Milling of olive paste during olive oil production is accompanied by continuous washing with water, i.e. malaxation. The resulting 'waste-water' is currently discarded. Since olives and olive oil are rich in natural antioxidants, we hypothesized that some of these might be extracted from the olive paste during malaxation, Interest in natural antioxidants is increasing because of the growing body of evidence indicating the involvement of oxygen-derived free radicals in several pathological processes, such as cancer and atherosclerosis. A waste-water extract was characterized by HPLC and tested in a model of lipid peroxidation, copper sulphate-induced oxidation of low density lipoproteins. The results demonstrate that waste-water extracts have powerful antioxidant activity and might therefore represent a cheap, as yet unused, source of natural antioxidants
