Design and fabrication of smart and biodegradable food packaging film using anthocyanins from eggplant peel based on starch-chitosan polymer modified with green-synthesized copper nanoparticles

The purpose of this research is to make completely natural and degradable food packaging using starch(S) -chitosan (C)-copper nanoparticles(N) and anthocyanins found in eggplant skin (E). The appearance and physical properties of this film (SCNE) were measured using FT-IR, SEM, XRD, and other physical parameters such as solubility, thickness, Water vapor permeability (WVP), pH sensitivity, and moisture absorption rate. After optimizing the amounts of each ingredient, 85% starch, 10% chitosan, 3% copper nanoparticles, and 2% eggplant skin anthocyanin was the most suitable option. The water vapor permeability (WVP) was measured to be 1.013±0.06 10 -7 g -1 s -1 m -1 Pa -1 , and the average thickness was 15.30 μm. The antibacterial and antioxidant properties of this film were also investigated for different percentages of anthocyanin extract. Therefore, this study suggests anthocyanin extract potential extracted from black eggplant peel as a powerful tool for improving eco-friendly films based on starch, chitosan, and copper oxide nanoparticles, directing it towards using it as smart, active, and bioactive films. The use of anthocyanins extracted from eggplant skin (as an agricultural waste) not only helps improve the properties of food films but also is a sustainable solution for the optimal use of natural resources and the reduction of environmental pollution.