Study on the origin identification of Anji Baicha based on mineral elements

Authenticating the geographical origin of Anji Baicha, a premium China Geographical Indication (GI) tea, is critical for combating fraud in high-value markets. This study established a robust traceability system by integrating elemental fingerprinting with advanced chemometrics. Using inductively coupled plasma-mass spectrometry and inductively coupled plasma-optical emission spectrometry (ICP-MS/OES), we profiled mineral signatures in 365 tea samples (185 authentic Anji, 180 non-Anji). The support vector machine (SVM) model demonstrated exceptional classification performance, achieving 94.9 % accuracy in the training set and 92.7 % in the test set. Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA) identified Mo, Cu and Rb as key discriminators of geographic origin. Substantiating the biogeochemical transfer paradigm, robust soil-tea correlation (R² > 0.5) was mechanistically established for Rb, Mn, Pb, Mg, and K. This integrated mineral profiling strategy delivers a scientifically verifiable framework for protecting the GI integrity of premium agri-products, with immediate applicability to Anji Baicha authentication.