ArticlePDF Available

Abstract and Figures

Olive oil is considered a valuable ingredient of human diet. It is a good source of mono- and polyunsaturated fatty acids, as well as other bioactive compounds, especially polyphenols. The composition of olive oil depends mainly on the variety of plant, cultivation practices, and manufacturing conditions. Traditional processing methods may ensure better quality and health benefits. Therefore, the aim of the study was the evaluation of antioxidant properties and fatty acid profile of Cretan extra virgin bioolive oils. These ones were compared with commercial Spanish, Italian, and Greek extra virgin olive oils. Obtained results showed that sample Cretan 1 had about 15% higher antioxidant capacity and about 60% higher total polyphenol content than commercial counterparts. This one had also a favorable profile of fatty acids, especially 20% more linoleic acid. We concluded that traditional production methods, using millstones, cold pressing, and without centrifugation and filtration ensure better olive oil quality and related health benefits.
Content may be subject to copyright.
Research Article
Antioxidant Properties and Fatty Acid Profile of Cretan Extra
Virgin Bioolive Oils: A Pilot Study
Dariusz Nowak , MichałGośliński, and Cezary Popławski
Department of Nutrition and Dietetics, Faculty of Health Sciences, Ludwik Rydygier Collegium Medicum in Bydgoszcz,
Nicolaus Copernicus University in Toruń,Dębowa 3, 85-626 Bydgoszcz, Poland
Correspondence should be addressed to Dariusz Nowak;
Received 17 February 2021; Revised 18 March 2021; Accepted 19 March 2021; Published 26 March 2021
Academic Editor: Eduard Hernández
Copyright © 2021 Dariusz Nowak et al. This is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Olive oil is considered a valuable ingredient of human diet. It is a good source of mono- and polyunsaturated fatty acids, as well as
other bioactive compounds, especially polyphenols. The composition of olive oil depends mainly on the variety of plant, cultivation
practices, and manufacturing conditions. Traditional processing methods may ensure better quality and health benets. Therefore,
the aim of the study was the evaluation of antioxidant properties and fatty acid prole of Cretan extra virgin bioolive oils. These
ones were compared with commercial Spanish, Italian, and Greek extra virgin olive oils. Obtained results showed that sample
Cretan 1 had about 15% higher antioxidant capacity and about 60% higher total polyphenol content than commercial
counterparts. This one had also a favorable prole of fatty acids, especially 20% more linoleic acid. We concluded that
traditional production methods, using millstones, cold pressing, and without centrifugation and ltration ensure better olive oil
quality and related health benets.
1. Introduction
Olive oil is a popular source of fats in the human diet, especially
in the Mediterranean diet. In general, olive oil is characterized
by high amounts of monounsaturated fatty acid (MUFA) and
contains minor components with biological properties (e.g.,
phenolic compounds, pigments, squalene, sitosterols, and
triterpenes) [1]. A specic composition of olive oil fatty acids
and other bioactive compounds, such as polyphenols, has
been proven to be protective against the development of car-
diovascular diseases [25]. The content of these components
depends on the cultivar, climate, harvesting time, and the
manufacturing conditions [1, 6].
According to the European Union legislation, olive oil is
classied into categories reecting its quality and organolep-
tic properties, namely, extra virgin olive oil (EVOO), virgin
olive oil (VOO), lampante virgin olive oil (LVOO), rened
olive oil (ROO), and also olive oil (OO) [7, 8]. EVOO pro-
duced by mechanically pressing the olives is considered the
best quality and possesses the best composition of bioactive
compounds, which aect its health benets [9, 10]. These olive
oils contain an array of phenolic antioxidants, from three
major chemical classes: the simple phenolics (tyrosol and
hydroxytyrosol), the secoiridoids (oleuropein aglycon and
oleocanthal), and lignans [1113] and phenolic acids (vanillic,
chlorogenic, gallic, caeic, p-coumaric, and ferulic) [13].
Greece is ranked third after Spain and Italy in virgin olive
oil production. In Greece and Italy, the extra virgin olive oil is
consumed in majority, whereas in Spain, this represents less
than half. The dominant olive cultivar in Greece is the cv.
Koroneiki, especially on Crete. This gives oils of medium to
high content of phenolic compounds. Greek extra virgin
bioolive oils, produced mainly with traditional, nonintensive
cultivation practices, are mostly of exceptional quality [14,
15]. Recent study shows that Greek EVOO had a high con-
tent of oleocanthal and oleacein and their derivatives [12].
These compounds are considered key oxidation inhibitors.
It is worthy to note that oleacein has been declared a more
potent antioxidant than hydroxytyrosol [16, 17]. A study
showed that the specic phenolic content within EVOO
can aect human health [18, 19]. Literature data for Greek,
especially Cretan extra virgin olive oils, are not as popular
International Journal of Food Science
Volume 2021, Article ID 5554002, 6 pages
as those for Spanish or Italian ones. Therefore, the aim of the
study was the evaluation of antioxidant properties and the
fatty acid prole of Cretan extra virgin bioolive oils. These
ones were compared with commercial Spanish, Italian, and
Greek extra virgin olive oils.
2. Materials and Methods
2.1. Materials. The analysis comprised ve extra virgin olive
oils. Spanish, Italian, and Greek samples were purchased at a
local health food store and declared as extra virgin. Cretan
extra virgin bioolive oils were produced from cv. Koroneiki
(Chania region, northwest Crete) and have been certicated
by BIO HELLAS no. B-515504 (Cretan 1) and no. B-515573
(Cretan 2). Moreover, sample Cretan 1 comes from two hun-
dred years of organic cultivation (i.e., manual harvesting,
without articial irrigation), and this olive oil was produced
by a traditional method using millstones, cold pressing, and
without centrifugation and ltration. All the analyzed olive
oils were produced between April and May 2018 (bottled into
250 mL) and had at least one-year best-before date.
