DPPH assay is one of the most widely
used methods for screening the antioxidant
activity of plant. The assay is based on the
measurements of the antioxidants ability to
scavenge the stable radical DPPH. DPPH is a
stable nitrogen-centred free radical, which
produces violet color. DPPH radicals react
with suitable reducing agents, during which
the electrons become paired off and the
solution loses color stoichiometrically
depending on the number of electrons taken
up