Multifunctional film of soy protein nanofiber/chitosan/zinc oxide for tomato postharvest freshness preservation

As single-function packaging increasingly fails to meet the demand for environmentally friendly convenience, multifunctional packaging is becoming increasingly important in food applications. In this study, inexpensive soybean protein is used as the raw material for membrane preparation, and it is fibrillated. Chitosan and Zinc oxide nanoparticle were added to it to improve its film-forming property, and a multifunctional film (SCZ) was made. SCZ exhibits high mechanical properties and water resistance. Furthermore, it displays exceptionally high antimicrobial activity (>99 %), antioxidant performance (>80 %), UV-blocking efficacy, and biocompatibility. Due to these multifunctional properties, SCZ has the potential to be used in food packaging applications, as demonstrated by tomato preservation experiments. It maintains good freshness both at room temperature and under refrigerator chilling conditions, and extends shelf life (25 °C, 6 d or 4 °C, 10 d). This research provides a new design concept for sustainable multifunctional food packaging materials. • An eco-friendly multifunctional packaging film was developed. • The film had good water resistance and UV blocking efficacy. • The film had good antimicrobial/antioxidant activity and biocompatibility. • The shelf life of tomatoes could be extended by about a week.