[Characterization of plant phenolic compounds by cyclic voltammetry]

Area of Science:

• Biochemistry
• Electrochemistry
• Food Chemistry

Background:

• Phenolic compounds are vital antioxidants found in plants.
• Understanding their antioxidant mechanisms is crucial for various applications.
• Electrochemical methods offer precise characterization of antioxidant activity.

Purpose of the Study:

• To characterize phenolic acids and flavonoids using cyclic voltammetry.
• To determine the relationship between electrochemical properties and antioxidant activity.
• To elucidate the reaction mechanisms of phenolics with ABTS cation radicals.

Main Methods:

• Cyclic voltammetry was employed to determine anode peak voltages (Eap) and pH dependence.
• Total antioxidant activity was assessed using the ABTS cation radical assay.
• Correlation analysis was performed between electrochemical parameters and antioxidant capacity (TEAC).

Main Results:

• A correlation was found between Eap and Trolox equivalent antioxidant capacity (TEAC) for polyphenols reacting in two steps.
• For irreversible compounds, a correlation was established between half-wave potential (Ep/2) and TEAC.
• Proposed reaction mechanisms involve one- and two-electron oxidation steps.

Conclusions:

• Electrochemical characterization provides valuable insights into the antioxidant potential of phenolic compounds.
• The study elucidates the electrochemical behavior and reaction pathways of phenolics.
• Findings contribute to understanding the antioxidant mechanisms of phenolic acids and flavonoids.