Assessment of antioxidant capacity for scavenging free radicals in vitro: A rational basis and practical application

► A method for the assessment of antioxidant capacity for radical scavenging was developed. ► The reactivity and concentration of antioxidants in mixtures were measured separately. ► Probes with various reactivities and solubilities were used for the assessment. ► The effect of localization of radicals and antioxidants in water and oil phases was assessed. ► The method was applied to human plasma, wine, and green tea powder.