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This paper (open access) reports a survey of 62 retail samples of processed whitefish products from British, Italian and Albanian retailers (mainly high-street supermarkets).  24 samples, spanning all regions, were reported as mislabelled using the criteria below.

The researchers used Next Generation Sequencing following DNA extraction using commercial kits.  Full details of the primers are given in the paper.  They prepared in-house positive and negative controls by blending various proportions of white fish species (from whole, identifiable, fillets) that are not used in commercial fish product manufacturing into mixtures of “authentic” species.

Since commercial designations of seafood species vary greatly both across and within countries, the researchers compared the ingredients provided for each product to the official list of commercial designation of the country where the product was purchased.. If a common name was declared on the label, the relevant species name was obtained searching FishBase , while if a scientific name was provided, it was contrasted directly with the molecular results.

Using matches and mismatches between label information and DNA-based identification, the researchers classified the examined products into the following categories: (i) “green” (correctly labelled product): when the proportion of reads of the declared species was at least twice as large as the second most abundant species and constitutes the majority of the bulk; (ii) “amber” (misleading product): when the proportion of the declared species was higher than any other species, but not necessarily amounting to the majority of the bulk; (iii) “red” (mislabelled product): when the declared species was either absent or not the most abundant in the mix; (iv) “grey” (undetermined product): when the declared species couldn’t be genetically identified with certainty.

The modern food industry is a rapidly evolving sector with complex supply chains that utilises a wide variety of analytical tools to support food integrity and authenticity.

Next Generation Sequencing (NGS)-based approaches represent an emerging analytical technology that is growing within the food sector, providing  the potential to not only screen and test input materials, but also the production process and end products. 

Photo by Braňo on Unsplash

This questionnaire is part of a UK Department for Environment, Food and Rural Affairs (Defra) funded project tasked with reviewing the application of NGS technology to food authenticity testing and supporting harmonisation and the development of standards for NGS approaches applicable to the verification of food authenticity. The questionnaire is targeted at individuals involved in the food and associated diagnostics sectors, including technology developers, suppliers and official controls.

Your participation in this questionnaire will directly help inform the direction of the project and contribute to guidance within the sector.

Please do not provide any information that could be used to identify you. Thank you for participating in our questionnaire which should only take around 15 minutes to complete. Your feedback is important.

Access questionnaire.

UK National Measurement Laboratory at LGC

In this study, the Thermo Scientific™ NGS Food Authenticity Workflow was used to analyse spices and herbs.  

Reference samples were analysed to verify the specificity, and spikings down to 1% (w/w) allowed verification of its sensitivity including in complex mixtures of five different spices and/or herbs. 

272 commercial samples were collected in Asian and European markets.  78% of the commercial samples were compliant with the declared content, whereas the rest were shown to contain undeclared species that were in a few cases allergenic or potentially toxic. 

The researchers conclude that the overall workflow is user-friendly and straightforward, which makes it simple to use and facilitates data interpretation.

Access abstract.

 Photo by Ratul Ghosh on Unsplash

Photo by Alice Pasqual on Unsplash

Foreword by the Government Chemist

Next Generation Sequencing (NGS) is a powerful tool for rapidly and cost-effectively identifying and characterising plant, animal and microbial species present in mixed food samples.

The application of NGS to food authenticity, adulteration and safety testing is a constantly evolving field with its own unique set of challenges that need to be explored. Further work needs to be conducted to better understand the performance characteristics and establish relevant performance criteria and metrics, to enable results generated in different laboratories to be compared and interpreted with equal confidence.

Following concerns raised from food industry members on the use of NGS for the quantitative determination of food ingredients, the Government Chemist engaged with Defra’s Authenticity Methodology Working Group (AMWG) [1] and its Technical Sub-Group (AMWG-TSG), resulting in the AMWG producing a view [2] on the use of NGS for food authenticity testing [3].

Download Defra’s Authenticity Methodology Working Group’s view on the use of Next Generation Sequencing for food authenticity testing

[1] An independent expert group that provides scientific and technical advice to support Defra’s food authenticity programme.

[2] The views/opinions expressed by AMWG were correct at the time of the note (November 2020).

[3] Government Chemist representatives: Selvarani Elahi, Deputy Government Chemist, is the Chair of AMWG and Dr Malcolm Burns, Head of GMO unit, Principal Scientist and Special Advisor to the Government Chemist, is a Member of AMWG; they both participated in the AMWG-TSG meeting on NGS and subsequent discussions, inputting into the AMWG view on NGS.