超声辅助提高大豆蛋白纳米复合膜包装性能及其保鲜应用

Ultrasonic Treatment for Improved Properties of Soybean Protein Nanocomposite Packaging Film and Its Application in Preservation of Cherry Tomatoes

本实验选取大豆分离蛋白(soy protein isolate,SPI)、聚乙烯醇(polyvinyl alcohol,PVA)、纳米纤维素(nanocellulose,NCC)为主要原料制备纳米复合膜,以复合膜的抗拉强度、断裂伸长率、水蒸气透过率、氧气透过率、二氧化碳透过率及透光率为评价指标,通过单因素试验得出制膜的最佳工艺为:SPI添加量3.0%,PVA添加量与NCC添加量比例1∶2、超声功率40 W、超声时间20 min。超声温度60℃。结果表明:经超声处理的纳米复合膜具有良好的包装性能;且由X射线衍射、扫描电子显微镜以及接触角分析可知,与纯SPI膜和未经超声处理的SPI/PVA/NCC复合膜相比,经超声处理的SPI/PVA/NCC复合膜表面更为平整,内部网状结构更加致密,且具有疏水性;将其应用于圣女果保鲜中,可更有效保持圣女果的硬度、水分、可溶性固形物质量分数以及VC含量,延长其货架期,说明其作为一种包装性能优良的大豆蛋白纳米复合膜在果蔬保鲜方面具有潜在的应用前景。

In this study,soybean protein isolate(SPI),polyvinyl alcohol(PVA)and nanocellulose(NCC)were selected as the main raw materials to prepare nanocomposite films.Based on tensile strength,elongation at break,water vapor permeability,oxygen permeability,carbon dioxide permeability and light transmittance,the optimum preparation conditions were obtained using single factor experiments as follows:SPI concentration 3.0%,ratio of PVA to NCC 1:2,ultrasonic power 40 W,sonication time 20 min,and temperature 60℃.The as-prepared composite film had good packaging properties.The results of X-ray diffraction(XRD),scanning electron microscopy(SEM)and contact angle analysis showed that the surface of this film was smoother and its internal reticular structure was denser than that of pure SPI film and the composite film without ultrasonic treatment.The ultrasonic-treated composite film could effectively maintain the hardness,moisture,soluble solids and VC contents of cherry tomatoes during storage,thereby extending its shelf life,indicating that this nanocomposite film,with excellent packaging performance,has potential application prospects in the preservation of fruits and vegetables.