What is in your cup of tea? < i > DNA Verity Test < /i > to characterize black and green commercial teas

In this study, we used several molecular techniques to develop a fast and reliable protocol (DNA Verity Test,DVT) for the characterization and confirmation of the species or taxa present in herbal infusions. As a model plant for this protocol,Camellia sinensis, a traditional tea plant, was selected due to the following reasons: its historical popularity as a (healthy) beverage, its high selling value, the importation of barely recognizable raw product (i.e., crushed), and the scarcity of studies concerning adulterants or contamination. TheDNA Verity Test includes both the sequencing of DNA barcoding markers and genotyping of labeled-PCR DNA barcoding fragments for each sample analyzed. This protocol (DVT) was successively applied to verify the authenticity of 32 commercial teas (simple or admixture), and the main results can be summarized as follows: (1) theDVT protocol is suitable to detect adulteration in tea matrices (contaminations or absence of certified ingredients), and the method can be exported for the study of other similar systems; (2) based on the BLAST analysis of the sequences ofrbcL+matK ±rps7-trnV(GAC) chloroplast markers,C.sinensis can be taxonomically characterized; (3)rps7-trnV(GAC) can be employed to discriminateC.sinensis fromC.pubicosta; (4) ITS2 is not an ideal DNA barcode for tea samples, reflecting potential incomplete lineage sorting and hybridization/introgression phenomena inC.sinensis taxa; (5) the genotyping approach is an easy, inexpensive and ...
Source: PLoS One - Category: Biomedical Science Authors: Source Type: research