Scientists Develop 'E-Tongue' That Lets You Taste Cake In Virtual Reality

An electronic tongue that can replicate flavours like cake and fish soup could help recreate food in virtual reality, but can't yet simulate other things that influence taste, such as smell, New Scientist reported. 

Researchers at Ohio State University, led by Yizhen Jia, have developed e-Taste, a system designed to analyse food samples and partially recreate their flavours in a person's mouth.

The technology works by using five key chemicals that correspond to the basic tastes: sodium chloride (salty), citric acid (sour), glucose (sweet), magnesium chloride (bitter), and glutamate (umami). "These five flavours already cover a large spectrum of the foods we consume daily," says Jia.

e-Taste employs sensors to detect the concentration of these taste components in food, converts the data into digital signals, and then uses a pump to deliver precise amounts of flavoured hydrogels through a small tube placed under a person's tongue.

To test its accuracy, researchers first evaluated how well the system reproduced individual flavours. Ten participants rated its ability to mimic sourness. In 70% of cases, participants rated the artificial taste the same as the real one. Next, they tested e-Taste's ability to replicate complex flavours, including lemonade, cake, fried egg, fish soup, and coffee. A group of six participants successfully distinguished these flavours more than 80% of the time.

However, Alan Chalmers from the University of Warwick cautions that taste is more than just flavour. Other sensory factors, such as aroma and colour, play a crucial role in how we perceive food. "If you close your nose and eyes while eating a strawberry, it tastes very sour, but we perceive it as sweet due to its aroma and red colour," he explains.

He adds that while e-taste can measure the intensity of flavours like sweetness and sourness, it does not fully replicate how the human tongue experiences taste.