Robot”s “taste sensor” : Visualizing Taste with the Eyes

Is it possible to communicate “taste” using your other senses? Is it possible to express it numerically? Is it possible to objectively represent it using a machine?

Electric signals obtained from the sensor are converted to taste quality based on the Weber-Fechner law which gives an approximately accurate generalization of the intensity of sensation. The base of logarithm is defined as 1.2. For example, 12.5 units means 10 times higher concentration than that of the original sample, and 25 units is 100 times higher concentration. After the simple conversion, we can visualize the taste as “taste map”. The axis shows taste and each unit represents the intensity of tastes.

There is an infinite variety of answers to those questions. “It’s impossible to quantify taste or communicate it to others because taste is very individual.” “Taste is subjective, and therefore cannot be measured numerically.” “I can appreciate taste, and so why does it need to be quantified using a machine?”

These answers were all made by self-claimed academic experts during the early stage of the development of a “taste sensor” (about 10 years ago). A “taste sensor” is “equipment, apparatus or a device that measures taste”.

The question that needs to be asked before exploring the nature of “taste” is whether or not “taste” is actually measurable, with the answer to that being “Yes”. This can be explained for physiological reasons. “Taste” is determined at the level of the nerve fibers, which then connect with gustatory cells. “Taste” is made up of five basic taste sensations: sour, bitter, sweet, salty, and umami. The fifth taste sensation, “umami” or savory, was discovered as an independent taste sensation by the Kiyoshi Toko & his teams, and is therefore known as “Umami” in English too. Continue reading