Measurement of antioxidant (reducing) power and/or antioxidant concentration

Abstract

A method for measuring the antioxidant capacity and/or the amount of a specific antioxidant in a sample, which comprises: a) at least two samples (A) and (B) to be assayed in parallel; b) addition of an antioxidant deactivator to sample (A) which selectively deactivates the antioxidant ability of an antioxidant in the sample; c) addition of a redox indicator to both samples (A) and (B), the indicator being capable of indicating the antioxidant capacity of each sample absorbance of electromagnetic radiation; d) measurement of the change in absorbance of electromagnetic radiation of the indicator in each sample at a given time interval, from the time when the redox indicator was added to or mixed with the samples or immediately prior to this addition or mixing until a given time after the redox indicator was added; e) determining the antioxidant capacity of the sample and/or the specific antioxidant in the sample, by relating the change in absorbance of electromagnetic radiation of step (d) to the absorbance value of a standard solution run under the same conditions or to molar absorptivity value.