Xanthoceras sorbifolium Bunge leaf extract activated chia seeds mucilage/chitosan composite film: Structure, performance, bioactivity, and molecular dynamics perspectives

Abstract

Biodegradable packaging films containing natural bioactive ingredients emerge nowadays to respond to increasing demands for safety, health, and sustainability in the food industry. The biodegradable active composite films were constructed for the first time using chia seed mucilage (CSM) and chitosan (CS) as film-forming materials and Xanthoceras sorbifolium Bunge (X. sorbifolium) leaf extract as an active ingredient, namely the CSM/CS/X films. The effects of active component contents (0, 2, 4, 6, and 8 wt%) on the microstructure, mechanical, thermodynamic properties, antioxidant, and antibacterial activities of the composite film were studied. Interestingly, the CSM/CS/X4 film which contains 4 wt% of X. sorbifolium leaf extract has relatively better micromorphology and performance than other films. Compared with the blank CSM/CS film, the CSM/CS/X films incorporated with X. sorbifolium leaf extract sustainably display good antioxidant and antibacterial activities. The all-atom molecular dynamics simulations reveal the helix structure of the CSM/CS/X films, showing that introducing extract promotes the formation of the composite film through enhanced Coulomb and van der Waals interactions. The results suggest that low-value X. sorbifolium leaf can be used to prepare eco-friendly functional packaging films, which are expected to replace petroleum-based packaging materials that can improve the quality and freshness of food. The study provides a new and effective way for the recycling and value-added utilization of biowaste.