Valorisation of lemongrass essential oils onto chitosan-starch film for sustainable active packaging: Greatly enhanced antibacterial and antioxidant activity

Abstract

To meet the global demand for sustainability aspects, the past few decades have witnessed magnificent evidence in the pursuit of sustainable active food packaging. As part of our contribution, herein, we explored the utilization of chitosan (Ch) modified with Dioscorea hispida (Dh) starch and incorporated with lemongrass essential oil (LO) as an attempt to obtain a novel active packaging formulation of Ch/Dh/LO in food. To obtain the optimum formulation of Ch/Dh/LO, 15 experiments were designed using the Box-Behnken design (BBD) with Ch (1–2% w/v), Dh starch (0.5–1.5% w/v) and LO (0.25–0.75% v/v) against E. coli, S. typhi, S. aureus and S. epidermidis bacteria. The presence of LO caused enhancements in physical, mechanical, and thermal stability, along with the antimicrobial, and antioxidant activity. Additionally, molecular docking and molecular dynamic (MD) simulations of the active compounds in LO against the active site of the FtsA enzyme were provided to unveil the mechanism of antibacterial action. Ultimately, this result suggests hydrogen bonds and hydrophobic interactions are involved between the active compounds in LO and FtsA enzymes. In general, this research provides valuable information that sheds light on the pivotal role of LO in enhancing the mechanical, thermal, and biological properties of sustainable active food packaging-based Ch film.