Bowland E L, Foegeding E A
and O' Lakes, St. Paul, MN 55112, USA.
J Dairy Sci. 2001 Nov;84(11):2372-80. doi: 10.3168/jds.S0022-0302(01)74686-3.
The rheological and microstructural properties of a model processed cheese were investigated. The cheese contained 20% protein (rennet casein), 27% anhydrous milk fat, 1.5% NaCl and 1 to 3% Na2HPO4 (DSP). Processing time (10, 20, or 30 min), DSP (1, 2, or 3%) and pH of the DSP-NaCl solution (5.4, 5.6, or 5.8) were adjusted to alter rheological properties. Small-strain oscillatory shear rheological parameters that correlated with transitions previously observed by large-strain (fracture) properties were moduli at 8 degrees C and changes in moduli with cooling from 80 to 25 degrees C. Mechanical spectra at 80 degrees C indicated cheeses containing less than 2.0% DSP were entangled macromolecular dispersions, and those containing more than 2.0% DSP were gels. A compilation of small strain results suggested samples could be divided into three basic rheological states. A model describing the gel network is proposed based on the results of this investigation and large-strain (fracture) rheological properties. The model was based on increased breakdown of para-casein aggregates into amphiphilic molecules and rheological properties being related to the combination of para-casein aggregates and amphiphilic molecules.
对一种模拟加工干酪的流变学和微观结构特性进行了研究。该干酪含有20%的蛋白质（凝乳酶酪蛋白）、27%的无水乳脂肪、1.5%的氯化钠和1%至3%的磷酸氢二钠（DSP）。调整加工时间（10、20或30分钟）、DSP含量（1%、2%或3%）以及DSP - 氯化钠溶液的pH值（5.4、5.6或5.8）以改变流变学特性。与先前通过大应变（断裂）特性观察到的转变相关的小应变振荡剪切流变学参数是8℃时的模量以及从80℃冷却至25℃时模量的变化。80℃时的力学谱表明，DSP含量低于2.0%的干酪是缠结的大分子分散体，而DSP含量高于2.0%的干酪是凝胶。小应变结果的汇总表明，样品可分为三种基本的流变状态。基于本研究结果和大应变（断裂）流变学特性，提出了一个描述凝胶网络的模型。该模型基于副酪蛋白聚集体分解为两亲分子的增加以及流变学特性与副酪蛋白聚集体和两亲分子的组合相关。
