Engineers Discovered How To Cook 3D Printed Chicken With Lasers

Who hasn’t dreamed of coming home after a long day and just pushing a few buttons for a hot, 3D printed, homemade meal from their digital personal chef? This could make conventional microwave ovens and frozen TV dinners obsolete. According to a recent article published in the journal npj Science of Food, engineers at Columbia University are trying to make this fantasy come true, and now they’ve figured out how to simultaneously print and cook layers of mashed chicken in 3D. Of course, it’s not on the same level as the Star Trek Replicator, which could synthesize full meals on demand, but it’s a start.

Co-author Hob Lipson runs the Creative Machines Lab at Columbia University, where the research was conducted. His team first introduced 3D food printing in 2007, using the Fab @ Home personal fabrication system to create edible, multi-material 3D objects with cake frosting, chocolate, melted cheese and peanut butter. However, there are as yet no commercial devices capable of printing and cooking layers of food simultaneously. There have been studies on how to cook food using lasers, and Lipson’s team thought this might be a promising avenue to explore further.

“We noted that while printers can produce ingredients with millimeter precision, there is no heating method with this same degree of resolution,” said co-author Jonathan Blutinger. “Cooking is essential for the development of the nutrition, flavor and texture of many foods, and we wondered if we could develop a method with lasers to precisely control these attributes. They used a blue diode laser (5-10 W) as the primary heating source, but also experimented with near and mid infrared lasers for comparison, as well as a conventional toaster oven.

Scientists bought raw chicken breast from a local convenience store, then pureed it in a food processor to achieve a smooth, even consistency. They removed all tendons and refrigerated the samples before repackaging them in 3D printing syringe barrels to prevent clogging. The cooking appliance used a high-power diode laser, a set of mirror galvanometers (devices that detect electric current by deflecting light beams), a device for custom 3D printing, laser shielding, and a removable tray on which to cook the 3D printed chicken.

“During the initial laser firing, our laser diode was mounted in the 3D printed holder, but as the experiments progressed we moved to a configuration where the laser was mounted vertically on the head of the mechanism. ‘extrusion,’ the authors wrote. “This setup allowed us to print and cook ingredients on the same machine.” They also experimented with cooking the printed chicken after sealing it in plastic wrap.

The results? Laser-cooked chicken retained twice as much moisture as conventionally-cooked chicken, and it shrunk half as much while retaining similar flavors. But different types of lasers have produced different results. The blue laser was found to be ideal for cooking chicken indoors, below the surface, while infrared lasers were better for browning and broiling at surface level. For the chicken in plastic wrap, the blue laser achieved a slight browning, but the near infrared laser was more effective at browning the chicken through the wrap. The team even managed to brown the surface of the wrapped chicken in a pattern reminiscent of grill marks.

“Millimeter-scale precision makes it possible to print and cook a hamburger that varies in doneness from rare to well done in lace, checkerboard, gradient or any other custom pattern,” the authors wrote. “The heat from a laser can also cook and brown foods in a sealed package … [which] could dramatically increase their shelf life by reducing their microbial contamination, and has great commercial applications for packaged take-out foods at the grocery store, for example. “

To ensure that the 3D printed chicken still appealed to the human palate, the team served samples of the 3D printed and conventionally cooked laser-cooked chicken to two taste testers. This is not a significant sample size, but both taste testers preferred laser-cooked chicken over conventionally-cooked chicken mainly because it was less dry and chewy and had a nicer texture.

A tester was even able to identify which sample was the laser cooked chicken and noted a slight metallic taste from the laser heating. “Ever been to the dentist and done fillings?” the tester told researchers. “They have a laser that they use to seal the toppings and you get that smell – a bit of an industry smell, a sharpness that you don’t get with normal chicken.”

This was essentially a proof of principle, involving only the use of chicken, but the authors are convinced that the method can be extended to other model food systems, including other animal meats and grains. In fact, “laser heating of grain-based substrates which more easily absorb water should also accelerate moisture loss and browning during cooking,” they wrote.

For future research, the team hopes to investigate ways to use multiple laser wavelengths to simultaneously perform internal and external baking. They would also like to understand how to reduce cross-contamination between cooked and raw printed layers and how to develop software to allow users to customize their own 3D printed meals in the future.

“What we still don’t have is what we call ‘Food CAD,’ a kind of Photoshop of food,” Lipson said. “We need top-level software that helps people who are not programmers or software developers wanting. And then we need a place where people can share digital recipes, like we share music. “

DOI: npj Science of Food, 2021. 10.1038 / s41538-021-00107-1 (About DOIs).

List image by Jonathan Blutinger / Columbia Engineering