2.2. Methods. For the spectrophotometric assays, 1±0:01 g of
olive oil was extracted with 9.3 mL n-hexane and homoge-
nized using a vortex mixer for 30 sec. For each olive oil, ve
parallel samples in three replicates were prepared.
2.3. DPPH Assay. The antioxidant capacity of the olive oils was
determined in extracts (1 g of olive oil and 9.3 mL n-hexane) by
a standard DPPH methodusing 0.1 mM methanol solution of a
1,1-diphenyl-2-picrylhydrazyl (DPPH, Sigma-Aldrich) [20].
This method is widely used to test the antioxidant capacity
of foods, including olive oils [21]. The absorbance was mea-
sured on a Hitachi U-1900 spectrophotometer at 517 nm after
30 min of incubation in the dark at room temperature. For
each olive oil, ve parallel samples in three replicates were
analyzed, from which the mean value was calculated. The
antioxidant capacity was expressed as milligrams of Trolox
per 1 liter of olive oil (mg Tx/L).
2.4. ABTS Assay. The antioxidant capacity of the olive oils
was determined by Re et al.s [22] method using 2,2-azino-
bis-(3-ethyl-benzothiazoline-6-sulfonic acid) diammonium
salt (ABTS, Sigma-Aldrich). The absorbance was measured
on a Hitachi U-1900 spectrophotometer at 734 nm after
6 min of incubation in the dark at room temperature. For
each olive oil, ve parallel samples in three replicates were
analyzed, from which the mean value was calculated. The
antioxidant capacity was expressed as milligrams of Trolox
per 1 liter of olive oil (mg Tx/L).
2.5. Folin-Ciocalteu Assay. The total polyphenols content
(TP) of the samples was determined by the Folin-Ciocalteu
assay [23]. The absorbance was measured on a Hitachi U-
1900 spectrophotometer at 765 nm after 30 min incubation
in the dark at room temperature. The results were expressed
as milligrams of gallic acid equivalents per 1 liter of olive oil
(mg GAE/L).
2.6. Determination of Fatty Acid Prole. The fatty acid prole
was analyzed according to the European Union Commission
Regulation [24] using a Hewlett-Packard 6890 gas chromato-
graph, equipped with a ame-ionization detector (FID) and a
SP-2560 fused silica capillary column (100 m × 0:25 mm;
0.20 μmlm thickness). The injector and detector tempera-
tures were set at 220
C and 240
C, respectively. Helium was
used as a carrier gas with a ow rate of 1 mL min
. The anal-
ysis was performed at the following temperature program:
C held for 5 min, then increased at rate of 4
C/min to
C, and held for the subsequent 20 min. The total run
time was approximat ely 50 min. Individual fatty acids were
identied by comparing their retention times with standards
and quantied as a percentage of the total fatty acids.
2.7. Statistical Analysis. The results were statistically analyzed
by calculating the mean and standard deviation. The inter-
pretation of the results was performed with MS Excel 2010
Analysis ToolPak software, with one-way analysis of variance
(ANOVA) using Tukeys as a posttest: dierent letters in the
same row indicate statistical signicance (at p<0:05).
3. Results and Discussion
3.1. Antioxidant Properties. Obtained results showed that
among all the analyzed olive oils, the signicantly highest
antioxidant capacity, both the DPPH and ABTS assays, was
determined in sample Cretan 1, i.e., 348 ± 5:0and 623 ± 7:0
mg Tx/L, respectively (Table 1). Olive oil Cretan 1 had also
the highest total polyphenol content (658 ± 40 mg GAE/L).
Other extra virgin olive oils were characterized by TP about
400 mg GAE/L, with no signicant dierences between them
(p<0:05). The sample Cretan 2 was similar in antioxidant
capacity to commercial Greek and Italian olive oils, but their
values were slightly lower than the Spanish one.
Other researchers reported a great variability in TP
ranged from 50 to 1000 mg/kg (usually 100-300 mg/kg) in
olive oils of dierent origin, i.e., Greek, Italian, Spanish,
Israeli, and Turkish [14, 25, 26]. Total polyphenol content
has been repeatedly proved to be a marker for olive oil stabil-
ity, which is also related to characteristic taste. Moreover, TP
was considered a parameter which categorized olive oils as
low (50200 mg GAE/kg), medium (200500 mg GAE/kg),
and high (5001000 mg GAE/kg) [14]. In addition, literature
data stated that cv. Koroneiki gives olive oils of higher TP
content, in general [27]. In another study, fty-ve mono-
or multivarietal extra virgin olive oils from Italy, Spain,
France, Turkey, Greece, Portugal, Australia, the USA, and
South Africa were analyzed. The oil samples produced from
Italian cv. Coratina possessed the highest amount of poly-
phenols and antioxidant capacity, whilst the sample pro-
duced from French cv. Cayon contained the lowest amount.
Among the analyzed olive oils was also some Cretan of cv.
Koroneiki, of which its antioxidant properties were average
in relation to the others [28]. Moreover, Sicari [29] deter-
mined the antioxidant capacity, TP, and structure of poly-
phenolic compounds in three dierent Italian extra virgin
olive oils from the province of Reggio Calabria. The analyzed
samples had a high content of polyphenols ranged 370-
2 International Journal of Food Science
530 mg GAE/kg. Moreover, in this study, a positive correla-
tion was observed between the antioxidant activity (deter-
mined by DPPH and ABTS assay) and the concentration of
total polyphenols [29]. Our results also conrmed positive
correlation between the DPPH and ABTS methods
(r=0:902). Furthermore, the ABTS assay resulted in a much
higher value of antioxidant capacity, which was also con-
rmed in other studies [30, 31]. De Bruno et al. [31] reported
that it could be due to the dierent composition of analyzed
samples containing hydrophilic and lipophilic antioxidant
compounds. The ABTS assay is more applicable to both
hydrophilic and lipophilic antioxidant systems, whereas
DPPH assay is more related to hydrophobic system response
[32]. In addition, our results showed a higher correlation
between ABTS and TP (r=0:912) than between DPPH and
TP (r=0:738).
