羧甲基壳聚糖干热改性淀粉的制备及性能

Preparation and properties of carboxymethyl chitosan starch modified by dry heat

用羧甲基壳聚糖对玉米淀粉进行辅助干热改性,制备了改性淀粉。研究了羧甲基壳聚糖的质量分数和pH对改性淀粉流变性能的影响;通过扫描电子显微镜、X射线衍射仪和红外光谱仪对淀粉的结构进行分析。结果表明:羧甲基壳聚糖对玉米淀粉的干热改性属于物理改性。随着pH的增加,淀粉的糊化初始温度先降后升,峰值黏度、谷值黏度和崩解值先升后降;随着羧甲基壳聚糖质量分数的增加,淀粉的糊化初始温度先降后升,而峰值黏度、谷值黏度和崩解值则一直降低。当羧甲基壳聚糖质量分数为1.0%、pH为7.0时,玉米淀粉的糊化初始温度、崩解值分别从原始的66.66℃和232 mPa·s降低至62.53℃和79 mPa·s。

Corn starch was modified by carboxymethyl chitosan with the aid of dry heat. The effects of carboxymethyl chitosan content and pH on the rheological properties of modified starch were studied. The structure of starch was analyzed by scanning electron microscopy, X-ray diffraction and infrared spectroscopy. The results showed that the dry heat modification of corn starch by carboxymethyl chitosan belonged to physical modification. With the increase of pH, the initial gelatinization temperature of starch decreased first and then increased, and the peak viscosity, valley viscosity and disintegration value increased first and then decreased. With the increase of carboxymethyl chitosan mass fraction, the initial gelatinization temperature of starch decreased first and then increased, while the peak viscosity, valley viscosity and disintegration value decreased all the time. When the mass fraction of carboxymethyl chitosan was 1.0 % and pH was 7.0, the initial gelatinization temperature and disintegration value of corn starch decreased from 66.66 ℃ and 232 mPa·s to 62.53 ℃ and 79 mPa·s, respectively.