The aim of this study was to evaluate the effects of variety and extraction system on the physico-chemical and sensorial characteristics of olive oils produced from three dominant varieties of Algeria (Azeradj, Chemlal and Sigoise). The olive oils were extracted by three different processes (pressure system, two-phase centrifugation and traditional process). Physicochemical parameters including free acidity, peroxide value, absorbance in ultra violet (K232, K270, ΔK) and sensory evaluation were studied. The results show that free acidity, peroxyde value and K270 were influenced by the extraction system and variety. Olive oils obtained from the two phases centrifugation and Chemlal cultivar were characterized by higher oxidative stability. Sensory characteristics of olive oils were mainly influenced by the variety and extraction system. Olive oils obtained from the two phases centrifugation, traditional cold process and Sigoise variety were characterized by the lower mean values of negative attributes.

To study the effect of the variety and process of extraction influences on the physico-chemical and organoleptic quality of the olive oil. In the objective, select three dominant varieties in Algeria: Azeradj, Chemlal and Sigoise, each variety was triturated by three processes of extraction: pressing method, Twophase Centrifugation method and traditional process. The parameters i.e. free acidity, peroxide value, saponification value, specific coefficients of extinctions K232, K270 and ΔK, were measured and a sensory analysis was done. The results of physico-chemical analyses showed that the parameters free acidity, peroxide value, saponification value and specific extinction at 270 nm are strongly influenced by the variety and the process of extraction, however the parameters specific extinction at 232 nm and variation of the specific extinction do not present a significant difference for the varietal aspect and the process of extraction. The sensory analysis which is based on the perception of the defects, made it possible to classify the olive oils in the current virgin category. The organoleptic quality of oils is also influenced by the variety on the one hand and the process of extraction on the other hand.