Characterization of olive oils obtained from wild olive trees (Olea ferruginea Royle) in Pakistan

Pakistan is lacking in edible oils and large amounts of resources are being used to import these. Olea ferruginea Royle (Oleaceae), locally known as Kahu, is native to Northern part of the country, and the fruit of this tree is currently not being utilized for any useful purpose. The present study was conducted to exploit a new source of virgin olive oil (OWOT) based on chemical composition and quality parameters. The fruits from wild olive trees were collected from different locations in Pakistan (i.e. Bhara Kahu, Kotli Sattian and Dir Swat); whereas a reference sample (OCOT) of a local variety (Zaitoon II) Olea europaea L was collected from Barani Agricultural Research Institute, Chakwal (BARIC) for comparison. The basic quality characteristics of oils such as free acidity, peroxide value, specific UV absorptions and sensory analysis demonstrated that the oils belong to the "lampante olive oil" commercial category due to low quality of processed olives. Some minor discrepancies with respect to the standard olive oil composition (linoleic acid slight exceeding 1% and traces of erucic acid and brassicasterol) were found that should be further studied to understand their etiology. Concerning minor compounds, tocopherols were found in low quantities whereas higher amounts of beta-carotene and lutein were observed in OWOT compared to OCOT. Finally, OWOTs showed a relatively low quantity of hydrophilic phenols that proportionally expressed three times less antioxidant activity compared with OCOT. Careful control of fruit quality and good practices before olive milling could improve not only quality of the product, but also provide a new promising source of edible virgin oils. (C) 2013 Elsevier Ltd. All rights reserved.