On the other hand, Condelli et al. [33] reported that the
dierences in antioxidant capacity may depend on the com-
position and prole of phenolic compounds, rather than total
polyphenol content. This study was conducted on 75 Italian
commercial extra virgin olive oils. Finally, Jimenez-Lopez
et al. [34] pointed out various factors that aect the quality
of EVOO and its bioactive compounds. Bruno et al. [31] con-
cluded that harvesting time and climate conditions inuence
the phenol composition as ratios of phenol compounds and
their total amount.
3.2. Fatty Acid Prole. The appropriate prole of fatty acids
determines the quality and health benets of olive oil. The
analyses showed that the tested olives had a typical content
of oleic acid C18 : 1 (above 72%) . Particularly important for
health are polyunsaturated fatty acids (PUFA). Sample Cre-
tan 1 had about 20% more linoleic acid C18 : 2, whereas the
content of α-linolenic acid C18 : 3 did not dier signicant
between all the samples (Table 2).
Table 1: Antioxidant capacity and total polyphenols of extra virgin olive oils.
Spanish Italian Greek Cretan 1 Cretan 2
DPPH (mg Tx/L) 324 ± 5:0
313 ± 3:0
290 ± 4:0
348 ± 5:0
282 ± 1:0
ABTS (mg Tx/L) 552 ± 7:0
513 ± 5:0
501 ± 5:0
623 ± 7:0
517 ± 6:0
TP (mg GAE/L) 409 ± 36
393 ± 62
403 ± 86
658 ± 40
423 ± 14
Data are mean ± SD (n=5). Dierent letters in the same row indicate statistical signicance at p<0:05; Tx: Trolox equivalents; GAE: gallic acid equivalents.
Table 2: Fatty acid prole of extra virgin olive oils (%).
Spanish Italian Greek Cretan 1 Cretan 2
Caprylic acid C8 : 0 nd nd nd nd nd
Capric acid C10 : 0 nd nd nd nd nd
Lauric acid C12 : 0 0:03 ± 0:04 nd nd nd nd
Tridecanoic acid C13 : 0 nd nd nd nd nd
Myristic C14 : 0 nd nd nd nd nd
Myristoleic acid C14 : 1 nd nd nd nd nd
Pentadecanoic acid C15 : 0 nd nd nd nd nd
Palmitic acid C16:0 13:08 ± 0:55 12:98 ± 0:08 12:93 ± 0:16 13:20 ± 0:25 12:94 ± 0:14
Palmitoleic acid C16 : 1 1:05 ± 0:23
0:67 ± 0:72
0:53 ± 0:57
0:12 ± 0:02
0:12 ± 0:01
Heptadecanoic acid C17 : 0 0:15 ± 0:04
0:63 ± 0:75
0:47 ± 0:58
0:84 ± 0:02
0:77 ± 0:01
Stearic acid C18 : 0 3:25 ± 0:02
2:86 ± 0:07
2:76 ± 0:06
2:87 ± 0:01
2:91 ± 0:03
Elaidic acid C18 : 1 n9t nd nd nd nd nd
Oleic acid C18 : 1 n9c 72:77 ± 0:14
73:74 ± 0:16
75:29 ± 0:01
72:49 ± 1:29
74:18 ± 0:10
Linoleic acid C18:2 8:13 ± 0:04
7:60 ± 0:10
6:44 ± 0:06
8:94 ± 0:62
7:56 ± 0:03
α-Linolenic acid C18:3 0:76 ± 0:04 0:72 ± 0:06 0:74 ± 0:01 0:73 ± 0:01 0:72 ± 0:01
Arachidic acid C20 : 0 0:39 ± 0:01
0:48 ± 0:11
0:41 ± 0:01
0:41 ± 0:03
0:44 ± 0:01
11-Eicosenoic acid C20 : 1 0:27 ± 0:02 0:27 ± 0:01 0:30 ± 0:04 0:26 ± 0:01 0:28 ± 0:01
Behenic acid C22 : 0 0:11 ± 0:01
0:06 ± 0:08
0:13 ± 0:01
0:14 ± 0:01
0:07 ± 0:11
Erucic acid C22 : 1 nd nd nd nd nd
MUFA (%) 74.09
PUFA (%) 8.89
SFA (%) 17.01 17.00 16.7 17.46 17.14
Data are mean ± SD (n=4). Dierent letters in the same row indicate statistical signicance at p<0:05; nd: not detected; MUFA: monounsaturated fatty acids;
PUFA: polyunsaturated fatty acids; SFA: saturated fatty acids.
3International Journal of Food Science
The mean values of fatty acid prole found in the pres-
ent study were the within limits established by the Interna-
tional Olive Oil Council for purity criteria of olive oils [35].
Stefanoudaki et al. [15] reported that Greek olive oils of cv.
Koroneiki were characterized by a higher concentration of
oleic acid C18 : 1 (74.779.9%), but the concentration of lino-
leic acid C18 : 2 and α-linolenic acid C18 : 3 was slightly lower
(ca. 5.07.0% and 0.550.76%, respectively). Mikrou et al.
[36] studied 68 monovarietal EVOOs, originating from three
regions of Greece and two local cultivars (Koroneiki and
Kolovi), and reported similar concentration oleic, linoleic,
and α-linolenic acid. The exception was the cultivar Kolovi,
which had a higher linoleic acid content of 11.63% [36].
Other studies showed that Italian and Spanish olive oils had
even lower values of C18 : 3, i.e., 0.490.54% [37] and 0.48%
[38], respectively. These values were much lower than
obtained for commercial olive oils in our studies, whereas
Morello et al. [39] reported similar to our values of C18 : 3.
Taking into account the content of PUFA, the tested samples
present the upper range of these compounds, which could be
found in literature data. Furthermore, Stefanoudaki et al. [15]
stated that lower concentration of oleic acid resulted in a
higher concentration of heptadecanoic C17 : 0 and linoleic
C18 : 2 acids, which was also conrmed in our research.
