The fabrication and the properties of pretreated corn starch laurate

The pretreated corn starch (PCS) were coagulated from a NaOH/urea/H2O solution of native corn starch (NCS) using ethanol as the precipitant. NCS laurate (NCSL) and PCS laurate (PCSL) were fabricated by transesterification with methyl laurate under solvent-free conditions. The esterification was characterized by Fourier transform infrared (FT-IR) spectroscopy and Solid carbon nuclear magnetic resonance (13C NMR) studies. Scanning electron microscopy (SEM) showed that the size of most PCS and PCSL were, respectively, about 500 and 50–100 nm. X-ray diffraction revealed that the NaOH/urea pretreatment changed the crystalline pattern and the esterification primarily occurred in amorphous domain. The smaller size and more amorphous domain of PCS improved the degree of substitution (DS) and reaction efficiency (RE) of PCSL. With the increasing of DS, PCSL exhibited the better water resistance, and it was not gelatinized in hot water. PCSL also could produce the oil/water emulsions with excellent stability.