The authors are grateful to the Foundation
for Science and Technology (FCT, Portugal) for financial support
by national funds FCT/MCTES to CIMO (UIDB/00690/2020)
and to CEB (UIDB/04469/2020) units, to the Associate Laboratory
SusTEC (LA/P/0007/2020), as well as to BioTecNorte operation
(NORTE‐01‐0145‐FEDER‐000004) funded by the European Regional
Development Fund under the scope of Norte2020 ‐ Programa Operacional
Regional do Norte. Nuno Rodrigues thanks to National funding
by FCT—Foundation for Science and Technology, P.I., through
the institutional scientific employment program-contract. Mª Carmen
Murillo-Cruz thanks to the University of Jaén and Cortijo de la Loma
S. L. for her pre-doctoral fellowship and also to the University of Jaén
Doctoral School for the stay financial support provided.
The consumption of carotenoids has several health benefits. It is known that the fortification of olive oils with carotenoids,
namely β-carotene or lutein, enhanced the oils’ physicochemical properties, being a possible strategy to increase carotenoids
intake. This study showed that a lab-made potentiometric electronic tongue, comprising lipid sensor membranes,
could discriminate non-fortified olive oils from those fortified with different levels β-carotene or lutein (repeated K-fold
cross-validation sensitivities: 87 ± 8%), confirming the impact of the fortification on the oils’ phenolic contents and sensory
sensations. Moreover, the device could, semi-quantitatively, discriminate oils fortified with different amounts (0, 0.05, 0.10,
and 0.15 mg/mL) of each carotenoid (repeated K-fold cross-validation sensitivities: 94 ± 9% and 97 ± 7%, for β-carotene
and lutein, respectively). This could be related to the capability of detecting increasing levels of the carotenoids and to the
ability to assess the changes induced by the addition of carotenoids on the total phenols’ contents and on the intensities of
the basic taste sensations. Indeed, satisfactory first- or second-order correlations could be established between the centroids
of the first discriminant functions of the linear discriminant models and the carotenoid fortification levels, the total phenols
contents, as well as with the sweetness, bitterness, and pungency intensities of the fortified oils (0.865 ≤ R2 ≤ 0.998). The
successful qualitative and (semi-)quantitative performance of the electronic tongue may foresee its future application as a
practical and cost-effective tool for assessing the impact of the fortification of olive oils with carotenoids at the carotenoids,
phenols, and basic taste levels.
