EVALUATION OF VIRGIN OLIVE OIL MINOR COMPOUNDS IN
PROGENIES OF CONTROLLED CROSSES
IMED RJIBA
1
, NOUREDDINE GAZZAH, SAMIA DABBOU and MOHAMED HAMMAMI
Laboratory of Biochemistry, UR “Human Nutrition and Metabolic Disorders” USCR Mass Spectrometry, Faculty of Medicine, Monastir 5019, Tunisia
1
Corresponding author. TEL: 216-73-462-200;
FAX: 216-73-462-737; EMAIL:
imed.rjiba@fst.rnu.tn
Accepted for Publication December 29, 2009
doi:10.1111/j.1745-4514.2010.00462.x
ABSTRACT
An experimental investigation was carried out to evaluate the quality of virgin olive oils
obtained by intervarietal cross-breeding program. Twelve extra virgin olive oil cultivars
were characterized by their chemical composition. The experimental data showed that
new releases were characterized by an appreciable a-tocopherol (ranging from 60.09 to
153.97 mg/kg) and by a high content of total volatile compounds especially of the trans-
2-hexenal. Simple phenols such as hydroxytyrosol, tyrosol, vanillic acid, p-coumaric
acid, ferulic acid and vanillin were identified and quantified by high-performance
liquid chromatography in most of the oils. The flavonoids compounds (apigenin and
luteolin) were also found. The results indicated that a considerable oil composition vari-
ability can be achieved genetically, by breeding.
PRACTICAL APPLICATIONS
The olive oil characterization of the new releases is an important way to study the
effect of the breeding method on their chemical composition in an attempt to select
new ones with superior genotypes.
INTRODUCTION
Virgin olive oil is the only vegetable oil appropriate for
direct human consumption without further treatment after
its mechanic extraction. It is valued for its balanced and
healthy composition that includes more than 230 chemical
compounds. These substances also contribute to the stabil-
ity of the oil (Ranalli and Martinelli 1995) and protect con-
sumers against cancer and atherosclerosis by impeding the
oxidative modification of low-density lipoprotein and its
adherence to the arterial wall (Armstrong et al. 1997; Nico-
laïev et al. 1998). The concentration of each of them
depends on the level and the activities of various endog-
enous enzymes of olives that are genetically determined and
strongly affected by the technological operations and the
extraction conditions (Servili et al. 2004).
In Tunisia, Olea europaea has a wide distribution, with a
cultivated area of 1.6 million ha, predominantly in the center
and south areas of the country. It represents an important
economical and environmental species, making Tunisia the
fourth major olive producing country in the world, account-
ing for 210,000 tons of olive oil production per year. (DGPA/
ONH 1996; Hannachi et al. 2007)
The CHEMLALI variety used in this study is the main
variety cultivated in Tunisia. It is widespread in the south of
the country and it’s characterized by a high capacity of adap-
tation to various pedo-climatic conditions and a high level of
phenolic and vitamin content, but this variety has a moderate
level of oleic acid (55–64%) and is relatively rich in palmitic
acid (17–22%), which makes it a very stable semisolid fat at
room temperature.
The duration of the juvenile period is one of the most
important drawbacks of fruit tree breeding including the
olive. But in the last years, the scientific progress in the meth-
odologies aimed at shortening the duration of the juvenile
period has been created (Lavee et al. 1996; Santos-Antunes
et al. 2005). This has promoted and facilitated the develop-
ment of olive breeding program. These programs were aimed
at improving oil yield and quality (Bellini et al. 2002), resis-
tance to disease especially to peacock eye (Spilocaea Oleagina)
(Rallo 1995), rooting ability of cuttings, suitability to
mechanical harvest, early bearing, high productivity and oil
content (Rallo 1995).
However, not so much information has been available on
the effect of cross-breeding and genetic improvement on the
chemical composition of the olive oil of the new cultivars.
Journal of Food Biochemistry ISSN 1745-4514
1413 Journal of Food Biochemistry 35 (2011) 1413–1423 © 2011 Wiley Periodicals, Inc.