Food and Bioprocess Technology

, Volume 10, Issue 7, pp 1310–1323 | Cite as

Assessment of Table Olives’ Organoleptic Defect Intensities Based on the Potentiometric Fingerprint Recorded by an Electronic Tongue

  • Ítala M.G. Marx
  • Nuno Rodrigues
  • Luís G. Dias
  • Ana C.A. Veloso
  • José A. Pereira
  • Deisy A. Drunkler
  • António M. Peres
Original Paper


Table olives are prone to the appearance of sensory defects that decrease their quality and in some cases result in olives unsuitable for consumption. The evaluation of the type and intensity of the sensory negative attributes of table olives is recommended by the International Olive Council, although not being legally required for commercialization. However, the accomplishment of this task requires the training and implementation of sensory panels according to strict directives, turning out in a time-consuming and expensive procedure that involves a degree of subjectivity. In this work, an electronic tongue is proposed as a taste sensor device for evaluating the intensity of sensory defects of table olives. The potentiometric signal profiles gathered allowed establishing multiple linear regression models, based on the most informative subsets of signals (from 24 to 29 recorded during the analysis of olive aqueous pastes and brine solutions) selected using a simulated annealing meta-heuristic algorithm. The models enabled the prediction of the median intensities (R 2 ≥ 0.942 and RMSE ≤ 0.356, for leave-one-out or repeated K-fold cross-validation procedures) of butyric, musty, putrid, winey-vinegary, and zapateria negative sensations being, in general, the predicted intensities within the range of intensities perceived by the sensory panel. Indeed, based on the predicted mean intensities of the sensory defects, the electrochemical-chemometric approach developed could correctly classify 86.4% of the table olive samples according to their trade category based on a sensory panel evaluation and following the International Olive Council regulations (i.e., extra, 1st choice, 2nd choice, and olives that may not be sold as table olives). So, the satisfactory overall predictions achieved demonstrate that the electronic tongue could be a complementary tool for assessing table olive defects, reducing the effort of trained panelists and minimizing the risk of subjective evaluations.


Table olives Sensory defects intensity Electronic tongue Multivariate linear regression models Simulated annealing algorithm 



This work was financially supported by Project POCI-01-0145-FEDER-006984—Associate Laboratory LSRE-LCM, by Project UID/QUI/00616/2013—CQ-VR, and UID/AGR/00690/2013—CIMO, all funded by Fundo Europeu de Desenvolvimento Regional (FEDER) through COMPETE2020—Programa Operacional Competitividade e Internacionalização (POCI) and by national funds through Fundação para a Ciência e a Tecnologia (FCT), Portugal. Strategic funding of UID/BIO/04469/2013 unit is also acknowledged. Nuno Rodrigues thanks FCT, POPH-QREN, and FSE for the Ph.D. Grant (SFRH/BD/104038/2014).

Compliance with Ethical Standards

Conflict of Interest

The authors declare that they have no conflict of interest.

Ethical Approval

This article does not contain any studies with human participants or animals performed by any of the authors.

Informed Consent

Not applicable.


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Copyright information

© Springer Science+Business Media New York 2017

Authors and Affiliations

  • Ítala M.G. Marx
    • 1
    • 2
  • Nuno Rodrigues
    • 3
    • 4
  • Luís G. Dias
    • 1
    • 5
  • Ana C.A. Veloso
    • 6
    • 7
  • José A. Pereira
    • 3
  • Deisy A. Drunkler
    • 2
  • António M. Peres
    • 8
  1. 1.School of AgriculturePolytechnic Institute of BragançaBragançaPortugal
  2. 2.Universidade Tecnológica Federal do Paraná (UTFPR)MedianeiraBrazil
  3. 3.Centro de Investigação de Montanha (CIMO)ESA, Instituto Politécnico de BragançaBragançaPortugal
  4. 4.Departamento de Ingeniería AgráriaUniversidad de LéonLéonSpain
  5. 5.Centro de Química - Vila Real (CQ-VR)University of Trás-os-Montes e Alto DouroVila RealPortugal
  6. 6.Instituto Politécnico de Coimbra, ISEC, DEQBCoimbraPortugal
  7. 7.Centre of Biological Engineering (CEB)University of MinhoBragaPortugal
  8. 8.Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Escola Superior AgráriaInstituto Politécnico de BragançaBragançaPortugal

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