Composition, quality and oxidative stability of virgin olive oils from some selected wild olives (&lt;i&gt;Olea europaea&lt;/i&gt; L. subsp. &lt;i&gt;oleaster&lt;/i&gt;)

Bechir Baccouri,Wissem Zarrouk,Mokhtar Guerfel,Olfa Baccouri,Douja Daoud,Issam Nouairi,Douha Krichene,Mokhtar Zarrouk

doi:10.3989/gya.2008.v59.i4.528

Abstract

A study on the characterization of virgin olive oils from wild olives ( Olea europaea L. subsp. oleaster ) was conducted in order to define new cultivars which are welladapted to the Tunisian environment and yield high quality oils. The study was done during the crop years 2003/04, 2004/05 and 2005/06. The main analytical parameters of the oils were evaluated: fatty acid compositions, chlorophylls, carotenoids, tocopherols and phenolic compounds as well as their relationship with oxidative stability. The fatty acid composition of all the wild olive trees tested produced virgin olive oil which complies with commercial standards, as well as for their appreciable amounts of tocopherols and phenolic compounds. Tocopherol analysis by HPLC revealed the presence of α, β, γ and δ tocopherols in all the studied olive oils. Total tocopherol content was significantly influenced by the varietal factor. It ranged from 310 (SB12) to 780 mg/kg (H3). As for total tocopherols, the amount of each tocopherol varied according to genotype. α tocopherol is the most prominent, whereas β, γ and δ tocopherols are less represented. Results showed a clear influence of total phenols and o-diphenols on virgin olive oil stability (R = 0.905, 0.963 P <10–3, respectively), and a much lower contribution of tocopherols (R = 0.568) and acidic composition (R = 0,563).

Highlights

The olive tree (Olea europaea L.) is a subtropical species typical of the Mediterranean basin where it represents the most important oilproducing crop
The increasing popularity of olive oil has been mainly attributed to its high content of oleic acid, which may affect the plasma lipid/lipoprotein profiles and its richness in phenolic compounds acting as natural antioxidants, which may contribute to the prevention of human disease (Visioli et al, 1998; Visioli et al, 2000)
Tunisia occupies the fourth place on a worldwide scale in terms of olive oil production (IOOC, 2004)

Summary

Introduction

The olive tree (Olea europaea L.) is a subtropical species typical of the Mediterranean basin where it represents the most important oilproducing crop. Due to its use without refining, shows very interesting nutritional and sensorial properties, being one of the pillars of the so-called Mediterranean diet. Sensory quality and health properties stem from a prominent and well-balanced chemical composition (Boskou, 1996; Servilli et al, 2004). Tunisia occupies the fourth place on a worldwide scale in terms of olive oil production (IOOC, 2004). Tunisian olive plantations are spread all over the country in different edapho-climatic conditions and account for about 63 million trees covering 1.6 million hectares. A major effort has been made recently for improving the quality of olive oil produced in Tunisia

Methods

Results

Conclusion