Membrane processing of xanthophylls in ethanol extracts of corn.

Abstract Xanthophylls such as lutein and zeaxanthin are naturally occurring yellow–orange oxygenated pigments of the carotenoid family. They can be extracted from plant materials with organic solvents such as ethanol or hexane. The objective of this research was to develop methods for concentrating and purifying xanthophylls extracted from corn using membrane technology. Ultrafiltration (UF) was used to separate ethanol-soluble protein (zein) and other large solutes from the extract. The xanthophyll-containing stream was concentrated and separated from the solvent using nanofiltration (NF). Ethanol can be recycled back to the process. This study focused on screening commercially available and prototype polymeric UF and NF membranes for the flux and rejection of model lutein solutions and aqueous ethanol extracts of whole ground corn.