Stability and antioxidant potential of purified olive mill wastewater extracts

► POE rich in phenolic and oleosidic compounds prepared by amphoteric polymer resin. ► High phenol content and structural diversity of POE confer high antioxidant potential. ► Stability of POE is greatly improved comparing to original OMWW matrix and crude extract. ► Oxygen is determinant factor which influences the stability of POE at low temperature. ► Compositional changes contribute to maintenance of antioxidant potency at high temperature.