Pomegranate juice concentration through the consecutive application of a plasma modified reverse osmosis membrane and a membrane contactor

A low-pressure nitrogen plasma (LPNP) modified commercial thin-film composite membrane was used for pre-concentration of the clarified pomegranate juice (C-PJ) by reverse osmosis (RO). Pre-concentrates then submitted to osmotic distillation (OD) for further concentration. The productivity of the integrated membrane process was benchmarked considering both the performance and the final product quality. The modified RO membranes had great potential for shortening duration of consecutive concentration process, enabling up to 36% time saving during concentration of the C-PJ from 15.6 degrees Brix to >65 degrees Brix. Aroma losses observed in stand-alone OD are also prevented by shortening the duration of OD. Lower retention of malic acid, gallic acid, glucose, and fructose was observed due to the increased permeability following LPNP modification. However, these losses did not seem to affect the total acidity, total phenolic content, and total antioxidant activity of the concentrates obtained. The total color change was also in the range of barely noticeable values. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.