As per the IUPAC technical report, an “electronic tongue” as analytical instrument including an array of non-selective chemical sensors with partial specificity to different solution components and an appropriate pattern recognition instrument, capable to recognize quantitative and qualitative compositions of simple and complex solutions[1][2] Chemical compounds responsible for taste are detected by human taste receptors.
Similarly, the multi-electrode sensors of electronic instruments detect the same dissolved organic and inorganic compounds.
A voltage is applied between each sensor and a reference electrode, and a measurable current response results that is consistent with the Cottrell equation.
This current response is a result of oxidizing reactions that take place in the solution due to the voltage difference and can be amplified through catalytic surface treatments.
The types of taste that are generated are divided into five categories sourness, saltiness, bitterness, sweetness, and umami (savoriness).