Microsatellite fingerprinting and metabolite profiling for the geographical authentication of commercial green teas

The authentication of geographical provenance is an important issue with respect to commercial tea products. Here, simple sequence repeat (SSR) fingerprinting and metabolite profiling were implemented to differentiate between 37 commercial green teas, produced in China, Japan and Korea. A set of 21 SSR assays detected 175 alleles, and a multiplex of three of these assays was sufficient to distinguish each of the samples. Metabolite profiling based on ultra-high performance liquid chromatography coupled with high resolution mass spectrometry detected features which proved to be correlated with a specific provenance. There was only a moderate level of correlation between the SSR and metabolite profiles. Such a level of correlation suggests that genotype, environment and post-harvest processing are all determinants of end-use quality. The two analytical approaches are complementary to one another, and are recommended to be used in conjunction.