Soy protein isolate-based active films functionalized with Zanthoxylum bungeanum by-products: Effects on barrier, mechanical, antioxidant and cherry tomato preservation performance.

In this work, soy protein isolate (SPI)-based films enriched with naturally sourced Zanthoxylum bungeanum leaf extract (ZBLE) were prepared. Different ZBLE contents (0, 1, 3, 5, and 7 % w/w SPI) were incorporated into the SPI matrix to investigate the effect of ZBLE on various properties of the obtained films. ZBLE exhibited excellent compatibility with SPI in terms of tensile strength, water barrier properties, UV-light resistance capability, and antioxidant activities. The films with 5 % ZBLE addition presented the most comprehensive performance. The release of total phenolic compounds in two different aqueous food simulants was analyzed. Furthermore, the films were employed to preserve fresh cherry tomatoes at 25 ± 1 °C for 18 days. The changes in the physicochemical properties (mass loss rate, decay rate, and vitamin C content) of cherry tomatoes revealed that the addition of ZBLE to films significantly extended the storage time. Therefore, the SPI/ZBLE composite film has the potential as an eco-friendly active packaging material for food preservation.