The University of Arkansas, U.S. public research institution, is advancing the development of sorghum protein as a stable, functional 3D bioink for foods and medical products. The project addresses a critical gap in current 3D food printing research, which has largely concentrated on water-absorbing proteins. In contrast, this research highlights hydrophobic, plant-based proteins as sustainable alternatives with improved cohesion and printability for AM applications.
Turning Sorghum into Printable Material
Sorghum is a drought-tolerant, gluten-free cereal grain that grows in a variety of climates and contains compounds associated with antioxidant activity, as well as cholesterol and inflammation reduction. A key characteristic of sorghum protein is its hydrophobicity—its tendency to repel water. This trait supports structural cohesion in 3D printed materials, as many commonly used food components, such as starches and proteins are hydrophilic, which can restrict formulation options.
“So far, most of the efforts in research on proteins for 3D food printing have been on hydrophilic proteins, and there has been a need for new hydrophobic proteins that are ideally from cost-effective and sustainable protein sources for 3D printing,” said Ali Ubeyitogullari, assistant professor of food engineering at the University of Arkansas.
Optimizing Sorghum Protein for Print Performance
Ubeyitogullari’s earlier research demonstrated that sorghum flour could be formulated into a bioink suitable for printing edible products such as cookies. Building on that foundation, a subsequent study published in the International Journal of Biological Macromolecules—co-authored with Sorour Barekat, a postdoctoral fellow in food science—pinpointed the optimal parameters for 3D printing with sorghum protein. The researchers found that a formulation containing 25% protein, printed at a speed of 20 millimeters per second through a 0.64 mm nozzle, yielded the best results. Increasing the protein concentration to 35% reduced printability, indicating a performance limit.
“What we’ve shown is that sorghum protein can be made into a novel 3D printable gel, which hasn’t been done before,” Ubeyitogullari said. “Due to their unique structure, these gels can be used in the food and pharmaceutical industries as a bioink to encapsulate medicine or as a carrier of hydrophobic compounds and nutrients.”
Innovations in 3D Food Printing
The work at the University of Arkansas contributes to a growing body of international research exploring how 3D printing technologies can transform food production. In June, a research team from the Spanish Universitat Politècnica de València (UPV), the Italian University of Foggia, and China’s Jiangnan University developed 3D printed gummy supplements enriched with vitamins and minerals. Published in the Journal of Food Engineering, the study investigates the potential of additive manufacturing (AM) to address nutritional deficiencies through personalized supplementation.
In March, researchers at the Hong Kong University of Science and Technology (HKUST) developed a new 3D food printing method that cooks the food during printing, eliminating extra steps. Published in Advanced Materials, this technique provides a more controlled and efficient cooking process. Unlike most current 3D food printers that first extrude cold food paste and then require separate cooking in an oven or fryer, this method combines printing and cooking into a single step.
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Featured image shows Ali Ubeyitogullari and Sorour Barekat working on developing a 3D “bioink” made from sorghum proteins. Photo via University of Arkansas.
