Hi,

Please see the descriptions in the following article.

Article Antioxidant capacity and total phenolics of Cyphostemma digi...

"Due to the circumstances mentioned above it was necessary to get a trend in the data to facilitate the comparison of antioxidant capacity between different methods, therefore, the data from each method were transformed to a relative antioxidant capacity index (RACI) by assuming the maximum value in each method as 100% and the others expressed as percentage of the maximum value (Table 2)."

I'm very skeptical to use RACI because it does not have much chemical sense. Each antioxidant assay is developed for certain conditions (solvent, pH, temperature, etc). Commonly, the results from different assays are expressed in different units and not consistent with each other. First, I would identify your goal and then choose the best assay(s) for you goal. The comparison of assays can not be the goal. The assays are tools to study certain properties of individual compounds or their mixtures.

Article Chemical composition, quality attributes, antioxidant activi...