The protein aggregation mechanism in UHT milk samples stored at ambient temperature for 1, 3 and 5 months was assessed in this study. Three phases of the UHT milks were studied: supernatants, dispersed phase and sediments. The supernatants showed a great variability, suggesting the presence of a dynamic arrangement within the protein system of UHT milk, which moves towards the formation of the sediment. The application of 2D-electrophoresis (AU-PAGE^NR-SDS-PAGE^R) and mass spectrometry analyses were carried out to study the main heat-induced supramolecular protein aggregates. These aggregates were found mainly in the supernatant and their composition changed along the storage, as a consequence of the medium chemical changes, which are temperature- and pH-depended, whereas the composition of the dispersed phase and sediment denoted a hierarchical mechanism of assembling.

中文翻译：

---

超高温灭菌牛奶中的蛋白质聚集机制：超分子证据

在这项研究中评估了在室温下储存1、3和5个月的UHT牛奶样品中的蛋白质聚集机制。研究了超高温灭菌奶的三个阶段：上清液，分散相和沉淀物。上清液显示出很大的可变性，表明UHT牛奶的蛋白质系统中存在动态排列，该动态排列向沉积物的形成方向移动。二维电泳（AU-PAGE ^NR -SDS-PAGE ^R）和质谱分析进行了研究主要的热诱导超分子蛋白质聚集体。这些聚集物主要存在于上清液中，其组成随存储的变化而变化，这是介质化学变化的结果，介质化学变化取决于温度和pH值，而分散相和沉积物的组成则表示组装的分级机制。