β-phycoerythrin (β-PE) was used as a target of free radical (or oxidant)
attack withAAPH (40mM) as a peroxyl radical generator. Trolox (1 μM)
was used as a standard and prepared fresh daily. The analyzer was
programmed to record the fluorescence of β-PE every 5 min after AAPH
was added. All fluorescence measurements were expressed relative to
the initial reading. A final ORACROO• value was calculated using
the differences of area under the β-PE decay curves between the blank
and the sample and expressed as μmol of Trolox equivalents per μmol
of sample.