oxygen consumption and hydroperoxide production of the control emulsion under chlorophyll-photosensitized oxidation were significantly higher than those under iron-catalyzed autoxidation (P 0.05); headspace oxygen consumption of the control emulsion without soybean lecithin addition after 6 and 10 d of oxi dation was 5.46 and 6.53 pumol O2/mL, while hydroperoxide content was 6.63 and 8.16 mmol CuOOH/kg, respectively. This result clearly confirms higher oil oxidation in the emulsions under light in the presence of chlorophyll than in the dark in the iron presence. Chlorophyll acts as a photosensitizer for the production of singlet oxygen, whose reactivity with lipids is approximately 1400 times higher than that of triplet oxygen (Choe and Min 2006) Unlike iron-catalyzed oxidation, addition of soybean lecithin did not significantly reduce oxygen consumption or hydroperoxide production in the emulsions under chlorophyll-photosensitized oxidation. Oxygen consumption and hydroperoxide content of the emulsion with added soybean lecithin after 2, 6, and 10 d of oxidation were 1.92 mol O2/mL and 2.47 mmol CuOOH/kg, 5.19 mol O2/mL and 7.57 mmol CuOOH/kg, and 6.52 mol O2/m L and 8.22 mmol kg, respectively, which were not significantly different from those of the control emulsion (P> 0.05). These results indicate that soybean lecithin did not affect chlorophyll-photosensitized oxidation of the canola oil emulsions. Until now, the effect of PLs on chlorophyll-photosensitized oxidation in emulsions has not been reported.