Research on the origin traceability of sea cucumber (Apostichopus japonicus) in Liaoning and Shandong based on the compound-specific carbon isotope analysis of amino acids

In this study, we measured the relative contents and stable carbon isotope compositions of amino acids(AAs) in Apostichopus japonicus from Liaoning and Shandong by GC-C-IRMS, and evaluated its applicability in establishing the origin traceability of Apostichopus japonicus.Results showed that, the relative content of Pro(F=4.13), Ile(F=9.08) and Tyr(F=8.78) revealed significant difference between those two locations, and AAs compositions combined with principal component analysis did not discriminate samples of those two locations; the δ¹³C values of A. japonicus from Liaoning ranged from -24.54‰~-11.87‰ and the δ¹³C values of A. japonicus from Shandong ranged from -27.36‰~-16.42‰, most of the AAs δ¹³C values revealed significant difference between those two locations, we selected two AAs:Tyr and Ser, and their δ¹³C values could clearly discriminate samples of those two locations.So the stable carbon isotope composition of AAs is more precise than the AAs compositions for discriminating the samples of A. japonicus between Liaoning and Shandong.Thus, compound-specific carbon isotope analysis of AAs will provide a theoretical basis for establishing the traceability of the geographical origins of A.japonicus.