Nano-starch for food applications obtained by hydrolysis and ultrasonication methods

In the present work, corn (CS) and waxy corn starch (WCS) with different amylose content (determined with the UV-vis spectroscopy) were subjected to acid hydrolysis, ultrasound, and a combination of both, performed at a raised temperature and short period, to obtain nanoparticles (nano-WCS and nano-CS). Scanning transmission electron microscopy (TEM-STEM) proved the effectiveness of the proposed method for nanoparticle synthesis with a size below 5 nm. FTIR spectroscopy and X-ray diffraction (XRD) delivered information on their molecular structure (i.e., reduction in nano-CS crystallinity degree (Xc) arising from higher amylose content and more stable Xc for nano-WCS). Thermogravimetric analysis (TGA) combined with FTIR analysis of gaseous products of thermal decomposition was also performed. The thermal stability decreased in varying degrees for nano-WCS and nano-CS. Less susceptibility of waxy corn starch for modification was proven. Nanoparticles are expected to be effective for functional food, and biomedical applications.

Automated summary

In this study, nanoparticles (nano-WCS and nano-CS) were successfully synthesized by acid hydrolysis and ultrasound treatment of corn and waxy corn starch with different amylose content. TEM-STEM confirmed the size of the nanoparticles to be below 5 nm. FTIR and XRD analysis provided information on the molecular structure and thermal stability of the nanoparticles. The results suggest that these nanoparticles have potential applications in functional food and biomedical fields.