Influence of nanofiltration membrane features on enrichment of jussara ethanolic extract (Euterpe edulis) in anthocyanins

Anthocyanins were concentrated from ethanolic jussara (Euterpe edulis) extract by nanofiltration. Six commercial flat-sheet membranes with nominal molecular weight cut-off ranging from 150 to 1000 g mol−1 (NF270 and NF90 from Filmtec Dow, NP010 and NP030 from Microdyn Nadir and Desal 5-DK and Desal 5-DL from GE Osmonics) were characterized in terms of their textural properties, surface morphology and further evaluated for jussara extract nanofiltration performance. Nanofiltration trials were conducted on a stainless steel stirred dead-end cell, in which permeate fluxes were recorded by keeping operational conditions constant at 25 bar and 25 °C. N2 adsorption isotherms and atomic force microscopy images revealed a nanoporous bulk for all membranes. Changes in roughness and contact angle of membranes were observed to occur after nanofiltration trials. The Desal 5-DK membrane showed the highest efficiency for jussara extract nanofiltration due to its highest flux and smallest flux decline, in addition to the highest anthocyanins retention capacity in relation to the other commercial nanofiltration membranes.