Microchannel emulsification study on formulation and stability characterization of monodisperse oil-in-water emulsions encapsulating quercetin

The study used microchannel emulsification (MCE) to encapsulate quercetin in food grade oil-in-water (O/W) emulsions. A silicon microchannel plate (Model WMS 1-2) comprised of 10,300 discrete 10 × 104 μm microslots was connected to a circular microhole with an inner diameter of 10 μm. 1% (w/w) Tween 20 was used as optimized emulsifier in Milli-Q water, while 0.4 mg ml-1 quercetin in different oils served as a dispersed phase. The MCE was carried by injecting the dispersed phase at 2 ml h-1. Successful emulsification was conducted below the critical dispersed phase flux, with a Sauter mean diameter of 29 μm and relative span factor below 0.25. The O/W emulsions remained stable in terms of droplet coalescence at 4 and 25 °C for 30 days. The encapsulation efficiency of quercetin in the O/W emulsions was 80% at 4 °C and 70% at 25 °C during the evaluated storage period.