Aromatic composition, catechins content, and metal elements profiling of forty-three Iranian black tea (Camellia sinensis (L.) Kuntze samples

Background: Tea (Camellia sinensis), belongs to the family Theaceae, is a well-known perennial and evergreen plant that is processed and widely used as a daily drink across the world. Objective: The present study was aimed to explore aromatic composition, catechins content, and metal elements (MEs) profiling of forty-three black tea samples collected across Iran. Method: Black tea samples were prepared from the Iranian Tea Research Institute. MEs content of the plant dried samples was measured by atomic absorption spectrometer. Aromatic composition and catechins content of the studied samples were analyzed by GC-FID, GC-MS and HPLC, respectively. Result: Hexanal (0.3-27.6 %), cis-linalool oxide (0.1-44.7 %), trans-linalool oxide (0.2-48.3 %), linalool (0.2-39.2 %), benzyl alcohol (0.2-38.9 %), phenylethanol (0.1-37.9 %), and (-)-Myrtenol (4.4-26.8 %) were the major volatile oil compounds of the studied samples. The highest content of hexanal, cis-linalool oxide, trans-linalool oxide, linalool, benzyl alcohol, phenylethanol and (-)-Myrtenol was measured in IR5 (Zarin), IR13 (Leil 1), IR23 (Shariat), IR31 (Roozmehr 1), IR34 (Noshiran), IR36 (Roozmehr 3) and IR18 (Amard 2), respectively. Catechin content was ranged from 0.589 ± 0.0285 in IR32 (Roozmehr 2) to 0.65 ± 0.0088 in IR29 (Aramgol 1). The level of the copper, Iron and lead were generally within the safe limitation mentioned in the world. Conclusion: Sample of Roozmehr was characterized with high aromatic compounds, catechins content, and low level of MEs. This information can be interestingly considered by food industrials to process black tea products.