Therefore, Kosma et al. [40] concluded that variations in
the fatty acid composition may be owed to factors such as
cultivar and other factors for example climatic conditions
and geographical origin. The reported statement for Greek
oils has been also conrmed in dierent studies on Italian
olive oils. Moreover, Piscopo et al. [41] demonstrated the
eect of olive cultivar and the environmental inuences on
the fatty acid composition of monovarietal olive oils, consid-
ering also the quality of a same cultivar in dierent areas.
We are aware that our study has some limitations. In the
next studies, the prole of polyphenolic compounds and
other valuable parameters such as tocopherol, squalene, oleo-
canthal, and oleacein should be examined.
4. Conclusions
The results of our research showed that the sample Cretan 1
had about 15% higher antioxidant capacity and about 60%
higher total polyphenol content than Spanish, Italian, and
Greek extra virgin olive oils. These olive oil had also a favor-
able composition of fatty acids, especially linoleic and α-lino-
lenic acid. The sample Cretan 2 did not dier signicant from
the commercial counterparts.
In conclusion, the antioxidant properties depend on the
manufacturing conditions. Oils from olives grown on organic
farms (manual harvesting, without articial irrigation) and
produced with traditional methods, i.e., using millstones, cold
pressing, and without centrifugation and ltration, had higher
antioxidant properties and favorable prole of fatty acids.
Data Availability
The results are in the article and in the corresponding author.
Conflicts of Interest
The authors declare no conict of interest.
D.N. is responsible for the design of experiments, experi-
ments, data analysis, and writing of manuscript; M.G. is for
the experiments and statistical analysissupport; and C.P
critically revised the paper. All the authors have approved
the nal version of the manuscript.
We are grateful to the management of the company GUEST
SI, Gliwice, Poland, for providing us with Cretan bioolive oil
[1] M. Fito, R. de la Torre, M. Farré-Albaladejo, O. Khymenetz,
J. Marrugat, and M.-I. Covas, Bioavailability and antioxidant
eects of olive oil phenolic compounds in humans: a review,
Annali dell'Istituto Superiore di Sanità, vol. 43, no. 4,
pp. 375381, 2007.
[2] M. I. Covas, K. Nyyssönen, H. E. Poulsen et al., The eect of
polyphenols in olive oil on heart disease risk factors: a ran-
domized trial,Annals of Internal Medicine, vol. 145, no. 5,
pp. 333341, 2006.
[3] EFSA, Panel on Dietetic Products, Nutrition and Allergies,
Scientic opinion on the substantiation of health claims
related to polyphenols in olive oil and protection of LDL par-
ticles from oxidative damage,EFSA Journal, vol. 9, 2011.
[4] S. Martín-Peláez, M. I. Covas, M. Fitó, A. Kušar, and I. Pravst,
Health eects of olive oil polyphenols: recent advances and
possibilities for the use of health claims,Molecular Nutrition
& Food Research, vol. 57, no. 5, pp. 760771, 2013.
[5] A. Hernáez, S. Fernández-Castillejo, M. Farràs et al., Olive oil
polyphenols enhance high-density lipoprotein function in
humans. A randomized controlled trial,Arteriosclerosis,
Thrombosis, and Vascular Biology, vol. 34, pp. 21152119,
[6] E. Gimeno, A. I. Castellote, R. M. Lamuela-Raventós, M. C. de
la Torre, and M. C. López-Sabater, The eects of harvest and
extraction methods on the antioxidant content (phenolics, α-
tocopherol, and β-carotene) in virgin olive oil,Food Chemis-
try, vol. 78, no. 2, pp. 207211, 2002.
[7] R. Garcia, N. Martins, and M. J. Cabrita, Putative markers of
adulteration of extra virgin olive oil with rened olive oil: pros-
pects and limitations,Food Research International, vol. 54,
no. 2, pp. 20392044, 2013.
[8] F. Venturi, C. Sanmartin, I. Taglieri et al., Development of
phenol-enriched olive oil with phenolic compounds extracted
from wastewater produced by physical rening,Nutrients,
vol. 9, no. 8, p. 916, 2017.
[9] E. Ros, Olive oil and CVD: accruing evidence of a protective
eect,The British Journal of Nutrition, vol. 108, no. 11,
pp. 19311933, 2012.
[10] M. Guasch-Ferré, F. B. Hu, M. A. Martínez-González et al.,
Olive oil intake and risk of cardiovascular disease and
4 International Journal of Food Science
mortality in the PREDIMED Study,BMC Medicine, vol. 12,
p. 78, 2014.
[11] A. Bendini, L. Cerretani, A. Carrasco-Pancorbo et al., Pheno-
lic molecules in virgin olive oils: a survey of their sensory prop-
erties, health eects, antioxidant activity and analytical
methods. An overview of the last decade,Molecules, vol. 12,
no. 8, pp. 16791719, 2007.
[12] E. Karkoula, A. Skantzari, E. Melliou, and P. Magiatis, Direct
measurement of oleocanthal and oleacein levels in olive oil by
quantitative (1)H NMR. Establishment of a new index for the
characterization of extra virgin olive oils,Journal of Agricul-
tural and Food Chemistry, vol. 60, no. 47, pp. 1169611703,
[13] G. P. Blanch, G. Flores, M. C. Gómez-Jiménez, and M. L. Ruiz
del Castillo, Eect of the treatment of the olive tree (Olea
europaea L.) on the phenolic content and antioxidant proper-
ties in olive fruits,Journal of Food and Nutrition Research,
vol. 6, pp. 4955, 2018.
[14] N. Kalogeropoulos and M. Z. Tsimidou, Antioxidants in
Greek virgin olive oils,Antioxidants, vol. 3, no. 2, pp. 387
413, 2014.
