Yousef Lotfi; Esmaeil Khaleghi; Norollah Moallemi
Abstract
Given that, the qualitative characteristics of olive oil are influenced by environmental conditions and cultivars. Therefore, this study was carried out to investigate some of the oil qualitative characteristics of Tarom 2 and Dezful cultivars of olive as a randomized complete block design with 3 replications ...
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Given that, the qualitative characteristics of olive oil are influenced by environmental conditions and cultivars. Therefore, this study was carried out to investigate some of the oil qualitative characteristics of Tarom 2 and Dezful cultivars of olive as a randomized complete block design with 3 replications at Shahid Chamran University of Ahvaz during 2016-2017. The results indicated that, the oil extracted from Tarom 2 cultivar exhibited the highest peroxide value (9.25 meq of O2/ kg of oil), chlorophyll content (8.10 mg/kg of oil), and carotenoid (0.16 mg/kg of oil) and K232 and K270 extinction coefficients of 2.32 and 0.61, respectively. However, total phenolic content of the oil extracted from Dezful cultivar (552.66 mg/kg of oil) was higher than that of the other cultivar. In addition, the highest oleic acid content (58.52%) and lowest palmitic acid content (17.6%) were measured on the oil obtained from the Tarom 2 cultivar, while the oil extracted from Dezful cultivar showed the highest linoleic acid content (18.05%). Furthermore, oleic acid-to-linoleic acid ratio was higher in the oil extracted from the Tarom 2 cultivar rather than the one taken from the Dezful cultivar. Therefore, based on the results obtained from the experiment, the oil extracted from Tarom 2 cultivar is expected to exhibit higher oxidative stability than that of the Dezful cultivar.
Mahmood Ghasemnezhad; Hossein Meighani; Somayeh Eftekhari
Abstract
To study the evaluation of ripening index on qualitative parameters of three olive cultivars ('Zard', 'Local-Roghani' and 'Arbequin') in Roudbar city of Gilan province, an experiment was carried out according to a factorial based on completely randomized design with three replications in 2014. Fruits ...
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To study the evaluation of ripening index on qualitative parameters of three olive cultivars ('Zard', 'Local-Roghani' and 'Arbequin') in Roudbar city of Gilan province, an experiment was carried out according to a factorial based on completely randomized design with three replications in 2014. Fruits were harvested at ripening index 3.5, 4 and 5 according to the method proposed by the international olive oil council and after oil extraction, its biochemical and qualitative characteristics were assessed. The results showed significant increases in dry mater, peroxide value, free fatty acid, extinction coefficient at 232 and 270 nm, coupled with significant decline in total phenolics and flavonoids, carotenoid and chlorophyll pigments and antioxidant activity with advancing ripening index. Also, significant differences were observed among the olive cultivars in the all above traits. Total phenolics of olive oil in the 'Local-Roghani' cultivar at ripening index 3.5, 4 and 5 respectively with averages of 941.27, 657.74 and 310.32 mg/kg were more than others. However peroxide value, that is an undesirable trait in the olive oil, was higher in the 'Local-Roghani' cultivar. Although the antioxidant activity among olive cultivars was varied at ripening index 3.5 and 4, but no significant differences were observed at ripening index 5. Overall, the results showed that an increasing in the fruit ripening index was accompanied with decreased in the antioxidant compounds and sensitivity to oxidation of olive oil. Therefore, the oils obtained from the fruits at ripening index 3.5 had greater stability and sustainability.