Food authentication by PCR-based methods

Mafra, Isabel; Ferreira, Isabel M. P. L. V. O.; Oliveira, M. Beatriz P.P.

doi:10.1007/s00217-007-0782-x

Cited by 338 publications

(199 citation statements)

References 201 publications

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“…Beef biltong and dried sausage have long been considered delicacies in South Africa, however, the popularity of dried meats produced from game species has recently increased due to consumer desires for leaner foods with more exotic qualities (Hoffman, Muller, Schutte, & Crafford, 2004;Hoffman & Wiklund, 2006). Due to the high commercial value of game meats and derived products, such products are increasingly becoming targets for adulteration (Mafra, Ferreira, & Oliveira, 2008). While seven of the eight biltong samples analysed in this study were found to be correctly described with regards to species, one case of seemingly deliberate substitution involved a sample purchased as 'springbok biltong' that was subsequently identified by DNA sequencing as blesbok (Table 3).…”

Section: Discussionmentioning

confidence: 99%

A high incidence of species substitution and mislabelling detected in meat products sold in South Africa

Steinman²,

2013

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Due to their high market value, meat products are often targets for species substitution and adulteration. DNA-based methods are recognized as the most appropriate means to detect such fraudulent practices, however, these have not been extensively employed for the authentication of meat products available in South Africa. The aim of this study was to utilize a variety of molecular techniques to evaluate the extent of meat product mislabelling prevailing on the local market. A total of 139 processed meat products (minced meats, burger patties, deli meats, sausages and dried meats) were collected from retail outlets and butcheries in South Africa. The enzyme-linked immunosorbent assay (ELISA) was employed for the detection of undeclared plant proteins (soya and gluten) in the samples. A commercial DNA-based LCD array was used to screen the samples for the presence of 14 animal species, the results of which were confirmed by species-specific polymerase chain reaction (PCR) and in some cases also DNA sequencing. The results revealed that 95 of 139 (68%) samples contained species which were not declared on the product labelling, with the incidence being highest in sausages, burger patties and deli meats. Soya and gluten were identified as undeclared plant proteins in a large number of samples (>28%), while pork (37%) and chicken (23%) were the most commonly detected animal species. Unconventional species such as donkey, goat and water buffalo were also discovered in a number of products. Overall, this study confirmed that the mislabelling of processed meats is commonplace in South Africa and not only violates food labelling regulations, but also poses economic, religious, ethical and health impacts.

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Section: Discussionmentioning

confidence: 99%

A high incidence of species substitution and mislabelling detected in meat products sold in South Africa

Steinman²,

2013

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“…Since Lipkin et al (1993) showed the technical convenience of milk as a source of DNA, several PCR-based methods have been developed for authenticity assessment of dairy products, as reported by Mafra et al (2008).…”

Section: Resultsmentioning

confidence: 99%

“…12S rRNA, 16S rRNA, cytochrome b, and cox1 gene) can be detected in matrices containing a pool of heterogeneous genomic DNA, such as milk (Galimberti et al, 2013;Mafra et al, 2008). Molecular methods may be the solution as the DNA from somatic cells persists even in the ripened cheese (Plath et al, 1997) and it is also possible to extract amplifiable DNA from pasteurized, filtered, and ultrafiltered milk (Bottero et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

12S rRNA mitochondrial gene as marker to trace Sicilian mono-species dairy products

et al. 2016

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A B S T R A C TFor a rapid, specific and sensitive identification of cows', ewes' and goats' milk in mono-species Sicilian dairy products, species-specific duplex-PCR protocol was applied. DNA samples from blood and experimental cheeses of Sicilian autochthonous breeds were extracted to amplify the 12S rRNA (and part of 16S rRNA in case of Ovis aries) mitochondrial species-specific gene fragment. The use of species-specific primers for Bos taurus, Capra hircus and Ovis aries species, after electrophoresis on agarose gel, yielded fragments of 256 bp, 326 bp and 172 bp, respectively. Amplification by duplex-PCR of DNA pools from two species showed detection thresholds of 0.1% of "contaminant" DNA in each mixture. Finally, duplex-PCR assay was applied to experimental cheeses in order to detect the minimum threshold of DNA belonging to one species in cheese made with milk of two species. The results showed a sensitive threshold of 0.1% of ewes' milk in cows' and goats' cheeses, 0.1% of cows' milk in ewes' and goats' cheeses, and finally 0.1% of goats' milk in cows' and ewes' cheeses. The proposed assay represents a rapid and straightforward method of species traceability for the detections of adulteration in Sicilian mono-species dairy products.

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“…An efficient application of this method relies on the availability of an international platform, BOLD (Barcode of life database), collecting DNA barcodes to create a reference library for all living species [4]. Several PCR-based methods have been developed for authenticity assessment of dairy products, targeting β-casein gene, cytochrome b or 12S rRNA [5]. Despite PCR methods allow to amplify small concentration of DNA, even traces, food processing may cause DNA degradation.…”

Section: Molecular Markersmentioning

confidence: 99%