Spectrophotometric determination of antioxidant activity

Area of Science:

• Biochemistry
• Analytical Chemistry

Background:

• The spectrophotometric technique for total antioxidant activity (TAA) is crucial for assessing the capacity of substances to neutralize free radicals.
• Measuring antioxidant potential is vital across various fields, including nutrition, medicine, and food science.

Purpose of the Study:

• To detail the spectrophotometric method for determining total antioxidant activity (TAA) using the 2,2'-azino-bis(3-ethylbenz-thiazoline-6-sulfonic acid) (ABTS) radical cation.
• To highlight the adaptability and applications of the ABTS assay for diverse sample types and analytical strategies.

Main Methods:

• The assay measures the relative ability of antioxidants to scavenge the ABTS radical cation (ABTS(•+)) compared to Trolox standards.
• It utilizes a spectrophotometric analyzer and is based on the consumption of antioxidant activity by ABTS(•+).
• Optimized conditions (hydrogen peroxide concentration, measuring time) are described for pure substances and biological samples, with enhanced sensitivity for LDL and saliva.

Main Results:

• The ABTS assay provides a simple, automatable method for TAA determination without specialized equipment.
• Measurement at 734 nm minimizes interference from turbidity and non-specific absorbance.
• The assay is versatile, applicable to plasma, saliva, lipoproteins, foods, and beverages.

Conclusions:

• The described spectrophotometric ABTS assay is a robust and adaptable tool for quantifying total antioxidant activity.
• Its simplicity and avoidance of interference make it suitable for a wide range of research and diagnostic applications.
• Further applications and discussions of the ABTS antioxidant assay are presented.