中文摘要：

偶氮甲酰胺（ADA）作为一种常用的面粉改良剂,其对杂粮馒头品质改善的机制仍鲜有报道。通过DTNB法测定自由巯基（—SH）含量的变化,借助高效液相（SE—HPLC）和激光共聚焦（CLSM）分别测定SDS可萃取蛋白（SDSEP）含量和蛋白网状结构,并采用油菜籽置换法、TPA和Image J统计法分别测定豆麦馒头的比容、全质构和气孔分布。结果表明,ADA能显著降低—SH含量,即增大二硫键含量;降低SDSEP含量,蛋白聚合程度增大;形成致密均匀的网络结构,淀粉—蛋白质基质紧密且均匀。ADA对比容无显著影响;增大了硬度、胶着性及咀嚼度;提高了气孔数目,降低气孔平均大小和气孔占有分率,使气孔更规律、致密均匀。因此,ADA使蛋白聚合程度增加,网状结构更均匀致密,豆麦馒头品质得到改善,表明蛋白交联程度与豆麦馒头品质之间存在内在的相关性。

英文摘要：

Report on protein cross-linking mechanism of soy-wheat Chinese steamed bread treated with azodicarbonamide（ADA）was less while it was known as quality improvement agent of wheat flour.The content of free thiol（—SH）was determined by DTNB method.Meanwhile,size-exclusion high performance liquid chromatography（SE—HPLC）and confocal laser scanning microscope（CLSM）were used to analyze the content of sodium dodecyl sulfate extractable proteins（SDSEP）and gluten network respectively.In addition,the specific loaf volume of soy-wheat Chinese steamed bread was determined by rapeseed displacement method.TPA was used to test the texture and the software Image J was applied to analyze the pore structure of soy-wheat Chinese steamed bread treated.The result showed that ADA reduced the content of—SH,which meant that the—S—S—content was increased.The SDSEP content was decreased and the extent of protein cross-linking was increased.ADA could promote proteins aggregating into dense and uniform network.Gelatinized starches were warped by protein framework.Moreover,ADA made no significant effect on specific loaf volume and also increased the hardness,gumminess and chewiness.The gas cell counts were increased,and average size and average friction of gas cells were decreased,along with the forming of uniform,dense and small pore structure.In combining the greater protein polymerization with the better quality characteristics of soy-wheat Chinese steamed bread,it indicated that there was inner relationship between protein cross-linking and the final quality characteristics of soy-wheat Chinese steamed bread.