Valorizing watermelon rind waste into eco-friendly bioplastics: A comprehensive overview from fundamentals to market potential

Growing environmental concerns about petroleum-based plastics (PBPs) have attracted interest in alternative, sustainable materials. Polysaccharides (complex sugars) derived from agri-food waste (AFW), such as watermelon rind ( C. lanatus ), offer an opportunity to develop eco-friendly bioplastics that can alleviate environmental issues associated with PBPs while meeting functional applications as per industrial benchmarks. Nonetheless, research on polymers derived from various agricultural residues is underway; there remains scope to investigate the composition and potential of watermelon rind (WMR) as a sustainable bioplastic production source. The present study aims to fill this knowledge gap by exploring the biochemical properties of WMR and evaluating its viability for producing biodegradable bioplastics, at par with conventional PBPs. The study includes a comprehensive assessment of WMR's polymer constituents and properties, along with strategies to enhance the performance parameters of the resulting bioplastics. Further, recent developments in smart packaging incorporating essential oils and antimicrobial agents have been discussed to analyze their impact on bioplastic properties. The viability of bioplastics for long-term applications was also examined, including end-of-life (EoL) options, life-cycle assessment (LCA), cost-benefit analysis, market potential, and regulatory frameworks. The analysis revealed that WMR is rich in complex sugars, making it an ideal candidate for eco-friendly bioplastic production. The mechanical properties of WMR-bioplastic demonstrate their suitability for industrial applications, particularly in food packaging. Furthermore, advancements in smart packaging technologies and futuristic market potential can enhance both the functionality and appeal of these bioplastics. The findings indicate significant opportunities to utilize such polysaccharide-enriched AFW to develop bioactive materials, thereby significantly reducing environmental impact while offering innovative solutions to food packaging challenges.