Quantitative estimation of β-glutamylethylamide in commercially available made teas [ Camellia sinensis (L.) O. Kuntze, Theaceae] in Kenya

Autor: K. O. Moseti, John K. Wanyoko, Francis N. Wachira, Janet Too, Thomas Kinyanjui
Rok vydání: 2016
Předmět:
Zdroj: International Journal of Tea Science.
ISSN: 0972-544X
DOI: 10.20425/ijts.v0iof.9575
Popis: A study was carried out to quantitatively estimate the L-theanine content in 19 teas commercially available in the Kenyan market by High Performance Liquid Chromatography (HPLC). The test tea samples analyzed were green (n = 4), black (n = 8) and flavored (n = 7) teas from different origins viz., Kenya (n = 4), Uganda (n = 2), Tanzania (n = 5), Rwanda (n = 4), Cameroon (n = 1) and Sri-Lanka (n = 2) commercially available in the Kenyan market. The estimated Limit of Detection (LOD) of the current method was 0.01 % L-theanine. The L-theanine content ranged from below the detection limit (< 0.01 % L-theanine) to 1.60 % L-theanine on a dry weight (d.w) basis. Statistically significant differences (p < 0.05) were observed in the L-theanine contents of black, green and flavoured teas. Rwandan green tea contained the highest L-theanine content with 1.60 % d.w. whereas six of the seven flavoured teas had very low theanine levels (< 0.01 %) that could not be quantified by the current method.
Databáze: OpenAIRE