Application of tools to identify seafood substitution

Seafood is an important source of protein for humans but is prone to substitution fraud. Substitution fraud comprises the replacement of an expensive species with a cheaper alternative, with the intent to make a financial gain. Earlier this year, The Guardian reported that, globally, 36 % of seafood samples were mislabelled. Substitution of seafood can have economical, ecological, ethical, and health consequences, as well as serve as a cover for illegal trade. It is therefore imperative that seafood substitution is properly assessed to create effective and efficient countermeasures. Here we show four DNA-based approaches, which can identify even heavily processed fish, and discuss their advantages and disadvantages.
First, we used DNA barcoding in a survey of 41 common sole (Solea solea) samples along the Belgian seafood supply chain, showcasing a substitution rate of 17 %. Second, we also applied a species-specific qPCR assay on 132 Atlantic cod (Gadus morhua) samples, which showcased a substitution rate of 3 %. Third, we designed a ddPCR-based tool to quantify Atlantic salmon (Salmo salar) DNA in multispecies food products. Application of this ddPCR tool found no substitution in the 31 Belgian and 15 Polish seafood samples. Fourth, we created a proof of concept to identify common soles in under an hour with limited lab equipment using Loop-mediated Amplification (LAMP) and fast DNA extraction. Our results demonstrate that seafood substitution is present throughout the seafood supply chain, but the rate at which fish get substituted appears to highly depend on the species. We believe that our research regarding the application and development of DNA-based techniques for the identification of seafood is valuable to those looking to carry out authentication of seafood on a large scale, and will contribute to more correct trading of fish and its products.

Jaar van publicatie:2021