Modified Oxygen Radical Absorbance Capacity Assay that can be Implemented at Low Temperatures: A pilot study

In this paper, the feasibility of a modified oxygen radical absorbance capacity assay based on fluorescence (ORAC-FL) was evaluated. In the modified ORAC-FL assay, a large quantity of radicals is generated in a short period of time by photolysis of 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH), through illumination with ultraviolet light. Importantly, no heating is required to generate the radicals, while the time required to monitor the fluorescence intensity (FI) is shortened, owing to the rapid fluorescence decay. In this study, the optimal experimental conditions for the modified assay were determined and the antioxidant capacity of two samples was evaluated at room temperature using the modified assay. Although relative ORAC values were obtained, some aspects of the modified assay require further optimization for eventual practical use.