Mechanical force-induced dispersion of starch nanoparticles and nanoemulsion: Size control, dispersion behaviour, and emulsified stability

High amylose starch nanoparticles (HS-SNPs) were rapidly synthesised by high-speed circumferential force of homogenisation (3000 and 15,000 rpm) during nanoprecipitation. Morphology and dynamic light scattering analyses showed that HS-SNPs fabricated by stronger circumferential shearing were excellent stabilisers in smaller sizes (20-50 nm). Their aggregates were liable to separate in the aqueous phase with the nano effect under either homogenisation over 6 min or ultrasonication in 2 min. SNP-based nanoemulsion (<200 nm) of high-water fraction was achieved, though the high hydrophilicity of the SNPs were identified by the contact angle. For homogenisation (with 100-2000 nm emulsion size), only time prolongation led to a better dispersion of SNP aggregates. Ultrasonication with periodic cavitation could disintegrate SNP aggregates into micro aggregates for a stable emulsion system in a short period. In contrast, long-term ultrasound caused simultaneous re-agglomeration and solubilisation of the SNPs, leading to weakened interface barriers and decreased storage stability.

Automated summary

High amylose starch nanoparticles (HS-SNPs) were rapidly synthesized by high-speed circumferential force of homogenization, showing excellent stabilizing properties in smaller sizes due to stronger circumferential shearing. Ultrasonication could disintegrate SNP aggregates into micro aggregates for a stable emulsion system, but long-term ultrasound led to re-agglomeration and decreased storage stability.