Novel Piper betle (L.) leaf extract-encapsulated chitosan nanoparticles as bioactive coatings for strawberry preservation

The excessive use of synthetic chemicals to extend agricultural product shelf life has harmed the environment and consumer health. Betel leaf extract (BLE), rich in bioactive compounds, possesses potent antioxidant and antibacterial activities for incorporating it into natural-based preservatives as a sustainable solution. However, BLE is susceptible to degradation under the ambient conditions. A novel nanosystem of chitosan nanoparticles encapsulating BLE (CS-BLE NPs) has been successfully synthesized by ionic gelation technique combined with ultra-sonication. The CS-BLE NPs have a particle size of around 500 nm with a polydispersity index of 0.24 and a zeta potential of 33 mV, indicating their excellent stability. CS-BLE NPs exhibit effective anti-bacterial inhibition of E. coli and S. aureus bacteria and high free radical scavenging activity. CS-BLE NPs as an edible coating can extend the shelf life of post-harvest strawberries to 15 days at a controlled temperature of 4 degrees C with a weight loss of 15.74%, which is 1.4 times lower than the control. The CS-BLE NPs coating effectively prevents mold growth on the strawberries, while the control shows white mold on the fruit peel after 11 days. Therefore, CS-BLE NPs are a promising material as a nature-based alternative for post-harvest strawberry preservation.