Antioxidant and Biocompatible CO2-Based Biocomposites from Vegetable Wastes for Active Food Packaging

In this study, an innovative and scalable strategy is developed to valorize vegetable wastes as valuable and cost-effective natural antioxidant resources in the development of CO2-based biocomposites. The dried vegetable stems (parsley and spinach) are firstly micronized and then incorporated into a CO2- derived poly(propylene carbonate) (PPC) polymer matrix by hot compression molding technique. The vegetable waste microparticles are found to be homogenously dispersed within the PPC matrix. Due to the establishment of a strong intermolecular hydrogen bond network between PPC and vegetable waste microparticles, the obtained biocomposites exhibit improved mechanical properties compared to pure PPC, comparable to these of common plastics use for packaging materials. The water barrier properties of the developed biocomposites are also promising for packaging applications. Additionally, the developed biocomposites are found to be biocompatible and show effective antioxidant scavenging activity against 2,2′-azinobis(3- ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS•+). Therefore, these antioxidant and biocompatible biocomposites deriving from CO2 greenhouse gas and industrial agro-food wastes are of great interest for active food packaging applications.