Novel starch based emulsion gels and emulsion microgel particles: Design, structure and rheology

Abstract Novel starch-based emulsion microgel particles were designed using a facile top-down shear-induced approach. The emulsion droplets were stabilized using octenyl succinic anhydride (OSA) modified starch and incorporated into heat-treated and sheared native starch gels, forming emulsion gels. Using gelation kinetics and small deformation rheological measurements of sheared native starch gels and emulsion gels, OSA starch-stabilized emulsion droplets were demonstrated to act as “active fillers”. By varying native starch concentrations (15–20 wt%) and oil fractions (5–20 wt%), optimal concentrations for the formation of emulsion microgel particles were identified. Microscopy at various length scales (transmission confocal laser scanning and cryo-scanning electron microscopy) and static light scattering measurements revealed emulsion microgel particles of 5–50 μm diameter. These novel emulsion microgel particles created via careful combination of gelatinized native starch and OSA stabilised-emulsion droplets acting as active fillers may find applications in food and personal care industries for delivery of lipophillic molecules.