Authentication of the geographical origin of Maca (Lepidium meyenii Walp.) at different regional scales using the stable isotope ratio and mineral elemental fingerprints.

Maca has shown broad application prospects as a new food resource. The function of maca is directly affected by its geographical origin, and an effective method for studying traceability must be established. This study aimed to discriminate maca from different regions at large scales (Peru and China) and small scales (Yunnan, Xinjiang, and Tibet in China) through geographical authentication using the stable isotope ratio (SIR) (δ13C, δ15N, δ2H and δ18O) and mineral elemental fingerprints combined with chemometrics. For Peruvian and Chinese maca, overall discriminatory accuracy of 100% and 96.2% were obtained by applying SIR and the mineral element analysis, respectively. For maca obtained from different Chinese regions, the order of the discriminatory accuracy was mineral elements (80.2%) = SIR combined with mineral elements (80.2%) > SIR (71.9%). K, B, Mn, Fe, Mo, Cd and As were identified as the main discriminating indicators for identifying maca from different Chinese regions.