Effects of phosphatidylcholine and phosphatidylethanolamine on the photooxidation of canola oil.

Effects of chlorophyll b, phosphatidylcholine (PC), and phosphatidylethanolamine (PE) on the oxidation of canola oil under 1700 lux light at 10 degrees C were studied by determining the headspace oxygen depletion and peroxide value. Chlorophyll b increased the oil oxidation under light via production of singlet oxygen. PC and PE did not affect the headspace oxygen depletion and peroxide formation in the oil in the absence of chlorophyll b at 10 degrees C; however, they increased in the presence of chlorophyll, with higher effect of PC than PE. Chlorophyll was degraded during the oil photooxidation and PC and PE decreased its photodecomposition with higher protection by PC than PE. There was no effect of light or singlet oxygen on PC and PE during the oil photooxidation. The results clearly showed that PC and PE were prooxidants in the photooxidation of canola oil containing chlorophyll b by protecting it from photodecomposition, and thus PC and PE should be removed from the oil containing chlorophyll to improve the photooxidative stability.