Enhancing 3D Printing Performance and Product Quality Through the Valorization of Food By-Products and Waste.

This review systematically explores the emerging use of food by-stream materials in 3D printing (3DP) applications, addressing the pressing need for sustainable resource utilization in the food sector. The review evaluates the potential of food by-products and waste, ranging from agricultural, animal, marine, microbial fermented biomass, and filamentous-fungi by-products to food consumption waste, for integration into 3DP techniques like fused deposition modeling, paste extrusion, direct ink writing, and selective laser sintering. Utilizing the PRISMA 2020 framework, a comprehensive literature analysis identified 80 relevant studies, categorized by material type and application. The findings indicate that plant-based by-stream materials encompassing sources like vegetable residues, fruit peels, nut and bean shells, and grain husks, dominate current 3DP research. These materials support biocomposite advancements across various fields, with notable applications in food-safe packaging, biomedical scaffolds, nutritious snacks, and sustainable construction materials. Several studies highlight significant improvements in mechanical strength, such as tensile and compressive performance, alongside enhanced biodegradability of nonedible printed products and nutrient content in edible printed products. Key process parameters, including extrusion speed, nozzle temperature, and layer thickness, have been optimized to accommodate the unique properties of these food by-stream materials, ensuring printing fidelity, smooth extrusion, and structural integrity, thereby maximizing their potential across diverse 3DP techniques and applications. This review highlights 3DP as a transformative approach in resource recovery, demonstrating how incorporating food by-stream materials aligns with circular economy goals by reducing waste and enabling eco-friendly production. By advancing customizable, nutrient-dense, and sustainable products, 3DP of food by-stream materials holds significant promise for addressing global food security and sustainability challenges.