2019Journal articleFree to read
Timotej Jankech, Mária Maliarová, Nicholas Martinka
Nova Biotechnologica et Chimica
Abstract Methylxanthines such as caffeine, theophylline, theobromine are significant and widespread psychoactive substances. We developed the isocratic method with optimum composition of the mobile phase 90 % water: 10 % acetonitrile and confirmed repeatability of retention times and peak areas. The developed HPLC method was applied to determine the content of methylxanthines in selected types of black and green teas available on the market. Of the black teas (tea bags), the highest concentration of theobromine was found in Ceylon tea (18.98 mg.L−1). The highest concentration of caffeine was in a cup of Earl Gray tea (254.09 mg.L−1). Among loose black teas, the highest content of both theobromine and caffeine was found in Pu Erh Superior tea, where the theobromine content was 24.62 mg.L−1 and the caffeine content was 520.67 mg.L−1. Of green powder teas, highest caffeine content (306.46 mg.L−1) was in Shizuoka Matcha Premium and the highest content of theobromine (8.45 mg.L−1) was found in GABA Midori. From the loose green tea, the highest concentration of theobromine (12.85 mg.L−1) was in Lung Ching West Lake. The highest caffeine content (484.85 mg.L−1) was in Gyokuro Shizuoka Premium Tea. In both types of teas the amount of theobromine and caffeine was quantified, but the presence of theophylline was not proven. Data on contents of these metabolites in tea products are highly informative for consumers.
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Study type
Observational (human)
Surveys, cohorts and consumer studies, with no intervention.
Assigned automatically from the title, abstract and subject terms.
Topics
Matcha is a main subject here (named in the keywords).
Timotej Jankech, Mária Maliarová, Nicholas Martinka. (2019). Determination of methylxanthines in tea samples by HPLC method. Nova Biotechnologica et Chimica. https://doi.org/10.2478/nbec-2019-0015
DOI: 10.2478/nbec-2019-0015 · Cited by 6 (OpenAlex)
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