Wagoner Ty B, Ward Loren, Foegeding E Allen
†Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Box 7624, Raleigh, North Carolina 27695-7624, United States.
§Glanbia Nutritionals, 450 Falls Avenue, Twin Falls, Idaho 83301, United States.
J Agric Food Chem. 2015 May 6;63(17):4335-44. doi: 10.1021/acs.jafc.5b00633. Epub 2015 Apr 28.
A method for evaluating aspects of colloidal stability of whey protein beverages after thermal treatment was established. Three state diagrams for beverages (pH 3-7) were developed representing protein solubility, turbidity, and macroscopic state after two ultrahigh-temperature (UHT) treatments. Key transitions of stability in the state diagrams were explored using electrophoresis and chromatography to determine aggregation propensities of β-lactoglobulin, α-lactalbumin, bovine serum albumin, and glycomacropeptide. The state diagrams present an overlapping view of high colloidal stability at pH 3 accompanied by high solubility of individual whey proteins. At pH 5, beverages were characterized by poor solubility, high turbidity, and aggregation/gelation of whey proteins with the exception of glycomacropeptide. Stability increased at pH 6, due to increased solubility of α-lactalbumin. The results indicate that combinations of state diagrams can be used to identify key regions of stability for whey protein containing beverages.
建立了一种评估热处理后乳清蛋白饮料胶体稳定性各方面的方法。绘制了三种饮料（pH值3 - 7）的状态图，分别表示两次超高温（UHT）处理后的蛋白质溶解度、浊度和宏观状态。利用电泳和色谱法探究状态图中稳定性的关键转变，以确定β-乳球蛋白、α-乳白蛋白、牛血清白蛋白和糖巨肽的聚集倾向。状态图呈现了在pH值3时具有高胶体稳定性且各乳清蛋白具有高溶解度的重叠视图。在pH值5时，饮料的特点是溶解度差、浊度高以及除糖巨肽外的乳清蛋白发生聚集/凝胶化。在pH值6时稳定性增加，这是由于α-乳白蛋白的溶解度增加。结果表明，状态图的组合可用于识别含乳清蛋白饮料的关键稳定区域。
