A PROCESS FOR THE PREPARATION OF A MATERIAL COMPRISING CONJUGATED ISOMERS OF A POLYUNSATURATED FATTY ACID COMPRISES: TREATING A FIRST FATTY ACID MIXTURE COMPRISING SATURATED FATTY ACIDS, MONOUNSATURATED FATTY ACIDS POLYUNSATURATED FATTY ACIDS IN THE PRESENCE OF ETHANOL TO FORM (I) A SOLID FRACTION AND (II) A LIQUID FRACTION COMPRISING A SECOND FATTY ACID MIXTURE, WHEREIN THE SECOND FATTY ACID MIXTURE HAS A HIGHER MOLAR RATION OF TOTAL POLYUNSATURATED FATTY ACIDS TO TOTAL SATURATED AND MONOUNSATURATED FATTY ACIDS THAN THE FIRST FATTY ACID MIXTURE SEPARATING THE SOLID FRACTION AND THE LIQUID FRACTION AND SUBJECTING THE SECOND FATTY ACID MIXTURE OR A DERIVATIVES OR REACTION PRODUCT THEREOF TO TREATMENT WITH A BASE IN THE PRESENCE OF A SOLVENT, TO FORM CONJUGATED ISOMERS OF AT LEAST SOME OF THE POLYUNSATURATED FATTY ACIDS.