Thermal oxidation of phospholipids 1,2‐dipalmitoyl‐sn‐glycerol‐3‐phosphoethanolamine

Abstract

The purpose of this study was to compare thermal oxidation of phospholipids with that of triglycerides. Two simple saturated sys‐tems were chosen: 1, 2‐dipalmitoyl‐sn‐glycerol‐3‐phosphoethanolamine and tripalmitoylglycerol. Samples were heated at 150 C for 1 hr in air and the resulting volatile compounds analyzed qualitatively and quantitatively. Alkanes, ketones and lactones were major products in both cases. However, qualitative and quantitative differences were observed. Alkanals were absent in the oxidized phospholipid. This apparently is largely due to their reaction with the amine group as evidenced by thin layer chromatography. In addition, the phospholipid produced 2‐pentanol, 2‐methyl‐l‐pro‐panol and ethyl hexadecanoate; smaller amounts of hydrocarbons and methyl ketones than with the triacylglycerol; and no 1‐alkanols. Mechanisms which could be responsible for these observations are proposed.

Effect of cysteine and ribose on the volatile thermal degradation products of a triglyceride and three phospholipids

“…A complete absence of aldehydes has been reported in heated 1,2-dipalmi toyl-sn-glycerol-3-phosphoethanolamine, in contrast to tripalmitin, and it was suggested that these compounds were undergoing immediate reaction with the ethanolamine group (Jewel1 and Nawar 1980). The reaction between cdrbonyl compounds and ethanolamine has also been shown to give browning (Suyama and Adachi 1979;Husain et af 1986).…”

Identification and kinetics of oxidized compounds from phosphatidylcholine molecular species

“…Most of these studies used drastic oxidative treatments (Fenton reaction: FeCl 2 + H 2 O 2 or FeSO 4 + tert-butylhydroperoxide) that did not reflect processing or cooking conditions that a food matrix is usually subjected to (Reis, Domingues, Amado, Ferrer-Correia, & Domingues, 2005, 2007Reis, Domingues, Ferrer-Correia, & Domingues, 2004;Spickett, Pitt, & Brown, 1998). In addition, while volatiles were investigated (Jewell & Nawar, 1980;Lin & Blank, 2003;Meynier, Genot, & Gandemer, 1998;Stephan & Steinhart, 1999), no data is available on heat-generated oxidation products.…”

Phospholipids of palm oil (Elaeis guineensis)

“…It is notable that, apart from our discussion of the direct and indirect roles of phospholipids in palm oil, other interesting observations have been documented (7)(8)(9)(10)(11)29,30). For example, the antioxidant activity of phospholipids has been taken for granted in many studies involving other lipids (12)(13)(14).…”