本文研究了酶解脱支和醚化复合改性淀粉为基材制备了淀粉膜，在此基础上添加其他助剂逐渐提升淀粉膜材料的性能，利用现代分析仪器解析其结构特征并初步探讨相关机理。通过优化实验确定了淀粉膜材料工艺参数：复合改性淀粉材料浓度为3%，甘油含量为30%，料液温度为95 ℃，柠檬酸含量为10%时，制备的复合改性淀粉膜材料性能较好，此时淀粉膜的抗拉强度为4.11 MPa，断裂伸长率为38%，提高了45%，水蒸气透过系数为0.51 g·mm/(m2·h·kPa)，降低了39%。结构分析结果表明淀粉膜体系具有较为开放的交联网络结构，淀粉链优先与柠檬酸与甘油形成的酯结合，此外柠檬酸的水解作用会导致体系网络结构减弱。因此，添加柠檬酸可有效改善复合改性淀粉膜材料的机械性能和阻隔性能，制备出综合性能优良的复合膜，为淀粉基食品包装应用研究提供了理论依据。

Starch films, which were prepared using starch composites that had been modified through enzymatic debranching and etherification processes, were further enhanced by the addition of citric acid and glycerin and their structural characteristics and relevant mechanisms were investigated. From the process optimization experiments, a 3% starch-based material concentration, 30% glycerin content, 10% citric acid content, and 95°C processing temperature were found to result in a starch film with the best physicochemical characteristics. The film had a tensile strength of 4.11 MPa, an elongation at break of 38% (a 45% increase over the non-enhanced film), and a water vapor permeability coefficient of 0.51 g·mm/(m2·h·kPa) (a 39% decrease over the non-enhanced film). Structural analysis revealed the starch film to have a relatively open crosslinked network structure, in which the starch chain was preferentially combined with the ester formed by citric acid and glycerin. Additionally, the network structure was weakened by the hydrolysis effects of citric acid. Therefore, the addition of citric acid can effectively improve the mechanical and barrier properties of modified starch films, enabling the preparation of composite films with excellent overall performance. The results of this study provide a scientific basis for future studies on the applications of starch-based food packaging materials.

国家重点研发计划项目（2018YFC1603204）；江苏省农业科技自主创新资金项目（CX(17)2022）