Kinetic of phospholipid oxidation in liposomal suspensions

Abstract

In this paper, the effects of temperature, the addition of a free radical generator and the lipid content on the oxidation rate of phospholipids were investigated. Soy lecithin liposomes obtained by reverse-phase evaporation method were employed to prepare liposomal suspensions containing 1 wt%, 5 wt% and 10 wt% of lipidic fractions. Different temperatures (37 °C, 60 °C and 80 °C) or 10 mmol/l of a water soluble free radical generator were used to promote lipid oxidation of suspensions. Peroxide value was measured as the lipid oxidation indicator and used to determine the kinetic parameters of oxidation. The results showed that the investigated factor exerted a significant effect (p<0.05) on the lipid oxidation rate, being these effects attributed to the modification of packing degree and radius of curvature by the studied factors. Besides, the temperature dependence of the reaction rate exhibited a normal Arrhenius pattern.