Oxygen-radical absorbance capacity ORAC assay

Oxygen Radical Absorbance Capacity (ORAC) assay... 

Furthermore, the oxygen radical absorbance capacity (ORAC) assay has been used to evaluate the total antioxidant activity of polyaniline/ PE blends by monitoring the oxidation of fluorescein, a fluorescence probe, into non-fluorescent products by the peroxy radicals generated in the analysis mixture [3]. The relative ORAC values, converted to trolox equivalents, indicated the antioxidant efficacy of the blend samples. As shown in Figure 4.6, the ORAC values and hence the total antioxidant activity, of the blend samples increased with increasing polyaniline content in the blend. 

Davalos A, Gomez-Cordoves C and Bartolome B. 2004. Extending applicability of the oxygen radical absorbance capacity (ORAC-Fluorescein) assay. J Agric Food Chem 52(l) 48-54. 

TAC assays referred to as oxygen-radical-absorbing capacity (ORAC) are based on the bleaching of fluorescence of R- or /3-phycoerythrin (C6, Cl5, G5, G10)... 

Over the years, a variety of assays to measure the total antioxidant capacity of pure substances, biological fluids, food extracts, and beverages have been developed. Among the most commonly used are the Trolox equivalent antioxidant capacity (TEAC), oxygen radical absorbance capacity (ORAC), and ferric reducing ability of plasma (FRAP) assays. 

Atala, E., A. Aspee, H. Speisky, E. Lissi, and C. Lopez-Alarcon. 2013. Antioxidant capacity of phenolic compounds in acidic medium A pyrogallol red-based ORAC (oxygen radical absorbance capacity) assay. J. Food Compos. Anal. 32(2) 116-125. 

---