A new perspective on geographical tracebility of sea cucumber (Apostichopus japonicus) in North China: Insight from multi-element stable isotope analysis of fatty acids

Abstract

Compound-specific stable isotope analysis has evolved a well-established method for origin traceability of aquatic products. Screening of origin fingerprint characterization factors can improve the efficiency and accuracy of traceability. However, there is no report on screening characteristic fatty acids for sea cucumber traceability. In this study, Apostichopus japonicus were collected in Shandong and Liaoning Provinces, bulk δ¹³C, and carbon and hydrogen stable isotopes of fatty acids were analyzed. Differences in bulk δ¹³C of Apostichopus japonicus from different origins were insignificant, but the fatty acid δ¹³C varied greatly. By Principal Component Analysis and Partial Least Squares Discriminant Analysis, two-dimensional stable isotopes of fatty acids can be an effective method for tracing the origin of sea cucumbers. Saturated fatty acids (17:0, 20:0), Monounsaturated fatty acids (16:1n-7, 18:1n-9), and Polyunsaturated fatty acids (22:6n-3, 18:3n-3) were screened as the characteristic factors of origin traceability (Variable importance value of more than 1), which the strongest correlation with the main components. Introduced multi-element stable isotopes analysis of single compounds, which provided an effective method for screening the characterization factors.