Who hasn’t dreamed of coming home after a long day and receiving hot, homemade 3D-printed meals at the press of just a few buttons, courtesy of one’s digital personal chef? It could make microwaves and traditional frozen TV dinners obsolete. Engineers at Columbia University are trying to make that fantasy come true, and they’ve now figured out how to simultaneously 3D print and cook layers of pureed chicken, according to a recent paper published in the journal npj science of food. Sure, it’s not on the same level as star trek replicator, Which can synthesize whole food on demand, but that’s a start.
Co-author Hobb Lipson runs the Creative Machines Lab at Columbia University, where the research was conducted. His team first introduced 3D printing of foods Back in 2007, using the [email protected] personal creation system to create multi-material edible 3D objects with cake frosting, chocolate, processed cheese and peanut butter. However, commercial equipment capable of simultaneously printing and cooking food layers does not yet exist. There have been few studies examining the way cooking is done using lasers, and Lipson’s team thought this could be a promising way to explore further.
“We noted that, while printers can produce material to a millimeter-precision, there is no heating method with similar resolution,” Co-author Jonathan Blutinger said. “Cooking is essential for the development of nutrition, flavor and texture in many foods, and we wondered if we could develop a method with lasers to precisely control these characteristics.” They used a blue diode laser (5–10 W) as the primary heat source, but also used lasers in the near and mid-infrared as well as a conventional toaster oven for comparison.
Scientists bought raw chicken breast from a local convenience store and then puréed it in a food processor to achieve a smooth, uniform consistency. They removed any tendons and refrigerated the samples before repackaging them in 3D-printing syringe barrels to avoid clogging. A high powered diode laser is used in cooking equipment, a set of mirror galvanometer (devices that detect electric current by deflecting beams of light), a fixture for custom 3D printing, laser shielding, and a removable tray on which to cook 3D-printed chicken.
“During the initial laser cooking, our laser diode was placed in a 3D-printed fixture, but as the experiments progressed, we transitioned to a setup where the laser was placed perpendicular to the head of the extrusion apparatus. ,” the authors wrote. “This setup allowed us to print and cook the ingredients on the same machine.” He also experimented with cooking printed chicken by sealing it in plastic packaging.
Result? Lager-cooked chicken retains twice as much moisture as conventionally cooked chicken, and shrinks in half while maintaining the same flavor. But different types of lasers gave different results. The blue laser proved to be ideal for internally cooking the chicken below the surface, while the infrared laser was better at browning and broiling at the surface level. For chicken in plastic packaging, the blue laser achieved a lighter browning, but the near-infrared laser was more efficient at browning the chicken through packaging. The team was also able to brown the surface of the packaged chicken, reminiscent of grill marks.
“Millimeter-scale precision allows printing and cooking a burger that has a level of work from rare to well-done in a lace, checkerboard, shield, or other custom pattern,” the authors wrote. “The heat from the laser can cook and brown foods even within sealed packages… [which] can significantly increase their shelf life by reducing their microbial contamination, and have great commercial applications for packaged to-go food at the grocery store, for example.”
To make sure the 3D-printed chicken still appealed to the human palate, the team served samples of both 3D-printed laser cooked and conventionally cooked chicken to two taste testers. That’s not a significant sample size, but both taste testers preferred the lager-cooked chicken over the traditionally cooked chicken, as it was less dry and rubbery and had a more pleasant texture.
One tester was also able to identify which sample was laser-cooked chicken and noticed a slightly metallic taste from the laser heating. “Ever go to the dentist and get a filling?” The examiner told the researchers. “They have a laser they use to seal the filling and you get that smell—a slight smell of industry, a pungency you don’t get with normal chicken.”
This was essentially a proof of principle, involving the use of only chicken, but the authors are confident that the method could be extended to other model food systems, including meat and grains from other animals. In fact, “laser heating of grain-based substrates that absorb water more readily should also accelerate moisture loss and browning during cooking,” they wrote.
For future research, the team hopes to investigate ways of using multiple laser wavelengths to achieve both internal and external cooking simultaneously. They would also like to learn how to reduce cross-contamination between cooked and raw printed layers and how to develop software to enable users to prepare their own 3D printed food in the future.
“What we don’t have yet is what we call ‘Food CAD’, which is photoshopping of food,” Lipson said. “We need a high level of software that enables people who are not programmers or software developers to design the foods they want. And then we need a place where people can share digital recipes. as we share music.”
DOI: NPJ Science of Food, 2021. 10.1038/s41538-021-000107-1 (About DOI).