【作者】 陈复生；

【导师】 李里特；

【作者基本信息】 中国农业大学 ， 食品科学， 2002， 博士

【摘要】 本论文的研究以分子生物学、植物蛋白工艺学、食品物性学、生物化学、有机化学、物理化学、电学、传热学、高分子材料学和现代仪器分析等多学科的理论为基础，首次提出并研究了大豆蛋白透明凝胶的光学性质。分析了影响大豆蛋白形成透明凝胶的主要因素，研究了分子作用力与大豆蛋白凝胶透明性的关系，通过大豆蛋白透明凝胶分子结构和微观结构的深入研究，首次创造性地提出了“均匀分布”的分子模型，建立了透明大豆蛋白凝胶的力学模型和力学方程。在此基础上首次研制了大豆蛋白可生物降解的高分子透明材料。 本论文首先探讨了大豆蛋白凝胶的透明机理，分析和研究了pH值、加热温度、加热时间、蛋白浓度与人豆分离蛋白凝胶透明性和流变学性质的关系。并进一步研究了这些因素对大豆7S球蛋白凝胶的透明性和流变学性质的影响。 通过溶剂(乙醇和丙三醇)、牛血清白蛋白、脂肪酸盐、氯化钠和巯基试剂等及其浓度对大豆分离蛋白和7S球蛋白凝胶光学性质与凝胶强度作用机理的试验研究，证明了氢键、二硫键、离子键和疏水作用对大豆分离蛋白和7S球蛋白凝胶光学性质与凝胶强度有重要的影响。随着氢键作用的加强，有利于提高大豆蛋白凝胶的透明性和凝胶强度；随着离子键作用的加强，有利于提高大豆蛋白的凝胶强度；而疏水作用的加强虽然提高了大豆蛋白凝胶强度，却影响大豆蛋白的溶解性，降低了大豆蛋白凝胶透明性；-S-S-的形成提高了凝胶强度，但降低了凝胶的透明性。根据试验结果提出了脂肪酸盐作用下7S球蛋白凝胶化的机理模型。 通过氨基酸系列分析，研究了决定蛋白质凝胶透明性和强度的蛋白质氨基酸组成；利用荧光光谱法测定了大豆蛋白质表面的疏水性，研究了蛋白质表面疏水作用与蛋白质凝胶化的关系；通过蛋白质的电泳分析，研究了大豆蛋白及其主要组分亚基组成的差异，分析了透明凝胶形成过程中亚基的变化；利用扫描电子显微镜(SEM)观察了大豆分离蛋白、大豆11S球蛋白和大豆7S球蛋白凝胶微观结构；并借助傅立叶变换红外光谱(FTIR)研究了大豆分离蛋白、大豆11S球蛋白和大豆7S球蛋白及其凝胶分子的二级结构，试验结果证明了大豆7S球蛋白凝胶化的机理不同于大豆分离蛋白和大豆11S球蛋白，透明大豆蛋白凝胶具有较高的有序结构。 首次从大豆蛋白的电特性和双电层模型上分析了直流电加热条件下，大豆蛋白分子定向的机理；通过对直流电加热条件下影响大豆蛋白凝胶透明性和强度主要因素的研究，分析和比较了直流电加热与水浴加热对大豆蛋白凝胶透明性和凝胶强度的不同影响，又进一步探讨了大豆蛋白凝胶透明的机理；直流电加热除了水浴加热中的温度作用以外，又增加了直流电场的定向作用，提高了加热速率，提高了大豆蛋白分子定向排列的程度，有利于蛋白质凝胶透明性和强度的提高；利用SEM对电场下大豆蛋白凝胶微观结构的观察，进一步证明了直流电加热比水浴加热形成的透明大豆蛋白凝胶微观结构具有更高的有序性。 试验结果证明了直流电加热下大豆7S球蛋白凝胶化的机理不同于水浴加热下大豆7S球蛋白凝胶化的机理，因此，根据试验结果首次提出了直流电加热下大豆7S球蛋白凝胶化的机理模型；并且试验证明：直流电加热是大豆蛋白形成透明凝胶的简捷、有效方法。 通过对大豆分离蛋白(SPI)和大豆7S球蛋白凝胶力学特性的研究，首次建立了大豆蛋白凝胶的力学模型，利用拉普拉斯变化推导出了大豆蛋白凝胶的力学方程。通过对SPI和大豆7S球蛋白凝胶力学特性的试验测试，以及对主要影响因素和拟合误差的分析，验证了大豆蛋白凝胶的力学模型和力学方程的可靠性与准确性；对大豆蛋白的透明凝胶更精确；这对 博士学位论文 摘 要 一 人豆蛋白的进一步研究和应川奠定了理论基础。 依据上述系列试验研究，芦次提出并建立了透明人豆7S球蛋白凝胶形成的机理模型，｛即：“均匀分布模刑’，，这对人B蛋白的进一步研究和应川奠定了理论基础。 利用差示扫描量热分析（仍C）、热重法门M）－差热分祈（mA）对人Rat白热力学性 质、玻璃化转变温度和熔点等进行了研究，这些数据对于研究人豆蛋白可生物降解材料具有 重要参考价值。 利用大豆蛋一研制出可生物降解的高分于材料，并对其光学性质和力学性质进行了研 究。对影响材料形成的主要囚素进行了详细研究。利用醇类、盐类和琉基试剂研究了氢键、 离于键和二硫键等分于作用力对人豆蛋白高分于降解材料特性和形成机理的影响。 对大豆蛋白可生物降解材料加卜性能、降解性、对折性和跌落性等特性进行了分析， 结果显示这些性能完全符合GB18006．11999的要求。 利用SEM对人。分离蛋白高分于材料微观结构进行了研究，透明的人Hffi白高分于材 料只有均匀的微观结构。 依据上述试验，首次提出了人豆分离蛋白形成透明高分于降解材料的机理，这为大豆更多还原

