(Inside Science) -- The cutting-edge kitchens of today boast appliances like internet-connected refrigerators, sous vide cookers and hydroponic terrariums that grow herbs and vegetables indoors. In the near future, these same kitchens may have 3-D printers that output food customized to your tastes and nutritional requirements.
Today, in San Diego at the annual Experimental Biology meeting, Jin-Kyu Rhee, associate professor at Ewha Womans University in Seoul, presented research on a new prototype, yet unnamed, that prints food pixel-by-pixel from the microscopic level up, so that it mimics the taste, texture and nutritional profile of familiar foods. Currently, the machine is able to print gumlike and gelatin edibles. In the future, it could use digital recipes and special cartridges of ingredients to tailor a range of foods to particular individuals or make it possible for people living in remote areas to eat healthy food.
“By manipulating the microstructure of the food, we can change its texture or flavor or add different nutrients based on a person’s own health data,” said Rhee.
To make food that mimics the real thing, Rhee and his team use technology common in the medical field, including X-ray tomography and electron microscopy to image real food and reveal its microscopic structure. Meat, for instance, has a fibrous matrix imbued with spots of fatty tissue. A muffin will have a spongy matrix with pockets of air. Using the images, the researchers will create software that can reproduce a 3-D figure, similar to a computer-aided design drawing. The printer would then use that drawing to output a morsel of food.
The researchers can embellish their creations to enhance flavor without sacrificing nutrition, said Rhee. For instance, a few strategically placed grains of salt can trick a person’s taste buds into thinking that a low-sodium food is well-salted. The same could be done for sweets.
Rhee said his team’s printer has 357 nozzles, each one shaped like an upside down “V” and capable of printing 5-picometer pixels of food bi-directionally. The researchers made the “ink” by flash-freezing different ingredients such as wheat protein, a thickening agent called carrageenan, a gummy substance known as dextrin, and agar, which is a gel -- and then grinding them into a powder. When mixed with water the ingredients can be sprayed through the printer’s jet nozzles to gradually build up a stick of gum or a piece of gelatin. They were solidified using a low heat.
Foods like gelatins, chocolates, pasta, or candies that get softer or colder with temperature have the best potential for 3-D printing using the current technology, said Ryosuke Sakaki, founder of the Tokyo-based research project Open Meals, which is not connected to Rhee’s team. “Something like vegetables or something fresh and crispy or juicy could be very difficult to reproduce with the current 3-D printer technology,” he told Inside Science through an interpreter.
Open Meals caused quite a stir this past March at SXSW, the music, media and culture festival in Austin, Texas. The researchers introduced their Pixel Food Printer, a robot with an arm that printed edible sushi made from fish and rice one pixel at a time. Each pixel was about 0.5 centimeter (0.2 inch) cubed. Sakaki said the company is working on developing printers that will eventually assemble food from pixels the size of grains of sand. By 2020, they aim to open a restaurant that will serve five different kinds of 3-D-printed food.
This kind of bottom-up method, which produces customized taste and texture starting with elemental building blocks, is one of two main aspects of 3-D-printed food, said Jeffery Lipton, a post doctoral associate at MIT's Computer Science and Artificial Intelligence Laboratory who is not associated with Rhee’s research. It’s a challenging approach technically, but also psychologically, he explained. People may initially reject it as artificial.
The other method is a top-down process that focuses on enhancing artistry, he said. Fresh, raw pasta dough, for instance could be put into a 3-D printer that manipulates it into more intricate shapes than a human chef can.
“One is trying to integrate into the kitchen,” Lipton said. “The other one is trying replace all traditional food supply chains and kitchens with one device that goes from base material to items.”
Sakaki said if ingredients are organic and people understand that 3-D-printed meals are sustainable and can reduce food waste, they may be more accepting of it. “We want every home to have a 3-D food printer," Sakaki said. "We want it to be the household staple.”