糊化处理对藜麦淀粉形态、结构及热特性的影响

Effect of Gelatinization Treatment on Morphology,Structure and Thermal Properties of Chenopodium quinoa Starch

利用碱性蛋白酶提取青海高原藜麦淀粉(白藜麦淀粉WCS、红藜麦淀粉RCS、黑藜麦淀粉BCS)后观察其直链、支链淀粉含量变化。三种藜麦淀粉经过高温高水分的糊化处理(温度100℃,料液比1∶12g/mL),使用扫描电镜、激光粒度分析仪、X射线衍射仪、傅里叶红外光谱仪、差示扫描量热仪等仪器将糊化前后藜麦淀粉的颗粒形态、粒径、晶体结构、分子结构、热特性等性质进行分析,比较得出藜麦淀粉糊化前后的差异。结果表明:扫描电镜图表明碱性蛋白酶提取的藜麦淀粉具有光滑完整的表面结构,糊化后的三种淀粉颗粒表面破坏程度高。激光粒度仪测定出淀粉颗粒粒径增大,糊化处理后,三种藜麦淀粉的粒径D(10)分别增加了25.58、9.16、27.00μm。X射线衍射图谱显示出糊化后淀粉晶体结构消失、定型区向不定型区转变。傅里叶红外光谱显示三种藜麦淀粉糊化后结构不变,分子键未受到破坏,仅表现为透过率增加。糊化处理可以改善藜麦淀粉的加工特性,为藜麦淀粉的应用提供理论依据。

The Chenopodium quinoa starch( white Chenopodium quinoa starch WCS,red Chenopodium quinoa starch RCS,black Chenopodium quinoa starch BCS) from Qinghai plateau extracted by alkaline protease were studied based on the changes of amylose and amylopectin contents.The gelatinization treatment was imposed on the three kinds of Chenopodium quinoa starch ( the gelatinization temperature was 100 ℃ and the ratio of material to liquid was 1∶ 12 g /mL).Scanning electron microscope, laser particle size analyzer,X-ray diffractometer,infrared spectrometer,differential scanning calorimeter and other instruments were used to analyze the morphology,crystal structure,molecular structure and thermal properties of Chenopodium quinoa starch.And the differences before and after gelatinization of Chenopodium quinoa starch were compared.The results showed that, the Chenopodium quinoa starch extracted by alkaline protease starch had smooth and complete surface structure by SEM,the surface of the starch granules was highly damaged after gelatinization,the size of starch granules was increased which determined by laser particle size analyzer,the particle size D( 10) of the three Chenopodium quinoa starches increased 25.58, 9.16 and 27.00 μm respectively after gelatinization treatment.The X- ray diffraction showed that the starch crystal structure disappeared after gelatinization,and the crystal region changed to amorphous region.The Fourier infrared spectrum results showed that the structure of the three kinds of starch were constant after gelatinization,molecular bonds were not destroyed,only with the increasing of the transmittance.Gelatinization could improve the processing properties of Chenopodium quinoa starch and provide a theoretical basis for the application of Chenopodium quinoa starch.