Research Progress on the Traceability of Tea Origin in China Based on the Fingerprint Analysis Technology of Rare Earth Elements

Tea is an important characteristic cash crop in China, and its origin and variety names are often synonymous with the commercial tea. Tracing the origin of tea plays an important role in maintaining the orderly development of the market and the sustainable development of the industry. The rare earth elements are often used as the tracing indicators of geochemical behavior and are the ideal elements for the traceability of tea origin. Through the literature review and statistics, it could be seen that the research on tracing the tea origin by using the fingerprint analysis technology of rare earth elements had the characteristics of late start and rapid development. There were 19 Chinese journals and 1 foreign journal that published the research articles, and the ″Journal of Food Safety and Quality Testing″ has the largest number of papers. At the same time, the advantages and difficulties of the fingerprint analysis technology of rare earth elements and the combined analysis techniques of rare earth element fingerprint and other chemical components in the traceability of tea origin were analyzed. In addition, three research suggestions were put forward, including establishing a tea standard product database suitable for the origin traceability, establishing a comprehensive characteristic database of tea rare earth elements, and setting up a low-cost discrimination model for the origin traceability of tea rare earth elements based on the coupling of supervised and unsupervised identification methods, which could provide positive references for the protection of tea origin and the industrial development in China.