Storage Stability of Wheat Germ Oil Encapsulated within Nanostructured Lipid Carriers

The present study aimed to evaluate the effect of surfactant composition on the physical properties of nanostructured lipid carriers (NLCs) containing wheat germ oil (WGO) and to investigate the influence of both surfactant composition and pH on the oxidative stability of WGO encapsulated within the NLCs. The results showed that the smallest particle size (52.7 nm) was related to the NLC with the poloxamer-to-lipid ratio of 1:1 (Polox-NLC-1). Polox-NLC-1 not only showed good stability during storage, but also indicated a suitable physical structure from differential scanning calorimetry (DSC) analysis. The oxidative stability results indicated that the NLCs were more successful than O/W emulsion in protecting the WGO from oxidation. Additionally, the oxidative stability of the NLC with the poloxamer-to-lipid ratio of 2:1 (Polox-NLC-2) looked promising. Furthermore, NLCs prepared with the surfactant of poloxamer as a non-ionic surfactant had greater oxidative stability at high pH, and NLC prepared with sodium dodecyl sulfate (SDS) as an ionic surfactant had greater oxidative stability at low pH. These findings indicated that NLC could be an effective delivery and protection system for the WGO as a source of bioactive compounds.