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Preparation and characterization of non-crystalline granular starch and corresponding carboxymethyl starch

2017; Elsevier BV; Volume: 103; Linguagem: Inglês

10.1016/j.ijbiomac.2017.05.131

1879-0003

Bao Zhang, Xiaomin Li, Qiu‐Tao Xie, Han Tao, Wu Wang, Han-Qing Chen,

Phytase and its Applications

Native corn starch slurried in 50% ethanol solution was treated at 60 °C, 70 °C, 80 °C, and 85 °C, respectively. The resultant starches were investigated by polarized microscopy, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and X-ray diffractometry (XRD). The Maltese cross of ethanol-heating treated starch gradually weaken with increasing temperature and completely disappeared at 85 °C. SEM data indicated the treated granular exhibited a rougher surface with more pores and grooves than native starch granular, but the shape of the treated starch was still intact. DSC and XRD data confirmed ethanol-heating treated starch changed from crystalline to non-crystalline structure at 85 °C. The highest degree of substitution (DS) and corresponding reaction efficiency (RE) for the carboxymethylation of native starch were 0.66 and 36.7%, respectively, while the corresponding DS and RE for non-crystalline granular starches increased by 0.29 and 16.1% at the same reaction condition, respectively.