FOOD companies cooking up a novel product will soon be able to check how elderly people will fare when they try to chew on it, thanks to a device that mimics the taste and 鈥渕outhfeel鈥� of food.
Already, virtual reality devices have been built that try to simulate experiences for four of our five senses 鈥� vision, hearing, touch and smell. But the complexity of the sense of taste has made it difficult for computers to conquer. Taste combines the feel of food in the mouth with chemical and even auditory cues. Hiroo Iwata of the University of Tsukuba in Japan and colleagues call it the 鈥渓ast frontier of virtual reality鈥�. But it is a frontier they have now crossed. 鈥淭he food simulator is the first media technology that is put into the mouth,鈥� says Iwata.
Before simulating a foodstuff, the team first measures and records various phenomena associated with chewing it. One such parameter is the force required to bite through a piece of the food. A thin-film force sensor placed in a subject鈥檚 mouth records these forces. Biological sensors made of lipid and polymer membranes record the major chemical constituents of the food鈥檚 taste. And a microphone records the audible vibrations produced in the jawbone while chewing.
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These parameters serve as inputs to the food simulator. The mechanical part of the simulator that is inserted into the mouth has cloth and rubber covers, mainly for sanitary reasons, and is intended to resist the user鈥檚 bite in a similar way to the real foodstuff. When someone chews the device, a sensor registers the force of the bite and a motor provides appropriate resistance.
To augment the experience, a thin tube squirts a mixture of flavourings onto the tongue. The chemicals stimulate the five basic taste sensations: sweet, sour, bitter, salty and umami 鈥� the taste of monosodium glutamate. Meanwhile, a tiny speaker plays back the sound of a chewing jawbone in the user鈥檚 ear.
Iwata says that his team has successfully simulated many foods, including cheese, crackers, confectionery and Japanese snacks. One remaining step still to be tackled is to use a vaporiser to deliver appropriate smells to the nose.
The researchers say their device is perfect for people designing new foods, and may even allow young designers to experience the difficulty older people may face in chewing food. The technology can also be entertaining 鈥� for the researcher at the controls, at least. By suddenly changing the properties of a food in mid-chew 鈥� from a cracker to a jelly, say 鈥� the result is uniquely funny, says Iwata.
