魔芋葡甘聚糖/酪蛋白复合物的温压协同改性机制研究

Polysaccharide and protein were the normal biomacromoleculars in food. The properties of polysaccharide-protein complex were very important to food processing, but the property adjustment has not been established due to the unknown modification mechanism. Based on the result of previous experiments that HHP processing could change the properties of Konjac glucomannan(KGM)/Casein(CS) complex and the analysis of molecular structure, molecular interaction, microstructure and properties of KGM/CS complex. The dynamics process and gel models of molecular reassembly and gel network rebuilding in KGM/CS complex during temperature assisted pressure treatment were gotten by using the methods of rheology, spectroscopy and computer simulation. Meanwhile, molecular conformation, functional groups, hydrogen bond, coordinate bond and the relationship between molecular structure, molecular interaction and property will be mainly studied during the modification process. Based on the above results, the modification mechanism was revealed, and the property adjustment of KGM/CS complex was achieved. Through this research, the modification mechanism of KGM/CS complex treated by temperature assisted pressure was finally expounded and a new property regulated technology of KGM/CS complex was exploited. Moreover, this research will also provide some scientific references for the modification research of other polysaccharide-protein complexes.

多糖与蛋白是食品体系中最常见的生物大分子，所形成多糖-蛋白复合物的性能对食品加工具有重要科学意义，但因缺乏对其性能改变(改性)机制的深入研究，人为调控其性能尚未有所进展。基于前期高压可改变魔芋葡甘聚糖(KGM)/酪蛋白(CS)复合物性能的研究，本项目拟从KGM/CS复合物的分子结构、分子相互作用、微观结构及功能特性等角度，采用计算机模拟结合流变学、光谱学等方法，研究温压协同改性处理下KGM与CS分子重组装及凝胶网络重塑的动态过程，构建其相关模型。重点研究分子构象、官能团等分子结构和氢键、配位键等分子作用力在改性过程中的变化，探索分子结构、相互作用力与性能关系，进而揭示其性能改变机制，实现KGM/CS复合物性能的调控。通过本研究，有望最终揭示KGM/CS复合物温压协同改性机制，形成一套切实可行的KGM/CS复合物性能调控新技术，并为其他多糖-蛋白复合物的改性研究提供科学依据。

温压协同改性处理旨在改善多糖-蛋白共混物相容性，提升多糖-蛋白类食品的稳定性与品质。本课题研究主要以魔芋葡甘聚糖(KGM)/酪蛋白(CS)共混物为研究基材，以单独高压(HHP)处理为参照，开展温压协同(T/HHP)改性处理研究；研究内容主要涉及探索KGM/CS共混物制备过程各因素对其的影响，以及T/HHP改性对共混物宏观性能、微观结构、分子间相互作用的影响。研究结果如下：通过响应面优化得到KGM/CS共混溶胶、凝胶制备模型；通过分析T/HHP对KGM/CS共混物宏观性质与微观结构的影响，显示低压可使共混物结构紧致，性能提升；过高压力会破坏共混物结构，使其出现裂缝、孔洞等，性能下降；在性能改善的处理条件上，溶胶与凝胶体系有所不同，但其中200MPa与600MP的处理条件最具有代表性；通过X-衍射、红外光谱及分子模拟等分析T/HHP对KGM/CS共混物分子间相互作用影响，显示T/HHP处理并未改变共混溶胶与凝胶的晶型结构与功能性集团，仅是使与氢键、电偶极矩等有关的结晶区、基团吸收峰的振动频率与吸收强度等发生变化。综上，T/HHP对KGM/CS共混物的改性机制主要为调控KGM与CS之间氢键、电偶极矩等非共价键。温压协同调控具有快速、高效、安全、便捷等优点，后期将在多糖、植物蛋白和乳品等组成多糖-蛋白复合食品体系中转化应用。