Phenolic compounds in mono-cultivar extra virgin olive oils from Algeria

Abstract

The high oxidative stability of virgin olive oil is related to its high monounsaturated/polyunsaturated ratio and to the presence of antioxidant compounds, such as tocopherols and phenols. In this paper, the isolation of phenolic compounds from virgin olive oil from several Algerian varieties was tested and discussed in order to know its potential uses and benefits. Quantification of phenolic and o-diphenolic substances was performed using the traditional Folin-Ciocalteau method and the sodium molybdate reaction, respectively. The qualitative and quantitative characterizations of phenolic compounds were carried out by HPLC. The experimental results show that tyrosol, hydroxytyrosol and 4-HBA (4-hydroxybenzoic acid) are the main individual phenolic compounds identified in the varieties studied. The varieties with large fruits (Grosse du Hamma, Aghenfas, Azeradj, Aguenaou, Aberkane, Bouchouk de Guergour, X-Aghenfas, Rougette de Guelma, Sigoise) are clearly distinguished from the varieties with medium-sized and small fruits by having the highest levels of individual phenolic compounds. Moreover, varieties with small fruits (Hamra, Chemlal, Boughenfas, Limli, Aimel and Mekki) presented the highest levels of oleuropein.