壳聚糖-乳清分离蛋白复合膜的制备、形态结构及理化性质

Preparation, Morphological Structure, and Physico-chemical Properties of Chitosan-Whey Protein Isolate Composite Film

以壳聚糖(chitosan,CTS)和乳清分离蛋白(whey protein isolate,WPI)为成膜基质,制备壳聚糖-乳清分离蛋白复合膜(chitosan/whey protein isolate composite fi lm,CWF),并分析CWF的理化性质。通过测定CWF的拉伸强度、断裂延伸率、水蒸气透过率、透明度,优化CWF的成膜条件为CTS脱乙酰度90%、分子质量300 kD,成膜液pH 3,甘油添加量1.5%,WPI添加量0.5%。CWF的机械性能和剥离性比CTS膜显著改善,WVP和透明度有良好的改善。扫描电镜分析显示CWF的横截面更规则、均匀,且外观为均匀半透明膜。傅里叶红外光谱扫描结果显示CTS、WPI制备CWF时在其分子之间形成了强烈的相互作用,二者有良好的相容性。

In this present work, chitosan-whey protein isolate composite film （CWF） was prepared by casting technique through mixing chitosan （CTS） dissolved in 2% （by volume） aqueous acetic acid with 1 g/100 mL whey protein isolate （WPI） dissolved in deionized water under continuous stirring. The tensile strength （TS）, breaking elongation rate （E）, water vapor permeability （WVP）, and transparency of CWF were determined. The preparation conditions of CWF were optimized to be CTS with a deacetylation degree （DD） of 90% and a molecular weight （Mw） of 300 kD in a film-forming solution at pH 3 with the addition of 1.5% glycerol and 0.5% WPI aqueous solution. The mechanical properties and stripping property of CWF were significantly improved over those of CTS, and CWF also showed a slight improvement in WPI and transparency. Scanning electron microscopy （SEM） analysis indicated that the cross-sectional microstructure of CWF was uniform and compact, and the appearance was semi-translucent. Fourier transform infrared spectrometer （FTIR） results showed a strong interaction and good compatibility between the molecules of CTS and WPI in the preparation of CWF.