Physicochemical and Biological Evaluation of Different Extracts of Edible Solanum nigrum L. Leaves Incorporated Chitosan/Poly (Vinyl Alcohol) Composite Films

In this work, composite films for food packaging were prepared from chitosan (CS) and polyvinyl alcohol (PVA) incorporated with extracts of edible Solanum nigrum L. (SN) leaves by solvent casting method. The effect of water (SW), ethanol (SE), and methanolic (SM) extracts of SN leaves on the mechanical, physical, barrier, optical, soil degradability, antimicrobial, and antioxidant properties of the films were studied. The composite films have smooth homogeneous surface morphology and showed enhanced UV blocking properties. Incorporation of SN leaves extract greatly enhances the tensile strength. The water vapor transmission rate also improved by the influence of SN extracts. The surface wettability of the composite films significantly (p < 0.005) enhanced. The soil degradability of the film samples was improved by 50%. All the composite films have an overall migration rate within the permitted limit. Besides, the SN leaves incorporated CS/PVA films showed enhanced antibacterial activity towards Staphylococcus aureus and Escherichia coli bacteria and samples did not show significant antifungal activity towards Candida albicans. All SN extracts incorporated samples showed enhanced antioxidant activity by DPPH scavenging assay. These results suggest that all three SN leaves extract induced CS/PVA composite films can be used for food packaging applications.