Chemical Profiles of Moroccan Picholine Olives and Its Brines during Spontaneous Fermentation
Hajar Kiai, Jihane Raiti, Abdelilah El‐Abbassi, Abdellatif Hafidi
Abstract
Changes in physical and chemical profiles during spontaneous fermentation of olives from the Moroccan Picholine cultivar at two degrees of ripeness (green and purple stages) were investigated in both olive flesh and brine. Purple olives exhibited the highest sugar, total phenolic and flavonoids content. Spontaneous fermentation led to an important loss of total phenolic, flavonoids and sugar content, particularly in green olives with reductions rate of 43%, 65% and 73%, respectively. The loss of phenolic compounds through fermentation was accompanied by a decrease of the antioxidant activity in olive flesh. The chromatographic analysis showed qualitative and quantitative differences among the olive flesh and brine studied. By the end of fermentation, an increase in hydroxytyrosol and caffeic acid concentrations and a decrease of protocatechuic acid, ferulic acid, p-coumaric acid and quercetine amounts were observed in both olive fleshes. The main phenolic compound identified and quantified in both tested brines was hydroxytyrosol. The purple-olive flesh and green olives brine were found to have the highest antioxidant activity after 66 days of natural fermentation.