Fingerprint of black teas from India: identification of the regio-specific characteristics

Abstract

In order to assess the intrinsic characteristics of black teas from different regions of India, a chemical and biochemical fingerprint was generated. Relevant constituents of black teas were analysed, using standard physico-chemical, spectrophotometric, HPLC and GC-MS analytical methodologies, to carry out the fingerprinting. Palampur teas had the lowest theaflavins (TFs) and total colour (TC) and high caffeine, total soluble solids (TSS) and viscosity. Teas from Nilgiris, Rosekandy and Kurti had the highest TFs and TC. Assam teas had moderate TFs and TC. Nilgiris and Annamalai teas had low caffeine, TSS and viscosities. Assam, Rosekandy and Kurti teas had high caffeine, moderate TSS and viscosities. Twenty-five volatile flavour compounds (VFCs) were identified by GC-MS as fingerprint markers. Only Palampur teas had nonanal but no dihydroactinidiolide. Annamalai tea had the lowest n-hexanol and Nilgiri-Wynad tea had the lowest geranyl acetate. Only Kurti tea contained xylene. This fingerprint will help to trace the origin of teas.