酸面团发酵过程中麦谷蛋白大聚体降解及调控机理研究

蛋白质降解是影响酸面团风味及品质的主要因素之一,麦谷蛋白大聚体(GMP)是小麦粉酸面团中结构最为复杂的蛋白质。本项目以小麦粉-植物乳酸菌-酵母菌制备酸面团,在研究酸面团发酵过程中植物乳酸菌及酵母菌生长变化规律的基础上，利用SE-HPLC分析GMP含量,分析酸面团中GMP降解与微生物生长之间的量值关系。以SDS-PAGE、CE及RP-HPLC分析其组成变化,阐明GMP降解规律并确立“阻抗性肽键”的分布;以FTIR、CD图谱表征GMP二级结构的变化,分析“阻抗性肽键”结构对GMP降解的影响,根据-SH/-S-S-的变化,分析-S-S-与“阻抗性肽键”之间的关系。本研究将为酸面团形成机理及控制提供基础理论信息,也将为酸面团标准化生产起到指导作用。

Protein degradation is one of the main factor influencing flavor and quality of sourdough. Glutenin macropolymer(GMP) is the protein with the most complex structure in wheat flour sourdough system. Wheat flour, lactobacillus plantarum and yeast are used to prepare for sourdough in the present study. The changes in growth of lactobacillus plantarum and yeast are analyzed during sourdough fermentation. GMP is separated by SE-HPLC and content is determined. Relationship between GMP degradation and microbial growth in sourdough fermentation will be analyzed. Change in composition of GMP is analyzed by SDS-PAGE, CE and RP-HPLC during sourdough fermentation. Degradation change of GMP will be clarified, and distribution of resistant peptide bond in GMP will be established. The change in secondary structure of GMP in fermentation is determined by FTIR and CD techniques. And then, effect of the structure of resistant peptide bond on GMP degradation is studied. After the contents of free -SH/S-S bond are analyzed in GMP, the relation of S-S bond to resistant peptide bonds will be studied. According to the change in characteristics and quality of sourdough in fermentation, the relationship between GMP degradation and characteristics, quality of sourdough will be revealed. GMP degradation in sourdough fermentation will be finally clarified. The research will not only lead to a much better understanding of development mechanism and quality control of sourdough, but also eventually lead to the standardization of sourdough process.