Physicochemical Properties of Potato Starch Nanoparticles Produced by Anti-Solvent Precipitation

This work aims to understand the physicochemical properties of potato starch nanoparticles (SNPs) obtained by anti-solvent precipitation. Moisture content, water activity, color, morphology, thermal behavior (differential scanning calorimetry), swelling factor, solubility in water, water sorption isotherms, rheological properties, and stability in water are analyzed and compared using native potato starch (PS) as control. The resulting SNPs after anti-solvent precipitation have a particle size between 50 and 150 nm, smaller than those observed in PS (between 10 and 100 mu m). SNPs behave as an amorphous material without gelatinization stage where the swelling factor is drastically reduced, while the solubility increased dramatically at low temperatures when compared with PS. The Guggenheim-Anderson-de Boer model from the isotherms data allows a calculation of the surface area, obtaining values of 105 and 211 m(2)g(-1)for PS and SNPs, respectively. The high surface area in SNPs is associated with an increase in the proportion of hydroxyl groups active for water adsorption throughout its structure. Both samples show Newtonian fluid behavior; however, SNPs solutions prove to be much more stable at room temperature than PS solution.

Automated summary

SNPs obtained by anti-solvent precipitation have smaller particle size, reduced swelling factor, significantly increased solubility, and exhibit amorphous material behavior with higher surface area and more stable fluid properties compared to PS.