摘要：Soy protein isolate (SPI) and zein were blended at different ratios, and native and microwave-modified films were prepared at pH 12 in an ethanol/water (20 : 80) mixture. The effect of the microwave modification on the mechanical properties and structural characteristics of the SPI and zein blended films was investigated. The results show that the microwave-modified blended film of 3 : 1 SPI-zein demonstrated the best mechanical properties: the highest breaking strength (2900 g) and the highest fracturing distance (16.08 mm). The morphology of the microwave-modified film was more homogeneous and had fewer pinholes than the zein-only film. In addition, the glass transition temperature of the microwave-modified film rose by nearly half compared to the zein-only film, while the melting temperature increased by almost 2.5%. The secondary structure analysis indicates that a moderate amount of microwave treatment will promote a decrease in α-helix, β-turn, and random coil content and an increase in β-sheet content. This study provides an edible material with better flexibility for food packaging.
关键词：protein film; protein modification; breaking strength; fracturing distance; structural characteristics
