An overview of most commonly used methods for detection of fish mislabeling

The increase of global fish consumption brings with it the problem of fish mislabeling, which leads to economic losses for consumers or may even result in consumers’ health risk. Thus, continuous development of methods used in identification of exact fish species is essential. There are numerous modern identification methods, which use DNA or specific fish proteins as biomarkers, but they all come with various benefits and drawbacks. Protein-based methods include electrophoretic methods, ELISA, HPLC and MALDI-ToF Mass Spectrometry, while the methods that use DNA as a biomarker include PCR-RFLP, SSCP, qPCR, RAPD, FINS, DNA microarray, DNA barcoding, pyrosequencing and metabarcoding. There is a continuous development of new or improved methods. Most of the methods display a much better performance when analyzing raw or lightly processed fish, such as chilled or frozen, while heat treatment often leads to changes in the biomarker molecules, making the species identification difficult. The ideal method does not yet exist, but methods such as DNA barcoding, MALDI-ToF Mass Spectrometry and metabarcoding are the ones that show most potential.