Quantitative Estimation of Caffeine Concentration in Three Commercial Black Teas, Purchased from Local Markets in Al-Kharj Province, Saudi Arabia

Determination of caffeine content in three commercial black tea packets purchased from the local markets in Al Kharj province, Saudi Arabia which was performed using a fast gravimetric technique. Different methods were applied, based on using UV/Vis spectrophotometer and chromatographic method compared with a standard caffeine for quantitative determination. The three samples were showed different concentrations of caffeine ranges from 15.3 – 25.8 mg/g. The highest concentration of caffeine was found in the black tea of Kenyan manufacturer, followed by the black teas of Sri Lankan manufacturer. Phytochemical properties identified in our study may be employed as a part of the pharmacopeial standard, playing an important role in its standardization. In addition, physicochemical, organoleptic, and phytochemical screening were evaluated for these three samples. The aim of our research on the commercial black tea obtained from different regions, is to confirm the quality and safety of the local commercial products sold in the local Saudi market to verify if the amount of caffeine that was not listed on the packaging is considered safe to human health or no. Currently, the Saudi Food and Drug Authority mandates to label caffeinated beverages must display the caffeine content.