One of the most difficult challenges in authenticity analysis is verifying the species of an ingredient or component in processed products where little or no intact DNA might remain. Verifying tuna species in processed products (e.g. canned tuna) has been a perennial problem.
This paper (purchase require) sets out to address the problem by discovering and validating species-specific peptides for distinguishing three commercial tropical tuna species. The peptides derived from trypsin digestion were separated and detected using ultrahigh-performance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC-Q-TOF/MS) in data-dependent acquisition (DDA) mode. Venn analysis showed that there were differences in peptide composition among the three tested tuna species. Screening through the National Center for Biotechnology Information’s Basic Local Alignment Search Tool (NCBI BLAST) revealed 93 candidate peptides. Finally, the detection specificity of species-specific peptides of raw meats and processed products was carried out by multiple reaction monitoring (MRM) mode based on a Q-Trap mass spectrometer. The results showed that three, one and two peptides of Katsuwonus pelamis, Thunnus obesus and Thunnus albacores, respectively could serve as species markers.
Graphical abstract from the paper
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