[15] E. Stefanoudaki, F. Kotsifaki, and A. Koutsaftakis, Classica-
tion of virgin olive oils of the two major Cretan cultivars based
on their fatty acid composition,Journal of the American Oil
Chemists' Society, vol. 76, no. 5, pp. 623626, 1999.
[16] F. Paiva-Martins, J. Fernandes, S. Rocha et al., Eects of olive
oil polyphenols on erythrocyte oxidative damage,Molecular
Nutrition & Food Research, vol. 53, no. 5, pp. 609616, 2009.
[17] V. Sánchez de Medina, H. Miho, E. Melliou, P. Magiatis,
F. Priego-Capote, and L. de Castro, Quantitative method for
determination of oleocanthal and oleacein in virgin olive oils
by liquid chromatography-tandem mass spectrometry,
Talanta, vol. 162, pp. 2431, 2017.
[18] K. Agrawal, E. Melliou, X. Li et al., Oleocanthal-rich extra vir-
gin olive oil demonstrates acute anti-platelet eects in healthy
men in a randomized trial,Journal of Functional Foods,
vol. 36, pp. 8493, 2017.
[19] T. Nikou, V. Liaki, P. Stathopoulos et al., Comparison survey
of EVOO polyphenols and exploration of healthy aging- pro-
moting properties of oleocanthal and oleacein,Food and
Chemical Toxicology, vol. 125, pp. 403412, 2019.
[20] G.-C. Yen and H.-Y. Chen, Antioxidant activity of various
tea extracts in relation to their antimutagenicity,Journal of
Agricultural and Food Chemistry, vol. 43, no. 1, pp. 2732,
[21] M. N. Franco, T. Galeano-Díaz, Ó. López et al., Phenolic com-
pounds and antioxidant capacity of virgin olive oil,Food
Chemistry, vol. 163, pp. 289298, 2014.
[22] R. Re, N. Pellegrini, A. Proteggente, A. Pannala, M. Yang, and
C. Rice-Evans, Antioxidant activity applying an improved
ABTS radical cation decolorization assay,Free Radical Biol-
ogy & Medicine, vol. 26, no. 9-10, pp. 12311237, 1999.
[23] V. L. Singleton, R. Orthofer, and R. M. Lamuela-Raventós,
[14] Analysis of total phenols and other oxidation substrates
and antioxidants by means of Folin-Ciocalteu reagent,
Methods in Enzymology, vol. 299, pp. 152178, 1999.
[24] Commission Implementing Regulation (EU) 2015/1833 of 12
October 2015 amending Regulation (EEC) No 2568/91 on the
characteristics of olive oil and olive-residue oil and on the rel-
evant methods of analysis,
[25] M. Tsimidou, Polyphenols and quality of virgin olive oil in
retrospect,Italian Journal of Food Science, vol. 10, pp. 99
116, 1998.
[26] D. Boskou, G. Blekas, and M. Z. Tsimidou, Phenolic com-
pounds in olive oil and olives,Current Topics in Nutraceutical
Research, vol. 3, pp. 125136, 2005.
[27] A. Agiomyrgianaki, P. V. Petrakis, and P. Dais, Inuence of
harvest year, cultivar and geographical origin on Greek extra
virgin olive oils composition: a study by NMR spectroscopy
and biometric analysis,Food Chemistry, vol. 135, no. 4,
pp. 25612568, 2012.
[28] B. Bayram, T. Esatbeyoglu, N. Schulze, B. Ozcelik, J. Frank,
and G. Rimbach, Comprehensive analysis of polyphenols in
55 extra virgin olive oils by HPLC-ECD and their correlation
with antioxidant activities,Plant Foods for Human Nutrition,
vol. 67, no. 4, pp. 326336, 2012.
[29] V. Sicari, Antioxidant potential of extra virgin olive oils
extracted from three dierent varieties cultivated in the Italian
province of Reggio Calabria,Journal of Applied Botany and
Food Quality, vol. 90, pp. 7682, 2017.
[30] A. Floegel, D. O. Kim, S. J. Chung, S. I. Koo, and O. K. Chun,
Comparison of ABTS/DPPH assays to measure antioxidant
capacity in popular antioxidant-rich US foods,Journal of
Food Composition and Analysis, vol. 24, no. 7, pp. 1043
1048, 2011.
[31] A. De Bruno, R. Romeo, A. Piscopo, and M. Poiana, Antiox-
idant quantication in dierent portions obtained during olive
oil extraction process in an olive oil press mill,Journal of the
Science of Food and Agriculture, vol. 101, no. 3, pp. 11191126,
[32] D. O. Kim, K. W. Lee, H. J. Lee, and C. Y. Lee, Vitamin C
equivalent antioxidant capacity (VCEAC) of phenolic phyto-
chemicals,Journal of Agricultural and Food Chemistry,
vol. 50, no. 13, pp. 37133717, 2002.
[33] N. Condelli, M. C. Caruso, F. Galgano, D. Russo, L. Milella,
and F. Favati, Prediction of the antioxidant activity of extra
virgin olive oils produced in the Mediterranean area,Food
Chemistry, vol. 177, pp. 233239, 2015.
[34] C. Jimenez-Lopez, M. Carpena, C. Lourenço-Lopes et al., Bio-
active compounds and quality of extra virgin olive oil,Food,
vol. 9, no. 8, p. 1014, 2020.
[35] International Olive Oil Council Trade Standard Applying to
Olive Oils and Olive: Pomace Oils, IOOC, Madrid, Spain,
[36] T. Mikrou, E. Pantelidou, N. Parasyri et al., Varietal and geo-
graphical discrimination of Greek monovarietal extra virgin
olive oils based on squalene, tocopherol, and fatty acid compo-
sition,Molecules, vol. 25, no. 17, p. 3818, 2020.
[37] M. P. Aguilera, G. Beltrán, D. Ortega, A. Fernández, A. Jiménez,
and M. Uceda, Characterisation of virgin olive oil of Italian
olive cultivars: `Frantoio' and `Leccino', grown in Andalusia,
Food Chemistry,vol.89,no.3,pp.387391, 2005.
