ABSTRACT In this paper, the amorphous starches of corn starch (NCS, A‐type), potato starch (NPTS, B‐type) and pea starch (NPS, C‐type) were successfully prepared by dissolving starches in choline chloride/oxalic acid dihydrate (CC/OXA). The microscopy results showed that the morphology and birefringence of NCS and NPS in CC/OXA were destroyed completely and birefringence of these starches disappeared from the field of view within 6 h, whereas NPTS required 8 h. X‐ray diffraction (XRD) results indicated that CC/OXA transformed the crystalline structures of the three starches into amorphous structures. Fourier transform infrared (FTIR) spectroscopy analyses exhibited that the destruction of starch structure by CC/OXA was primarily associated with the weakening of hydrogen bond interactions in starch, leading to a reduction in short‐range ordered structures. Compared with the native starches, the amorphous starches exhibited significantly enhanced cold‐water solubility, reduced enthalpy of thermal transition and pasting viscosity. The starch paste had high clarity and was less prone to retrograde. Therefore, starch amorphization of different crystalline types can be achieved in CC/OXA with low‐temperature (50°C), and the prepared amorphous starch had a broad application prospect in many starch processing fields, such as quick soluble, high clarity and anti‐retrogradation materials.
He et al. (Sun,) studied this question.