酸湿热处理对米粉性质的影响研究

Effect of Acid and Heat-moisture Treatment on the Properties of Rice Flour

摘要:

本文在实验室条件下采用酸湿热处理米粉样品，测定处理前后米粉的化学组成变化、颗粒形貌、结晶性质、红外图谱、热力学性质、糊化性质和消化特性。研究表明，经过酸湿热处理后的米粉蛋白质含量减少较多，其它的粗脂肪、还原糖变化不大。显微结构分析得出米粉保持原有的团粒结构，但偏光十字稍微变得模糊，颗粒的有序结构遭到一定破坏，少数淀粉脐点处出现凹坑。红外图谱变化不大，结晶度变小。处理后米粉的起糊温度升高，糊的峰值粘度降低，吸收焓减小。酸湿热处理可以一定程度下提高米粉中慢速消化淀粉(SDS)的含量。

Abstract:

The rice flour was modified by acid and heat-moisture treatment in the experimental condition in this paper. Polarization microscope, scanning electron micrograph, infrared spectrometer, X-ray diffraction (XRD), differential scanning calorimetry (DSC) instrument, Brabender viscosity instrument were used to study the properties of rice flour before and after the treatment. The results indicated that its protein content was reduced, while other components kept constant. The processed rice flour granules were damaged lightly by acid and heat-moisture. X-ray diffraction analysis showed that the acid and heat-moisture treatment made crystalline structure of starch reduced. No clear change was observed in infrared spectrometer. DSC showed that the endothermic peak of rice starch moved backward, and the absorption enthalpy (△H) decreased. Brabender paste viscosity curve showed that the samples had low viscosity. The in-vitro classification of nutritional segments of modified rice flour showed that its slowly digestible starch (SDS) content increased to some extent.