shaker (100 rpm) at 22 °C. Then, 1 ml of diluted (100×) supernatant
or 1 ml of diluted (100×) SBE was added to the freshly prepared
solution of DPPH in methanol (0.08 mg/ml) and stirred vigorously.
After 30 min of incubation in the dark at ambient temperature, the
absorbance was measured at 517 nm on a Spectronic Genesis 20
spectrophotometer (Spectronic Instruments, USA). Percentage DPPH
scavenging activity was calculated as [(control absorbance – film or
SBE absorbance)/(control absorbance)] × 100