Multi-Method Screening of Commercial Antioxidant Supplements: Antioxidant Activity and Selected Antioxidant Compound...

Area of Science:

• Nutritional Science
• Food Chemistry
• Pharmacognosy

Background:

• Growing interest in dietary antioxidant supplements due to potential dietary shortfalls.
• Need for comprehensive evaluation of commercially available antioxidant supplements.
• Focus on supplements in the Polish market, including single and multi-component types.

Purpose of the Study:

• To assess and compare the antioxidant activity and polyphenol profiles of various antioxidant supplements.
• To investigate the relationship between polyphenol content, specific compounds, and overall antioxidant capacity.
• To evaluate the suitability of different analytical methods for supplement characterization.

Main Methods:

• Analysis of 96 antioxidant supplements from diverse manufacturers.
• Quantification of total polyphenol content using the Folin-Ciocalteu method.
• Evaluation of antioxidant activity via Ferric Reducing Antioxidant Power (FRAP), DPPH radical scavenging, and electrochemical assays.
• High-Performance Liquid Chromatography (HPLC) for profiling specific antioxidant compounds.

Main Results:

• Significant variation in total polyphenol content (0.146–177.499 mg GAE/g) and antioxidant activity across supplements.
• Strong correlations found between FRAP, DPPH assays, and total polyphenol content.
• Electrochemical response showed moderate correlation with total polyphenols and specific compounds like rutin, quercetin, and resveratrol.
• Antioxidant activity linked to specific compound profiles and distribution, not solely total polyphenol content.

Conclusions:

• Antioxidant supplement efficacy is influenced by the specific composition and interplay of various compounds.
• Total polyphenol content is an indicator but does not fully represent the antioxidant potential.
• Employing multiple complementary assays is crucial for a thorough evaluation of antioxidant supplements.