Chemical Fingerprint Analysis for the Quality Evaluation of Deepure Instant Pu-erh Tea by HPLC Combined with Chemometrics

A simple and efficient fingerprint analysis method was developed and validated for the quality consistency control and authentication of Deepure instant pu-erh tea within different manufacturers using high-performance liquid chromatography (HPLC) coupled with chemometrics. To compare the HPLC fingerprint chromatograms between batches, varieties and manufacturers, the correlation coefficients of similarities of 60 samples and the relative peak areas of 11 characteristic compounds were calculated. Different pattern recognition procedures, including hierarchical cluster analysis, principal component analysis and partial least squares discriminant analysis, were then applied to classify the instant pu-erh tea samples according to their variety and manufacturer. Results showed that the developed method has potential application for the quality consistency evaluation and discrimination of instant pu-erh tea samples from similar products.