Edible solid lipid nanoparticles (SLN) as carrier system for antioxidants of different lipophilicity

Ferulic acid (FA) and tocopherol (Toc) loaded solid lipid nanoparticles (SLN) were prepared
by a hot homogenisation method. The particle size distribution, zeta potential and melting
behaviour of the SLN as well as the stability, encapsulation efficiency and radical scavenging
activity of FA and Toc in the SLN were analysed. The different formulations containing
up to 2.8 mg g−1 of FA or Toc were stable during at least 15 weeks of storage at room temperature.
Despite partial degradation and / or release of FA and Toc during storage, significant
radical scavenging activity was maintained. DSC measurements and radical
scavenging tests after different time periods revealed that the re-structuring of the lipid
matrix was connected to the enhanced antioxidant activity of Toc but did not affect the activity
of FA.