Chemometric assisted RP-HPLC for fingerprinting of Indian orthodox black tea†
In view of the large variation in tea quality, this study aims to fingerprint the best quality of Indian orthodox black tea depending upon the production region, variation of seasons, mechanical grading and processing with different fermentation times. A HPLC method reported by us earlier has been adapted to separate biochemical constituents in various tea samples, in which Thermo Hypersil ODS column has been found to be more efficient in terms of resolution and retention time. Even black tea processed from the same region but processed in different seasons or mechanically graded resulted in significant compositional changes. The average data from HPLC was subjected to chemometric analysis i.e. principal component analysis (PCA). Different clusters were obtained for each type of tea which can act as a fingerprint for further analysis and interpretation of tea quality for its ranking. Thus, HPLC integrated with chemometrics can be explored as a routine diagnostic tool for online monitoring of black tea quality.