2.4.3. DPPH Radical-Scavenging Activity

The DPPH scavenging assay using 0.5 g/mL of LEO and LEO-NEs (stored for 7 days) was measured following the kit instructions. The EOs were diluted with extraction buffer in the kit. Firstly, 380 μL of Reagent 1 was added to 20 μL of sample and then shaken vigorously for 20 min. The change in absorbance was measured at 515 nm by the microplate reader (Thermo Scientific, Waltham, MA, USA). The percentage inhibition free radical scavenging rate of DPPH was calculated as follows:

DPPH scavenging activity (Inhibition%) = [(Acontrol − Asample)/Acontrol] × 100 (1)
