阿拉伯木聚糖与壳聚糖复凝聚物的制备及表征

研究了不同因素对壳聚糖-阿拉伯木聚糖复凝聚的影响，通过测定平衡相的浊度和复凝聚相收率确定玉米阿拉伯木聚糖（CAX）和壳聚糖（CS）间复合物形成的条件。采用红外光谱、热重分析、扫描电子显微镜和流变学特性对复凝聚物进行表征。研究结果表明，在CAX/CS配比为9:1，体系pH值为4.0，总固形物浓度为3%（m/m），室温下反应10 min，最大复凝聚相产率达76.04%。红外光谱和热重分析结果表明，CAX/CS复凝聚物是通过CS中的-NH3+和CAX中-COO-之间的相互吸引形成的。用SEM扫描成像显示复凝聚物具有规则且分布均匀的多孔网络结构。CAX/CS复凝聚物粘弹特性取决于发生复凝聚的pH值。在pH值3.5和4.0时，复凝聚物为液体粘弹行为；在pH值5.0时，复凝聚物为固体粘弹性行为。pH值5.0下形成的复凝聚物的G’最高，说明除静电作用外，其他因素也可能对CAX/CS复凝聚物粘弹特性起重要作用。CAX/CS复凝聚物可以作为包封营养素和功能性因子的微囊化壁材。

Preparation and Characterization of Arabinoxylan/Chitosan Complex Coacervates

The influences of different factors on the complex coacervates of corn arabinoxylan (CAX) and chitosan (CS) were investigated and the conditions for the formation of arabinoxylan/chitosan complexes were determined by measuring the turbidity at equilibrium and the complex coacervate yield obtained by precipitation. Complex coacervates were characterized using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis, scanning electron microscopy (SEM), and rheological properties. A maximum complex coacervate yield of 76.04 % was obtained under the optimum conditions of an arabinoxylan/chitosan mass ratio of 9:1, total biopolymer concentration of 3 % (m/m), pH of 4.0, the room temperature, and reaction time of 10 min. FTIR and thermogravimetric analysis results suggested that complex coacervates are formed via electrostatic interactions between the CS amine group (-NH3+) and the CAX carboxyl group (-COO-). SEM micrographs revealed a regular and uniformly distributed porous network structure for the complex coacervates. Viscoelastic properties of CAX/CS complex coacervates depend on the coacervation pH, with coacervates formed at pH 3.5 and 4.0 showing liquid viscoelastic behavior and those formed at pH 5.0 exhibiting solid viscoelastic behavior. The coacervates formed at pH 5.0 had the highest elastic modulus, implying that factors other than electrostatic interaction are important in the viscoelastic properties. The results indicate that CAX/CS coacervates can be applied for the encapsulation of nutrients and other functional factors.