Dentex dentex Frauds: Establishment of a New DNA Barcoding Marker

Marina Ceruso,Iolanda Venuti,Paolo Sordino,Tiziana Pepe,Celestina Mascolo,Pasquale De Luca,Elio Biffali,Rosa Luisa Ambrosio,Giorgio Smaldone

doi:10.3390/foods10030580

Marina Ceruso, Iolanda Venuti + Show 7 more

Open Access

https://doi.org/10.3390/foods10030580

Copy DOI

Abstract

The common dentex (Dentex dentex (Linnaeus, 1758)) is an iconic fish in the Mediterranean diet. Due to its commercial and organoleptic importance, this sparid is highly appreciated in European markets and is often subjected to species substitution frauds. Comparative mitogenomics is a suitable approach for identifying new and effective barcode markers. This study aimed to find a molecular tag useful for unequivocally discriminating the sparid species D. dentex. The comparison of the complete mitochondrial DNA (mtDNA) sequences of 16 sparid species allowed us to highlight the potential of the NAD2 gene for direct identification purposes. Common dentex-specific primers were created and successfully evaluated by end-point and real-rime PCR (Polymerase Chain Reaction) for several fish species, achieving amplification only in the D. dentex. The method proposed in this study appears fast, simple, and inexpensive and requires affordable instrumentation. This approach provides unambiguous results for the common dentex authentication without the sequencing step. The presence/absence assay for D. dentex can be executed in a few hours of lab work. Therefore, national authorities responsible for food safety and traceability could apply and make full use of DNA-testing methods for deterring operators from false seafood declarations.

Highlights

Fish and fish products have a central role in human nutrition as they embody a source of nutrients and micronutrients with essential health benefits [1]
Fraud by substitution of valuable species with others of a lower commercial value is very common. Another reason correlated to frauds is that Sparidae whole species identification is not always achievable, even if morphological integrity is conserved [5], and becomes harder to realize after processing procedures, when typical external features are lost
The fish species other than Dentex dentex were carefully chosen with the aim to include (i) those used to substitute Dentex dentex (e.g., Dentex gibbosus), (ii) phylogenetically related sparid species (e.g., Pagellus erythrinus) [18], and (iii) other species commonly found in Mediterranean fish markets

Summary

Introduction

Fish and fish products have a central role in human nutrition as they embody a source of nutrients and micronutrients with essential health benefits [1]. Some members of the family are commercially valuable for the nutritional properties and organoleptic features of their flesh. Sparidae species have external characteristics quite similar to those of species of inferior value belonging to the same or different genera and families [3,4]. Fraud by substitution of valuable species with others of a lower commercial value is very common. Another reason correlated to frauds is that Sparidae whole species identification is not always achievable, even if morphological integrity is conserved [5], and becomes harder to realize after processing procedures, when typical external features are lost. The demand in the European market of precious fish species is increasing, so they are commonly replaced with species of minor value, raw and processed, imported from non-EU countries from around the Atlantic and Indo-Pacific Oceans

Objectives

Methods

Results

Discussion

Conclusion