Real-time PCR method applied to seafood products for authentication of European sole (Solea solea) and differentiation of common substitute species

Abstract

Judged by quality and taste, the European sole (Solea solea) is considered one of the finest flatfish and is, thus, of considerable commercial value. In the present work, a specific fast real-time PCR was developed for the authentication of S. solea, i.e. to distinguish it from other related species and avoid substitution of this species, either deliberately or unintentionally. The method is based on a species-specific set of primers and MGB Taqman probe which amplifies a 116-bp fragment of the internal transcribed spacer 1 (ITS 1) ribosomal DNA region. This assay combines the high specificity and sensitivity of real-time PCR with the rapidity of the fast mode, allowing the detection of S. solea in a short period of time. The present methodology was validated for application to all types of manufactured products for the presence of S. solea, with successful results. Subsequently, the method was applied to 40 commercial samples to determine whether correct labeling had been employed in the market. It was demonstrated that the assay is a useful tool in monitoring and verifying food labeling regulations.

Substitution of high-priced fish with low-priced species: Adulteration of common sole in German restaurants

“…For example, Reinhardtius hippoglossoides was often found to be labelled and marketed as common sole in Spain (Sotelo et al, 2001). In another Spanish study S. senegalensis, Microchirus azevia, and Pegusa lascaris have been identified as substitutes for common sole (Herrero et al, 2012) and Arnoglossus laterna is often used as common sole substitute in Italy (Pappalardo & Ferrito, 2015). This difference might be due to the dissimilar sampling approach as restaurant samples had not been analysed in these studies.…”

“…B enard-Capelle et al, 2015;Carvalho, Palhares, Drummond, & Frigo, 2015;Cutarelli et al, 2014;Espiñeira, Gonz alez-Lavín, Vieites, & Santaclara, 2008;Griffiths et al, 2013;Herrero, Lago, Vieites, & Espiñeira, 2012;Pappalardo & Ferrito, 2015;Stamatis et al, 2015;Warner, Timme, Lowell, & Hirshfield, 2013). However, most of these studies deal with products from supermarkets and other retail forms whereas fish and seafood is rarely sampled directly from restaurants.…”

“…High exploitation levels (Oceana, 2013) and increased worldwide consumption of common sole have resulted in a shortage of supply and increasing prices (Herrero et al, 2012;Rehbein, 2008) which is also true for a lot of other North Atlantic flatfish species ). In the last years fish from other seas (e.g.…”

Genetic system for an integral traceability of European eel (Anguilla anguilla) in aquaculture and seafood products: authentication by fast real-time PCR

“…In contrast to conventional PCR techniques, real-time PCR is a technology that has been developed recently as a technique for species authentication in food products [17][18][19][20][21][22][23][24][25]. This is a robust technique with elevated sensitivity, specificity and rapidity, and it is easily automatable.…”

Rapid method for controlling the correct labeling of products containing common octopus (Octopus vulgaris) and main substitute species (Eledone cirrhosa and Dosidicus gigas) by fast real-time PCR

“…In contrast to conventional PCR techniques, real-time PCR is a technology that has recently developed as a technique for the authentication of species in food products (Herrero, Lago, Vieites, & Espiñeira, 2011a, 2012a, 2012bHerrero, Madriñán, Vieites, & Espiñeira, 2010;Rojas et al, 2011;Trotta et al, 2005). Particularly relevant is the study (Herrero et al, 2012a) that describes a methodology for controlling the correct labeling of products containing Loligo vulgaris.…”