Mechanism and Kinetics of Quenching of Quercetin on Photosensitizing Effect of Synthetic Food Colorant Erythosine in Palm Oil Oxidation
AbstractThe 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 Ãƒâ€” 109 M-1 S-1.
Key words : quercetin, Erythrosine, photo sensitized oxidation, singlet oxygen, palm oils and quenching mechanism and kinetics.