Interaction of Phosphatidylcholine and α‐Tocopherol on the Oxidation of Sunflower Oil and Content Changes of Phosphatidylcholine and Tocopherol in the Emulsion under Singlet Oxygen

Abstract

Interaction of phosphatidylcholine (PC) and α-tocopherol (α-Toc) on the oxidation of oil in the emulsion consisting of sunflower oil and water under singlet oxygen at 25 °C was studied by determining peroxide value (PV) and conjugated dienoic acid (CDA) contents. Singlet oxygen was produced by chlorophyll b under 1700 lux. Single addition of PC or α-Toc decreased the values of peroxides and CDAs of oil in the emulsion via singlet oxygen quenching. PC and α-Toc showed simply additive interaction in decreasing the singlet oxygen oxidation of oil in the emulsion. α-Toc was a physical quencher of singlet oxygen in the emulsion, but PC involved chemical quenching in the antioxidant action. Chlorophyll and PC contents were decreased in the emulsion under singlet oxygen, while α-Toc was not. α-Toc protected chlorophyll and PC from degradation, and was a more important component than PC in the oil oxidation under singlet oxygen in the emulsion.

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

“…An emulsion was prepared with purified oil (50 g) obtained from one of SFO, SBO, CO, and OO, distilled water (50 g), and xanthan gum (0.35 g) as a stabilizer, according to the method of Lee and Choe (2011) by using an Ultra‐Turrax T25 homogenizer equipped with an S25N‐25F dispersing tool (IKA Instruments, Staufen, Germany). Chlorophyll b dissolved in methylene chloride was added at 4 ppm to the emulsion followed by nitrogen blowing, and the chlorophyll and the emulsion was mixed at room temperature for singlet oxygen production, which was shown previously via indirect way with DABCO known as a singlet oxygen quencher (Lee and Choe 2011). The β‐carotene (0, 1, 5, 10 ppm) and PC (0 or 250 ppm) were then additionally put to the mixture at room temperature.…”

“…Degree of oil oxidation in the emulsion was determined by measuring the peroxide value (PV) and conjugated dienoic acid (CDA) contents through the AOCS (1998) methods Cd 8–53 and Ti1a‐64, respectively, after the phase separation by freezing of the emulsion at −20 °C for 48 h, thawing at room temperature for 24 h, and then centrifuging (Mikro 200; Hettich, Tuttlingen, Germany) at 3,420 × g for 10 min (Lee and Choe 2011). …”

“…Antioxidants or prooxidants and their polarity, oxygen concentration, and composition and conformation of fatty acids are important factors affecting the autoxidation of oil in the emulsion mostly catalyzed by metals (McClements and Decker 2000). Phosphatidylcholine (PC) used as an emulsifier was reported to decrease the oil oxidation and show a simple additive antioxidation with α‐tocopherol in an emulsion under singlet oxygen (Lee and Choe 2011). It is not easy to find reports on the interaction between phospholipids and carotenoids in the singlet oxygen oxidation of oil in the emulsion.…”

Effects of oil-droplet diameter on the stability of squalene oil in spray-dried powder

“…Conversely, some papers reported the opposite results. [39,[43][44][45] Regarding the effect of the oil-droplet diameter in the emulsion form, the underlying mechanism of SQ degradation is far from understood. A small number of reports demonstrate no significant effect of oil-droplet diameter on oxidative stability.…”

Effects of Basil Extract and Iron Addition on the Lipid Autoxidation of Soybean Oil-in-Water Emulsion with High Oil Content

“…콩기름(정제유, RBD oil; refined bleached and deodorized oil)은 삼양사(Seoul, Korea)로부터 공여받아 관크로마토그래피법 (Lee Y & Choe E 2011)에 의해 토코페롤을 제거한 후(tocopherolstripped soybean oil, TSSO) 사용하였다. 즉 RBD 콩기름 (60 g)을 n-헥세인(600 mL)에 녹여, 활성탄(2.5 g)과 180°C에서 활성화한 규산(silicic acid, 6 g), 알루미나(42 g), 규산(18 g), 셀라이트(celite, 16 g)를 순서대로 충진한 유리관(30 × 2.5 cm)에서 용출시켰다.…”