Recovery of bioactive compounds from artichoke brines by nanofiltration

In this work a membrane-based process for the fractionation of artichoke brines was investigated in order to separate flavonoids and caffeoylquinic acids from salt compounds.Therefore, the performance of different spiral-wound nanofiltration (NF) membranes in thetreatment of clarified artichoke brines was evaluated in terms of productivity and selectivitytowards bioactive compounds in selected operating conditions. Membranes with differentpolymeric material (polyethersulphone, polyammide) and molecular weight cut-off (MWCO) (from 200 to 1000 Da) were tested. NF membranes of 200 Da produced better results in termsof recovery and concentration of compounds of interest. A better separation of salt com-pounds from caffeoylquinic acid derivatives was reached by using Filmtec-Dow NF 200 andDesal DL membranes. For these membranes a low rejection towards dry residue (between14% and 18%) was observed, while rejections towards total caffeoylquinic acids, flavonoidsand cynarin were higher than 92%. According to the obtained results the NF permeate, enriched in salt compounds, can bereused in the working cycle for the preparation of new acidulated brines through the adjust-ment of the standard salt concentration; the concentrated stream, enriched in phenoliccompounds, is a good source of possible ingredients to functionalize foodstuffs.