Comparison of antioxidant activities expressed as equivalents of standard antioxidant

Abstract The quantitative antioxidant activity of foods is expressed as the equivalent weight of the authentic standard compounds with antioxidant function. Even in the same food sample, antioxidant activity is defined differently depending on the standard antioxidant compounds, making it difficult to compare them. Antioxidant activity was measured by DPPH radical and ABTS radical scavenging assay using Trolox, ascorbic acid, catechin, and gallic acid as standard antioxidant compounds. The relationship between the antioxidant activity and the standard was used to convert the antioxidant activity expressed as the equivalent of a specific antioxidant standard to the equivalent of another antioxidant standard. To verify the converted antioxidant activity, the antioxidant activity of apples was analyzed with several antioxidant standards and compared with the antioxidant activity converted with other standard compounds. As a result of comparing the antioxidant activity measured using various antioxidant standards and the converted antioxidant activity of apples, it was confirmed that there was no difference. The results of this study show that antioxidant activity expressed as a specific antioxidant standard compound can be accurately converted into the equivalent of another standard antioxidant compound.