Identification criteria for black tea

The purpose of the study is to establish the identification criteria for black tea varieties to identify the geographical place of origin and to determine the nature of the influence of certain phenolic compounds on the taste profile of tea extracts. The objects of study are black Ceylon teas packaged in Russia. All samples of tea in the appearance of the infusion were bright and transparent, with delicate aromas and tart taste, which corresponds to the type of product. The exception was tea sample No. 2, which, by the appearance of the boiled tea leaf, did not meet the standards for the beverage category. The content of total polyphenols in aqueous extracts ranged from 116.0-162.0 mg/g of tea, caffeine - 5.7-7.1; catechins - in the range of 4.4-8.7 mg/g of tea. In terms of the total content of phenolic compounds, tea No. 3 and No. 4 had the highest content of various classes of phenolic compounds. The content of quercetin in the samples was 0.32-0.47 mg/dm3, rutin - 60.96-94.22 mg/dm3. In aqueous extracts, phenolic acids were recorded in the amount of 0.37-13.1 mg/dm3 and phenolic aldehydes in the amount of 0.11-5.55 mg/dm3, thanks to which it was possible to establish that coniferyl and synapic aldehydes can be identification criteria to determine the regional affiliation of tea cultivation. Mathematical analysis revealed a strong correlation between a positive tasting score of samples and changes in caffeine content, as well as rutin. There is a close correlation between the change in the content of caffeine and rutin (r = 0.99), as well as the content of catechins and syringic acid and synapaldehyde (r = 0.93 and r = 0.97, respectively), which is associated with the structure of the tea plant matrix.