采用质构、动态流变分析等方法，研究了pH对羊血浆蛋白热诱导凝胶特性的影响。研究结果表明，pH对羊血浆蛋白热诱导凝胶特性具有显著影响（P<0.05）。pH 5.0时，羊血浆蛋白热诱导凝胶硬度最小且保水性较差，微观结构粗糙、松散、孔径较大，为典型的颗粒状凝胶结构；pH 8.6时，热诱导凝胶的硬度、保水性最大，且具有致密有序的微观结构，是典型的良好线状凝胶。pH 5.0和8.6时羊血浆蛋白热胶凝过程中储能模量—温度曲线均呈现"稳定于0 Pa附近后骤升"的两段式变化；pH 5.0时，羊血浆蛋白的变性温度为71.5 ℃，pH 8.6时为80.9 ℃，与其凝胶点温度一致。SDS-PAGE电泳结果表明球蛋白与白蛋白聚集体是形成羊血浆蛋白凝胶体的主要蛋白，其中pH 5.0时，部分51 kU的蛋白质先以二聚体、再以多聚体的形式进行聚集。本研究表明pH可以调控和改变羊血浆蛋白热诱导凝胶。

The effect of pH on the heat-induced gel properties of lamb plasma proteins under various pH conditions was investigated by texture and rheology analysis. The pH had a significant impact on each of the properties tested. The lowest water-holding capacity and hardness were observed at pH 5.0, which resulted in a typical particulate gel with a coarse and disordered microstructureas well as large holes (based on diameter) in the network. The highest water-holding capacity and hardness of the lamb plasma proteins were both detected at pH 8.6, which resulted in a typical fine-stranded gel with a compact and ordered microstructure. The storage modulus vs temperature curve of the heat-induced gelation included two segments, stabilizing at 0 Pa and then increasing. The denaturation temperatures of the lamb plasma protein were 71.5 ℃ at pH 5.0 and 80.9 ℃ at pH 8.6. The temperature corresponded to that of the gelation point obtained from rheology analysis for the respective pH value. Based on SDS-PAGEpatterns, globins and albumin aggregates are the main structural blocks of the gels, for gels, and part of proteins with MW of 51 kU aggregated to form dimers, aggregates, finally 3-dimentional network of gels at pH 5.0. This work indicated that the performance of Lamb Plasma Protein gels can be improved via the modulation of pH values.

国家农业科技创新工程；国家现代肉羊产业技术体系项目（CARS-39）；内蒙古民族大学科学研究项目（NMD1211）