Chapter 57 - Electronic Tongues Purposely Designed for the Organoleptic Characterization of Olive Oils

Abstract

Electronic tongues are defined as an array of non-specific chemical sensors with partial sensitivity (cross-sensitivity) to different components, able to analyze complex liquids. The sensor array produces signals which are not necessarily specific for any particular species in the liquid, but a signal pattern is generated which can be related to certain features or qualities of the sample using the appropriate software. Electronic tongues are normally used to give qualitative answers about the sample studied and only in some cases to predict the concentration of individual species in the sample. The basic principle behind an electronic tongue is to analyze the signals obtained from an array of non-specific overlapping sensors with pattern recognition routines. So, it can be considered that electronic tongues consist of two different blocks: the first is formed by the array of sensors, the second by the data-processing techniques. The heart of any electronic tongue is the multisensor system. Much effort has gone into developing new sensors with improved characteristics. Sensors used in electronic tongues can use several measurement principles including mass detection, optical transduction, or electrochemical sensors. In particular, electrochemical sensors (voltammetric, impedimetric, or potentiometric) are the most widely used sensing units.