Ultrafine Starch Particles as Pickering Emulsion Stabilizers With Different Interfacial Behaviors

Native starch Pickering stabilizer without chemical modification has attracted research interest in food field. However, the behaviors of starch particles at interface are seldom studied. In this paper, ultrafine starch particles (USPs) are grounded with a planetary ball mall from various starch species down to 1–2 µm in size. USP and starches are used to prepare Pickering emulsions. With size decrease, USP has more negative zeta potentials, stronger hydrogen bonds, better hydrophilicity, and better emulsifying abilities than their counterparts of starches. Millet starch has better emulsion stability than OSA modified starch. Glutinous USP outperforms in stabilization due to higher emulsion height and no oil phase separation. USP behaves differently at interface or in water phase, which is attributed to starch species, amylose and amylopectin contents, and gelatinization. This work can inspire the behavior investigation of starch particles in nano/micrometers at interface during storage.