大豆分离蛋白作为完全可降解性的生物聚合物，无抗菌性、机械性能及阻隔性能差限制了其在包装领域中的应用，该研究通过将纳米ZnO和纳米TiO2分别加入大豆分离蛋白（Soy Protein Isolate，SPI）中制备SPI/纳米ZnO复合膜和SPI/纳米TiO2复合膜，并对复合膜的包装特性进行比较，确定一种更有利于提升大豆分离蛋白基薄膜相关性能的纳米材料。分析结果表明：纳米ZnO在SPI膜液中的分散性优于纳米TiO2在SPI膜液中的分散性，纳米ZnO和大豆蛋白的相容性更好，且成膜后能更好的发挥协同作用，SPI/纳米ZnO复合膜较SPI/纳米TiO2复合膜的机械性能、阻隔性能和抗菌性能更为突出（P<0.05）。纳米ZnO和大豆蛋白以3%的质量比制备复合膜时，SPI/纳米ZnO（SZ3）复合膜相比较于SPI膜，拉伸强度从6.64 MPa升至18.33 MPa，水蒸气透过率从 20.63×10-2 g•mm/(m2•h•kPa)降至2.94×10-2 g•mm/(m2•h•kPa)，氧气透过率从3.32×10-5 g•m/(m2•d•kPa)降至1.54×10-5 g•m/(m2•d•kPa)。此外，复合膜对大肠杆菌和短小芽孢杆菌表现出优异的抗菌性能，抑菌性随着纳米粒子的添加呈上升趋势，在活性包装应用中具有极大潜力。以上研究结果将为大豆蛋白基薄膜的未来应用提供理论参考。

Soybean protein isolate (SPI) is a biodegradable biopolymer. However, its application in the packaging industry has been limited by its lack of antibacterial properties, poor mechanical performances, and deficient barrier properties. SPI/nano-ZnO (SZ) and SPI/nano-TiO2 (ST) composite films were prepared herein by the addition of different amounts of nano-ZnO and nano-TiO2 to SPI. Furthermore, various packaging properties of the composite films were compared to identify the nanomaterial more conducive to enhancing the properties of SPI films. The results showed that the dispersity of nano-ZnO in the SPI film solution was superior to that of nano-TiO2. Moreover, Nano-ZnO exhibits better compatibility with SPI and superior synergistic effects. The mechanical performance, barrier properties, and antibacterial properties of SZ composite films were also superior to those of their ST counterparts (P<0.05). Compared to the SPI film, the SZ3 composite film, containing 3% ZnO, showed a higher tensile strength. More specifically, tensile strength increased from 6.64 MPa to 18.33 MPa. Meanwhile, the water vapor permeability (WVP) decreased from 20.63×10-2 to 2.94×10-2 g•mm/(m2•h•kPa), and the oxygen permeability (OP) reduced from 3.32×10-5 to 1.54×10-5 g•m/(m2•d•kPa). In addition, the composite films exhibited excellent antibacterial performance against Escherichia coli and Bacillus cereus, with a more pronounced effect observed as the nanoparticle concentration increased. Thus, both films demonstrated considerable potential in the application of active packaging. Collectively, these results provide a theoretical reference for the improved application of SPI films.

黑龙江省“百千万”工程科技重大专项课题（2021ZX12B04-04）；黑龙江省省属科研院所科研业务费项目（CZKYF2022-1-B009）