1,720,983 research outputs found
Multiplex conventional and real-time PCR for fish species identification of Bianchetto (juvenile form of Sardina pilchardus), Rossetto (Aphia minuta), and Icefish in fresh, marinated and cooked products
No full textA conventional and a realtime multiplex PCR were developed to detect fraudulent substitutions of Bianchetto (juvenile form of Sardina philcardus) and Rossetto (Aphia minuta) with Icefish (Neosalanx spp.), which show similar morphological characteristics. Since it is the major by-catch species, Engraulis encrasicolus was also included in the analytical procedure. A common reverse primer and forward species-specific primer were designed on the mitochondrial cytochrome b gene to amplify sequences of different lengths by conventional PCR. Specific peaks were therefore also provided after melting temperature analysis in real-time PCR, thus enabling each species to be clearly differentiated. The two PCR methods were validated on fresh and processed products after preparing four typical dishes: two marinades (from raw or lightly boiled fish), a pasta sauce, and batter-fried fish cakes. All samples were correctly identified, although there was some DNA degradation after processing
Species identification in petfood by using BLAST analysis of a fragment of the mitochondrial 16s ribosomal RNA gene (16srRNA).
Full text linkThe aim of this work was to verify the label information of pet food for cats, reporting the commercial denomination of Bianchetto among the ingredients, by sequencing and BLAST analysis of a short fragment of the mitochondrial 16SrRNA gene. Fifteen samples of petfood for cats were collected from the retail market. Three fish per samples were
analyzed. After DNA extraction, performed according to Armani et al. (2011) (1), the DNA degradation pattern was assessed by electrophoretic analysis. On the basis of the 108 sequences available in GenBank belonging to the order Clupeiformes and Osmeriformes, four different primers were designed and used in combination with those reported in Armani et al. (2012) (2), for the amplification of short fragments of the mitochondrial 16SrRNA gene with a length ranging from 77 to 246 pb. Such fragments were preventively tested by BLAST analysis (http://blast.ncbi.nlm.nih.gov/Blast.cgi?PROGRAM=blastn&BLAST_PROGRAMS=megaBlast&PAGE_TYPE=Bl
astSearch&SHOW_DEFAULTS=on&LINK_LOC=blasthome) to assess their discriminatory power at inter and intra specific level. After PCR amplification, the samples associated to the expected amplicon were sequenced and the 45 sequences obtained were analyzed using the program Clustal W in Bioedit version 7.0.9.0 (3) and identified by BLAST analysis. The BLAST analysis returned an identity values of 100% with different species of the genus Encrasicholina. In particular, the most part of the samples were identified at the species level as E. heteroloba, and E. punctifer.
The obtained results confirms that the molecular marker selected in this study can be used for the identification of species belonging to the Clupeiformes order, allowing a discrimination even among close species. All the 15 market pet food samples were mislabeled. In fact, while the species identification performed by molecular analysis clearly showed the presence of the juvenile form of Encrasicholina sp, also known as tropical anchovies, all the labels reported the commercial denomination of Bianchetto, which, in Italy, is allowed only for the juvenile form of Sardina pilchardus (4)
Molecular characterization of icefish, (Salangidae family), using direct sequencing of mitochondrial cytochrome b gene
No full textSeafood fraud incidents control: Histological based methods as reliable tools for fresh and frozen/thawed products discrimination
Full text linkFreezing is one of the commonest methods applied for seafood shelf-life extension and long-term preservation. Nevertheless, the quality decay caused by water crystallization and cellular dehydration is responsible of significant reduction of the frozen-thawed products commercial value. Therefore, according to the European Legislation on food labelling, the declaration of freezing process represents a mandatory information for the protection of consumers’ rights. In fact, the lack of such information, besides entailing a non-conformity, can favor commercial frauds. The present work aims to present the development and validation of a histological approach, based on quali-quantitative histological markers, for the discrimination between fresh and thawed-frozen fishery products. In particular, the results of the application of the histological method on Merluccius merluccius and Octopus vulgaris, respectively selected as study models for white meat fish and cephalopods species, will be presented
Mislabeling in seafood products sold on the Italian market: a systematic review and meta-analysis
