Mini-electronic Tongue Used to Discriminate between Coffee Samples of Different Geographical Origin

Abstract

This paper presents a mini-electronic tongue that used a polymeric sensor array made from polypyrrole to discriminate between coffee samples of different geographical origin. The electronic tongue consisted of a system with a voltammetric sensor array coupled to a multichannel measuring device (multi-potentiostat) that was controlled by a multivariable data collection and processing application. The samples analyzed comprised two types: a series of substances with different chemical and taste properties and a group of samples of coffee of the Arabica variety harvested from different geographical areas of Colombia. The electronic tongue demonstrated the ability to discriminate between solutions with different gustatory properties. In the analysis of the coffee samples, each sensor showed a particular voltammetric response to each of the samples studied. A principal component analysis was undertaken, which resulted in clear discrimination between each of the coffee samples. It was concluded that the portable electronic tongue equipped with polymer sensors is able to discriminate between samples of coffee of different geographical origin.

Keywords

• coffee
• electronic tongue
• electrochemistry
• polypyrrole
• sensors