Crosslinking alginate at water-in-water Pickering emulsions interface to control the interface structure and enhance the stress resistance of the encapsulated probiotics.

HYPOTHESIS

The strategies for stabilizing water-in-water (W/W) emulsions include the adsorption of solid particles at the water-water interface and the generation of interfacial films. We hypothesize that if sodium alginate is crosslinked at the water-water interface of W/W Pickering emulsions, the microstructure and rheological properties of the emulsions could be improved, thus enhancing the activity of encapsulated probiotics in simulated gastrointestinal digestion.

EXPERIMENTS

The W/W Pickering emulsions comprised a dispersed maltodextrin (MD) phase in a continuous hydroxypropyl methylcellulose (HPMC) phase. The crosslinking W/W Pickering emulsion with fine-tuned internal structure was designed by leaching the CaCO particles packed in the dispersed phase to release Ca crosslinked with sodium alginate.

FINDINGS

Confocal laser scanning microscope results revealed sodium alginate crosslinked with Ca at the W/W interface. The rheological results of the crosslinking W/W Pickering emulsions suggested that the loss modulus (G″) was higher than the energy storage modulus (G'). The microstructure indicated that the emulsions formed a dense porous network structure after crosslinking conditions. The viable cell count of Lactobacillus helveticus CICC 22536 (LC) encapsulated in crosslinking W/W Pickering emulsion after simulated gastrointestinal digestion was 7.563 × 10 CFU/mL, which was three orders of magnitude higher than that of naked cells.