New Potentiometric Electronic Tongue for Analysing Teas and Infusions

Abstract

In this work, an electronic tongue (ET) system is developed for the discrimination of infusions and teas made from different herb leaves. The ET is based on an array of four non‐specific potentiometric sensors plus principal component analysis (PCA) data processing. The four sensors used are a cation‐selective electrode and an anion‐selective electrode, containing both a plasticized polymeric membrane with different ionic additives, a commercial pH electrode and a redox electrode. These provide simple, rapid and very reproducible potentiometric responses after direct exposure to infusions and teas, which do not need any pre‐treatment. A radar plot of potentiometric values for each sensor, obtained after sixty seconds of array exposure to the samples, revealed a differentiated response for each sensor and infusion. This was especially marked for anion‐selective and redox electrodes. The PCA results of the potentiometric signals point to certain trends that can be used for classification purposes. Although a small number of sensors is used in the developed ET, interesting classification functions have been achieved, which will be exploited in the near future with a larger number of samples. The concept of an ET formed by a reduced number of potentiometric sensors is starting to spread to other types of beverages.

Bioinspired Electronics for Artificial Sensory Systems

“…Bioelectronic tongues can be designed with similar transduction principles to the bioelectronic noses. Electrochemical transductions, including potentiometry, amperometry, and cyclic voltammetry have been the most prominent method to mimic the taste recognition system. Figure n shows that the potentiometric measurement‐based bioelectronic taste sensor consists of a working electrode attached to a lipid/polymer membrane, which mimics the structure of lipid‐composed biological cell membranes .…”

Potential use of electronic noses, electronic tongues and biosensors as multisensor systems for spoilage examination in foods

“…Most electronic tongue systems reported in the specialized literature are based on potentiometric sensors (Mimendia, Gutiérrez, Leija, Hernández, Favari, Muñoz, & del Valle, 2010;Ciosek & Wróblewski, 2011;Cuartero, Carretero, Garcia, & Ortuño, 2015). By using the potentiometric methods, one measures the potential between two electrodes in the absence of an external flow of current.…”

Solid-Contact Potentiometric Sensors and Multisensors Based on Polyaniline and Thiacalixarene Receptors for the Analysis of Some Beverages and Alcoholic Drinks

“…Potentiometric ETs based on PVC and polyurethane membranes were applied to distinguish black and green tea and coffee (Lvova et al, 2003 ). Similar plasticized membranes have been employed in the assembly of cation- and anion-selective ISEs combined together with commercial pH- and redox-sensitive electrodes in the ET system for differentiation of black and herbal tea based on PCA method (Cuartero et al, 2015 ).…”