Multifunctional Chitosan Composite Films Reinforced With Rhodiola rosea Extract/ZnO/Palygorskite Nanocomposites for Fruit Preservation

The potential of chitosan (CS) films for the preservation has been explored, and it is recognized as one of the promising approaches to enhancing the comprehensive capability of CS films for food control after incorporation of functional nanofillers. Herein, Rhodiola rosea extract/ZnO/palygorskite (RRE/ZnO/Pal) nanocomposites were facilely prepared and incorporated into CS matrix to obtain RRE/ZnO/Pal/CS (RZPC) composite films, in which ZnO/Pal nanocomposites were synthesized by a green phyto-mediated method followed by loading of R. rosea extract via a semi-dry grinding process to form organic/inorganic bioactive nanocomposites. The composite films exhibited significantly enhanced antioxidant, antibacterial, mechanical and UV-shielding properties compared with the pure CS film, as well as the maximum scavenging activities on hydroxyl radicals and 2,2-diphenyl-1-picrylhydrazine radicals of composite films were 92.85% ± 1.59% and 56.89% ± 0.56%, respectively. The antibacterial ratios of composite films containing 6.25% of RRE/ZnO/Pal nanocomposites were 94.92% ± 2.67% and 95.48% ± 2.08% for E. coli and S. aureus , respectively. In addition, the RZPC films effectively delayed browning and deterioration of bananas. This study provides a green method for construction of bioactive nanocomposites and new strategy to design multifunctional CS films for food preservation based on the synergistic effect of organic and inorganic components.