The extracts and standards respectively were
reacted with 5% NaNO2, 10% AlCl3 and 1 M
NaOH. Quercetin was used as standards with
concentration varied from 200ppm to 1000ppm.
The mixture was measured at 510 nm using UVVis
spectrophotometer. Each measurement was
repeated five times and TFC was expressed as mg
Quercetin equivalent per gram extract weight (mg
QE/g extract weight)