【Abstract】 The thesis is based on theories of molecular biology , vegetable protein technology, food physics, biochemistry , organic chemistry, physical chemistry, electricity, transmit heat, high molecular materials science and modern instrument analysis .Optic properties of soy protein transparent gel are proposed and studied for the first time .The main factors which affect soy protein forming transparent gel are analyzed .The relationships between molecular forces and the transparency of soy protein gel are studied. After molecular structure and microstructure of soy protein transparent gels being studied thoroughly, molecular model of "even distributed" is creatively put forward for the first time. Mechanical models and equations of soy protein transparent gels are founded . Based on these, high molecular transparent materials of biodegradable plastics making from soy protein are manufactured for the first time.The transparent mechanisms of soy protein gels are firstly explored in this thesis .The relationships among pH values heating temperatures, heating times, protein concentrations and transparency as well rheology properties of SP1 gels are analyzed and studied .Affects of these factors on transparency and rheology properties of soy 7S globulin gels are further studied .Mechanisms of solvents (alcohol and glycerin), BSA , FAS , NaCl and sulfhydryl group reagents as well their concentration which affect gel optic properties and gel strength of SPI and soy 7S globulins have been studied. These results prove that hydrogen bonds , ionic bonds, hydrophobic bonds and disulfide linkages have more important affection on gel optic properties and gel strength of SPI and soy 7S globulins. With actions of hydrogen bonds being strengthened, these advantageously improve gel transparency and strength of soy proteins. With actions of ionic bonds being strengthened, these advantageously improve gel strength of soy proteins. Although reinforcement of hydrophobic actions improves gel strength of soy protein, it also affects solubility of soy proteins, therefore transparency of soy protein gels is decreased. The forming of disulfide linkages increase gel strength of soy proteins, but gel transparency of soy protein gels is decreased. Based on these experimental results, mechanism model of soy 7S globulins gelation on FAS action condition is put forward for the first time.Through amino acid analyzing, composition of soy protein amino acids of affecting protein gels transparency and strength is analyzed. Through hydrophobic actions of soy protein molecule surface are determined by fluorescence spectrometric method ,the relationships between hydrophobic action of soy protein molecule surface and protein gelation are studied . Differences of soy protein and their main fraction subunits are studied by SDS-PAGE and changes of subunits during forming transparent gels are analyzed.Microstructures of SPI, soy 11S globulins and soy 7S globulins are observed by SEM. Fourier transformed infrared spectroscope (FTIR) measurements are performed to study the secondary structures of SPI, soy 11S globulins and soy 7S globulins molecule. The experimental results have shown that the gelation mechanisms of soy 7S globulins differ from these of SPI and soy 11S globulins. Transparent soy protein gels have highly ordered structures.Based on electro-characteristic and double electric layers models, directional mechanisms ofsoy protein molecular are analyzed for the first time on DC heating condition. After the main factors which effect soy protein gels transparency and strength being studied on DC heating condition ,the different affects on soy protein gels transparency and strength by DC heating and water bath heating are analyzed and compared ,and the transparent mechanisms of soy protein gels are further explored .In addition to temperature action as water bath heating ,DC heating is added as electric field directional action .As a results , heating rate is increased. Directional range degrees of soy protein molecules are raised. These更多还原