Le Mans Université, IMMM UMR-CNRS 6283, Polymères, Colloïdes et Interfaces, 72085 Le Mans, cedex 9, France; Université de Tunis El Manar, Faculté des Sciences de Tunis, LR99ES16 Laboratoire Physique de la Matière Molle et de la Modélisation Électromagnétique, 2092, Tunis, Tunisia.
Université de Tunis El Manar, Faculté des Sciences de Tunis, LR99ES16 Laboratoire Physique de la Matière Molle et de la Modélisation Électromagnétique, 2092, Tunis, Tunisia.
Colloids Surf B Biointerfaces. 2018 Sep 1;169:257-264. doi: 10.1016/j.colsurfb.2018.05.030. Epub 2018 May 15.
Hybrid protein-polysaccharide particles were formed by complexation of fractal whey protein aggregates and the cationic polysaccharide chitosan. The fractal aggregates were preformed by heating native whey protein isolate at pH 7 and subsequently mixed with chitosan at pH 3 where these proteins and polysaccharides don't interact with each other. Stable dispersions of protein-polysaccharide particles were formed spontaneously when the pH was gradually increased between 4.1 and 6.8, whereas in the absence of chitosan the fractal aggregates precipitated between pH 4.1 and 5.4. Potentiometric titration of the mixtures showed that deprotonation of both components was affected by complexation. With increasing pH, the size of the complexes increased sharply between pH 4.1. and pH 4.5, remained constant up to pH 5.6 and then increased again. A minimum amount of chitosan was needed to form stable complexes at pH 5.0 and the size of the complexes decreased with increasing chitosan concentration. Light scattering showed that the complexes were stable to dilution and had a self similar structure with a fractal dimensions close to two. The effect of changing the pH on the size and stability of the complexes was investigated. Suspensions of complexes of preformed whey protein aggregates and chitosan are more stable up to high pH (6.8) than complexes between native WPI and chitosan as reported in the literature.
通过分形乳清蛋白聚集物与阳离子多糖壳聚糖的复合，形成了杂化蛋白-多糖颗粒。分形聚集物是通过在 pH7 下加热天然乳清蛋白分离物预先形成的，然后在 pH3 下与壳聚糖混合，在这种条件下这些蛋白质和多糖不会相互作用。当 pH 在 4.1 到 6.8 之间逐渐升高时，蛋白质-多糖颗粒的稳定分散体自发形成，而在没有壳聚糖的情况下，分形聚集物在 pH4.1 到 5.4 之间沉淀。混合物的电位滴定表明，两种成分的去质子化都受到了复合的影响。随着 pH 的增加，复合物的大小在 pH4.1 到 pH4.5 之间急剧增加，在 pH5.6 之前保持不变，然后再次增加。在 pH5.0 下形成稳定复合物需要最少量的壳聚糖，并且复合物的大小随壳聚糖浓度的增加而减小。光散射表明，复合物在稀释时稳定，并且具有自相似结构，分形维数接近 2。研究了改变 pH 对复合物大小和稳定性的影响。与文献中报道的天然 WPI 与壳聚糖之间形成的复合物相比，预先形成的乳清蛋白聚集物和壳聚糖的复合物悬浮液在高 pH（6.8）下更稳定。
