Abstract:
The phytochemical constituents and in vitro antioxidant potentials of green, black, un-caffeinated, and herbal teas were evaluated and results compared. Green tea was found to be significantly (p < 0.05) higher in both total flavonoid content (TFC) (215.61±48.83 QE/mg) and total phenol content (124.81±79.05 GAEmg/ml) than others while un-caffeinated (411.55±9.21 GAEmg/ml), green (406.83±22.71 GAEmg/ml) and herbal (402.74±13.2 GAEmg/ml) teas exhibited significantly higher total tannin content (TTC) than black tea (325.14±108 GAEmg/ml). The un-caffeinated (184.32±33.62 QE/mg) and herbal (167.25±31.25 QE/mg) teas showed significantly higher TFC than the black tea (142.32±22.73 QE/mg). A positive correlation (r = 0.448) was observed between the TFC and ferric reducing antioxidant power (FRAP) assay as well as between TFC and 2,2-diphenyl-2-picrylhydrazyl DPPH (r = 0.347) radical scavenging activities of the tea samples. Results suggest that tea samples contain phytochemicals of which green tea exhibited least radical scavenging activity while black tea showed the highest antioxidant potentials highlighting their roles in neutralizing the excess free radicals arising from metabolic activities in living systems.
