Patent ID: 8066881

Claim:
A method of obtaining a hydroxytyrosol-rich concentrate from olive tree residues and sub-products using clean technologies consisting essentially of: supplying a flow stream containing hydroxytyrosol and other bioactive compounds to a nanofiltration unit with a molecular weight cut-off lower than 300 Da, wherein said hydroxytyrosol and other bioactive compounds are recovered in a permeate stream from a permeate compartment of said nanofiltration unit, and followed by supplying the permeate stream from said nanofiltration unit to a feed compartment of a reverse osmosis unit, wherein said hydroxytyrosol and other bioactive compounds are retained and concentrated in a retentate stream, and wherein the transport of solvents and solutes in both said nanofiltration unit and said reverse osmosis unit is driven by a pressure gradient between said feed compartment and said permeate compartment.