玉米淀粉的机械活化及其流变特性研究

Study on mechanical activation and rheological properties of maize starch

通过搅拌球磨机对玉米淀粉进行机械活化降解,并利用X-射线衍射仪(XRD)和旋转粘度计对玉米淀粉的降解程度及流变学特性进行了研究。结果表明:机械活化使得淀粉颗粒结晶结构受到破坏,结晶程度降低,最终由多晶态转变成非晶态。同时所有的机械活化淀粉均呈现假塑性流体特征,符合幂定律,机械活化使玉米淀粉偏近牛顿流体,且活化时间越长、活化温度越高的样品,其糊的表观粘度越低,触变性和剪切稀化也越低。

Maize starch was mechanical activation degraded by a stirringtype ball mill, degraded degree of maize starch was analysed with X-ray diffractometer and theological properties of its pastes was investigated with rotating viscometer respectively. The results indicated that the crystal structure of maize starch could be destroyed by mechanical activation and the crystallinity decreased from polycrystalline to amorphous state. All mechanical activated starch samples with pseudoplastic characteristics in accordance with the power law, which indicated that the mechanical activation degradation would cause maize starch solution in a tendency near Newton fluid. The apparent viscosity, thixotropy and shearthinning nature of the samples pastes decreased with the increase of activating time and temperature.