Unlike other popular antioxidant ac

Unlike other popular antioxidant activity methods, the ORAC
assay uses fluorescein as the fluorescent probe directly measures
the antioxidant activities of chain-breaking antioxidants against
peroxyl radicals (Ou, Hampsch-Woodill, & Prior, 2001). One of
the advantages of the ORAC assay is that it uses biologically relevant
free radicals. It also differs from the DPPH and FRAP assays
in terms of the mechanism of chain breaking ability. The FRAP
and DPPH assays operate on the basis of single electron transfer,
whereas the ORAC assays is a hydrogen atom transfer-based
reaction. On the basis of ORAC values, the strength of peroxyl radical
scavenging activity was in the order: ellagic acid > sesamol
> olive leaf extract > lutein (Table 1). A good correlation
between radical scavenging activities as measured using FRAP,
DPPH, ABTS and ORAC assays was observed (Table 3).