Effects of dual modification by cationization and acetylation on the physicochemical and structural characteristics of glutinous rice starch

In this research, the effects of cationization, acetylation and dual modification by cationization and acetylation on the physicochemical and structural characteristics of glutinous rice starches were investigated. The rapid viscosity analyzer revealed a substantial increased paste viscosity post modification. Particularly, for dually modified starch, the peak viscosity increased from 3071.67 to 4082.00 cP. The freeze-thaw stability substantially enhanced, with both single cationic and dually-modified starches standing out by exhibiting no water syneresis even at 21 freeze-thaw cycles, while native starch exhibited higher syneresis, up to 74.55 %. Both single cationization and cationization-acetylation destroyed the starch granules, characterized by the roughness and cracks. But, for single acetylation, there was no notable changes on granules' morphology. Fourier transform infrared spectroscopy exhibited notable shifts after modification, both acetylation and dual modification, resulting in a new peak at 1728 cm−1. 13C cross-polarization magic angle spinning nuclear magnetic resonance spectra displayed new peaks at 52–55 and 19–22 ppm following cationization and acetylation, respectively. These structural alterations indicate the successful incorporation of functional groups during modification. Overall, this study provides valuable insights for the industrial utilization of these three modified glutinous rice starches.