Membrane-based biorefinery in agro-food processing: recovery of bioactive compounds from agro-food wastewaters

The recovery of fine bioactive chemicals and/or production of high added-value products appear to be a new frontier in agro-food waste valorization. New perspectives and potentialities for the valorization of agro-food wastes are expected from the combination of membrane unit operations such as ultrafiltration (UF) and nanofiltration (NF). A critical overview of the on ongoing developments aimed at improving the separation, fractionation and concentration of bioactive compounds from their original sources through membrane-based processes is given. Specific applications in different areas of the agro-food processing industry, including olive mill, artichoke and citrus wastewaters, are analysed and discussed in relation to separation processes, molecule properties, membrane characteristics and key factors affecting the membrane performance in terms of productivity and selectivity towards target compounds. The combination of membrane operations in sequential design is proposed for the production of formulations enriched in valuable bioactive compounds in a market-competitive and environmentally sustainable way.