文献：

Investigation on complex coacervation between fish skin gelatin from cold-water fish and gum arabic: Phase behavior, thermodynamic, and structural properties.

文献链接：

https://pubmed.ncbi.nlm.nih.gov/29580524/

作者：

Yong Li , Xiyue Zhang, Yu Zhao , Jie Ding, Songyi Lin

相关产品：

乙交酯 glycolide

原文摘要：

The study is aimed to investigate phase behavior, thermodynamic, and structural properties based on complex coacervation between fish skin gelatin (FSG) from cold-water fish and gum arabic (GA). Phase separation behavior between FSG and GA was investigated as a function of pH through varying mixing ratios from 4:1 to 1:4 at 25 °C and 1.0 wt% of total biopolymer concentration. The turbidity of FSG-GA mixture reached the maximum (1.743) at the 1:2 of mixing ratio and pHopt 3.5, and stabilized at zero. Then physicochemical properties of FSG-GA coacervates at pHopt 3.5 and FSG-GA mixtures at pH 6.0 (>pHc) were evaluated. Hydrogen bondings in FSG-GA mixtures at pH 6.0 and 3.5 were found to be stronger than pure FSG at pH 6.0 and 3.5 owing to that the amide II peaks shifted to high wavenumbers. Electronic interaction was proven to exist in FSG-GA mixtures at pH 6.0 through the vanishment of asymmetric COO- stretching.

乙交酯本身并不直接作为阿拉伯胶复合凝聚体系中的核心组分参与反应，但通过其聚合物形式（如聚乙交酯）可与阿拉伯胶结合，或利用阿拉伯胶特性优化乙交酯基微胶囊的制备效果。阿拉伯胶作为阴离子多糖，在复合凝聚法中常与明胶等阳离子聚合物配合使用。其核心作用机制是通过pH调节使带相反电荷的高分子发生静电相互作用，形成复合物并析出。该过程的关键在于阿拉伯胶与明胶在特定pH值（如pH4.0）下形成溶解度降低的复合物，从而实现微胶囊壁材的构建。乙交酯作为环状二聚体，是合成聚乙交酯（PGA）的单体。

图为：乙交酯 glycolide结构式

（FSG）明胶与阿拉伯树胶（GA）之间基于复杂凝聚的相行为、热力学和结构性质。在25°C和1.0wt%的生物聚合物总浓度下，通过从4:1到1:4的不同混合比，研究了FSG和GA之间的相分离行为作为pH的函数。FSG-GA混合物的浊度在1:2的混合比和pHopt 3.5时达到（1.743），并稳定在零。

扫描电子显微镜（SEM）和X射线衍射（XRD）表明：FSG和GA之间的相互作用在pHopt 3.5时发生，在pH6.0时非常弱（>pHc）。等温滴定量热法（ITC）的结果包括负吉布斯自由能变化（ΔG=-18.71±1.300 kJ/mol）、结合焓（ΔH=-41.81±1.3000 kJ/mol。FSG-GA凝聚层在pHopt 3.5下的ζ电位（ZP）为-9.00±0.79mV，不接近电中性，表明除了电子相互作用之外还有其他相互作用。发现在pH 6.0和3.5的FSG-GA混合物中的氢键比在pH 6.0或3.5的纯FSG更强，这是因为酰胺II峰向高波数移动。通过消除不对称COO-拉伸，证明在pH 6.0的FSG-GA混合物中存在电子相互作用。