Chemical Properties, Qualitative Parameters and Antioxidant Activity of Virgin Oil Obtained from Olea europaea Linn cultivar Zard Cultivated in Three Different Regions of Iran (Roudbar, Shiraz and Dezful)

Abstract

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.