With the rapid increase in global salmon consumption, China has become the largest market for Atlantic salmon ( Salmo salar ) in Asia. However, the ambiguous labeling of "Atlantic salmon" products in the marketplace has led to widespread mislabeling and fraud in China. The aim of this study was to develop a molecular approach for accurately distinguishing Atlantic salmon from other salmonid products on a large scale. The authenticity of salmon products was verified using a fragment of the mitochondrial 16S ribosomal RNA gene (16S rRNA). During PCR amplification, an adaptor primer with a 6-nucleotide multiplexing tag was used to distinguish samples among the amplified sequences. In combination with next-generation sequencing (NGS) technology, a total of 186 commercially available salmon samples across China were definitively identified through comparative bioinformatic analysis. Our results showed that 53.76% of these samples were Atlantic salmon ( S. salar ), 33.33% were rainbow trout ( Oncorhynchus mykiss ), 3.23% were coho salmon ( Oncorhynchus kisutch ), 1.61% were chum salmon ( Oncorhynchus keta ), and 8.06% were pink salmon ( Oncorhynchus gorbuscha ). The overall mislabeling rate was 24.73% (95% CI: 19.08%–31.40%), with Atlantic salmon ( S. salar ) products most frequently mislabeled as rainbow trout ( O. mykiss ). The mislabeling rate of salmon products purchased from online platforms (36.54%, 95% CI: 27.92%–46.12%) was significantly higher than that from traditional offline stores (9.76%, 95% CI: 3.33%–16.18%) (χ² = 17.68; p 0.05). Our results revealed that mislabeling of Atlantic salmon products is widespread in China. Therefore, proper labeling of species is essential to ensure the sustainable development of the global Atlantic salmon trade.
Feng et al. (Mon,) studied this question.