Transforming nutshell waste into next-generation bioplastics for a sustainable and circular economy

Review article, 2026

The growing concern over plastic pollution has driven the development of sustainable alternatives, such as bioplastics derived from agricultural waste. Nutshells, an abundant lignocellulosic biomass, have garnered attention for their potential in creating biodegradable plastic-based biocomposites. Traditionally considered low-value by-products used for mulch, animal bedding, or fuel, nutshells from almonds, walnuts, chestnuts, hazelnuts, peanuts, and pistachios hold untapped potential for high-value applications in sustainable biomaterials. This review explores the upcycling of nutshell waste into bioplastics, emphasizing their rich content of cellulose, lignin, and phenolic compounds and their conversion into diverse biomaterials. Innovations in extraction techniques, such as deep eutectic solvents and microwave-assisted methods, have enhanced the efficiency and sustainability of recovering these valuable components. The review examines various applications of nutshell-derived biomaterials beyond packaging, including their use in film matrices, fillers, antioxidants, antibacterial agents, UV barriers, plasticizers, biochar, and adsorbents. By transforming nutshell waste into high-value products, the nut industry can significantly contribute to a circular economy, reducing environmental impact while creating economic benefits. This comprehensive analysis highlights advancements in biorefinery processes, the potential of nutshell-derived materials in various industries, and the promising future for sustainable biomaterials sourced from agricultural waste.