Food waste-derived 3D printable materials: A carbon neutral solution to global foodloss

The overwhelming global food loss and waste – 2.3 billion tonnes per year – call for timely deployment of recycling/upcycling technologies with high processing capacity. The huge opportunity lies in the unavoidable fraction of food lost from the production and processing line in commercial and industrial (C&I) sector. Taking the leap into the era of mass customization for the best customer fit, three-dimensional printing (3DP) technology is expected to deeply penetrate the manufacturing industry. It is one of the prospective fields that can be integrated with C&I food waste upcycling to excercise circular economy. The amounts of various significant C&I food wastes are estimated to illustrate their potential for materials recovery as a low-carbon upcycling pathway. We then review the materials development using C&I food waste and/or the recovered components for 3DP approaches – direct ink writing (DIW), fused deposition modeling (FDM), and stereolithography (SLA). Considering FDM materials as a representative, the impacts of food waste incorporation are discussed on the strength performance, thermal properties, and 3D printability. We also discuss possible added values offered by food waste-derived materials, such as antimicrobial activity and scent. Food waste-to-3DP material has been proved successful yet the limited food waste content in the formulae (∼10–30% in FDM materials) appears as a bottleneck. Scientific questions are yet to be answered regarding the chemical interactions at interface in a biocomposite matrix as well as shear- and temperature-dependent material flow properties. Bridging those scientific gaps will propel innovative materials engineering and stimulate the niche market of bio-based 3DP materials for broader impact.