Journal of Environmental Treatment Techniques  
2020, Volume 8, Issue 3, Pages: 1075-1080  
J. Environ. Treat. Tech.  
ISSN: 2309-1185  
Journal web link:  
Study of the Chemical Composition of Olive Oil  
According to Its Mode of Extraction and Its Age  
from the Olive Tree  
Miloudi Hilali *, Nadia Maata , Hanae El Monfalouti and Badr Eddine Kartah  
Laboratory of Plant Chemistry and Organic and Bioorganic Synthesis, Faculty of Science, University Mohamed-V, Av. Ibn Battouta, BP 1014 Agdal-  
Rabat, Morocco  
Official Laboratory for Chemical Analysis and Research 25, Rue Nichakra Rahal, Casablanca, Morocco  
Received: 12/04/2020  
Accepted: 29/06/2020  
Published: 20/09/2020  
A comparative study of the chemical composition of olive oil was carried out in the Massmouda district of Ouezzane, a city in  
northern Morocco. It was made in order to study the influence of the extraction temperature and the age of the olive tree on the  
chemical composition of olive oil. To carry out this work, we selected four samples of olive oil of the same kind (Moroccan  
Picholine), from the same place and extracted at different temperatures, but these samples were collected from olive trees of different  
ages. For this we performed physico-chemical analyzes such as acidity, peroxide index, absorbance in ultraviolet, fatty acids, sterols  
and triglycerides. The result of this work shows that the temperature of olive oil extraction can increase the peroxide index, acidity, the  
percentage of oleic fatty acid (C18: 1), the percentage of stigmasterol, and the percentages of triglycerides OOO, POO and can  
decrease the percentage of fatty acid such as: C18: 0, C18: 2 (vitamin F) and the percentages of triglycerides LLL, LOL, OLO, PLO.  
The results of the chemical composition according to the age of the olive tree reveal that the percentages of oleic acid (C18: 1), the  
percentages of the triglycerides LLL, OOO are decreased with the increase in the age of the olive tree. On the other hand, our study  
demonstrates that the percentage of linoleic acid C18: 2 (vitamin F) is increased with the increase of the age of the tree. In the end our  
study proved the high quality of olive oil extracted by cold mechanical pressing.  
Keywords: Olive, Fatty acids, Sterols, Triglycerides, Extraction temperature, Olive age  
Olive oil is practically the only vegetable oil that can be  
consumed in its raw form without prior treatment.  
Appreciated for its flavor and nutritional characteristics, it is  
known for its multiple virtues in the prevention of diabetes,  
high blood pressure [4], certain cancers and aging [5]. It is  
also used in the pharmaceutical and cosmetic fields [6].  
Making the pillar of the Mediterranean diet, several studies  
have been carried out, on the fruit and leaves, to confirm the  
ancestral virtues attributed to it [7-9]. This study is part of the  
continuity of the research series performed by The Laboratory  
of Plant Chemistry, Organic and Bio-organic Synthesis on  
vegetable oils. To enhance olive oil and improve its nutritional  
effect we followed some steps: (a) the study of the chemical  
composition of olive oil according to the age of the olive tree;  
The olive tree is a Mediterranean fruit tree that belongs to  
the Oleaceae family. This tree produces olives; a fruit  
consumed in various forms and from which olive oil is  
extracted. In Morocco, the main cultivated fruit species is the  
olive of the popular variety "Moroccan Picholine" [1] which  
occupies an area of 560,000 ha. Olive groves contribute to  
employment in rural areas with 11 million working days  
annually. Olive production reaches the approximate figure of  
60,000 T, generates 50,000 T of olive oils and 90,000 T of  
industrial table olives [2]. The olive tree develops in four  
periods [3].  
and flowering. The olive tree settles, expands but produces  
Period of youth (1-7 years): it is the period of growth, size  
b) the study of the chemical composition of olive oil  
according to its mode of extraction and (c) to accomplish this  
work, 4 olive samples belonging to the same region of  
Morocco (the town of Ouezzane Douar Ghnioua) and of the  
same variety "Moroccan Picholine" were selected.  
Period of entry into production (7-35 years): it is in a way  
the adolescence period of the tree which prepares for the  
establishment of regular and significant productions.  
Adult period (35-100 years): full production period (yield of  
5 to 25 kg of olives per tree). The olive tree is in the prime of  
2 Materials and methods  
2.1 Presentation of the study area  
Period of senescence (beyond 150 years): end of the tree's  
productive life, little by little it produces less. Carpenter  
branches die, trunk bursts.  
The study region is the city of Ouezzane which belongs to  
the southern margins of the Jebala area whose major tribes  
bordering the city are: Masmouda, Rhouna, Ghzaoua and Beni  
Mesara. The Ouezzane region, in the North of Morocco,  
extends over an area of 1861.2 km², and has an altitude of 614  
meters [10] (figure 1).  
Corresponding author: Miloudi Hilali, Laboratory of Plant  
Chemistry and Organic and Bioorganic Synthesis, Faculty of  
Science, University Mohamed-V, Av. Ibn Battouta, BP 1014  
Agdal-Rabat, Morocco. Email address: