Recovery of phenolic compounds from bergamot juice by nanofiltration membranes

In this work, nanofiltration (NF) membranes were used to produce purified and concentrated fractions of phenolic compounds from the bergamot juice that was previously clarified by ultrafiltration. In particular, the performance of three commercial NF membranes (NFPES 10, N30F, and NF270) with different molecular weight cut-off and polymeric material was evaluated in terms of productivity and selectivity towards compounds of interest (flavonoids and total phenolic compounds), total antioxidant activity, and sugars. Experimental results indicated that the NFPES10 membrane showed the largest gap between the rejection coefficients towards sugar and phenolic compounds. Therefore, the produced retentate fractions, characterized by high antioxidant activity, can be considered of interest for nutraceutical applications. The hydrophobic character of NF PES10 and N30F membranes accounted for their higher fouling index when compared to the NF270 membrane.