Phenolic profile and antioxidant activities of olive mill wastewater

► OMW exhibited comparable antioxidant activity to the ascorbic acid. ► OMW showed a higher iron(II) chelating activity than EDTA. ► Microfiltrated OMW higher antioxidant capacity than the corresponding phenolic extract. ► OMW storage increased its extractable phenolic content and its antioxidant activity.