Ultrafiltration of Broccoli Juice Using Polyethersulfone Membrane: Fouling Analysis and Evaluation of the Juice Quality

摘要

In this study, fouling behavior and juice quality were studied during sequential ultrafiltration of broccoli juice. Resistance-in-series model was used to analyze membrane fouling. Membrane pore size did not cause a significant difference in the amount of sulforaphane during ultrafiltration treatment. The total phenolic compound of broccoli juice decreased at a ratio of 5.5%, 9.6%, and 2.7% for 50-kDa, 10-kDa, and 5-kDa membrane, respectively. The rejection of 10-kDa membrane towards chlorogenic acid, sinapic acid, kaempferol, quercetin, and rutin was in the range of 4.2-44%. Rutin was the most retained phenolic compound due to the higher number of a benzene ring on the molecular structure and higher acidity coefficient. Fifty-kilodalton membrane exhibited the highest amount of bioactive compounds in the permeate compared to other ultrafiltration membranes; therefore, the 50-kDa membrane was considered as the most suitable membrane for clarification of broccoli juice.