Solid lipid nanoparticles stabilized with poloxamer 188 and tween 20; beta carotene stability and bioaccessibility
Canola stearin solid lipid nanoparticles (SLN) and canola oil emulsions with 10 Poloxamer 188 (P188) or Tween 20 (T20) with and without 0.01 wt % [beta]-carotene (BC) were produced by high pressure homogenization. D4,3 in the range of 130 nm were obtained for both SLN and emulsion droplets. The influence of encapsulation on SLN properties, BC stability and bioaccessibility was determined. The presence of BC did not alter SLN size, polymorphism or melting behaviour over 90 days of storage at 4 or 20 °C. BC losses in the emulsions were higher than in the SLN (P<0.05) and with T20 compared to P188 (P<0.05). P188 SLN contained only the [beta] polymorph, while the T20 SLN contained both [beta]' and [beta] polymorphs up to Day 90. Bioaccessibility experiments using an 'in vitro' model of digestion revealed higher lipolysis for the emulsions versus SLN, but similar and low micellization of BC for all systems.