Optimising Gelatinisation–Ultrasound processing for starch nanoparticle production from cassava, quinoa, and faba Bean: Structural and functional characterisation

This study optimised the production of starch nanoparticles (SNPs) from cassava, quinoa, and faba bean starches using a combined gelatinisation-ultrasound treatment. Response surface methodology with a Box-Behnken design was used to optimise ultrasound parameters (power: 140-700W, sonication time: 10-30 min, and starch concentration: 1-5%). Optimised conditions (420W, 20 min, 3% concentration) effectively produced uniform nanoparticles (65.7-87.6 nm) with narrow size distributions (PDI: 0.317-0.410) across all three botanical sources, achieving a substantial 99.7% reduction in particle size compared to native granules. The modified SNPs displayed altered crystallinity patterns (transitioning from type-A and C to type-V) with significantly reduced relative crystallinity (60-65% reduction) and amylose content (29.6-58.7% reduction), while maintaining their fundamental chemical structure as confirmed by FTIR and NMR analyses. Notably, the SNPs exhibited substantially increased water solubility (95.1-98.2% compared to 5.3-10.4% for native starches), improved oil absorption capacity (87.2-105.5% versus 58.9-69.5%), and significantly increased slowly digestible starch fractions (up to 63.8% in faba bean SNPs). This optimised treatment provides a sustainable, chemical-free method for producing functional starch nanoparticles with tailored digestibility profiles and enhanced technological properties for diverse food applications. • Gelatinisation-ultrasound method produced uniform SNPs from cassava, quinoa, and faba starches. • SNPs showed reduced crystallinity and amylose content compared to native starches. • Water solubility and oil absorption capacity increased after nanoparticle formation. • SNPs displayed enhanced slowly digestible starch fractions, especially in faba bean.