[38] E. Gimeno, K. de la Torre-Carbot, R. M. Lamuela-Raventós
et al., Changes in the phenolic content of low density lipopro-
tein after olive oil consumption in men. A randomized cross-
over controlled trial,British Journal of Nutrition, vol. 98,
pp. 12431250, 2007.
[39] J. R. Morelló, M. J. Motilva, M. J. Tovar, and M. P. Romero,
Changes in commercial virgin olive oil (cv Arbequina) during
storage, with special emphasis on the phenolic fraction,Food
Chemistry, vol. 85, pp. 357364, 2004.
5International Journal of Food Science
[40] I. Kosma, A. Badeka, K. Vatavali, S. Kontakos, and
M. Kontominas, Dierentiation of Greek extra virgin olive
oils according to cultivar based on volatile compound analysis
and fatty acid composition,European Journal of Lipid Science
and Technology, vol. 118, no. 6, pp. 849861, 2016.
[41] A. Piscopo, A. Zappia, A. De Bruno, and M. Poiana, Eect of
the harvesting time on the quality of olive oils produced in
Calabria,European Journal of Lipid Science and Technology,
vol. 120, no. 7, p. 1700304, 2018.
6 International Journal of Food Science
... The total run time was approximately 50 min. The identification of the peaks was performed by comparing the corresponding retention times to those of several standards and quantified as a percentage of the total fatty acids [21]. ...
... In most of the literature, studies reported fatty acid composition has a great influence on the health benefits of extra virgin olive oil [21,33]. The European Food Safety Authority (EFSA) has also evidenced that unsaturated fatty acids, mainly monounsaturated, help to keep LDL cholesterol at low concentrations in the blood [13]. ...
... These samples had also significantly similar TPC values (1.85 and 1.80 mg GAE/g, respectively). Our findings are in agreement with those of Nowak et al. [21] where a positive correlation between the antioxidant activity (determined by ABTS •+ assay) and the concentration of total polyphenols was observed. Also, in relation to sensorial characteristics, the analysis of variance found that no significant differences for "bitter" and "pungent" were found for samples A and D (Table 2). ...
Full-text available
Antioxidant capacity and sensory analysis of olive oils of different quality grades (Extra virgin, Virgin, Ordinary and Lampante) were investigated to define their possible differences useful for quality discrimination. Total phenolic content discriminated the sample Lampante olive oil (LVOO) with values (0.95 mg GAE/g) significantly lower than the other oils (1.85, 1.80 and 1.98 for A, D and E samples, respectively). The principal component analysis (PCA) revealed that sensory attributes (“bitter” and “pungent”) and antioxidant capacity (expressed by FRAP and ABTS•+) are positively correlated with Extra-virgin olive oil (EVOO) and Virgin olive oil (VOO) categories, evidencing high values. In conclusion, based on the evaluated parameters, differences between the different olive oil categories were found. Still, they did not allow us to clearly separate the two categories of Extra-virgin olive oil (EVOO) and Virgin olive oil (VOO) oils.
... Parâmetros químicos também foram analisados em azeites de oliva virgem grego, em que os achados demonstraram características especiais de amostras de quatro cultivares e sua diferenciação botânica bem sucedida com base na composição de ácidos graxos (Revelou et al., 2021). Em Creta foram avaliadas propriedades antioxidantes e do perfil de ácidos graxos bioativos de azeites extra virgem em comparação com os espanhóis, italianos e gregos comerciais, onde perceberam que a amostra 1 de Creta tinha capacidade antioxidante cerca de 15% maior e teor de polifenol total cerca de 60% maior do que os azeites de oliva extra virgem espanhóis, italianos e gregos, demonstrando também composição favorável de ácidos graxos, principalmente linoléico e αlinolênico, já a amostra 2 de Creta não diferiu significativamente de gregas comerciais (Nowak, et al., 2021). ...
Full-text available
O objetivo do estudo foi investigar acerca do que está sendo questionado por renomados pesquisadores em todas as partes do mundo, ou seja, especular em relação aos países que mais publicam quando o assunto se refere a azeite e seus subprodutos, quais são os maiores produtores, qual a qualidade desses produtos oferecidos ao mercado, quais as melhores técnicas para preservar os compostos benéficos à saúde, além de lacunas que possam instigar a mais pesquisas elucidativas. Ocorreu através de revisão da literatura, utilizando os descritores ¨Azeite de Oliva¨ e ¨Bioativos¨. A pesquisa foi refinada almejando como forma de documento somente artigos, estes com publicação nos anos de 2021 e 2022. Posteriormente os artigos selecionados foram direcionados para análise bibliométrica. Em posse dos 109 artigos pré-selecionados, fez-se um novo refinamento, analisando-se então 78 artigos, os quais foram categorizados em cinco tópicos de maior importância: Resíduos da produção do azeite de oliva, processo tecnológico para análise do azeite, parâmetros químicos de diferentes cultivares, compostos bioativos, processo para determinação dos compostos bioativos. Após análise minuciosa de todos os artigos selecionados, referente inicialmente a compostos bioativos e azeite de oliva, e no decorrer adicionado subprodutos da produção do azeite, pode-se comprovar acerca dos benefícios dos compostos bioativos, formas de melhor preservá-los, além de algumas tendências em relação a sustentabilidade e preservação do meio ambiente, e por fim, identificação de métodos que podem se tornar promissores: bioinformática a fim de predizer propriedades medicinais e análise sensorial corroborando com técnicas analíticas e químicas.
... In parallel, food consumption patterns have changed during the last 50 years in most regions, including Crete [31], with adaptation to Westernized dietary patterns, leading to a poor MedDi quality index [32][33][34]. The cardinal feature of a Mediterranean-type diet, olive oil, however, still serves as the principal source of dietary fat in Crete, as in many Mediterranean regions, providing the precious monounsaturated fatty acids (MUFAs) and polyphenols [35,36]. ...
