Multiple fish species identified from China's roasted Xue Yu fillet products using DNA and mini-DNA barcoding: Implications on human health and marine sustainability

Abstract

Roasted fish fillet (Fig.1) represents a popular snack food in China and a preliminary analysis of the label found only fish common names, without any reference to a particular species (Table 1). Since there is still not a harmonization around the definition of these common names in China, retailers are thus induced to mislabel roasted fish fillet products for lucrative profits. This study used direct sequencing method based on fragments of 16S rRNA gene and subsequent BLAST analysis to investigate the species composition of roasted fish fillet products circulated on Chinese market. An exclusive criterion was defined to determine the labeling accuracy and only the identified species beyond the expected family was considered as mislabeling. Results highlighted an inadequate enforcement of relative rules and a high mislabeling rate of 75.9%. A worse fact was the identification of multiple fish species not only from several packages under the same common name, but also from several specimens belonging to a single package. In order to protect the consumers from economic loss and even health risk, we recommended the amendments to the existing legislations and the compilation of list of acceptable market names for fish species in China.

Development of conventional PCR and real‐time PCR assays to discriminate the origins of Chinese pepper oil and herbal materials from Zanthoxylum

“…Efficiency of PCR amplification is an important factor in the evaluation of DNA barcoding regions . Recent work showed that ITS (or ITS2) can be used for species identification and discrimination between authentic and substitute/adulterant plants .…”

Development of a rapid method for codfish identification in processed fish products based on SYBR Green real‐time PCR

“…As it has been widely discussed (Teletchea et al , ; Rasmussen & Morrissey, ; Böhme et al , ), both nuclear DNA (nDNA) and mitochondrial DNA (mtDNA) are suitable for fish species identification. Although the limitation in the applicability of quantitative approaches has been highlighted (Mohamad et al , ; Amaral et al , ), mtDNA is still preferentially chosen as the target in many studies for qualitative analysis (Prado et al , ; Taboada et al , ; Xiong et al , ), due to the advantages of high mutation rate, multi‐copy nature and maternal inheritance. Moreover, the candidate gene marker should have a high inter‐specific variability and display either low or no intra‐specific variations (Teletchea et al , ).…”

“…Fish species authentication in the marketplace has become an international concern, mainly due to the widely reported species adulteration, where expensive or high‐demand species is replaced by a cheaper or more readily available one (Miller & Mariani, ; Ferrito et al , ; Xiong et al , ; Kim et al , ; Sultana et al , ; Xiong et al , ; Zeng et al , ; Sánchez et al , ). In particular, substitution of fish species in processed fish products is substantial, with an average prevalence rate of 30% in a recent investigation (ranging from less than 5% to 100%) (Pardo et al , ).…”

“…In a broad sense, the term ‘codfish’ generally refers to fish of the family Gadidae and to related species within the order Gadiformes (Xiong et al , ). However, due to the significant legislative and managerial shortcomings (D'Amico et al , ), there is still not a harmonisation around the definition of codfish in China, and our previous studies have highlighted species belonging to Gadiformes, Scorpaeniformes, Tetraodontiformes and Lophiiformes from codfish products (Xiong et al , ; Xiong et al , ). This is quite different from previous studies in other countries, where codfish mislabelling generally involved species in the family Gadidae (Miller & Mariani, ), or the order Gadiformes (Di Pinto et al , ).…”

“…This is quite different from previous studies in other countries, where codfish mislabelling generally involved species in the family Gadidae (Miller & Mariani, ), or the order Gadiformes (Di Pinto et al , ). Moreover, only eight Gadiformes species were identified, including Atlantic cod ( Gadus morhua ), Pacific cod ( Gadus macrocephalus ), Alaska pollock ( Theragra chalcogramma ), Saithe ( Pollachius virens ), haddock ( Melanogrammus aeglefinus ), European hake ( Merluccius merluccius ), Southern hake ( M. australis ) and giant grenadier ( Albatrossia pectoralis ) (Xiong et al , ; Xiong et al , ).…”