Characterisation of olive oil by an electronic nose based on conducting polymer sensors

The selection and test of an array of conducting polymer sensors with extra -virgin olive oil samples is presented in this paper as a first step toward s the development of an electronic nose dedicated to the detection of olive oil aroma. Different sensors produced by both electrochemical and chemical techniques were initially exposed to a set of pure substances present in t he headspace of extra-virgin olive oil and meaningful for the evaluation of its overall organoleptic characteristics. Four sensors showing the best se nsitivity to these standard substances were chosen to carry out further exp eriments on samples of commercial olive oil. Two different experimental set -ups and protocols for olive oil sampling were tested and compared, providi ng evidence on the best procedure needed to handle this foodstuff and on th e possibility of using a dedicated sensing system for practical purposes in the olive oil industry. Three different extra-virgin Italian types of oliv e oil can be easily distinguished with an array of four sensors and it is a lso possible to detect changes in the aromatic content of the headspace aft er handling of the samples. Different samples of the same oil show reproduc ible responses. (C) 2000 Elsevier Science S.A. All rights reserved.