Encapsulation of β-sitosterol plus γ-oryzanol in O/W emulsions: Formulation characteristics and stability evaluation with microchannel emulsification

beta-Sitosterol and gamma-oryzanol have reduced solubility in aqueous based formulations. In this study beta-sitosterol (beta-st) and gamma-oryzanol (gamma-oz) were encapsulated at relatively high concentrations in different foodgrade oilinwater (O/W) emulsions using straightthrough microchannel emulsification. The innovative aspect of this study was the production of monodisperse droplets with high encapsulation efficiency and stability of beta-sitosterol and gamma-oryzanol. Milli-Q water containing 1% (w/w) Tureen 20 or decaglycerol monolaurate (ML-750) was used as the continuous phase and the dispersed phase contained 0.5-4% (w/w) each of beta-st and gamma-oz in medium chain triglycerides. Successful droplet generation was conducted with different concentrations of beta-st and yoz. The Sauter mean diameter of 1% (w/w) beta-st and gamma-oz loaded O/W emulsions ranged between 26 and 28 mu m with relative span factor width below 0.21. These emulsions were stable at 4 and 25 degrees C during evaluated storage period. The emulsions stabilized with Tureen 20 have encapsulation efficiencies of beta-st and gamma-oz (EE beta.st and EE gamma-oz) above 80% at 4 and 25 degrees C; those stabilized with ML-750 have EE beta-st over 80% and EE gamma-oz above 50% at 4 and 25 degrees C. (C) 2017 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.