Formulation of monodisperse oil-in-water emulsions loaded with ergocalciferol and cholecalciferol by microchannel emulsification: Insights of production characteristics and stability

Nutritional deficiencies of ergocalciferol (VD<inf>2</inf>) and cholecalciferol (VD<inf>3</inf>) cause skeletal deformations. The primary aim of this study was to encapsulate VD<inf>2</inf> and VD<inf>3</inf> in food-grade oil-in-water (O/W) emulsions by using microchannel emulsification (MCE). Silicon asymmetric straight-through microchannel (MC) array consisting of 10 313 channels, each having an 11 × 104 μm microslot connected to a 10 μm circular microholes. 1% (w/w) sodium cholate or Tween 20 in water was used as the continuous phase, while 0.5% (w/w) of each VD<inf>2</inf> and VD<inf>3</inf> in different oils served as the dispersed phase. Monodisperse O/W emulsions with Sauter mean diameters of 28 to 32 μm and relative span factor widths below 0.3 were formulated via an asymmetric straight-through MC array under appropriate operating conditions. The monodisperse O/W emulsions stabilised with Tween 20 remained stable for >30 days with encapsulation efficiencies (EEs) of VD<inf>2</inf> and VD<inf>3</inf> of above 70% at 4 and 25 °C. In contrast, those stabilised with sodium cholate had stability of >30 days with their EEs of over 70% only at 25 °C.