Temperature-controlled 3D printing of dairy structures using cold-renneted protein-fortified milk

The use of dairy ingredients in 3D food printing is a promising research area for producing customised products. This study investigated the feasibility of using cold-renneted protein-fortified milk (PFM) for 3D printing. The ability of instantaneous gelation of cold-renneted PFM by heating was assessed using oscillatory rheology. The printability of different structures was assessed at different printing speed factors (100–20%) and bed temperatures (50–40 °C). Post-cold storage, printed cylinders' dimensions, texture, and syneresis were examined. Rheological results suggest cold renneting ≥1 h is needed for instant PFM gelation by heating. Optimal printing temperatures and speed factors were 50 °C - 20% for small structures and 40 °C - 35% for larger ones. Post-overnight storage (5 °C), printed cylinders retained their dimensions, hardness increased (∼48%) and exhibited low moisture loss (2.48%). In conclusion, cold-renneting can produce dairy structures using a temperature-controlled 3D printer.