Structurally natural chitosan films decorated with Andrographis paniculata extract and selenium nanoparticles: Properties and strawberry preservation

Abstract

In this study, selenium nanoparticles (SeNPs) were synthesized using Annona glabra leaf extract as a reducing agent. In addition, the solution-casting method was employed to prepare the food preservation film from the chitosan-Andrographis paniculata extract-selenium nanoparticles (CS-APE-Se). The effects of SeNPs with different contents (equivalent to 1, 2, 3, and 4% of chitosan mass) on fundamental properties and bioactivities of the films were also tested. According to the results, the prepared films possess good biodegradability after 30 days of burial. Besides, the antioxidant activity of the material was also investigated via free radical scavenging toward 2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), which showed the inhibition rate up to 45 and 82%, respectively. Additionally, the antibacterial performance of the films was assessed against Staphylococcus aureus and Pseudomonas aeruginosa, which indicated the highest antibacterial capacity with the inhibition diameter of 18.1 ± 0.03 and 19.25 ± 0.01 mm, respectively. Furthermore, the coating of the CS-APE-Se films also effectively prevented physical damage and prolonged the shelf life of the strawberries by up to 10 days. The aforementioned results demonstrated the potential for applying chitosan (CS) film in combination with Andrographis paniculata leaf extract and SeNPs as a secure alternative to the harmful chemicals currently used in food preservation.