丙酮醛改性对麦醇溶蛋白功能特性及结构的影响  

Effects of Modification with Methylglyoxal on Functional Properties and Structure of Wheat Gliadin

作　　者：杨土娣 张烘焜 庞鑫鑫 陈展鹏 杨容 郑文宇 吴晓梅 曾新安 廖兰[1,2] YANG Tu-di;ZHANG Hong-kun;PANG Xin-xin;CHEN Zhan-peng;YANG Rong;ZHENG Wen-yu;WU Xiao-mei;ZENG Xin-an;LIAO Lan(Guangdong Key Laboratory of Food Intelligent Manufacturing Department of Food Science,Foshan 528225,Guangdong,China;College of Food Science and Engineering,Foshan University,Foshan 528225,Guangdong,China;College of Food Science and Engineering,South China University of Technology,Guangzhou 510640,Guangdong,China)

机构地区：[1]广东省食品智能制造重点实验室,广东佛山528225 [2]佛山科学技术学院食品科学与工程学院,广东佛山528225 [3]华南理工大学食品科学与工程学院,广东广州510640

出　　处：《食品研究与开发》2023年第5期48-56,共9页Food Research and Development

基　　金：广东省教育厅佛山科学技术学院省下达2019年教育发展专项基金高等教育“冲一流,补短板,强特色”重点项目(CGZ07309);佛山科学技术学院高层次人才科研启动项目(CGZ07001)。

摘　　要：该文模拟小麦制品热加工条件,建立麦醇溶蛋白(gliadin,Gli)-丙酮醛(methylglyoxal,MGO)体系,用邻苯二甲醛法和荧光光谱法测定不同丙酮醛添加量、糖化温度、糖化时间下,体系中游离氨基含量变化及晚期糖基化终产物(advanced glycation end-products,AGEs)生成规律,并对改性后的麦醇溶蛋白的功能特性和结构特性进行表征。结果表明,在麦醇溶蛋白与丙酮醛质量比1∶6、反应温度140℃、反应时间75 min时,产物游离氨基含量较低,AGEs生成量较少。麦醇溶蛋白与丙酮醛反应后的样品(methylglyoxal-gliadin,MGO-Gli)的乳化活性较未处理的麦醇溶蛋白(native-gliadin,N-Gli)提高50.03%,乳化稳定性提高79.51%;起泡性和泡沫稳定性分别提高13.33%、28.20%;十二烷基硫酸钠-聚丙烯酰胺凝胶电泳结果表明,麦醇溶蛋白与丙酮醛发生糖基化反应;MGO-Gli的紫外光谱结果显示,光谱峰值发生红移,说明MGO-Gli的内部结构发生伸展,使内部的色氨酸暴露;傅里叶红外光谱(Fourier transform infrared spectroscopy,FT-IR)结果表明,Gli经MGO糖基化改性后α-螺旋结构含量减少、β-折叠结构含量增加、α-螺旋/β-折叠由0.608降为0.508,说明MGO-Gli的分子柔性增加。The gliadin-methylglyoxal(Gli-MGO)system was established and used for the simulated thermal processing of wheat products. The effects of different MGO additions,modification temperature and time,free amino content,and the formation rule of advanced glycation end-products(AGEs)were determined by ophthaldialdehyde(OPA)-based spectrophotometric assay and fluorescence spectroscopy. The effect of MGO on the functional properties and structure modification of gliadin were evaluated. The results showed that the reaction with the Gli-to-MGO mass ratio of 1 ∶ 6 at 140 ℃ for 75 min had the product with low free amino content and moderate formation of AGEs. Compared with native gliadin(N-Gli),MGO-Gli showed the emulsion capacity,emulsion stability,foaming capacity,and foaming stability increasing by 50.03%,79.51%,13.33%,and 28.20%respectively. The result of sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE)indicated the occurrence of glycation between Gli and MGO. The result of ultraviolet spectroscopy showed a red shift in the peak,implying the structure of Gli-MGO was extended,leading to exposure of tryptophan residues. The result of Fourier transform-infrared spectroscopy showed that the α-helix content decreased while the β-sheet content increased and the α-helix/β-sheet ratio decreased from 0.608 to 0.508 after modification with MGO,indicating that the molecular flexibility of MGO-Gli was improved.

关 键 词：麦醇溶蛋白 丙酮醛 游离氨基含量 糖基化 功能特性 结构 

分 类 号：TS210.1[轻工技术与工程—粮食、油脂及植物蛋白工程]