The role of alginate in starch nanocrystals-stabilized Pickering emulsions: From physical stability and microstructure to rheology behavior

Sodium alginate (SA) was used as co-stabilizers to improve the Pickering emulsions stabilized by starch nanocrystal (SNC). Compared with pure SNC, SNC/SA complexes possess better neutral wettability with the contact angle approaching to 90°, more surface negative charges, and lower oil–water interfacial tension. These properties of particles make as-prepared emulsion higher stability with the lower creaming index, average droplet size. Furthermore, the emulsion exhibited good stability against salt concentration (0–600 mM) and pH (2.0–6.0) at higher SA concentration (1.0 wt%). Confocal laser scanning microscopy (CLSM) images proved that SNC could be effectively adsorbed at the oil–water interface with the aid of SA. The higher viscosity and strength of emulsion were formed as the SA content increasing in rheological analysis results. Results from this work indicating that SA could be useful co-stabilizer to fulfill the demands of Pickering emulsions stabilized by SNC with stable characteristics.