场辅助玉米醇溶蛋白微观形貌与理化特性调控机制研究

It is the necessary trend that low value protein should be used in high value during the science and technology development in the grain processing industry. As the main grain and industrial resources, the corn protein of byproducts from process is more than 5 million tons annually. The nutritional value and bioavailability of zein are low because of poor aqueous solubility and inhomogeneous dispersion. In this project, the physicochemical properties of zein are efficiently and accurately regulated under a suitable auxiliary field conditions by analogizing and calculating. (1) The general mathematical model or theoretical formula for the properties of the solution and the micromorphology of the zein products are obtained. By adjusting the condition parameters of the solution, the micromorphology of the product is controlled and the solubility, film-forming and gel properties of zein are effectively controlled. The key factors of the process are screened, and the relationship mechanism between the properties of the solution, micromorphology and physicochemical properties is explained. (2) The influence of the micromorphology and physicochemical properties of zein is investigated by using high electrostatic field and high hydrostatic pressure field technique. The key influencing factors and regulation mechanism of the process are screened. The reasons for the difference of controlling effects are analyzed. The characteristic parameters of different field conditions are determined, the form of the theoretical formula is corrected, and the universal application range of the formula is widened, which provides a useful theoretical basis and experimental data reference for the high-value utilization of corn byproducts, especially the precise development and application of new zein food improver.

低值蛋白的高值化利用是粮食加工业科技发展的必然趋势。玉米作为主要的粮食和工业资源，加工产生的副产物玉米蛋白粉年均超过500万吨，其中主要组分醇溶蛋白由于水溶性差、微观分散不均匀，存在生物利用率差和营养价值低等利用瓶颈问题。本项目拟开展场辅助溶醇蛋白理化特性有效调控机制研究：（1）构建醇溶蛋白醇溶液性质与调控产物微观形貌的普适数学模型或通用理论公式，通过调节溶液条件参数，控制产物微观形貌，实现醇溶蛋白溶解性、成膜性和凝胶特性的有效调控，明确过程关键因素，阐明溶液性质-微观形貌-理化特性影响关系机理。（2）考察高压静电场、高静压场对醇溶蛋白微观结构形貌及理化特性的影响关系，阐明关键影响因素与调控过程机理，分析调控效果差异性原因，确定场辅助控制参数，修正理论公式形式，拓宽公式的普适应用范围，为玉米副产物高值化利用，特别是新型醇溶蛋白食品改良剂的精细化开发与应用提供有益科学理论依据及试验数据参考。

当前我国在玉米加工副产物醇溶蛋白利用方面存在不足，亟待开展醇溶蛋白高值化利用技术研究与开发。本项目围绕场辅助醇溶蛋白微观形貌及其理化特性的影响机制开展研究，实现了对成膜性、理化特性的有效调控，为玉米副产物高值化综合利用，特别是新型醇溶蛋白食品改良剂及其载体包材开发提供了有益科学理论依据及试验数据参考。主要研究结果如下：.（1）采用高压静电场辅助单轴电纺制备醇溶蛋白基功能载体包材，通过改变溶液性质，实现产物结构、微观形貌与品质性能的有效可控。通过表观黏度计算混合溶液的增比黏度，获得缠结浓度，推导出静电纺丝纤维的理论形成浓度，并由形貌分布图衍射出黏度形貌分布图。.（2）开展高压静电场辅助同轴电纺制备研究，所得醇溶蛋白基产物微观形貌为纳米套管结构，可包裹加载功能因子，应用于功能性食品包装和生物医用缓释材料。表面粘附性测试结果显示，含有聚环氧乙烷的位点较多，粘附性更强。.（3）探索了乳酸开环聚合反应机理，找到关键过渡态和中间体结构，进行能量计算和分解。动力学因素所引起的链端控制是立体选择性的主导因素。高压静电场实验结果表明聚乳酸的加入增加了醇溶蛋白的可纺性，溶液黏度从0.2Pa/S提升至2.1Pa/S，微观形貌由带状纤维变成均匀圆柱状结构，热加工温度最高提升20℃。.（4）高静压场处理会使醇溶蛋白发生不同程度的折叠和展开，破坏三、四级结构，也会影响二级结构，但不会影响一级结构。300 MPa压力处理的醇溶蛋白与绿原酸的结合最好，复合物的热稳定性最高。超高压处理会影响Zein及其与CA复合物的表面疏水性、流变特性和热特性。.（5）天然醇溶蛋白纺丝产物结构和机械性能优于超高压处理后的。所制备的纳米纤维是壳核结构，负载CA后比表面积增加，平均孔径减小。CA的加入使Zein基纳米纤维膜具有抗氧化和抗金黄色葡萄球菌特性。