State-of-the-art Membrane Processing of Solution Rich in Phenolic Compounds

Abstract

Polyphenols and phenolic acids extracted from plants are natural antioxidants with high market value. However, they are susceptible to thermal processes, and a significant loss throughout food and beverage processing has been widely reported. This work reviews the state-of-the-aft membrane processing of the solution rich in phenolic compounds. Novel membrane processing allows phenolic concentration and water recovery simultaneously without using hazardous chemicals and high temperatures. Comparing pressure-driven membrane filtration processes with the advanced membrane processes at the low pressure in this review allowed the proper process selection to concentration phenolic coumpounds. Pressure-driven membrane filtration processes, namely microfiltration, ultrafiltration, nanofiltration, and reverse osmosis, have been studied. Nanofiltration membranes offer high retention of polyphenols due to their matching molecular weight cut-off. Osmotic distillation, membrane distillation and forward osmosis are membrane processes operated at low pressure. Osmotic distillation and forward osmosis require drawing solutions with osmotic pressure differences to separate water from phenolic compounds. A similar separation is attained in membrane distillation by creating vapour pressure differences. Membrane distillation without drawing solution is recommended since membrane fouling can be mitigated using superhydrophobic membranes with self-cleaning properties.