The Future of Sustainable Packaging: Exploring Biodegradable Solutions Through Extrusion, Thermo-Expansion, 3D Printing and Supercritical Fluid from Agro-Industry Waste.

Due to environmental disasters caused by the use of plastic packaging, particularly expanded polystyrene (EPS), there is an urgent need to identify sustainable alternatives. Biodegradable foams derived from renewable polysaccharides have emerged as highly promising candidates to replace EPS, given their comparable cushioning and barrier properties. However, despite the rapid growth of research in this area, there has not yet been a comprehensive review addressing biodegradable foams as a specific class of packaging materials, particularly regarding their processing routes, raw materials, and functionalization. This work discusses conventional techniques for producing biodegradable foams, such as thermoforming and extrusion, as well as innovative methods, including supercritical fluids and 3D printing. It also examines key renewable polysaccharides and the incorporation of agro-industrial residues into foam matrices, aiming to improve performance and reduce costs. Furthermore, the article highlights advances in composite and nanocomposite foams, with particular emphasis on active properties such as ethylene absorption and antimicrobial activity capable of extending food shelf life. By directing attention to biodegradable foams as substitutes for expanded polystyrene, this review provides a unique contribution, filling a critical gap in the field and offering a foundation for future studies aimed at developing scalable, low-cost, and eco-friendly alternatives to plastics.