A taste sensor

A multichannel taste sensor, namely an electronic tongue, with global selec tivity is composed of several kinds of lipid/polymer membranes for transfor ming information about substances producing taste into electrical signals, which are input to a computer. The sensor output exhibits different pattern s for chemical substances which have different taste qualities such as salt iness, sourness and bitterness, whereas it exhibits similar patterns for ch emical substances with similar tastes. The sensor responds to the taste its elf, as can be understood from the fact that taste interactions such as the suppression effect, which appears for mixtures of sweet and bitter substan ces, can be reproduced well. The suppression of the bitterness of quinine a nd a drug substance by sucrose can be quantified. Amino acids can be classi fied into several groups according to their own tastes on the basis of sens or outputs. The tastes of foodstuffs such as beer, coffee, mineral water, m ilk, sake, rice, soybean paste and vegetables can be discussed quantitative ly using the taste sensor, which provides the objective scale for the human sensory expression. The flavour of a wine is also discriminated using the taste-odour sensory fusion conducted by combining the taste sensor and an o dour-sensor array using conducting polymer elements. The taste sensor can a lso be applied to measurements of water pollution. Miniaturization of the t aste sensor using FET produces the same characteristics as those of the abo ve taste sensor by measuring the gate-source voltage. Use of the taste sens or will lead to a new era of food and environmental sciences.