Abstract Polyelectrolyte complexes (PECs) of biopolymers have been used for many applications, including emulsion stabilization and improvements in the properties of biopolymers, such as interfacial tension. The enhance of interfacial activity of biocompatible compounds is essential to the development of new natural stabilizers. Thus, the aim of this study was to understand how modifications on chitosan structure affect the interfacial tension of PECs. Positive, neutral and negative PECs were formed by varying chitosan or chitosan oligomers: whey protein isolate (WPI) mass ratios. Hydrolysis reduced chitosan size and increased zeta potential. FT-IR, 1H NMR analyses and crystallinity index confirmed structure modification. Chitosan oligomers showed lower crystallinity index and higher deacetylation degree than native chitosan. Positive chitosan PEC showed the lowest interfacial tension, suggesting a strong adsorption at interface oil–water and better interfacial stabilization than other PECs. Therefore, changes on chitosan structures enhance PECs interfacial properties and its use as emulsion stabilizer.

中文翻译：

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壳聚糖结构修饰与复合乳清分离蛋白对油水界面稳定性的影响

摘要 生物聚合物的聚电解质复合物 (PEC) 已被用于许多应用，包括乳液稳定和生物聚合物性能（如界面张力）的改进。增强生物相容性化合物的界面活性对于开发新的天然稳定剂至关重要。因此，本研究的目的是了解壳聚糖结构的修饰如何影响 PEC 的界面张力。阳性、中性和阴性 PEC 由不同的壳聚糖或壳聚糖寡聚体：乳清蛋白分离物 (WPI) 质量比形成。水解减少了壳聚糖的大小并增加了 zeta 电位。FT-IR、1H NMR 分析和结晶度指数证实了结构改性。与天然壳聚糖相比，壳聚糖低聚物显示出更低的结晶度指数和更高的脱乙酰度。正壳聚糖 PEC 显示出最低的界面张力，表明在油水界面处有很强的吸附作用，并且比其他 PEC 具有更好的界面稳定性。因此，壳聚糖结构的变化增强了 PEC 的界面性质及其作为乳液稳定剂的用途。