高水分挤压温度对绿豆蛋白结构的影响

本文以绿豆蛋白为原料，在不同挤压温度下通过高水分挤压技术制备组织化绿豆蛋白，利用傅里叶红外光谱、内源荧光光谱、SDS-PAGE凝胶电泳、扫描电镜等方法对蛋白质结构进行分析。结果表明，高水分挤压后，离子键、疏水相互作用、二硫键含量呈先上升后下降的趋势，游离巯基含量呈先降低后上升的趋势。绿豆蛋白二级结构中β-折叠含量显著降低（P<0.05），α-螺旋和β-转角含量显著增加（P<0.05）。通过内源荧光光谱发现，蛋白质在130和140℃条件下最大发射波长发生红移，在150和160℃条件下蛋白的最大发射波长没有明显变化。通过扫描电镜可以明显观察到绿豆蛋白形成了纤维结构。综上，经过高水分挤压处理后的绿豆蛋白结构会发生变化，挤压温度对绿豆蛋白高水分挤压组织化产品有显著影响。

Effect of Extrusion Temperature on the Structure of High-moisture Extruded Mung Bean Protein

In this paper, mung bean protein was prepared by high moisture extrusion technology at different extrusion temperatures. The structure of the protein was analyzed by Fourier transform infrared spectroscopy, internal fluorescence spectroscopy, SDS-PAGE gel electrophoresis, and scanning electron microscopy. The results showed that the content of ionic bond, hydrophobic interaction, and disulfide bond increased first and then decreased, and the content of free thiol decreased first and then increased, after high-moisture extrusion. The content of β-sheet in the secondary structure of protein decreased significantly (P<0.05), and the content of α-helix and β-turn increased significantly (P<0.05). The endogenous fluorescence spectra showed that the maximum emission wavelength of protein showed redshift at 130 and 140 ℃, while the maximum emission wavelength of protein did not change significantly at 150 and 160 ℃. The fiber structure of mung bean protein was observed by scanning electron microscope. In conclusion, the structure of mung bean protein after high moisture extrusion treatment would change, and extrusion temperature would have a significant effect on the high-moisture extrusion textured products of mung bean protein.