Evaluation of synergistic and antagonistic effects between some selected antioxidants by means of an electrochemical technique

Abstract

This work presents a systematic study of the possible interactions in mixtures of the natural antioxidants eugenol, thymol, sesamol and limonene. The antioxidant capacity is measured from the decrease of the DPV signal corresponding to the H2O2 oxidation on a mercury electrode in the presence of the antioxidants. A three-level full factorial design was used to analyse the antioxidant capacity of forty five mixtures. The higher synergistic effect was reached in the mixtures containing eugenol and sesamol (antioxidant capacity increases in a 28.5%). The synergistic and antagonistic effects of the combinations having the lower antioxidant capacity (thymol, sesamol and limonene) ranged between 20.2–26.3% and 8.6–11.8%, respectively. An increase in the eugenol concentration implies a progressive increase in the global synergy, not proportional to the concentration. A possible explanation of the synergy related to the oxidation mechanisms and to the possibility of interaction with the radicals is given.