Mechanism and Kinetics of Quenching of Quercetin on Photosensitizing Effect of Synthetic Food Colorant Erythosine in Palm Oil Oxidation

Abstract

The effect 0, 200, 400, 600, 800 and 1000 ppm (wt/vol) quercetin on the singlet oxygen oxidation of palm oil in methylene chloride containing 100 ppm erythrosine, were studied during storage under 400 lux fluorecent light for 5 h by measuring peroxide value. Steady-state kinetic approximation was used to determine the quenching mechanism and quenching rate constant of quercetin in the erythrosine-sensitized photo oxidation of palm oil. Erythrosine greatly increased the As photo oxidation of palm oil, as was expected. Quercetin was extremely effective at minimizing erythrosine-sensitized photo oxidation of palm oil. As the concentration of quercetin increased from 0 to 200, 400, 600, 800 and 1000 ppm, the peroxide value of palm oils decreased significantly (p<0.05). The steady-state kinetic studies indicated that quercetin quenched singlet oxygen only to minimize the peroxide value of palm oils. The calculated total quenching rate of quercetin was 3,8 × 10⁹ M^-1 S^-1.

Key words : quercetin, Erythrosine, photo sensitized oxidation, singlet oxygen, palm oils and quenching mechanism and kinetics.