The aim of this paper was to investigate the effect of whey protein isolate (WPI) and polymerised whey protein isolate (WPP) addition on physicochemical properties of processed cheese with partial fat replacement. Surface properties were determined by advancing (θ_a) and receding (θ_r) contact angles, apparent free surface energy (γ_s). Roughness measurements, cheese meltability and Turbiscan Stability Index (TSI) were evaluated by Turbiscan. Higher WPP concentrations produced the more hydrophobic surfaces of the samples. Conversely, increase in WPI addition promoted the hydrophilic cheese surfaces. The effect of roughness was much larger for samples containing WPI. The increase in protein addition caused a decrease in meltability and an increase in stability of cheeses. The optical and confocal images have proved that cheeses with WPP demonstrated more packed and denser structure in comparison to samples with WPI.

中文翻译：

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天然和聚合乳清蛋白分离物的添加对加工奶酪的表面和微观结构特性的影响及其可溶性（通过Turbiscan测定）

本文的目的是研究添加乳清蛋白分离物（WPI）和聚合乳清蛋白分离物（WPP）对部分脂肪替代加工奶酪的理化特性的影响。表面性质通过前进（θ确定_一个）和后退（θ _{- [R} ）的接触角，表观表面自由能（γ_小号）。通过Turbiscan评估粗糙度测量，奶酪的可融性和Turbiscan稳定性指数（TSI）。WPP浓度越高，样品的疏水表面越多。相反，WPI添加量的增加促进了亲水干酪的表面。对于含有WPI的样品，粗糙度的影响要大得多。蛋白质添加量的增加导致奶酪的融化性降低，稳定性提高。光学和共聚焦图像已经证明，与具有WPI的样品相比，具有WPP的奶酪显示出更密集和致密的结构。