PCR-based methodology for the authentication of grouper (Epinephelus marginatus) in commercial fish fillets

Single nucleotide polymorphism-based methodology for authentication of bovine, caprine, ovine, camel, and donkey meat cuts

To guarantee food safetyand sustainability, it is necessary to verify meat authenticity. This study focused on the development of single nucleotide polymorphism-based polymerase chain reaction-restriction fragment length polymorphism (SNP-based PCR-RFLP) and forensically informative nucleotide sequence (FINS) methodologies based on PCR amplification of the mitochondrial 12S rRNA gene for discrimination of six red meat species, that is, cattle, buffalo, goat, sheep, camel, and donkey. FINS allowed the unambiguous identification of all species analyzed. In addition, six SNPs, where a restriction site for TasI could be localized using a preliminary in silico analysis, gave a unique RFLP pattern for each species. The results revealed a low level of species substitution (8%) in the tested meat samples. In particular, one buffalo and goat samples have been substituted with cow and sheep, respectively. Finally, the developed techniques herein showed high potentials to be routinely used as reliable and fast tools to avoid meat species substitutions. PRACTICAL APPLICATION: This research deals with genetic techniques to trace meats. This kind of research helps the concerned agencies to build capacity to safeguard consumer sentiments as well as providing better market access and better food price and quality for the consumer.

Development of a MALDI-TOF MS-Based Protein Fingerprint Database of Common Food Fish Allowing Fast and Reliable Identification of Fraud and Substitution

Fish substitution and fish fraud are widely observed in the global food market. To detect and prevent substitution, DNA-based methods do not always meet the demand of being time- and cost-efficient; therefore, methodology improvements are needed. The use of species-specific protein patterns, as determined by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry, has recently improved species identification of prokaryotes both time- and cost-wise. We used the method to establish a database containing protein patterns of common food fish prone to substitution. The database currently comprises 54 fish species. Aspects such as the sensitivity of identification on the species level and the impact of bacterial contamination of fish filets are assessed. Most database entries are characterized by low intraspecies but high interspecies variability. Hitherto, 118 validation samples were successfully determined. The results presented herein underline the potential and reliability of eukaryotic species identification via MALDI-TOF mass spectrometry.

Molecular identification of Atlantic goliath grouper Epinephelus itajara (Lichtenstein, 1822) (Perciformes: Epinephelidae) and related commercial species applying multiplex PCR

ABSTRACT The Atlantic goliath grouper, Epinephelus itajara , is a critically endangered species, threatened by illegal fishing and the destruction of its habitats. A number of other closely related grouper species found in the western Atlantic are also fished intensively. While some countries apply rigorous legislation, illegal harvesting followed by the falsification of fish products, which impedes the correct identification of the species, is a common practice, allowing the catch to be marketed as a different grouper species. In this case, molecular techniques represent an important tool for the monitoring and regulation of fishery practices, and are essential for the forensic identification of a number of different species. In the present study, species-specific primers were developed for the Cytochrome Oxidase subunit I gene, which were applied in a multiplex PCR for the simultaneous identification of nine different species of Epinephelidae: Epinephelus itajara , E. quinquefasciatus , E. morio , Hyporthodus flavolimbatus , H. niveatus , Mycteroperca acutirostris , M. bonaci , M. marginata , and M. microlepis . Multiplex PCR is a rapid, reliable and cost-effective procedure for the identification of commercially-valuable endangered fish species, and may represent a valuable tool for the regulation and sustainable management of fishery resources.

Advances in DNA-based techniques for the detection of seafood species substitution on the commercial market

Increased worldwide trade and processing of seafood has increased the potential for species substitution on the commercial market. To detect and prevent species substitution, several deoxyribonucleic acid (DNA)-based methods have been developed that can be used to identify species in a variety of food types. For large-scale applications, such as regulatory screening, these methods must be rapid, cost-effective, reliable, and have high potential for automation. This review highlights recent technological advances in DNA-based identification methods, with a focus on seafood species identification in automated, high-throughput settings. Advances in DNA isolation methods include silica-based columns for use in high-throughput operations and magnetic bead particles for increased and targeted recovery of DNA. The three most widely used methods for seafood species identification (polymerase chain reaction [PCR] sequencing, PCR-restriction fragment length polymorphism, and species-specific PCR) will be discussed, with a focus on the incorporation of technologies such as rapid PCR cycling, microfluidic chips, and real-time PCR. Emerging methods, including DNA microarrays and next-generation sequencing will also be explored for their potential to identify seafood species on a large scale. Overall, many of the technological advances discussed here offer complementary properties that will enable species identification in a variety of settings and with a range of products.