Rapid high-throughput assay to assess scavenging capacity index using DPPH

Area of Science:

• Analytical Chemistry
• Food Science
• Biochemistry

Background:

• Assessing antioxidant capacity is crucial for understanding the health benefits of compounds and foods.
• The 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay is a widely used method for this purpose.
• Traditional DPPH assays can be time-consuming and require larger sample volumes.

Purpose of the Study:

• To develop a rapid, microplate-adapted DPPH assay for efficient antioxidant capacity determination.
• To introduce the scavenging capacity index (SCI) as a key parameter for quantifying antioxidant potential.
• To validate the assay's performance with both pure compounds and food matrices.

Main Methods:

• A microplate-adapted DPPH assay was optimized using a buffered methanol-Tris system (pH 7.5).
• The reaction time was reduced to 10 minutes for increased speed.
• The scavenging capacity index (SCI) was calculated to represent antioxidant capacity.

Main Results:

• The assay demonstrated high reproducibility with a relative standard deviation (RSD) below 8.12%.
• SCI values obtained for pure compounds (gallic acid, quercetin, catechin, trolox, ascorbic acid, glutathione) were comparable to literature.
• Antioxidant capacities of various juices and date syrup were successfully quantified and aligned with previous findings.

Conclusions:

• The developed microplate-adapted DPPH assay is a rapid, reliable, and efficient method for assessing antioxidant capacity.
• This assay is suitable for high-throughput screening of antioxidant properties in diverse samples.
• The SCI parameter provides a valuable metric for comparing antioxidant potential across different substances.