Freeze-dried extracts of
peanut milk (PM) and peanut milk kefir (PMK) samples
were dissolved in ethanol (50%). Each sample (0.8 mL)
was mixed with 0.2 mL of methanolic solution containing
DPPH radical (0.2 mM). The mixture was vortex well,
incubated for 30 min in the dark, and the absorbance was
then measured at 517 nm using a UV-spectrophotometer
(UV6x Series; Bluwave, Shanghai, China). The capability
of the test samples to scavenge DPPH radicals was
calculated as (%)=[1−(absorbance of the sample at
517 nm)/(absorbance of the control at 517 nm)]×100.
The extract concentration providing 50% inhibition
(IC50) was calculated from the graph of scavenging effect
percentage against extract concentration