热处理对不同直链淀粉含量的玉米淀粉理化性质的影响

采用快速黏度分析法、离心法、差示扫描量热分析法、动态流变仪分析法等,研究了干热与湿热处理对3种不同直链淀粉含量的玉米淀粉糊化性质、膨润性质、热力学性质、流变性质的影响,为淀粉的物理改性研究和加工应用提供理论依据。结果表明,干热处理使淀粉更易糊化,表现为3种玉米淀粉糊化温度降低,溶解度、膨胀度增加。湿热处理加大糊化难度,使3种玉米淀粉的糊化温度升高,膨胀度降低。热处理使玉米淀粉糊稠度、糊化焓值降低。蜡质玉米淀粉经热处理后,溶解度和老化率增加。流变性质测定结果表明,湿热处理不利于高直链玉米淀粉黏弹性凝胶的形成。

Effect of Thermal Treatment on Physicochemical Properties of Corn Starches with Different Amylose Content

To provide theoretical support for the research and application of physical modified starches, effects of thermal treatment on corn starches with different amylose content were analysed by method of Rapid Viscosity Analyser, centrifugation, Differential Scanning Calorimeter and Dynamic Rheometer. The study can be used as the basis for physical denaturation and utilization of cereal starch. The results indicated that corn starches with different amylose content were easier to be pasted after dry thermal treatment, for the decreased pasting temperature and increased swelling power. But the corn starches with different amylose content were harder to be pasted after moisture thermal treatment, with the increased pasting temperature, and the decreased amylose solubility and swelling power. By dry and moisture thermal treatment, the paste viscosity and gelatinization enthalpy of corn starches were decreased. After thermal treatments, retrogradating rate and solubility of waxy corn starch were increased. The results of rheological properties showed that gelling properties of high amylose corn starch was hindered by moisture thermal treatment.