2,20–Azino-bis(3-ethylbenzothaiazoline)-6-sulfonic acid (ABTS)
radical scavenging activity. A stock solution containing 7mM ABTS
(Fluka) and 2.450mM potassium persulfate (Fluka) stored in a light
protected vessel for 16 h at ambient temperature was diluted with
EtOH (Merck). The working solution, having an absorbance of
0:700 0:200 at 750 nm, was applied in the assay. The absorbance at
750 nm of the mixture of samples (20 mL), and the working ABTS
solution (180 mL) was determined following 5 min of mixing. Antioxidant
activity was calculated. The IC50 of ascorbic acid was
compared to the IC50 of the extracts. All measurements were done in
triplicate.18)