The authors are grateful to the Foundation for
Science and Technology (FCT, Portugal) for financial
support by national funds FCT/MCTES (PIDDAC) to
CIMO (UIDB/00690/2020 and UIDP/00690/2020), to
CEB (UIDB/04469/2020) and to the Associate
Laboratory SusTEC (LA/P/0007/2020). Nuno Rodrigues
thanks the 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 Jaen Doctoral School for the stay
financial support provided.
This study evaluated the effects of lutein or β-carotene incorporation
(0.1 mg/ml) on the quality, sensory attributes and stability of Arbequina, Picual
or Royal monovarietal extra virgin olive oils. The fortification significantly
decreased (p value < 0.05) the chemical quality of the fortified oils (peroxide
values: +3% to +34%; extinction coefficients: +4% to +55%). The negative
impact was higher on Arbequina oil, followed by Royal and Picual oils, especially
in lutein fortified oils. Nevertheless, all fortified oils fulfilled the legal
thresholds required by extra virgin category. Compared with the unfortified
ones, fortified oils showed significantly lower (p value < 0.05) stability and total
phenol content ( 6% and 12%, respectively). The fortification changed the
oils’ green color into a yellowish-orange color. Bitterness, pungency and sweetness
varied significantly (p value < 0.05) with the type of monovarietal olive oil.
Bitter and pungent intensities increased in Arbequina and Picual fortified oils
(+29% to +191%, especially for the former) and decreased in Royal fortified
oils ( 42% and 62%, respectively). The fortification increased the sweetness
of Picual and Royal oils (+109% and +10%), but decreased in Arbequina oils
( 74%). The physicochemical-sensory changes induced by the fortification
allowed a clear differentiation of the monovarietal oils and, for each oil cultivar,
by fortification agent. The use of an electronic tongue further confirmed the fortification
impact at the phenolic and sensory levels, allowing the discrimination
of unfortified and fortified oils and the quantification of oils’ bitterness, pungency
or sweetness and, in a less extent, the total phenols contents.
