Storage of olives (Olea europaea): effect on the quality parameters and the radical scavenging activity of the total fraction, lipidic and methanolic fractions of the VOO

The aim of the present work is to study the effect of the olive fruit storage on the olive oil quality. ‘Chemlali’ used for oil production were stored in plastic containers, at room temperature during three different periods (0-3 weeks) before oil extraction. After storage, the oils were extracted from the fruits and the acidity, peroxide value, coefficients of specific extinction at 232 and 270 nm, the radical scavenging activity of the total fraction, lipidic and methanolic fractions of the virgin olive oil (VOO) were determined. The effect of the olive fruit storage on the olive oil quality was investigated by measuring the radical-scavenging activity (RSA) toward 1,1-diphenyl-2-picrylhydrazyl radical (DPPH•). The results showed that storage of fruits produced losses in all the VOO quality parameters. During storage, a marked decrease in the capacity of the total fraction of the VOO to scavenge the free radical DPPH (week 0: 77% - week 3: 60%). Similar changes were observed in the capacity of the polar fraction to scavenge the free radical DPPH (week 0: 4790 μmol Trolox/kg oil - week 3: 3357 μmol Trolox/kg oil). A drastic decrease was observed in the capacity of the lipidic fraction to scavenge the free radical DPPH (week 0: 62% - week 3: 47%). The results demonstrate that the storage conditions of the olive fruits have a remarkable impact on the VOO quality