New Method Developed to 3D Print Milk-Based Products

Three-dimensional food printing is a unique way to prepare food that is nutritionally customized. Scientists from the Singapore University of Technology and Design developed a new way to print milk-based products a room temperature using direct ink writing.

A recent study published in the journal Royal Society of Chemistry states that one of the challenges of 3D printing milk-based products is preserving the temperature sensitivity of certain nutrients.

3D printing goes back to the 1980s when Chuck Hull initially developed the technology to create industrial parts. Eventually, the first 3D printers were used to print items made of materials such as ceramic, metal, or synthetic resin.

Later on, the same technology was adopted for bioprinting purposes, such as creating layers cells to create tissue. Organoids, or stem cells bioengineered to make tissues that form organ-like parts, have also been printed with 3D printers.

3D Food Printing

3D printing was also useful in printing food, such as NASA hiring an engineer to develop a pizza printer for astronauts. A company called Foodini even developed a 3D printer for homeowners and in the food business where users can fill the stainless steel food capsules with fresh ingredients. The 3D printers could design anything from fruits, vegetables, and raw meat (which would need to be cooked afterward).

3D food printing has also evolved into several methods, such as hot-melt extrusion and selective laser sintering. Selective laser sintering is when a laser melts and fuses powder particles. On the other hand, extrusion methods would be typically used for liquid-based food and temperature-sensitive food like chocolate. Not all food products, such as milk, are compatible with these hotter methods due to temperature-sensitive nutrients such as protein and calcium.

Cold-extrusion methods at high temperatures also exist but would mean adding modifiers or additives to the food to print out stabilized structures. The additions would make the process even more complicated.

Making Milk Ink

Using commercially available powdered milk without additives, the team initially made pastes at room temperature called formulated milk inks. The team's experiments compared milk inks with various powder to deionized water ratios at different viscosities to find the right formulated ink. They also compared their printable milk inks to previous milk products with additives like xanthan gum or glycerol using a cold-extrusion method.

They also demonstrated printing several milk-based products with the new method and applied it to other edible inks such as chocolate ink using chocolate syrup. In conclusion, the authors wrote that their findings "demonstrated a simple way to modify the rheology of food inks.

"This novel yet simple method can be used in formulating various nutritious foods, including those served to patients in hospitals for their special dietary needs," said Lee Cheng Pau. Using a cold-extrusion method did not compromise the milk's temperature-sensitive nutrients and offered "vast potential in 3D printing of aesthetically pleasing, nutritionally controlled foods customized for individual requirements," said Michinao Hashimoto.