Scientific African (Mar 2021)
Comparative evaluation of antioxidant properties of lemongrass and other tea brands
Abstract
The aim of the study was to determine the antioxidant capacity in fresh Lemongrass (LGF), dried Lemongrass (LGD), processed teabags; Lipton black tea (LBT), Super black tea (SBT), Lipton green Tea(LGT) and Zesta green tea (ZGT) and the impact of time and temperature on them. The total phenol and flavonoid contents were determined by Folin Ciocalteu and aluminum chloride techniques respectively. The antioxidant capacity was determined by ABTS and DPPH assays. The effect of temperature regulation and the leach time duration of the various teas were also determined. ZGT recorded the highest antioxidant capacity of 47% and 56% for both DPPH and ABTS respectively for methanol extracts. SBT had the highest phenol content (74.99 mgGAE/100 ml) and LBT had the highest flavonoid (102.40 mgCE/100 ml). The antioxidant capacities for the different temperature regulations for all the samples ranged from 4% to 99% and 8% to 85% for ABTS and DPPH respectively. A similar trend of 2% to 87% and 3% to 66% was also seen for the time regulations for ABTS and DPPH respectively. There was a significant difference in antioxidant capacity between the tea samples for leach time regulation; however, there was no significant difference for the temperature regulations.In conclusion, the antioxidant capacity, total phenol and total flavonoid content of the tea infusion were impacted by variations in duration of extraction and temperature of exposure. The extraction time at 5 min recorded the highest antioxidant capacity for temperature regulation for most of the tea infusions between 25 and 80°C. In respect of the samples, SBT had the highest TPC and TFC whiles Camellia sinensis showed higher antioxidant activity over Lemongrass. Further research on the effect of time and temperature on local tea brands is warranted to ensure that appropriate choices are made towards the consumption of tea to boost wellness.
