Determination of total polyphenol index in wines employing a voltammetric electronic tongue
Cetó Alsedà, Xavier (Universitat Autònoma de Barcelona. Departament de Química)
Gutiérrez, Juan Manuel (Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional. Department of Electrical Engineering)
Gutiérrez-Capitán, Manuel (Institut de Microelectrònica de Barcelona)
Céspedes Mulero, Francisco (Universitat Autònoma de Barcelona. Departament de Química)
Capdevila Mestres, Josefa (Institut Català de la Vinya i el Vi)
Minguez, Santiago (Institut Català de la Vinya i el Vi)
Jiménez Jorquera, Cecilia (Institut de Microelectrònica de Barcelona)
Valle Zafra, Manuel del (Universitat Autònoma de Barcelona. Departament de Química)

Date:	2012
Abstract:	This work reports the application of a voltammetric electronic tongue system (ET) made from an array of modified graphite-epoxy composites plus a gold microelectrode in the qualitative and quantitative analysis of polyphenols found in wine. Wine samples were analyzed using cyclic voltammetry without any sample pretreatment. The obtained responses were preprocessed employing discrete wavelet transform (DWT) in order to compress and extract significant features from the voltammetric signals, and the obtained approximation coefficients fed a multivariate calibration method (artificial neural network-ANN-or partial least squares-PLS-) which accomplished the quantification of total polyphenol content. External test subset samples results were compared with the ones obtained with the Folin-Ciocalteu (FC) method and UV absorbance polyphenol index (I₂₈₀) as reference values, with highly significant correlation coefficients of 0. 979 and 0. 963 in the range from 50 to 2400 mg L⁻¹ gallic acid equivalents, respectively. In a separate experiment, qualitative discrimination of different polyphenols found in wine was also assessed by principal component analysis (PCA).
Grants:	Ministerio de Ciencia e Innovación TEC2007-68012-C03 Ministerio de Ciencia e Innovación CTQ2010-17099
Rights:	Tots els drets reservats.
Language:	Anglès
Document:	Article ; recerca ; Versió sotmesa a revisió
Subject:	Voltammetric sensors ; Electronic tongue ; Artificial neural network ; Wine analysis ; Folin-Ciocalteu ; Polyphenol
Published in:	Analytica chimica acta, Vol. 732 (Jun 2012) , p. 172-179, ISSN 1873-4324

DOI: 10.1016/j.aca.2012.02.026

Pre-print 28 p, 2.1 MB

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