Effects of Phosphatidylcholine and Phosphatidylethanolamine on the Photooxidation of Canola Oil

Abstract

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.

Effects of Seed Roasting on Tocopherols, Carotenoids, and Oxidation in Mustard Seed Oil During Heating

“…Tocopherols were determined by using HPLC [21]. The oil was dissolved in hexane and filtered through a 0.2-lm PTFE membrane filter (Toyo Roshi Kaisha, Tokyo, Japan).…”

Effects of solubility characteristics of sensitiser and pH on the photooxidation of oil in tuna oil-added acidic O/W emulsions

“…Tocopherols were completely removed from these oils by passing the oil with n-hexane through a glass column (30 mm i.d. Â 300 mm) packed with alumina (Type WN-3; SigmaAldrich Co., St. Louis, Mo., USA) according to the method of Lee and Choe (2009). The n-hexane in the eluent was completely removed by a rotary evaporator (N,N series; Eyela, Tokyo, Japan) at 40°C to achieve tocopherol-stripped canola (TSCO) and tuna oil (TSTO).…”

“…The headspace oxygen content was determined by gas chromatography (Lee & Choe, 2009). The headspace gas (0.5 ml) of the sample vial was injected into a Younglin M600D gas chromatograph (Younglin Co., Ltd.) with a 2.5 ml gas-tight syringe (Hamilton Co., Reno, NV, USA).…”

“…The n-hexane in the eluent was completely removed by a rotary evaporator (N,N series; Eyela, Tokyo, Japan) at 40°C to achieve tocopherol-stripped canola (TSCO) and tuna oil (TSTO). The fatty acid compositions, peroxide and conjugated dienoic acid contents, and tocopherol contents of the TSCO and TSTO were analyzed by gas chromatography (Lee & Choe, 2009), AOCS Cd 8-83 and Ti 1a-64 methods (1990), and HPLC (Lee, Lee, & Choe, 2007), respectively. Chlorophyll b, diazabicyclooctane (DABCO), and cumene hydroperoxide (CuOOH) were products of Sigma-Aldrich Co. (St. Louis, Mo., USA), and egg yolk powder was purchased from Into Food Co. (Incheon, Korea).…”

“…It has been shown that oil autoxidation in an emulsion system occurs differently from that in a bulk oil system since an interface is present (McClements & Decker, 2000), and thus mass transfer is an important key in the oil oxidation of emulsions (Liu, Fu, Yin, & Liao, 2005;McClements & Decker, 2000). Pigments, such as chlorophyll or riboflavin can cause fast singlet oxygen-related oxidation in emulsions under light (Huang, Choe, & Min, 2004;Lee & Choe, 2008). Depending on the composition of an emulsion, pH varies, which might have different effects on the photooxidation of oil in an emulsion containing sensitisers.…”