Hydrophobically modified starch using long-chain fatty acids for preparation of nanosized starch particles

An efficient method for synthesis of hydrophobically modified starch without using organic solvents is described. The esterification of starch was performed with long chain fatty acid chlorides (C8, C12, C16), in two steps. In the first step, native starch was dispersed in an alkali reaction medium, and in the second step, it was treated for esterification. Finally, hydrophobic starch esters were obtained with moderate degrees of substitution (DS-values < 0.45). The reactivity of corn and potato starches under the same reaction conditions was also studied. The chemical structural determinations of the obtained products were investigated using common spectroscopy methods, such as FTIR and 1H NMR spectra. Starch nanoparticles and nanodispersion solutions were prepared via a dialysis method. The particle size distribution of the nanoparticles was determined using a laser diffraction particle size analyzer in an aqueous dispersion. The morphology investigation of the starch and the grafted starch nanoparticles was performed using SEM after freeze drying.