İnce CoŞkun Alev Emine
Department of Food Engineering, Faculty of Engineering, Ege University, İzmir Turkey.
Turk J Chem. 2020 Oct 26;44(5):1314-1326. doi: 10.3906/kim-2004-57. eCollection 2020.
In this study, phase separation of colloidal whey protein isolate (WPI) particle dispersions was studied using a rod-like polysaccharide xanthan. Effects of different xanthan concentration, particle volume fraction, and temperature were analyzed by visual observations, turbidity measurements, and particle mobility tracking method. Particle mobility was determined using a diffusing wave spectroscopy (DWS) set up. Xanthan concentration was kept low in order not to increase the viscosity of dispersions, so that the phase separation could be observed easily. Visual observations showed that there was a minimum concentration of xanthan to induce phase separation at a constant particle volume fraction, and xanthan concentration was found to have an important effect on the degree of phase separation. The temperature was also found to have an effect on depletion mechanism. Phase separation was mainly a result of different sizes of WPI particles, and xanthan induced the depletion interaction between WPI particles, as supported by the data obtained from DWS. The results of this study explained both the mechanism and the stability range of particle dispersions in the presence of xanthan, which is important for the design of stable systems, including colloidal particles.
在本研究中，使用棒状多糖黄原胶研究了胶体乳清蛋白分离物（WPI）颗粒分散体的相分离。通过肉眼观察、浊度测量和颗粒迁移率跟踪方法分析了不同黄原胶浓度、颗粒体积分数和温度的影响。使用扩散波谱（DWS）装置测定颗粒迁移率。黄原胶浓度保持较低，以免增加分散体的粘度，从而便于观察相分离。肉眼观察表明，在恒定的颗粒体积分数下，存在一个诱导相分离的黄原胶最低浓度，并且发现黄原胶浓度对相分离程度有重要影响。还发现温度对耗尽机制有影响。相分离主要是WPI颗粒大小不同的结果，并且黄原胶诱导了WPI颗粒之间的耗尽相互作用，这得到了从DWS获得的数据的支持。本研究结果解释了在存在黄原胶的情况下颗粒分散体的机制和稳定性范围，这对于包括胶体颗粒在内的稳定系统的设计很重要。