Full-text available
We are currently riding the second wave of the allergy epidemic, which is ongoing in affluent societies, but now also affecting developing countries. This increase in the prevalence of atopy/asthma in the Western world has coincided with a rapid improvement in living conditions and radical changes in lifestyle, suggesting that this upward trend in allergic manifestations may be associated with cultural and environmental factors. Diet is a prominent environmental exposure that has undergone major changes, with a substantial increase in the consumption of processed foods, all across the globe. On this basis, the potential effects of dietary habits on atopy and asthma have been researched rigorously, but even with a considerable body of evidence, clear associations are far from established. Many factors converge to obscure the potential relationship, including methodological, pathophysiological and cultural differences. To date, the most commonly researched, and highly promising, candidate for exerting a protective effect is the so-called Mediterranean diet (MedDi). This dietary pattern has been the subject of investigation since the mid twentieth century, and the evidence regarding its beneficial health effects is overwhelming, although data on a correlation between MedDi and the incidence and severity of asthma and atopy are inconclusive. As the prevalence of asthma appears to be lower in some Mediterranean populations, it can be speculated that the MedDi dietary pattern could indeed have a place in a preventive strategy for asthma/atopy. This is a review of the current evidence of the associations between the constituents of the MedDi and asthma/atopy, with emphasis on the pathophysiological links between MedDi and disease outcomes and the research pitfalls and methodological caveats which may hinder identification of causality. MedDi, as a dietary pattern, rather than short-term supplementation or excessive focus on single nutrient effects, may be a rational option for preventive intervention against atopy and asthma.
Full-text available
Extra virgin olive oil (EVOO) is an important component of the Mediterranean diet and a highly priced product. Despite the strict legislation to protect it from fraudulent practices, there is an increasing demand to characterize EVOOs and evaluate their authenticity. For this purpose, 68 monovarietal EVOOs, originating from three regions of Greece (Peloponnese, Crete, and Lesvos) and two local cultivars (Koroneiki and Kolovi), were obtained during the harvesting period of 2018–2019. Fatty acids, squalene, and tocopherols were determined chromatographically according to official methods in order to study the effect of cultivar and geographical origin. Squalene and γ-tocopherol differed significantly amongst the cultivars tested. Koroneiki samples exhibited higher squalene content than Kolovi samples, whereas the opposite was observed for γ-tocopherol. The tocopherol level was highly geographical dependent, with EVOOs from Peloponnese displaying the highest concentration of α-tocopherol, whereas the content of γ-tocopherol was significantly higher in samples from Lesvos. Unsupervised and supervised multivariate analysis resulted in a satisfactory grouping of EVOOs according to cultivar. γ-Tocopherol, squalene, and the majority of fatty acids were the most discriminant variables, with γ-tocopherol, linoleic, linolenic, and gadoleic acid being present at higher levels in samples from the Kolovi cultivar. Koroneiki samples were characterized with higher levels of squalene, palmitic, palmitoleic, and arachidic acid.
Full-text available
1) Background: Extra virgin olive oil (EVOO) is responsible for a large part of many health benefits associated to Mediterranean diet as it is a fundamental ingredient of this diet. The peculiarities of this golden, highly valued product are in part due to the requirements that must be met to achieve this title, namely, it has to be obtained using exclusively mechanical procedures, its free acidity cannot be greater than 0.8%, it must not show sensory defects, and it has to possess a fruity taste. (2) Methods: All these characteristics are key factors to EVOO quality, thus the chemical composition of these many health-promoting compounds, such as unsaturated fatty acids (which are also the major compounds, especially oleic acid), as well as minor components such as tocopherols or phenolic compounds (which behave as natural antioxidants) must be preserved. (3) Results: Due to the presence of all these compounds, the daily consumption of EVOO entails health benefits such as cardioprotective, antioxidant, anti-inflammatory, anti-tumor properties or acting as regulator of the intestinal microbiota, among others. (4) Conclusions: Taking all together, conserving EVOO chemical composition is essential to preserve its properties, so it is worth to control certain factors during storage like exposure to light, temperature, oxygen presence or the chosen packaging material, to maintain its quality and extend its shelf-life until its consumption.
Full-text available
We here investigate the effects of the application of methyl jasmonate to olive trees on antioxidant composition of olive fruits. Two cultivars (ie, Arbequina and Picual) were evaluated in our study. As a result, the total phenol content increased significantly with the treatment in Arbequina (from 155.89 to 434.22 mg gallic acid kg-1) whereas decreases were observed in Picual (from 338.27 to 127.71 mg gallic acid kg-1). Similarly, decreases in phenolic acid content were measured in Arbequina whilst no effect was observed in Picual olives. However, the contents of oleuropein and hydroxytyrosol did not increase with the pre-harvest methyl jasmonate for both Arbequina and Picual. Also for both cultivars the treatment of the olive trees increased the free radical scavenging activity of the olive fruits (IC50 from 514.36 to 1125.46 µg/mL in Arbequina and from 611.98 to 114.55 µg/mL in Picual). The results here found are deeply discussed.
Full-text available
While in the last few years the use of olive cake and mill wastewater as natural sources of phenolic compounds has been widely considered and several studies have focused on the development of new extraction methods and on the production of functional foods enriched with natural antioxidants, no data has been available on the production of a phenol-enriched refined olive oil with its own phenolic compounds extracted from wastewater produced during physical refining. In this study; we aimed to: (i) verify the effectiveness of a multi-step extraction process to recover the high-added-value phenolic compounds contained in wastewater derived from the preliminary washing degumming step of the physical refining of vegetal oils; (ii) evaluate their potential application for the stabilization of olive oil obtained with refined olive oils; and (iii) evaluate their antioxidant activity in an in vitro model of endothelial cells. The results obtained demonstrate the potential of using the refining wastewater as a source of bioactive compounds to improve the nutraceutical value as well as the antioxidant capacity of commercial olive oils. In the conditions adopted, the phenolic content significantly increased in the prototypes of phenol-enriched olive oils when compared with the control oil.
