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Advisor(s)
Abstract(s)
Olive oils may be commercially classified, in a
decrease order of quality and economic value, as
extra-virgin (EVOO), virgin (VOO) or lampante
(LOO) olive oils, being quite prone to frauds. Thus
legal protection regulations have been approved
by the European Union Commission [1,2], being
required the fulfilment of several physicochemical
and sensory thresholds [3,4]. Unfortunately, the
mixture of expensive olive oils with low quality
oils aiming fraudulent economic revenue is still a
common practice difficult to detect.
In this work, a potentiometric electronic tongue
(E-tongue) was used to detect adulteration of
an EVOO with different added levels (2.5%,
5%, 10%, 20% and 40%; v/v) of an LOO with
an intense sensory defect (rancid or wineyvinegary).
Previously, similar electrochemical
devices, also comprising lipid polymeric sensor
membranes, showed to be able to give qualitative
and/or quantitative responses towards basic taste
sensations (acid, bitter, salty, sweet, and umami),
positive sensory attributes (bitter, fruity, green and
pungency) or defects (e.g., butyric, musty, putrid,
winey-vinegary and zapateria) [5-8]. The E-tongue
coupled with linear discriminant technique (based
on the signal profiles of 19 or 20 E-tongue sensors,
chosen using a simulated annealing meta-heuristic
variable selection algorithm, for rancid and wineyvinegary
adulterations, respectively) allowed to
semi-quantitatively distinguish olive oils with different adulteration levels (repeated K-fold crossvalidation
predictive correct classifications of
84±10% and 94±8% for rancid and winey-vinegary
adulterations, respectively). The preliminary results
showed the practical potential of the E-tongue as a
taste device for the successful detection of EVOOs
adulterated with LOO containing organoleptic
defects.
Description
Keywords
Citation
Veloso, Ana C.A.; Harzalli, Ussama; Rodrigues, Nuno; Dias, L.G.; Oueslati, Souheib; Pereira, J.A.; Peres, António M. (2017). Electrochemical taste sensor for unmasking extra-virgin olive oils adulterated with rancid or winey-vinegary olive oils. In Book of Abstracts 18th European Meeting on Environmental Chemistry - EMEC18: Chemistry Towards an Infinite Environment. Porto. ISBN 978-972-752-228-6