Characterization and Properties of Long‐Chain Fatty Acid Starch Esters Prepared with Regenerated Starch by Dry Method

Abstract

AbstractRegenerated starch (RS) prepared from 14% urea/4% NaOH aqueous solution is used as a raw material to synthesize esterified starch. Starch stearate (SS), a kind of long‐chain fatty acid starch ester, is synthesized through the esterification of RS with stearic acid by a dry method under normal pressure and without an organic solvent or catalyst. Scanning electron microscopy, Laser Particle Sizer, Fourier transform infrared, 1H NMR, X‐ray diffraction, differential scanning calorimetry, and thermogravimetric analysis are used to characterize and analyze the prepared SS. The effect of degree of substitution (DS) on the properties of SS, such as moisture adsorption, transparency, emulsion ability (EA) and emulsion stability (ES), freeze–thaw stability, and retrogradation, is also studied. The results show that the prepared SS has better EA and ES, good freeze–thaw stability, and excellent retrogradation, all of which increase with the increase of DS. The transparency of SS pastes is significantly improved when its DS is under 0.3. The moisture adsorption of SS decreases due to the introduction of stearate groups. All these improved properties make SS a better material for a myriad of industrial applications.