products.

Fatty acid composition and stable isotope ratios of carbon (delta(13)C) and nitrogen (delta(15)N) were determined in muscle tissue of turbot (Psetta maxima). The multivariate analysis of the data was performed to evaluate their utility in discriminating wild and farmed fish. Wild (n=30) and farmed (n=30) turbot of different geographical origins (Denmark, The Netherlands, and Spain) were sampled from March 2006 to February 2007. The application of linear discriminant analysis (LDA) and soft independent modeling of class analogy (SIMCA) to analytical data demonstrated the combination of fatty acids and isotopic measurements to be a promising method to discriminate between wild and farmed fish and between wild fish of different geographical origin. In particular, IRMS (Isotope Ratio Mass Spectrometry) alone did not permit us to separate completely farmed from wild samples, resulting in some overlaps between Danish wild and Spanish farmed turbot. On the other hand, fatty acids alone differentiated between farmed and wild samples by 18:2n-6 but were not able to distinguish between the two groups of wild turbot. When applying LDA isotope ratios, 18:2n-6, 18:3n-3, and 20:4n-6 fatty acids were decisive to distinguish farmed from wild turbot of different geographical origin, while delta(15)N, 18:2n-6, and 20:1n-11 were chosen to classify wild samples from different fishing zones. In both cases, 18:2n-6 and delta(15)N were determinant for classification purposes. We would like to emphasize that IRMS produces rapid results and could be the most promising technique to distinguish wild fish of different origin. Similarly, fatty acid composition could be used to easily distinguish farmed from wild samples.

Filter feeders, like mussels and clams, are suitable bioindicators of environmental pollution. These shellfish, when destined for human consumption, undergo a depuration step that aims to nullify their pathogenic microorganism load and decrease chemical contamination. Nevertheless, the lack of contamination by drugs may not be guaranteed. Antimicrobials are a class of drugs of particular concern due to the increasing phenomenon of antibiotic resistance. Their use in breeding and aquaculture is a major cause of this. We developed a multiclass method for the HPLC-MS/MS analysis of 29 antimicrobials, validated according to the Commission Decision 2002/657/UE guidelines, and applied it to 50 mussel and 50 clam samples derived from various Food and Agricultural Organisation marine zones. The results obtained, indicate a negligible presence of antibiotics. Just one clam sample showed the presence of oxytetracycline at a concentration slightly higher than the European Union Maximum residue limit set for fish. The topic of antibiotic resistance drives more and more the search for contaminants in food towards this class of pharmacological compounds. Although bivalve molluscs are bred offshore, where the antibiotics, eventually illicitly used, could undergo a drastic dilution, these filter-feeding animals, may constitute a means for the bio accumulation of antimicrobials and the distribution through the food chain from the aquatic environment to consumers. We used a validated multiclass method for the HPLC-MS/MS analysis of 29 antimicrobials, and the results of our work are very reassuring for the consumer indicating a very low presence and frequency of antibiotics in the edible tissue of mussels and clams; at the same time it could be hypothesized that the illegal treatment takes place in the purification stage prior to sale.The provenience of the molluscs from various FAO marine areas, even if mostly from the Mediterranean Sea, could be an added value of the study, also accounting that the samples were collected at the Milan fishery market, which supplies all Italy, so being a verisimilar representation of the molluscs consumed by Italian people.Before the submission, the British English was checked and revised by Proof-reading.com. Italy PS; after your request we referenced the 10% similarities you found with iThenticate. The citations were two: all belonging to our research group and dealt with Materials and Methods. This was an imprecision but, as an excusatory, we did not try to auto-cite at any cost. Obviously we added in references the two works We are very grateful to Editor for the opportunity to improve our research and to the reviewers for their helpful comments. We carefully followed their suggestions as well as the Food Chemistry author guidelines in order to make the manuscript more clear and as complete as possible. Therefore, the manuscript was managed as indicated by the reviewers and the editor. A professional English editor carefully revised the manuscript.We hope that the reviewer's suggesti...