Effect of edible antioxidants on chemical stability of β-carotene loaded nanostructured lipid carriers

Nanostructured lipid carriers (NLC) containing beta-carotene was produced using solvent diffusion method. Edible antioxidants of butylated hydroxytoluene (BHT), vitamin E and vitamin C were successfully incorporated in NLC to protect beta-carotene. Response surface methodology (RSM) was employed in order to evaluate the effect of different antioxidants on beta-carotene stability. A quadratic polynomial model was fitted to empirical data with high accuracy. The beta-carotene retention improved with raising the BHT concentration while addition of vitamin C resulted in beta-carotene instability. Increasing the vitamin E concentration first elevated the beta-carotene degradation rate and then decreased it. However, the total effect of vitamin E alone was less significant. The statistical analysis demonstrated that the interactions between BHT and two other antioxidants had important effect on beta-carotene stability. The optimum formulations predicted by the model contained BHT and vitamin E combinations. They had minimum beta-carotene degradations of 2.12-4.51% which were in a reasonable agreement with model predictions. Furthermore, particles size analysis indicated that addition of antioxidants to NLCs results in production of larger nanoparticles.