Using neodymium isotope ratio in Ruditapes philippinarum shells for tracking the geographical origin

Geographical traceability of marine bivalves is becoming increasingly important to assure their quality and to defend the interest of consumers and producers. This study verifies the neodymium isotopic ratio (¹⁴³Nd/¹⁴⁴Nd) in Ruditapes philippinarum shells as a tracer of the geographic origin, based on the geochemical aspect that ¹⁴³Nd/¹⁴⁴Nd of their habitats strongly depends on the geology of its catchment areas. The ¹⁴³Nd/¹⁴⁴Nd ratios of clam shells from the Japanese and Chinese coastal areas displayed a heterogeneous pattern from local to international scales, reflecting the geological age of the catchment area. The blind test suggested that a part of Manila clam was sold with mislabeling in the Japanese market, demonstrating the high potential of ¹⁴³Nd/¹⁴⁴Nd to unmask the fraud labeling in a food market. Our findings emphasize the potential of ¹⁴³Nd/¹⁴⁴Nd as a tracer for the geographical origin of marine bivalves, and also as a strong deterrent against mislabeling.