Abstract
Background: Tea is one of the most consumed beverages in the world and is rich in natural compounds called phenols. These phenolic compounds act as antioxidants that help protect the body from damage caused by free radicals. Measuring the phenol content in black and green tea helps understand their nutritional and health benefits. Objectives: To evaluate the total phenolic content in various commercial black and green tea samples. Methodology: Using the Folin–Ciocalteu (F–C) colorimetric assay, a widely recognized method for quantifying phenolics based on their reducing capacity. Tea infusions were prepared in methanol, followed by extraction and reaction with F–C reagent in the presence of sodium carbonate. Absorbance was measured at 765 nm using a UV-Vis spectrophotometer, and results were compared against a caffeic acid calibration curve to express phenolic concentrations as caffeic acid equivalents. Results: The study revealed that green tea generally possessed higher phenolic content than black tea, with Aziz Green Tea exhibiting the highest concentration (35.739 mg/L), while Millat Green Tea showed the lowest (12.474 mg/L). The higher phenolic content in green tea is linked to minimal oxidation during processing, which preserves bioactive compounds. Conclusion: These findings confirm that green tea possesses greater antioxidant potential compared to black tea and results also support ongoing efforts to promote polyphenol-rich diets for the prevention of chronic diseases.