Influence of ball milling on the production of starch nanoparticles and its effect on structural, thermal and functional properties.

The starch nanoparticles from water chestnut (WS), lotus stem (LS) and horse chestnut (HS) starch were synthesized using planetary ball milling. The starch nanoparticles were investigated by using various techniques like particle size analyser, differential scanning colorimeter (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), rheometer, and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). The particle size of horse chestnut starch nanoparticles (HNS), water chestnut starch nanoparticles (WNS) and lotus stem starch nanoparticles (LNS) was found to be 343,271 & 855 nm with zeta potential of -18.75, -20.45 & -12.2 mV, respectively. SEM revealed small and damaged starch granules. The relative crystallinity was decreased from 13.13 to 6.22, 22.27 to 7.96 and 26.16 to 7.98% in HS, LS and WS starch after ball milling and average crystallite size of starch nanoparticles was found to be 9-12 nm. The starch nanoparticles also showed increase in transition temperature and viscosity as analysed by DSC and rheometer, respectively. These properties could be useful in particular food and drug formulations.