Guinea Grass Seed Starch Nanoparticles and Their Modification: Characterization and Applications in Pickering Emulsions

Abstract

Guinea grass seed starch nanoparticles (GSNPs) Were prepared via nanoprecipitation and dual‐modified with 3% octenyl succinic anhydride (OSA) and pulsed electric fields (PEF) (1.5, 3.0, and 4.5 kV cm⁻¹). Native and modified GSNPs Were assessed for cytotoxicity (Caco‐2 cells), in vitro digestibility, and their ability to stabilize Pickering emulsions. The cytotoxicity results showed no significant impact on cell viability or metabolic activity across all concentrations and modifications. The digestibility profile revealed that native GSNPs Were more digestible (62.61%) compared to modified samples (53.49%). The logarithmic slope analysis indicated that the digestion profiles of all samples followed a linear trend (r² 〉 0.86), characterized by first‐order kinetics. Pickering emulsions containing 0.25–2% GSNPs exhibited good stability, with higher concentrations (1–2%) ensuring 100% emulsified phase coverage and excellent storage stability. Droplet sizes ranged from 171.32 to 536.41 nm, and zeta potentials from −28.68 to −9.87 mV over two months. Microscopy confirmed that all emulsion droplets Were spherical, with smaller droplet sizes observed. The emulsions displayed shear‐thinning flow behavior, where apparent viscosity decreased with increasing shear rate, and increased with modification. These findings suggest that GSNPs have significant potential for use in forming stable Pickering emulsions.