Stabilization of emulsions by high-amylose-based 3D nanosystem

Abstract

High-amylose maize starch (HAS) was used to produce a fibrous 3D network nanosystem aiming at providing an efficient and stable emulsion stabilizer characterized by being robust against storage, freeze-thawing, high temperatures and mechanical shearing. This approach is principally different from the usually applied stabilization systems based on surfactants or small solid particles. Here, we utilized a sodium hydroxide-based low-temperature, chemical gelatinization protocol to minimize molecular degradation, and ethanol nanoprecipitation to reassociate the polysaccharides nanoparticles (NPs) to form a 3D nanosystem. Octenyl succinic anhydride (OSA) substitution was used for modulation of the amphiphilic properties of the nanosystem to enhance the emulsfying capacity. With increased OSA substitution, light transmittance of the NPs solutions increased and the size distribution of the NPs decreased down to 100 nm. The obtained emulsions were characterized by being water in oil (W/O) systems, and the NPs were distributed in the oil phase. OSA substitution and NPs concentration contributed combinedly to the emulsification capacity. The nanosystem, at 5% concentration with 20% OSA modification, had droplets of approximately 1 μm in diameter, and could withstand a 60-day-long storage, five-cycle freeze-thaw and thermal stability tests. In addition, it also displayed higher mechanical stabilities to shear-thinning. • High amylose maize starch-based 3D network was processed by a simple method. • Such nanosystems can stabilize the emulsions with high performance. • The emulsions were resistant to storage, freeze-thaw, heat, and mechanical shear. • The emulsion droplets were restricted in the range from 1 to a few μm.