Engineers have successfully used lasers to cook 3D-printed food.
The work could one day lead to the development of personalised digital chefs that produce foods with tailored shape, texture, and flavour, all at the push of a button.
In 2007, Professor Hod Lipson at Columbia University in New York began developing 3D printing capability for food production. Since then, food printing has progressed to multi-ingredient prints and has been explored by researchers and a few commercial companies.
The technology works by extruding blended food from a nozzle to build one layer at a time. This requires food of even consistency and proper viscosity to ensure it emerges smoothly from the nozzle and maintains its shape upon deposition.
While this may not sound appetising, know that foods such as pasta, sausages, breadsticks and certain breakfast cereals are already produced via extrusion.
In a new study published in npj Science of Food, Lipson and his colleagues have explored various modalities of cooking such foods by exposing them to laser light of varying wavelengths.
‘We noted that, while printers can produce ingredients to millimetre-precision, there is no heating method with this same degree of resolution,’ said Jonathan Blutinger, a PhD student in Lipson’s lab who led the project. ‘Cooking is essential for nutrition, flavour, and texture development in many foods, and we wondered if we could develop a method with lasers to precisely control these attributes.’
They therefore used lasers of blue (445nm) and near-infrared (980nm) and mid-infrared (10.6μm) light to cook 3mm-thick printed chicken samples in square and triangular configurations.
‘We used a cooking pattern that can be easily adjusted to optimise the heating conditions for chicken,’ said Blutinger. ‘By tuning parameters such as circle diameter, circle density, path length, randomness and laser speed, we can optimise the distribution of energy that hits the surface of the food with higher precision than conventional heating methods.
‘Unlike convection heating in an oven, “laser broiling” provides pulsed heating as it propagates across the surface of the food. There’s an implicit trade-off between speed and amplitude of the energy pulse, which is only limited by the total power of the laser.’
The team used a range of parameters to assess the process, including cooking depth, colour development, moisture retention, and flavour differences between laser-cooked and stove-cooked meat. They found that laser-cooked meat shrinks 50 per cent less, retains double the moisture content, and shows similar flavour development to conventionally cooked meat.
‘In fact, our two blind taste-testers preferred laser-cooked meat to the conventionally cooked samples, which shows promise for this burgeoning technology,’ remarked Blutinger. ‘This is the first step in digitising the cooking process, and is poised to change the way we cook and think about foods.’
While Lipson and Blutinger are excited about the possibilities of this new technology, whose hardware and software components are fairly low-tech, they note that there is not yet a sustainable ecosystem to support it.
‘What we still don’t have is what we call “Food CAD,” a sort of Photoshop for food,’ stated Lipson. ‘We need high-level 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, like we share music. Food is something that we all interact with and personalise on a daily basis – it seems only natural to infuse software into our cooking to make meal creation more customisable.’
