Comparative analysis of the phytochemical content and antioxidant capacities of five pure green tea brands

Abstract

Background: There are different brands of tea in the market with diverse claims on their antioxidant potentials. It is necessary to verify these claims and help consumers make informed choices.

Objectives: This study was undertaken to analyze and compare the phytochemical composition and antioxidant capacity of five brands of pure green teas (coded: GTQ, GTL, GTN, GTLp and GTT) sold in Nigeria.

Methods: Five brands of pure green tea were purchased and infused to obtain their extracts. The extracts were screened for phytochemical content using standard methods and their in-vitro antioxidant capacities were also determined using 1, 1- diphenyl-2- picrylhydrazyl radical (DPPH.), nitric oxide (NO.) and total antioxidant capacity assays.

Results: The result indicated that all the tea samples recorded the presence of phenolic compounds, GTQ and GTT recorded the highest and lowest total phenol content respectively. All the samples differed significantly (p < 0.05) in their flavonoid content. The tannins content of GTQ (8.76±0.07 mg/100g) and GTL (8.78±0.06 mg/100g) did not differ significantly (p > 0.05). The alkaloid content of GTQ (527.33±21.93) was significantly (p < 0.05) higher than the others, except GTN. GTQ recorded the highest steroids (0.42±0.02 mg/100g). The results showed the tea samples scavenged 1, 1- diphenyl-2-picrylhydrazyl radical (DPPH.) and nitric oxide (NO.). They also possessed strong total antioxidant capacity. However GTL was more potent among all the tea samples.

Conclusion: All the green tea samples processed strong phytochemical content and were potent in scavenging free radicals.