水热处理对醇溶蛋白粘弹性的影响机制研究

摘要：醇溶蛋白在加热过程中的粘弹性变化会影响面团焙烤初期膨胀能力，从而决定最终产品的食用品质。本文研究了不同水热温度处理下醇溶蛋白聚集行为和构象重排规律，并以此揭示醇溶蛋白粘弹性变化的机制。结果表明，40℃和60℃水热处理后，醇溶蛋白无共价聚集行为。而在90℃条件下，α-醇溶蛋白和γ-醇溶蛋白会通过分子间二硫键（SS）键发生聚集反应，导致其在乙醇水溶液的溶解度降低。在水热处理过程中，氢键逐渐被破坏，疏水相互作用力增强，导致蛋白二级结构发生变化。在40℃和60℃条件下，非共价作用力的重排导致醇溶蛋白的粘性逐渐下降。在90℃下，蛋白弹性升高主要是归咎于共价聚集所形成的醇溶蛋白聚集体，而粘性变化则是由非共价力和共价SS键的共同作用所致。本研究可为调控焙烤初期醇溶蛋白粘弹性变化提供理论依据和科学指导。30667
毕业论文关键词：醇溶蛋白；热聚集；构象；粘弹性
Effect mechanism of hydrothermal treatment on the gliadin viscoelasticity
Abstract: The viscoelasticity of gliadin during heating could affect the initial expansion of dough during early baking process, thus determining the quality of the final product. In this paper, the aggregation behavior and conformational rearrangement of gliadin were studied under different hydrothermal temperature treatments to reveal the mechanism of gliadin viscoelasticity variations . The results showed that there was no covalent aggregation behavior of the gliadin during 40 °C and 60 °C hydrothermal treatment. At 90 °C, α-gliadin and γ-gliadin were aggregated by intermolecular disulfide bond (SS), resulting in a decrease in solubility in aqueous ethanol. During the hydrothermal treatment, the hydrogen bonds were gradually destroyed and the hydrophobic interactions were enhanced, resulting in the secondary structure changes. At 40 °C and 60 °C the rearrangement of non-covalent forces resulted in the gradual decrease in the viscosity of the gliadin. At 90 °C, the increase of protein elasticity was mainly due to the covalent aggregation behavior of gliadin, and the change of viscosity was due to the combined effect of noncovalent and covalent SS bond. This study could provide theoretical basis and scientific guidance for the regulation of glidin viscoelasticity in the initial stage of baking.
Keywords: Gliadin, thermal, polymerization, conformation, viscoelasticity
目录
摘要    1
关键词    1
Abstract    1
Keywords    1
引言    1
1材料与方法    2
1.1试验材料    2
1.2 试验试剂    2
1.3仪器与设备    3
1.4试验方法    3
1.4.1醇溶蛋白的提取    3
1.4.2水热处理醇溶蛋白    3
1.4.3分子排阻高效液相色谱（SE-HPLC）    4
1.4.4游离巯基（SH）含量的测定    4
1.4.5反相高效液相色谱（RP-HPLC）    4
1.4.6醇溶蛋白在不同溶剂中的溶解度    4
1.4.7傅里叶变换红外光谱（FTIR）    4
1.4.8流变学研究    4
1.5统计分析方法    5
2 结果与分析    5
2.1热处理对醇溶蛋白分子量分布和游离SH的影响    5
2. 2热处理期间乙醇提取率和醇溶蛋白亚基分布变化    6
2. 3热处理对醇溶蛋白非共价力的影响    8
2. 4热处理对醇溶蛋白二级结构含量的影响    9
2. 5热处理对醇溶蛋白粘弹性的影响    10
3结论    10 水热处理对醇溶蛋白粘弹性的影响机制研究:http://www.youerw.com/shiping/lunwen_26516.html