The radical scavenging activity (DPPH), was determined following
the modified protocol of Brand-Williams, Cuvelier, and Berset (1995).
Sample (10 μL) and deionized H2O (90 μL) were added in a 96-well microtiter
plate and the reaction started by adding 200 μL of freshly prepared
DPPH solution (0.024 g/L DPPH). The absorbance was measured
at 515 nm every 4 min for 32 min in total, when the absorbance value
remained constant.