小麦面筋蛋白酶解物中鲜味肽的呈味特性与构效关系研究

Umami peptides play an important role in sensory taste of gluten protein hydrolysates. The objective of this work is to purify and identificationthe key umami peptides from gluten protein hydrolysates using gel filtration chromatography, reversed phase high permance liquid chromatogram (RP-HPLC) and liquid-mass spectrometry/mass spectrometry, and to investigate the relationship between primary structure of umami peptides and taste characteristics. Based on our previous researches, this work will identify the umami peptides contributed to the falvour of the gluten protein hydrolysates by the method of omitting or adding the peptides combinated sense test and electronic tongue. we will evaluate contribution of the umami peptides to the taste of gluten protein hydrolysates. In the present work, the correlations between the structure and activity are investigated. Different umami peptides derivatives synthesized are used to approve above hypothesis. The gulten protein hydrolysates are prepared from modified protein (thermal or deamidation treatment). The discrepancy of umami peptides in sensory taste are investigated. This work will abtain important information for summarizing umami taste theory to improve the quality of gluten protein hydrolysates.

鲜味肽是小麦面筋蛋白酶解物特征滋味物质的重要组成成分。本项目拟以小麦面筋蛋白酶解物为研究对象，应用分级膜分离、凝胶过滤色谱、反相高效液相色谱和液相-质谱/质谱等技术对面筋蛋白酶解物中鲜味肽进行分离、纯化；通过组别减除、添加感官实验和电子舌分析鉴定出面筋蛋白酶解物中主要鲜味肽，明确鲜味肽对面筋蛋白酶解物滋味的贡献；在此基础上研究鲜味肽的一级结构、空间构象和呈味特性之间的内在联系，通过对鲜味肽进行分子修饰进一步验证构效关系，最后研究蛋白质变性和侧链基团修饰与面筋蛋白酶解物中主要鲜味肽种类和含量变化的内在联系。本项目的研究不仅可丰富鲜味感知理论，而且还将为高品质呈味基料提供理论基础和技术指导，具有重要的理论价值和现实意义。

鲜味肽是小麦面筋蛋白酶解物特征滋味物质的重要组成成分。本项目以小麦面筋蛋白为原料，通过固态发酵制备蛋白酶实现面筋蛋白的深度水解，采用超滤、凝胶和反相高效液相色谱等一系列分离技术对酶解液进行分离纯化得到一个呈味肽，分析其分子量和氨基酸序列，结果表明该鲜味肽的分子量为293.15 Da，氨基酸序列为Asp-Cys-Gly（DCG）。采用滋味稀释法评价合成多肽，结果显示该合成的三肽（DCG）具有鲜味作用，其呈鲜味阈值为100mg/L，其是MSG鲜味阈值的三分之一，200mg/L的合成DCG 添加量对I+G有鲜味增强作用，但其对MSG并无鲜味增强作用。项目组成员还发现酸性蛋白酶具有较高的脱酰胺活性，对面筋蛋白脱酰胺处理不仅可提高面筋蛋白酶解产物的呈味强度，还能提高其酶解敏感性。本项目的研究不仅可丰富鲜味感知理论，而且还将为高品质呈味基料提供理论基础和技术指导，具有重要的理论价值和现实意义。