Colloidal phytosterols: synthesis, characterization and bioaccessibility

We demonstrate the synthesis of phytosterol colloidal particles using a simple food grade method based on antisolvent precipitation in the presence of a non-ionic surfactant. The resulting colloidal particles have a rod-like shape with some degree of crystallinity. The colloidal dispersions display good stability assured by surface charge, due to the presence of water and hydroxyl groups on the particle surface, and by steric stabilisation, due to the presence of a non-ionic stabiliser. In vitro bioaccessibility experiments demonstrated that colloidal phytosterol can be effectively solubilised in model dietary mixed micelles and the micellar cholesterol concentration can be effectively reduced by 47% within two hours.