Factors influencing the antioxidant activity determined by the ABTS.+ radical cation assay.

This study introduces a simple direct antioxidant assay, based on the reduction of the ABTS.+ radical cation, and compares it with the myoglobin/ABTS.+ assay. The methods give closely similar results, establishing that the antioxidants studied to date in the latter assay act by scavenging the ABTS.+ radical cation and not by inhibiting its formation through reduction of ferryl myoglobin or reaction with H2O2.