Food & Nutrition

Arab Journal of Food & Nutrition
79. Characterization of the Fatty Acids Composition and Minor Components of
the Olive Oil Extracted from Fruits of the Improved Nabali Olive Tree Grown in
Different Geographical Areas in Jordan (2005)
Hamzeh A. S. Al-Juneidi\ University of Jordan
Supervisor: Dr. Khalid Al-Ismail
The influence of harvesting date on fatty acids composition, squalene, and β-
sitosterol was evaluated of olive oil obtained from Improved Nabali “Nabali
Muhassan” olive cultivar from three different locations in Jordan, one was the region
of Salt representing high land rain fed area, the second was Jordan Valley averaging
land 300m below see level and the third was Mafrak representing desert. Both the
valley and desert represent irrigated agriculture. The effectiveness of using fatty acid
profile, oleic acid to linoleic acid (ol/lnl), unsaturated to saturated fatty acids
(unsat/sat) and squalene to β-sitosterol (squ/sito) ratios in detecting olive oil
adulteration with four different edible oils (corn, soybean, sunflower and palm oils) at
levels of 1, 5, 10, 15, 20 and 25% was also studied. Results were compared with those
of Bellier test.
The fatty acid composition of all olive oil samples was within the normal ranges
set by different local and international standards. The results indicated that palmitoleic,
linoleic and linolenic acids increased with ripening while palmitic acid decreased. No
significant changes in oleic acid, stearic acid, arachidic acid, squalene and β-sitosterol
were observed due to different harvesting dates. On the other hand, oleic and linoleic
acid content of olive oil samples obtained from high land farm were significantly
higher than those from Jordan Valley and desert. The average content of oleic acid in
samples collected from high land, Jordan Valley and desert were 76.84, 75.47 and
75.02 respectively. However, olive oil samples collected from desert and Jordan
Valley were significantly higher in palmitic acid than those collected from high land.
No significant differences were observed in squalene and β-sitosterol among oil
samples collected from the three locations.
Ratio of ol/lnl was suitable to detect the adulteration of olive oil with corn,
soybean and sunflower oils at levels of 10%, 10% and 5% respectively, while it failed
to detect the adulteration of olive oil with palm oil up to a level of 25%. squa/sito ratio
was suitable to detect the adulteration of olive oil with corn, soybean, sunflower and
palm oils at adulteration levels of 10%, 10%, 10% and 25%. The most effective
parameter to be used in detecting olive oil adulteration with palm oil was found to be
unsat/sat ratio which was suitable to detect the adulteration of olive oil with palm oil at
level of 10%, this ratio failed to detect the adulteration of olive oil with corn, soybean
and sunflower oils up to a level of 25%.
Bellier test and the ratios of ol/lnl and squa/sito showed comparable results for
detecting the presence of soybean and corn oils in olive oil, since they were able to
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