Background:
Zard variety is a popular olive variety widely cultivated in different regions
of Iran. Despite the extensive cultivation of this olive cultivar, little research has been carried out on
its various properties. Thus, chemical properties, qualitative parameters and antioxidant activity of
Olea europaea Linn cultivar Zard oil cultivated in three different regions including Roudbar, Shiraz
and Dezful could be an interesting topic for research.
Methods:
After oil extraction of different olive samples, their different characteristics were
compared. For this purpose, fatty acid composition, unsaponifiable matters, antioxidant compounds,
qualitative parameters (acid value, peroxide value, carbonyl value, total polar compounds) Antioxidant
activity assay (DPPH radical-scavenging assay and ferric reducing-antioxidant power (FRAP))
and oxidative stability index were measured.
Results:
Palmitic acid, oleic acid and linoleic acid contents in Zard variety cultivated in Roudbar
(ZR), Zard variety cultivated in Shiraz (ZS) and Zard variety cultivated in Dezful (ZD) oils were
13.1, 15.2, 13.2; 72, 60.4, 68.8; 9.1, 17 and 12.2; respectively. The highest phenolic and tocopherol
content was observed in ZD oil (90.4, and 160.2 mg/kg), followed by ZR (73.3, and 121.2 mg/kg)
and ZS (52.2 and 67.5 mg/kg) oils. Evaluation of qualitative parameters in the oils revealed that they
have suitable quality. Antioxidant activity assay indicated that ZD oil had the highest antioxidant activity,
followed by ZR and ZS oils.
Conclusion:
Results of this investigation indicated that there was a direct relation between antioxidant
activity and antioxidant content. Also, climatic difference in cultivation regions was a reason of
significant difference in the properties of ZR, ZS and ZD oils.
Effect of storage time and gamma irradiation on the chemical properties of olive (Olea europaea) oils