DNA Barcoding Revealed Mislabeling and Potential Health Concerns with Roasted Fish Products Sold across China

Abstract

ABSTRACTRoasted fish fillet is a popular snack food in the People's Republic of China, and the market appeal can be reflected by the high price, which exceeds 330 RMB/kg in some cases. However, the labeled fish common name generally cannot be connected with a particular species, and the processing treatments make it a challenging task to identify fish species based on morphological characteristics. This study used full DNA barcoding and mini-DNA barcoding for species identification of 202 specimens sorted from 64 roasted fish fillet products sold across China, which belonged to 32 distinct brands and claimed 16 fish common names on the label. Given the absence of a harmonization in defining these common names in China, scientific literature and the Latin-Chinese dictionary of fish names (http://fishdb.sinica.edu.tw/) were consulted to define at least the family for each common name, and an identified species outside the expected family was determined to be mislabeled. Results highlighted a high mislabeling rate of 75.5%. Even worse, fish species were identified as belonging to multiple families, not only from several products of the same brand under the same common name but also from several specimens sorted from the same product. Moreover, a health issue was highlighted by the identification of toxic Tetraodontidae species from one product. To protect the consumers from economic loss and even health risks, we recommended amendments to existing legislation and the compilation of a list of acceptable market names for fish species in China. Meanwhile, DNA barcoding is a powerful tool in fish forensics, and we recommended the use of this technique to assure the accurate species labeling of fish products.HIGHLIGHTS