DPPH Measurements and Structure—Activity Relationship Studies on the Antioxidant Capacity of Phenols

Abstract

The consumption of foods that are high in antioxidant capacity is believed to contribute to good health. Moreover, the addition of highly antioxidant compounds to foods is believed to prevent food deterioration. Among the known antioxidants in food, phenols have been identified as the primary antioxidants. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay is a simple, inexpensive, and rapid method widely used to evaluate the antioxidant capacity. Although the results of the DPPH assay depend on conditions such as the reaction time and concentration, the experimental conditions have not been standardized. Further, previous research that compared the antioxidant capacity determined through the DPPH assay largely focused on the differences in the specific substructures of approximately several dozen compounds. In this study, we conducted DPPH assays on 169 phenols under the same experimental conditions and summarized the correlation between their structures and activity. This DPPH assay study is the first single-laboratory investigation of the largest number of components in terms of their Trolox equivalent antioxidant capacities. Further, the analysis method was reproduced in an interlaboratory collaborative study, enabling its application in the reproduction and comparison of measurements in other laboratories.

Capsule Dosage Forms Containing Natural Antioxidant Microcapsules of Cantigi Extract

“…After microcapsules formed, filtered, washed three times with n-hexane, and dried in an oven for 2 hours at 40-50˚C (Song et al, 2022;Brlek et al, 2021;& Yasin et al, 2021). Characterizations of microcapsules include organoleptic (color, odor, shape), recovery, moisture content, entrapment efficiency, drug loading, particle size distribution, bulk and tapped density (Raj et al, 2024;Hibrah et al, 2022;Ditjen Farmalkes, 2022;Song et al, 2022;& Choudhury et al, 2021), and antioxidant activity (Yamauchi et al, 2024).…”

“…Antioxidants may neutralize free radicals and protect the body from degenerative diseases such as cancer, heart disease, arthritis, cataracts, diabetes, and liver disease. They can destroy a reaction chain of free radical formation by donating H-atoms, reducing the concentration of reactive oxygen, reducing free radicals at the initiation stage, and chelating transition metal catalysts (Yamauchi et al, 2024).…”