Full text linkIn this study the results of a systematic review and meta-analysis on mislabeling in seafood products sold on the Italian market are presented The aim was especially targeted to answer the research question “What is the mislabeling rate in seafood products sold on the Italian market?“. Scientific papers (SPs), were filtered using pre-determined inclusion criteria and data related to sampling and mislabeling was analysed. Samples were categorized according to their taxon (species, family order) or generic market group (MG), market form (unprocessed/processed), distribution channel and geographical area. Samples were considered mislabeled when the species found by molecular analysis did not comply the information indicated in the label. The mislabeling rate (m. r.) was weighted on the sample size and provided overall and for each category. In the 51 selected SPs (published from 2005 to 2022) the most sampled taxa were fish (83.8%): mackerels, cods, herrings, flatfishes and jacks were the most represented. Unprocessed fillet/slice was the most analysed market form (61.4%), and samples were especially collected at retails (76.5%). Ten regions were sampled, especially Tuscany and Apulia. The overall weighted m. r. was 28.4% (CI 26%–30%), falling within the m. r. range found at international level (Luque & Donlan, 2019). M. r. over the CI (>30%) were observed in 1) jellyfishes, European perch, European grouper, Atlantic mackerel and samples labeled as “spinarolo”, “baccalà” or “palombo”; 2) Unprocessed fresh, processed salted and highly processed samples; 3) small distribution channel; 4) Southern regions. Significative differences in m. r. concerned taxa, distribution channels and geographical areas. Despite some bias of the SPs may affect the results (lack of sampling plans; poor data on molluscs and crustaceans; no standardization in m. r. interpretation) this is the first systematic review and meta-analysis that, synthesizing evidence on Italian seafood mislabeling, can support policy making for minimizing frauds impacts
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Mussels (Mytilus spp.) products authentication: A case study on the Italian market confirms issues in species identification and arises concern on commercial names attribution
No full textIn November 2019, the FishLab was consulted by a wholesaler for solving an authentication issue concerning a batch of products labelled as “Chilean mussels” (Mytilus chilensis). Samples of the batch had been molecularly identified first as M. chilensis by an external private lab and, subsequently, as Choromytilus chorus through a second analysis entrusted to another external lab by the customer company. The analysis carried out at the FishLab only allowed to identify the samples to genus level (Mytilus spp.) by sequencing the mitochondrial COI gene. The amplification of the Polyphenolic Adhesive Protein (PAP) gene, a nuclear marker reported as informative for mussel, allowed to suppose the presence of M. chilensis and M. galloprovincialis based on the length of the obtained fragment. In parallel, an in silico analysis of the PAP sequences currently available on GenBank highlighted the lack of the typical mutation point in some sequences of M. galloprovincialis that were identical to those of M. chilensis. Based on a case study investigating mussel products suspected to be mislabelled, this work wants to confirm issues in molecular species identification of Mytilus spp. and highlight concerns on commercial names attribution. Results first confirmed previous scientific community opinion discouraging the use of mtDNA for Mytilus spp. identification due to both its unusual inheritance mechanism and introgression phenomena. The outcomes of the in silico analysis of the PAP sequences called into question the reliability of this marker in discriminating among M. chilensis and M. galloprovincialis. Therefore, also considering the uncertainties of the taxonomic status of these species, a proper re-evaluation process of this marker is needed. However, also the approach one species-one name, currently adopted by the Italian legislator, should be revised for solving labelling issues affecting the market
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Seafood cross-contamination by tetrodotoxin (TTX): management of an unusual route of exposure
No full textIn this study, liquid chromatography with tandem mass spectroscopy was applied to detect Tetrodotoxin and analogues (TTXs) on pufferfish (Sphoeroides marmoratus) tissues, accidentally found in the stomach of a cuttlefish (Sepia officinalis). The cuttlefish tissues were also analysed. Pufferfish (digestive tract, skin, gonads, liver/spleen, muscle) and cuttlefish (mantle, head/visceral mass) tissues were tested positive for TTXs. In pufferfish, the highest concentration of TTX was found in the digestive tract (4.94 mg/ kg), while in cuttlefish in the mantle (0.21 mg/kg). The presence of TTXs in S. marmoratus was linked to its geographical area of origin while a TTXs cross-contamination of the cuttlefish was hypothesized. Despite the European ban on pufferfish commercialization, campaigns addressed to their morphological identification by consumers and operators might improve its risk management. The risk related to TTXs cross-contamination of edible seafood such as cuttlefish might require specific control measures. Moreover, the collaboration between competent authorities and medical personnel are essential for the monitoring of human poisoning
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