小麦面筋蛋白脱酰胺改性过程中分子的聚集态研究  

Studies on Aggregation of Modified Wheat Gluten in the Process of Citric Acid Deamidation

作　　者：廖兰[1] 林维杰 李章发 赵谋明[2] 倪莉[1] Liao Lan;Lin Weijie;Li Zhangfa;Zhao Mouming;Ni Li(Institute of Food Science and Technology,College of Bioscience and Biotechnology,Fuzhou University,Fuzhou 350108;College of Food Sciences and Technology,South China University of Technology,Guangzhou 510640)

机构地区：[1]福州大学食品科学技术研究所生物科学与工程学院,福州350108 [2]华南理工大学轻工与食品学院,广州510640

出　　处：《中国食品学报》2018年第9期68-75,共8页Journal of Chinese Institute Of Food Science and Technology

基　　金：国家自然科学基金项目(31201287);福建省自然科学基金项目(2015J05067);福建省教育厅高校杰出青年教师计划;福建省教育厅科技类项目(2016LSX);福州市科技项目(2018-G-81)

摘　　要：以极稀到亚浓调控的原始聚集态(0.01~10 mg/m L)小麦面筋蛋白溶液为研究对象,分析在湿热柠檬酸脱酰胺过程中,随着小麦面筋蛋白的浓度和脱酰胺时间的变化,小麦面筋蛋白聚集态的变化行为和结构差异。研究发现改性小麦面筋蛋白的脱酰程度、水解度、表面疏水性随着原始聚集度的降低和脱酰胺时间的增加而增大;随着蛋白浓度的降低和脱酰胺时间的增加,α-螺旋结构向β-转角和β-折叠的转变,蛋白结构发生红移。Zeta电位、SDS-PAGE、FTIR和内源性荧光的结果表明:在脱酰胺处理过程中小麦面筋蛋白的原始聚集态对蛋白结构的展开以及氢离子与酰胺基团和肽键的接触有显著影响,且氢离子易于与高分子质量的麦谷蛋白亚基接触并水解其肽键。Wheat gluten was deamidated by citric acid at 121 ℃ for 2, 4, 6, 8 min. The change of structure and state of its aggregative behavior controlled by the concentration of protein（from dilute to sub-concentrated, 0.01-10 mg/m L） and deamidation time upon the process of deamidation was investigated. Results demonstrated that degree of deamidation and hydrolysis enhanced with increasing of deamidated time and decreased with the lowering of original aggregative state. Surface hydrophobicity of deamidated wheat gluten decreased with as the reducing of its original aggregative state,but raised up with deamidated time. Furthermore, it prompted the content of α-helix decreased and shifted to β-turn andβ-sheet as prolonging the processing deamidation time and/or reducing original aggregative state of wheat gluten. Results from Zeta potential, SDS-PAGE, FTIR and endogenous fluorescence demonstrated that original aggregative state of wheat gluten had significantly impact on unfolding of protein structure and the accessibility of H＋to amide groups and peptide bonds. Furthermore, hydrogen ions from citric acid was susceptible to high molecular weight glutenin subunits during deamidation.

关 键 词：小麦面筋蛋白 脱酰胺 聚集态 浓度 时间 

分 类 号：TS210.1[轻工技术与工程—粮食、油脂及植物蛋白工程]