A process for separating components in an essential oil, which is a hydrophobic non-lipid natural oil being derived from plant matter and containing less than 40 % by weight of lipids, said process comprising: (i) providing an essential oil, wherein the essential oil is obtained from a natural raw material of plant origin either by steam distillation or by mechanical processes from the epicarp of Citrus fruits or by dry distillation, followed by separation of the aqueous phase, if any, by physical processes, or the essential oil is obtained by mechanical expression from plant material other than Citrus fruits, or the essential oil is obtained by extraction of the plant material with supercritical solvents, preferably supercritical CO 2, (ii) providing a selectively permeable nanofiltration membrane having a first surface and a second surface; (iii) separating the essential oil by transferring one or more components of the essential oil from the first surface to the second surface across the membrane through contacting the essential oil with the first surface, wherein the oil in contact with the first surface forms a retentate and the oil contacting the second surface forms a permeate, wherein the pressure at the first surface is greater than the pressure at the second surface, and wherein the concentration of the one or more components of the essential oil is reduced in the oil contacting the first surface compared to the initial essential oil. (i) providing an essential oil, wherein the essential oil is obtained from a natural raw material of plant origin either by steam distillation or by mechanical processes from the epicarp of Citrus fruits or by dry distillation, followed by separation of the aqueous phase, if any, by physical processes, or the essential oil is obtained by mechanical expression from plant material other than Citrus fruits, or the essential oil is obtained by extraction of the plant material with supercritical solvents, preferably supercritical CO 2, the essential oil is obtained from a natural raw material of plant origin either by steam distillation or by mechanical processes from the epicarp of Citrus fruits or by dry distillation, followed by separation of the aqueous phase, if any, by physical processes, or the essential oil is obtained by mechanical expression from plant material other than Citrus fruits, or the essential oil is obtained by extraction of the plant material with supercritical solvents, preferably supercritical CO 2, (ii) providing a selectively permeable nanofiltration membrane having a first surface and a second surface; (iii) separating the essential oil by transferring one or more components of the essential oil from the first surface to the second surface across the membrane through contacting the essential oil with the first surface, wherein the oil in contact with the first surface forms a retentate and the oil contacting the second surface forms a permeate, wherein the pressure at the first surface is greater than the pressure at the second surface, and wherein the concentration of the one or more components of the essential oil is reduced in the oil contacting the first surface compared to the initial essential oil.