Membrane-based agro-food production processes for polyphenol separation, purification and concentration

Polyphenols, one of the main classes of secondary metabolites derived from plants, have received more and more attention in recent years due to their bioactive functions. Consequently, the interest in the extraction and separation of such compounds from agro-food sources has remarkably grown. Membrane processes can be considered leader technologies and very efficient unit operations in the recovery of food polyphenols. In this review, the main properties and fundamentals of pressure-driven membrane processes and membrane contactors are first presented. Then, specific applications for the separation, purification and concentration of polyphenols from agro-food products and by-products are analysed and discussed, emphasizing the key technological advantages and improvements over conventional separation technologies.