Food waste reduction with three/four-dimensional printing: A bibliometric analysis of research trends, applications, and future perspectives (2015–2025)

Global food waste is a critical environmental challenge that demands sustainable valorization pathways to support a circular bioeconomy. Although three-dimensional (3D) and four-dimensional (4D) printing offer innovative manufacturing platforms for upcycling food by-products into functional matrices, the scientific trajectory and research structure of this domain remain systematically unevaluated. This study presents a bibliometric analysis of 200 peer-reviewed documents published between 2015 and 2025, retrieved from the Web of Science Core Collection. The results revealed continuous growth in publications, peaking in 2024 with 44 documents. Geographically, China emerged as the most productive country (58 documents), whereas Germany and the United States achieved the highest citation impacts. Foods was the most prolific journal, and thematic mapping highlighted printability, hydrogels, and cultivated meat as core research themes, with burgeoning frontiers in upcycled food inks and stimulus-responsive 4D systems. We contend that while 3D and 4D printing hold substantial promise for sustainable food by-product valorization, their practical contribution to waste mitigation remains largely confined to laboratory-scale proofs of concept. Future research must prioritize industrial scalability, material functionality, and commercial validation to transition from benchtop exploration to real-world impact.