Mango kernel starch-based biodegradable films reinforced with eggshell powder as a sustainable plastic alternative

This study explores the development of biodegradable plastics using Mango Kernel Starch (MKS), an eco-friendly alternative to traditional plastics. The investigation examines how sodium metabisulfite affects starch yield and inherent properties. Glycerol and eggshell powder were added to improve the resulting films’ heat resistance, strength, and flexibility. Films were prepared by solution casting with varying glycerol concentrations of 0, 25, and 50% w/v, eggshell powder content of 0, 5, and 10% w/w, and gelatinization temperatures of 70 °C, 75 °C, 80 °C. A Central Composite Design (CCD) with three factors at five coded levels, executed using Response Surface Methodology in Design-Expert software, was employed to optimize and analyze the impact of these variations on the film moisture, strength, stretchability, and biodegradability. Statistical modeling reveals significant correlations ( p < 0.0001), with optimal film properties achieved using 28.39% glycerol, 6.77% eggshell powder, and an 80 °C gelatinization temperature. The optimized film composition achieved tensile strength of 8.03 MPa, elongation at break of 36.25%, moisture content of 7.06%, and biodegradability of 36.43% after 28 days, demonstrating superior performance compared to conventional starch-based films. FTIR and TGA analysis revealed that eggshell powder alters the films chemical composition and enhances their thermal stability. The findings suggest that MKS with eggshell powder is a promising possibility for sustainable, biodegradable films with enhanced functionality, offering a potential solution to plastic waste.