Tunable high internal phase emulsions stabilized by cross-linking/ electrostatic deposition of polysaccharides for delivery of hydrophobic bioactives

We have explored a controllable approach to produce polysaccharide-based high internal phase emulsions (HIPEs) without the use of any surfactants, synthetic particles, or synthesis of Pickering emulsions. This strategy required only the centrifugation of ultrasonication-produced shell cross-linked polysaccharide microspheres, and simultaneously provided facile control over the properties of HIPEs. By this means, the strong viscoelastic HIPEs with high oil volume fraction (up to 85.6%) can be stabilized solely by 0.5 wt% polysaccharide. We can further strengthen the HIPEs by generating an additional complex shell through the electrostatic deposition of non-cross-linked polysaccharides back on the cross-linked microsphere surface. Using β-carotene as a model hydrophobic bioactive, these HIPEs stabilized by cross-linking/electrostatic deposition of polysaccharides featured high encapsulation efficiency, oxidation stability, and pH/redox dual stimuli-responsive release. Further development of this strategy could exhibit a great potential to construct tunable HIPEs with desired functionalities for smart delivery and oral adsorption of hydrophobic food active ingredients. • An ultrasonication/centrifugation combined strategy is used for HIPE production. • HIPEs are stabilized by cross-linking/electrostatic deposition of polysaccharides. • The properties of HIPEs can be precisely tuned with desired functionalities. • The HIPEs feature pH and redox dual stimuli-responsive release.