Discrimination of dried sea cucumber (Apostichopus japonicus) products from different geographical origins by sequential windowed acquisition of all theoretical fragment ion mass spectra (SWATH-MS)-based proteomic analysis and chemometrics

The article reports on discrimination of dried sea cucumber Apostichopus japonicus (A. japonicus) products from different geographical regions in China (Xiapu, Jiaonan, Weihai, Yantai, Dalian). For this purpose, sequential window acquisition of all theoretical fragment ion mass spectra (SWATH-MS)-based proteomic analysis combined with chemometrics was evaluated. Proteome variations of A. japonicus samples determined by SWATH-MS using ultra-high performance liquid chromatography coupled to quadrupole time of flight mass spectrometer were mined by chemometric tools to clarify the correlation between protein quantitation data and geographical origin. A differentiating OPLS-DA model was constructed with 55 SWATH-MS quantified proteins. A. japonicus samples from five locations were clearly classified by the developed OPLS-DA model and 100% prediction accuracy was achieved in validation testing as well as real-life sample analysis. Seventeen proteins were identified as discriminatory biomarkers allowing geographical provenance. The proposed method might be applied in origin authentication of commercially dried A. japonicus products.