Preparation and Characterization of Chitosan/Carboxymethylated Konjac Glucomannan Blend Films

In order to improve the mechanical and water swelling properties of the chitosan (CS) film, a series of transparent films were prepared by blending 2%(weight) chitosan acetic acid solution with 1.5%(weight) carboxymethylated konjac glucomannan (CMKGM) aqueous solution according to predetermined ratio and drying at 30°C. The morphological structure, miscibility, thermal stability, mechanical properies, and swelling capacity of the blend films were studied by infrared (IR), X-ray diffraction (XRD), differential thermal analysis (DTA), scanning electron micrograph (SEM), and measurements of the mechanical properties and swelling properties. The results demonstrated that there was strong interaction and good miscibility between CS and CMKGM resulted from intermolecular hydrogen bonding and electrostatic force. The mechanical properties in dry state and wet state, thermostability, and water swelling properties of the blend films were obviously improved. The best values of the tensile strength in the dry and wet state achieved 89 MPa and 49 MPa, respectively, when the CMKGM content was 30%(weight). The CS/ CMKGM blend films provided promising biomedical applications.

Gelation and Swelling Behavior of Oxidized Konjac Glucomannan/Chitosan Hydrogel

The gelating and swelling mechanisms of the hydrogel formed from oxidized konjac glucomannan (OKGM) and chitosan (CS) were studied by Fourier transform infrared (FT-IR) spectrometry. FT-IR spectra illustrate that the interaction of polysaccharides forms the hydrogen bonds and interchain salt bonds and the dissocation of which dominates the swelling behavior in buffer solutions of different pH. The concentration of salt ion has effect on swelling behavior through the difference of salt ion concentration between in solution and in network of hydrogel, which causes penetrating pressure. Moreover, the Swelling degree and hydrogel strength could be modulated by varying conditions. It is indicated that the hydrogel has pH-sensitive and salt ion sensitive properties. The prepared optimum condition selected by varying conditions is thatr=0.2;t=30 min;T p

响应面法优化魔芋多糖蛋白互配体系凝胶特性

采用响应面分析法研究多糖中魔芋精粉含量、K+浓度、pH值、溶胀温度对魔芋多糖蛋白互配体系凝胶特性的影响。在单因素试验基础上,采用二次正交旋转组合设计试验,以魔芋精粉含量、K+浓度、pH值、溶胀温度为影响因素,凝胶强度、黏聚性和咀嚼性为响应值建立二次回归方程,通过响应面分析得到对3种凝胶特性影响的主次因素和优化条件,并采用组合赋权法确定三者权重,利用回归分析获得高性能魔芋多糖蛋白凝胶的最终优化工艺。结果表明:各因素对凝胶强度的影响由大到小依次为K+浓度、pH值、魔芋精粉含量、溶胀温度,对凝胶黏聚性和咀嚼性的影响由大到小依次为魔芋精粉含量、K+浓度、溶胀温度、pH值;凝胶强度、黏聚性和咀嚼性对评价高性能凝胶所占权重分别为0.356、0.221、0.423,高性能魔芋多糖蛋白凝胶的最终优化工艺:多糖中魔芋精粉含量为22.35%,K+浓度为1.05%,pH值为12.6,溶胀温度为82.8℃。