Leaf-inspired multifunctional zein films with CD-MOFs and Pickering emulsions for fruit preservation

Multifunctional zein films were developed using Pickering emulsions and γ-CD-MOFs. • Pickering emulsions improved mechanical performance while providing active preservation. • γ-CD-MOFs create an effective gas barrier, minimizing O 2 and CO 2 permeability. • The non-toxic, biodegradable film extended shelf-life of cherry tomatoes (15 d) and grapes (10 d). The development of eco-friendly food packaging from biomacromolecules offers a sustainable alternative to conventional petrochemical-based materials. However, effectively addressing both intelligent control and biodegradability remains a significant challenge. Herein, inspired by the nature leaf defense and respiration, for the first time, γ-cyclodextrin-metal-organic frameworks (CD-MOFs) and cinnamaldehyde-loaded Pickering emulsions (PE) are combined within a zein matrix to simultaneously target both external microbial spoilage and internal respiratory physiology of fresh produce. The resulting composite film with an optimal 4 wt% CD-MOFs loading exhibited exceptional gas barrier properties because of its CO 2 adsorption ability, achieving a minimal O 2 permeability and CO 2 permeability, which can efficiently inhibit the respiration of fruit. Furthermore, the PE conferred exceptional UV resistance (~100% at 280–400 nm), potent antioxidant activity (92.5% DPPH and 91.2% ABTS scavenging), and broad-spectrum antimicrobial efficacy (about 100% inhibition of E. coli and S. aureus ). The resulting composite films also exhibited improved mechanical properties and flexibility while maintaining biodegradability and biocompatibility. Application of these films effectively preserved the freshness and visual appeal of various fruits, demonstrating their potential as a safe and effective food preservation material. This work offers a promising strategy for fabricating advanced, multifunctional packaging materials from natural polymers. Download: Download high-res image (144KB) Download: Download full-size image