Singlet Oxygen Quenching Effects of Phosphatidylcholine in Emulsion Containing Sunflower Oil

Abstract

Effects of phosphatidylcholine (PC) on the oxidation of oil by singlet oxygen in a W/O microemulsion and an emulsion food model containing tocopherol-stripped sunflower oil (TSSO) have been studied. The W/O microemulsion consisted of methylene chloride, butanol, and sodium dodecyl sulfate with PC (0, 250, 1000 ppm) and TSSO (0, 3.3, 16.5, 33 mg/mL). Production of singlet oxygen in the microemulsion was done chemically with hydrogen peroxide in the presence of sodium molybdate, and indirectly evaluated by rubrene oxidation at A529. The emulsion food model consisted of TSSO, distilled water, and xanthan gum with addition of 250 ppm PC and 4 ppm chlorophyll b, and was placed at 25 degrees C under fluorescent lights (1700 lux) for 24 h. The oxidation of TSSO was determined by thin-layer chromatography and values of conjugated dienoic acid (CDA) and peroxides (POV). PC significantly decreased the oxidation of rubrene and TSSO in the W/O microemulsion, but its content was decreased to approximately one-half by a 20-min reaction, indicating its degradation. This clearly shows that PC acted as an antioxidant via chemical quenching of singlet oxygen in the W/O microemulsion. A possible synergism between PC and TSSO was observed in singlet oxygen quenching in the microemulsion. PC also significantly decreased the chlorophyll-photosensitized oxidation of TSSO in the emulsion food model, possibly by singlet oxygen quenching. This study clearly suggested that PC be used as an antioxidant to improve the lipid oxidative stability of an emulsion food containing chlorophyll under light.

Effects of Phosphatidylcholine and Phosphatidylethanolamine on the Photooxidation of Canola Oil

“…PC and PE were, therefore, definite prooxidants in the photooxidation of TSCO containing chlorophyll. This result on the prooxidant activity of PC and PE in the photooxidation of triacylglycerol containing chlorophyll is the 1st report, although singlet oxygen quenching activity of PC in the emulsion containing sunflower oil was reported elsewhere (Lee and Choe 2008). Krasnovsky and Kagan (1979) reported singlet oxygen quenching by egg lecithin with the reaction rate of 5 × 10 4 M −1 s −1 in a single system of carbon tetrachloride photosensitized by protoporphyrin under 627 nm light.…”

Effects of Fatty Acid Composition and β‐Carotene on the Chlorophyll Photosensitized Oxidation of W/O Emulsion Affected by Phosphatidylcholine

“…This indicates that both β‐carotene and PC decreased the singlet oxygen oxidation of oil in the emulsion under chlorophyll photosensitization. β‐carotene is a very well‐known antioxidant via singlet oxygen quenching (Choe and Min 2005), and PC decreases the oil oxidation by chemical quenching on singlet oxygen (Lee and Choe 2008). Although addition of β‐carotene decreased the PV of the emulsion, addition level of β‐carotene, 1, 5, or 10 ppm, did not show significantly different effects on PV decreases.…”

Large-Scale Production of Phospholipase D from Streptomyces racemochromogenes and Its Application to Soybean Lecithin Modification

“…The PL content of lecithin is predominantly phosphatidylcholine (PC), with smaller amounts of phosphatidylethanolamine (PE), phosphatidylglycerol (PG), phosphatidylserine (PS), and phosphatidylinositol. Owing to their interfacial activity, emulsification properties, and ability to form liposomes, lecithin-derived PLs are included in food products, cosmetics, and pharmaceuticals as an emulsifier, stabilizer, and antioxidant [1][2][3][4][5]. Of the minor PL constituents of lecithin, PG provides emulsification stability to oil-in-water emulsions over a wide range of temperatures [6].…”