3D printers are in the kitchen

3D food printing is developing all over the world: scientific or technological articles follow one another in an uninterrupted flow, start-ups are born to sell equipment and more and more chefs are equipping themselves in the kitchen or even in the dining room so that their customers can see their dishes being prepared. For example, Dutch chef Jan Smink has been serving honeycomb-shaped sausages since 2018. Spanish chocolate makers offer their customers the possibility to choose their own shapes, from online catalogs. And recently the possibility of baking the layers deposited by printers has opened up.

The idea of ​​the technique? To give shape to an object, instead of using a mold, it is formed layer by layer, starting from the base, depositing preparations capable of easily passing from the solid state to the liquid state, before returning to the solid state. The shape is given, during the transition to the liquid state, by a series of round trips of a nozzle that crosses a square surface, nozzle controlled according to a computer model of the desired preparation.

From the first machine, presented in 1984, until 2020, 3D printers for food were limited to depositing a single material, and the “recipes” remained rudimentary. For example, the manufacturer’s standard recipe for an inexpensive machine involved corn starch, sugar, soy protein, salt, oil and water, the resulting form then having to be cooked at 150 degrees for ten minutes – nothing very tempting!

Very recently systems have become more complex, with multiple nozzles controlled simultaneously, and the addition of lasers that allow the deposited systems to be fired during their deposition. Jonathan Blutinger and his colleagues at Columbia University in New York compared a blue laser, a near-infrared laser, and a mid-infrared laser: with ground chicken, the infrared becomes browner than blue, while the laser in the middle. infrared can both brown and bake through packs, and all with less waste than the oven.

There remains the double question of consistency and taste, absent in the previous recipe, and of the number of tests already carried out. Producers are interested in full military rations, in “customized” foods, in meat products with more interesting textures than those of minced steaks. They make use of meat powders or vegetable juices added with xanthan gum, deposited by 3D printers. How to give more interest to what is likely to resemble homogeneous gels?

To impart taste and color, very small quantities of coloring, savory or fragrant compounds are dispersed in the deposited masses. But the challenge is above all to produce new shapes and textures, through controlled heterogeneous distributions of different assembled materials. The grail, for the explorers, is the consistency of green apples, with its crunchiness due to 25% by volume of air distributed in small unconnected pockets. The next step will be to converge towards a standardization of the software that drives 3D printers, so that the culinary community can move forward together, sharing ideas that will then be used by all.