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Keywords:

  • Catechin;
  • gas chromatograph mass spectrometer;
  • high performance liquid chromatograph;
  • tea discrimination;
  • volatile compounds

Summary

As tea is one of the most popular beverages consumed worldwide, it is important for customers and business investigators to develop an easy and reliable method to discriminate between different types of teas from each other. A total of eighty-seven types of various white, green, oolong, black and Puer teas were collected from the major tea estates in China, and their catechin contents and volatile compounds were compared by high performance liquid chromatograph and gas chromatograph mass spectrometer. It was found green tea contained the highest concentrations of total catechins, (−)-epicatechin gallate (ECG) and (−)-epigallocatechin gallate (EGCG), while oolong teas contained the highest concentrations of (−)-epigallocatechin (EGC) among these five types of teas. The aroma composition and their quantities in different types of teas varied quite widely. The concentration of ECG, EGCG, pentanal, hexanal, methyl jasmonate, indole, (E,E)-2,4-hexadienal and 1,2,3-trimethoxybenzene was shown to be different and could be used to discriminate white, green, oolong, black and Puer teas. The result showed that different types of teas could be partially classified by cluster analysis using index of individual catechins and volatile components.