ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Electrode and electrodeless impedance measurement for determination of orange juices parameters

Romana Seidlová, Jaroslav Poživil, Jaromír Seidl, Stanislav Ďaďo, Petra Průšová, and Lukáš Malec

Department of Computing and Control Engineering, Faculty of Chemical Engineering, University of Chemistry and Technology, Technická 6, 166 28 Prague 6, Czech Republic

E-mail: romana.seidlova@vscht.cz

Abstract: Electrical impedance spectroscopy (EIS) is a non-destructive, rapid and real-time measurement method which does not require special high-tech measurement devices and can be applied to food quality assessment. This method is rapid, effective and affords low-cost investigation of the product. The conventional EIS method requires a set of metal electrodes in direct contact with the medium to be measured. The complicated electrochemical processes on the electrodes-electrolyte interface could substantially affect the value of the impedance measured. The present study sought to explore the possibilities of using the impedance method for quality control in orange juices, to introduce the electrodeless method of electrolyte impedance measurement and to compare this with the conventional impedance methods. The electrical properties of the orange juices were described with the help of an equivalent circuit. An equivalent circuit was designed with constant phase element approximation. The values of the equivalent circuit components were fitted using a non-standard algorithm inspired by the behaviour of actual ant colonies. Implementing the electrodeless method obviated the electrodes phenomena effects and the behaviour of the electrolyte is similar to inductance. The proposed electrodeless method is generally applicable to measuring the electrochemical properties of electrolytes.

Keywords: electrical impedance spectrometry – transformer-based electrodeless impedance measurement – ant colony algorithm – equivalent circuits – assessment of juice parameters

Full paper is available at www.springerlink.com.

DOI: 10.1515/chempap-2015-0101

Chemical Papers 69 (7) 938–949 (2015)