Fingerprint identification method of Pu’er raw tea based on high performance liquid chromatography profiles

Different recognition methods of the fingerprint for solar dried Pu’er raw tea was investigated based on their high performance liquid chromatography (HPLC) profiles, in order to identify Pu’er raw tea from different places. Similarity of the fingerprint was calculated by comparing their HPLC profiles using three methods, namely correlation coefficient, angle cosine and overlap rate, respectively. Based on the digitalized fingerprint, tea samples were systematically clustered. The main components of 18 tea samples were analyzed, in which the former two main components were employed to plot a two-dimensional scatter map. The results showed that each of the three employed methods could reflect the similarity of the fingerprint accurately, by which solar dried Pu’er raw tea could be well identified from green tea. Although the component of tea sample is complicated and the main component is rich, the selected seven main components contributed 88.61% of the total. Solar dried Pu’er raw tea samples could be distinguished obviously from green tea samples by using method of either systematic clustering or two-dimensional map. The recognition modes described could not only provide an identification method for fingerprints, but also provide an experimental foundation for quality control of raw material for Pu’er tea.