Chaotropic离子诱导肌球蛋白重组装对其在脂肪球表面吸附特性的影响机制

Reducing the salt content will increase the cooking loss of emulsion-type meat products, and how to avoid such problem has been one of the research emphases of the low-salt meat products. Our previous studies demonstrated that the conformation changes of meat batter protein were induced by different salts. Based on these results, a hypothesis is proposed that changing the types and concentration of salt will induce the oriented adsorption transition of myosin recombinant at the oil-water interface. This project will select the Chaotropic-myosin-fat as a carrier, changing the types and concentration of Chaotropic to control the conformation and conformation transformation driving force of myosin, and then further to establish the correlation between Chaotropic and conformation changes of myosin in the emulsion process. Explain the way of myosin recombinant induced by Chaotropic. Then through changing Chaotropic control and measure the changes of myosin adsorption kinetics, interfacial expansion rheological property and emulsion stability, and then analyze the oriented adsorption transition mechanism of myosin recombinant at the oil-water interface induced by the Chaotropic. Eventually the reasons for the changes in interface protein membrane and gel matrix induced by reducing salt content in meat batter was clarified. Expected results will be helpful to provide theoretical foundation for processing high-quality low-salt meat products.

降低乳化型肉制品的盐含量会增加产品汁液流失，如何避免减盐引起的缺陷是低盐肉制品研究领域的重点。项目组前期研究发现不同离子会诱导肌肉蛋白质分子构象产生不同变化，据此提出"离子诱导肌球蛋白重组装影响其在脂肪球表面吸附特性转变"的假说。本项目拟以"Chaotropic离子-肌球蛋白-脂肪"乳化体系为载体，通过研究乳化过程中Chaotropic离子属性对肌球蛋白分子构象、构象变化驱动力的影响，确定离子属性与肌球蛋白构象变化之间的关系，明确离子诱导肌球蛋白重组装的具体方式；通过改变离子属性调控并测定其对肌球蛋白吸附动力学、界面扩张流变及乳化稳定性的影响，解析Chaotropic离子诱导肌球蛋白重组装影响其在脂肪球表面吸附特性转变的机制，最终阐明因降低肉糜中盐含量诱导其界面蛋白膜及凝胶基质发生改变的原因，为开发优质低盐肉制品提供理论依据。

减少乳化型肉制品的盐含量和饱和脂肪含量容易引起产品质量缺陷，解决该问题的同时如何提高产品的营养价值是新型乳化型肉制品加工领域的研究重点。本项目以"Chaotropic离子-肌肉蛋白质-油脂"乳化体系为研究对象，通过研究乳化过程中Chaotropic离子属性对蛋白分子构象、构象变化驱动力的影响，确定离子属性与蛋白构象变化之间的关系，明确离子诱导蛋白重组装的具体方式；通过改变离子属性调控其对蛋白吸附动力学、界面扩张流变及乳化稳定性的影响。以解析Chaotropic离子诱导肌肉蛋白重组装影响其在脂肪球表面吸附特性转变的机制。主要取得以下几方面的研究成果：（1）体相溶液中低浓度Chaotropic离子（L-组氨酸、氯化钾）通过协同调控疏水、静电相互作用抑制猪肉肌原纤维蛋白的横向聚集组装，进而影响低盐条件下乳液的理化特性；（2）体相溶液pH值影响肌原纤维蛋白的聚集组装形态，进而影响乳液的界面蛋白膜结构，最终影响乳液的理化特性和功能特性；（3）基于上述理论构建简单、低能耗、油相适应范围广及稳定性良好的肌原纤维蛋白基高内相皮克林乳液，解决了两种典型食品活性因子易氧化、荷载量低、生物利用率低的问题。相关研究结果发表在Food Hydrocolloids、Journal of Food Science、食品科学、中国食品学报等杂志。项目执行期间负责人入选辽宁省黄大年教学团队、辽宁省百千万人才万人层次，培养硕士研究生3人。此外，本项目完善的低盐乳化凝胶理论应用于低盐乳化型香肠、低盐高内相皮克林乳液的开发，获得了一款“盐值有道”肠道友好型低盐香肠，该产品获得2019年辽宁省普通高校本科大学生食品创新大赛二等奖，具备一定的推广前景。