Investigating the Antioxidant Effects of a Commercial Sunflower Derived Lecithin and Phosphatidylserine

Abstract

The search for natural antioxidants for use in food and nutritional supplements led to an in-depth investigation into the antioxidant effect of a commercial sunflower derived lecithin (CSL), consisting of high levels of phosphatidlyserine (PS) and smaller quantities of other phospholipids (PL) in a medium chain triglyceride base, stabilized with rosemary extract (RME) and DL-α-tocopherol (αT). This ingredient was found to have an antioxidant effect in fish oil stored at 40 °C under accelerated oxidation conditions. Therefore, the antioxidant effects of the three main active components in CSL, PS, RME and αT, were assessed in fish oil by monitoring the formation of primary and secondary oxidation products during oxidation.

PS was found to chelate metal ions and form Maillard browning products, both of which may have contributed to a slight protection against formation of primary oxidation products; PS did not offer any protective effect against the formation of secondary oxidation product.

RME was able to chelate metal ions and, in combination with PS, had a synergistic protective effect against the formation of hydroperoxides, the major primary oxidation products. However, there was no evidence of synergism with respect to secondary oxidation and the overall antioxidant effect of RME alone and PS+RME was not as great as CSL.

αT seemed to provide much of the antioxidant effect of CSL with respect to secondary oxidation products. The combination of RME and αT provided a hydroperoxide protective effect similar to CSL during early stages of oxidation and overall, the combination of PS, RME and αT had an equivalent protective effect against the rate of hydroperoxide development compared to CSL. However, the high cost of a lecithin rich in PS, such as CSL, or pure PS limits their industrial usefulness. Further investigation is recommended on the combination of RME and αT and their ability to achieve an equivalent or greater antioxidant effect as CSL.