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The presence of biogenic amines (histamine, tyramine, putrescine, and cadaverine) in seafood is a significant concern for food safety. This review describes for the first time a shotgun quantitative proteomics strategy to evaluate and compare foodborne strains of bacteria that produce biogenic amines in seafoods. This approach recognized 35,621 peptide spectrum matches, belonging to 20,792 peptides, and 4621 proteins. It allowed the determination of functional pathways and the classification of the strains into hierarchical clusters. The study identified a protein-protein interaction network involving 1160 nodes/10,318 edges. Proteins were related to energy pathways, spermidine biosynthesis, and putrescine metabolism. Label-free quantitative proteomics allowed the identification of differentially regulated proteins in specific strains such as putrescine aminotransferase, arginine decarboxylase, and l-histidine-binding protein. Additionally, 123 peptides were characterized as virulence factors and 299 peptide biomarkers were selected to identify bacterial species in fish products. This study presents the most extensive proteomic repository and progress in the science of food biogenic bacteria and could be applied in the food industry for the detection of bacterial contamination that produces histamine and other biogenic amines during food processing/storage.

Adulteration and mislabeling of food products and the commercial fraud derived, either intentionally or not, is a global source of economic fraud to consumers but also to all stakeholders involved in food production and distribution. Legislation has been enforced all over the world aimed at guaranteeing the authenticity of the food products all along the distribution chain, thereby avoiding food fraud and adulteration. Accordingly, there is a growing need for new analytical methods able to verify that all the ingredients included in a foodstuff match the qualities claimed by the manufacturer or distributor. In this sense, the improved performance of most recent DNA-based tools in term of sensitivity, multiplexing ability, high-throughput, and relatively low-cost give them a game-changing role in food-authenticity-related topics. Here, we provide a thorough and updated vision on the recently reported approaches that are applying these DNA-based tools to assess the authenticity of food components and products.

A proteomic approach aimed at species identification and taxonomic analysis of shrimp species of commercial interest is presented. Six different species belonging to the order Decapoda were considered. Preliminary, two-dimensional gel electrophoresis (2-DE) analysis of the sarcoplasmic proteome revealed interspecific variability in the isoelectric point (pI) of arginine kinase. For this reason, arginine kinase spot was selected as a potential molecular marker and subjected to tryptic digestion followed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) peptide mass fingerprinting (PMF) analysis. Arginine kinase PMF allowed the differentiation of the six species studied. Four samples of commercial origin obtained in local markets were analyzed to validate the methodology. The PMF cluster analysis also provided information about the phylogenetic relationships in these species. The application of this methodology may be of interest for the differentiation and taxonomic analysis of shrimp species complementing DNA-based phylogenetic studies.

The molecular identification of several strains of Campylobacter jejuni and Campylobacter coli involved in foodborne disease was carried out by investigating the restriction profiles of their chromosomal DNA and by DNA/DNA hybridization. Cleavage with EcoRV allowed the visualization of a 3 kb DNA fragment characteristic of C. jejuni, whereas restriction with ClaI allowed the identification of a 9.3 kb DNA fragment, also characteristic of C. jejuni, and a DNA duplet of 9.5-10 kb, specific to C. coli. Restriction analysis with enzyme BglII allowed the visualization of DNA fragments of 3.5, 4, and 6.7 kb, characteristic of C. jejuni. C. jejuni subsp. doylei strains investigated shared a higher genetic homology among themselves-as determined by DNA/DNA hybridization-than with C. jejuni subsp. jejuni. A DNA probe, initially designed by Korolik et al. (Korolik, V.; Coloe, P. J.; Krishnapillai, V. J. Gen. Microbiol. 1988, 134, 521-529), including a DNA fragment encoding an antigenic membrane protein of 31.5 kDa in C. jejuni, when used as probe, allowed the specific identification of all strains of C. jejuni through the detection of strong hybridization signals in two BglII DNA fragments of 2.3 and 2.5 kb, which were not observed in C. coli. Cleavage of chromosomal DNA with BglII-either alone or coupled with probing assays with specific probes-proved to be a valuable tool for the speciation of Campylobacter isolates involved in foodborne disease.