【摘要】 以大豆分离蛋白（soybean protein isolate,SPI）、聚乙烯醇（polyvinyl alcohol,PVA）和蓝莓花青素（blueberry anthocyanin,BA）为原料，通过流延法制备一种新型pH值智能指示膜（SPI/PVA-BA膜），用于监测巴氏杀菌乳的新鲜度。对不同BA添加量的指示膜进行微观结构、机械性能、含水率、水溶性、紫外线透过率、水蒸气透过率和pH值敏感性表征。结果表明，当BA添加量为12%时，指示膜的断裂伸长率最高（105.12%）;BA添加量为8%时，拉伸强度达到最高值（11.58 MPa），且对pH值变化的颜色敏感性最佳。将含8%BA的指示膜应用于巴氏杀菌乳新鲜度监测中，发现72 h内（（22±1）℃），随着pH值下降、酸度上升，杀菌乳变质，指示膜颜色随之改变，能够有效反映其新鲜度。此外，指示膜在土壤中经过10 d基本完全降解，显示其良好的生物降解性。因此，该智能包装膜不仅能够指示产品新鲜度，还可避免生物基塑料对环境的污染。更多还原

【Abstract】 In this study, a novel pH-sensitive intelligent indicator film(SPI/PVA-BA film) composed of soybean protein isolate(SPI), polyvinyl alcohol(PVA), and blueberry anthocyanin(BA) was prepared via a casting method for freshness monitoring of pasteurized milk. The microstructure, mechanical properties, moisture content, water solubility, ultraviolet(UV) transmittance, water vapor permeability(WVP), and pH sensitivity of the indicator film with different BA levels were characterized. The results showed that the f ilm containing 12% BA exhibited the highest elongation at break(105.12%),while that containing 8% BA had the highest tensile strength(11.58 MPa) and showed the best color sensitivity to pH changes. The pH decline in pasteurized milk during storage for 72 hours at(22 ± 1) ℃ caused color changes in the film containing 8% BA, showing that this film could reflect the freshness of pasteurized milk. Additionally, the indicator film was almost completely degraded after being buried in soil for 10 days, demonstrating its good biodegradability. Therefore, this intelligent packaging film not only holds potential as a freshness indicator, but also contributes to reducing environmental pollution associated with bio-based plastics.更多还原