本文采用SDS-PAGE凝胶电泳比较了3种酶改性玉米粉及未处理玉米粉中醇溶蛋白和谷蛋白亚基组成的差异，并对谷蛋白亚基分子量进行了分析；采用傅里叶红外光谱(FT-IR)研究了酶改性过程中谷蛋白二级结构的变化。结果表明：酶法改性对玉米谷蛋白的结构产生了较大影响，而对醇溶蛋白的影响较小；α-淀粉酶与碱性蛋白酶复合处理会产生协同效应，促进玉米谷蛋白的水解，产生大量低分子量亚基；单一酶改性会使玉米谷蛋白结构变得无序，经复合酶处理后，α-螺旋比例最高，结构趋于稳定。以上结果说明，酶法改性过程中，谷蛋白结构的变化可能是玉米粉面团成团性改良的一个重要因素。本研究揭示了玉米粉酶法改性工艺的部分作用机理，为玉米面粉面团改性研究及产品研发提供了科学依据。

The differences in the subunit compositions of gliadin and glutenin extracted from three kinds of enzyme-modified corn flours and untreated corn flour were compared by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and the molecular weights of the subunits were analyzed. Changes in the secondary structure of glutenin during enzymatic modification were determined by Fourier transform infrared (FT-IR) spectroscopy. The results showed that enzymatic modification had a relatively large influence on glutenin structure and a relatively small influence on gliadin. Treatment combining α-amylase and alkaline protease had a synergistic effect, promoting the hydrolysis of corn gluten, and a large number of low molecular weight subunits were produced. The structure of the corn glutenin modified by individual enzymes was more disordered than that of the untreated sample, but the combined enzyme treatment produced the highest percentage of α-helices and the structure tended to be stable. The above results showed that the change in the glutenin structure might be an important factor for the improvement of corn dough-forming properties. This study revealed some of the mechanisms underlying the enzymatic modification of corn flour, and provided a scientific basis for the modification of corn dough and product development.

国家自然科学基金资助项目（31171782）