Na2CO3改善了馒头的品质，包括比容和质地。
Na2CO3通过抑制异味化合物的产生改善了香气特征。
Na2CO3诱导了谷蛋白大聚合体(GMP)的水解。
江南大学食品科学与技术国家重点实验室的Jinzhong Xi、Dan Xu和Xueming Xu*等人研究了Na2CO3对用酸面团发酵的馒头（sourdough-CSB）和用酵母发酵的馒头（yeast-CSB）品质、蛋白质亚基变化和挥发性化合物的影响。结果表明，较低的Na2CO3含量使馒头的碎屑更软且表面颜色变化很小。此外，添加Na2CO3可以抑制异味化合物（丁酸、1-辛烯-3-醇、己醛和庚醛）的产生，从而改善了整体香气特征。
十二烷基硫酸钠聚丙烯酰胺凝胶电泳分析表明，低分子量蛋白质带强度明显增加，与尺寸排除高效液相色谱分析（result of size-exclusion high-performance liquid chromatography analysis）和游离巯基（SH）含量的结果一致，表明酵母发酵馒头中谷蛋白大聚合体（GMP）在碱性条件下水解。
在酸面团发酵馒头中，谷蛋白大聚合体和游离巯基含量在低Na2CO3水平（0-0.2％）时降低，然后在高Na2CO3水平（0.3％-0.5％）时上升。
Abstract
Effect of Na2CO3 on quality and volatile compounds of steamed bread fermented with yeast or sourdough
Jinzhong Xia,b, Dan Xua,b,c, Fengfeng Wua,b, Zhengyu Jina,b, Xueming Xua,b,*
a State Key Laboratory of Food Science and Technology, Jiangnan University, 214122 Wuxi, China
b School of Food Science and Technology, Jiangnan University, 214122 Wuxi, China
c Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta T6G2P5, Canada
The effects of Na2CO3 on the quality, change of protein subunits and volatile compounds of sourdough leavened Chinese steamed bread (sourdough-CSB) and yeast leavened CSB (yeast-CSB) were investigated. Results suggested that, low Na2CO3 level endowed both CSB with softer crumb and little change of surface color. Besides, Na2CO3 addition improved the overall aroma profile by inhibiting the production of aroma-negative compounds (butanoic acid, 1-octen-3-ol, hexanal and heptanal). Sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis showed an obvious increase in intensity of protein bands with low molecular weight, consistent with the result of size-exclusion high-performance liquid chromatography analysis and free sulfhydryl group (SH) content, indicating the hydrolysis of glutenin macropolymer (GMP) under alkaline condition in yeast-CSB. While in sourdough-CSB, GMP and SH content firstly decreased at low Na2CO3 level (0-0.2%) and then increased at high Na2CO3 level (0.3%-0.5%).