Background Different antioxidant compounds are generally transferred from olives to olive oil during the production process. This work characterised the principal total bioactive compounds (tocopherols and phenols) in olives, olive oil and by‐products of four cultivars grown in Calabrian areas (Southern Italy), considering the effect of harvesting period. Antioxidant capacity, total and individual phenolic compounds were also analysed. Results Drupes, olive paste, pomace and olive waste water showed similar phenolic compounds, while olive oil possessed a different composition, suggesting that phenols are not only transferred from drupe to oil, but also they change during oil production. Tocopherols varied among cultivars and harvesting period: generally, they were more abundant in samples produced in the first harvesting period. Qualitative and quantitative differences in phenolic composition and antioxidant activity were significantly found among cultivars in all the matrices. Conclusion The highest amount of total phenolic antioxidants ended up in olive waste water with variability due to the olive cultivar, while only a small part of them finished in the oil. This work evidenced so the availability in bioactive compounds of different portions from the olive oil extraction belonging to different varietal origins. In particular, new information was acquired on Ottobratica Calipa, a new olive clone, that produced an olive oil with an interesting antioxidant amount. This article is protected by copyright. All rights reserved.
Olive oil is widely accepted as a superior edible oil. Great attention has been given lately to olive oil polyphenols which are linked to significant health beneficial effects. Towards a survey of Greek olive oil focusing on polyphenols, representative extra virgin olive oils (EVOOs) from the main producing areas of the country and the same harvesting period have been collected and analyzed. Significant differences and interesting correlations have been identified connecting certain polyphenols namely hydroxytyrosol, tyrosol, oleacein and oleocanthal with specific parameters e.g. geographical origin, production procedure and cultivation practice. Selected EVOOs polyphenol extracts, with different oleacein and oleocanthal levels, as well as isolated oleacein and oleocanthal were bio-evaluated in mammalian cells and as a dietary supplement in the Drosophila in vivo model. We found that oleocanthal and oleacein activated healthy aging-promoting cytoprotective pathways and suppressed oxidative stress in both mammalian cells and in flies.
The aim of this work was to evidence the quality of four monovarietal olive oils (Carolea, Grossa di Gerace, Ottobratica, and Sinopolese cv) produced at two crop years and at different harvesting times in Calabria region, located in the South of Italy. Qualitative parameters of oils were evaluated by analysis of major and minor components, in particular: free acidity, peroxide value, fatty acid composition, sterol composition, total polar phenolic compounds and tocopherols, and total pigments. The total antioxidant activity of olive oils was evaluated by DPPH and ABTS assays. Two variables were evaluated in the statistical data elaboration: the cultivar and the harvesting time. Their effect was studied on the chemical parameters and antioxidant components. The harvesting at October and November did not reduce the quality of two monovarietal olive oils (Carolea and Sinopolese) produced in Calabria, whereas Ottobratica and Grossa di Gerace olive oils produced at November had a lower quality. However a reduction of qualitative parameters was observed in extra virgin olive oils produced from lately harvested olives with some differences among cultivars. Practical applications: Practical application for the study entitled ‘Effect of the harvesting time on the quality of olive oils produced in Calabria’ regards the study of chemical composition on olive oils produced under a controlled experimental procedure. Varietal characteristics and environmental variables affect in general the quality of the olive productions and the obtained olive oils. The results of this work showed that the considered harvesting times did not involve a decay of quality on Carolea and Sinopolese olive oils produced in the South of Italy, obtained following right processing procedures.
The phenolic profiles of extra virgin olive oils (EVOOs) may influence their cardiovascular benefits. In a randomized crossover of acute EVOO intake on platelet function, participants (n = 9) consumed 40 mL of EVOO weekly. EVOOs were matched for total phenolic content and were either tyrosol-poor with 1:2 oleacein/oleocanthal (D2i0.5), or 2:1 oleacein/oleocanthal (D2i2), or predominantly tyrosol (D2i0). Ibuprofen provided a platelet inhibition control. Blood was collected pre- and 2 h post-EVOO intake. D2i0.5 and D2i2 reduced 1 µg/mL collagen-stimulated maximum platelet aggregation (Pmax), with effects best correlated to oleocanthal intake (R = 0.56, P = 0.002). Total phenolic intake was independently correlated to eicosanoid production inhibition, suggesting that cyclooxygenase blockade was not responsible for the Pmax inhibition. Five participants exhibited >25% ΔPmax declines with D2i0.5 and D2i2 intake and plasma metabolomic profiles discriminated subjects by oil responsivity. Platelet responses to acute EVOO intake are associated with oil phenolic composition and may be influenced by diet.
In this study, the physicochemical properties and bioactive compounds of olive oils from cultivars "Roggianella", "Sinopolese" and "Ottobratica", grown in the province of Reggio Calabria (Italy) have been evaluated. Polyphenols are a large family of compounds found in fruits and vegetables, which exhibit strong antioxidant activity by scavenging different families of Reactive Oxygen Species (ROS). Dialdehydic form decarboxymethyl oleuropein aglycon, hydroxytyrosol acetate, dialdehydic form oleuropein aglycon, pinoresinol, 1-acetoxypinoresinol, tyrosol and vanillic acid were the main phenolic compounds in all samples analyzed. Pinoresinol was the most abundant compound in the lignin fraction. In all oil samples analyzed the highest antioxidant capacity was attributed to Roggianella oil (36.85% I of DPPH and 4.07% I of ABTS) compared to Ottobratica (27.37% I of DPPH and 2.52% I of ABTS) and Sinopolese (18.33% I of DPPH and 1.72% I of ABTS). The main characteristics of the Roggianella cultivar were a very high concentration of total phenols (530 mg/kg of gallic acid) and α-tocopherol (211 mg/kg).