An improved process for the recovery of water-soluble plant substances such as ascorbic acid and also fat soluble vitamins, pro-vitamins and other non-saponifiable constituents from chlorophyll-containing parts of vegetable materials

摘要

The extract obtained from the expressed leaves of Rheum (see Group VI) is irradiated to form vitamin D. Specification 552,704 is referred to.ALSO:Vitamin C and fat-soluble vitamins, pro-vitamins and other non-saponifiable constituents are recovered from the leaves of Rheum by pressing them. The expressed juice contains the vitamin C and is recovered by precipitaing organic acids and then adding lead acetate at pH 7 to precipitate vitamin C. The leaf residue is extracted (see Group III) and carotene, tocoferol, sterols, vitamins K and F, can be recovered. Vitamin D may also be obtained by irradiation of the extract from the leaf residue. Specification 552,704 is referred to.ALSO:Leaves of Rheum are pressed to remove a substantial part of the juice which contains vitamin C, and the solid residue is extracted with a fat-dissolving agent, the agent being removed from the solution obtained, by evaporation to give fat-soluble vitamins, provitamins and other non-saponifiable constituents. In an example, the expressed juice is atomised and dried and vitamin C recovered therefrom by precipitation with lead acetate at pH7 after organic acids have been removed. The residue of leaves is dried and extracted with benzene and the latter subsequently evaporated. This extraction residue may be used as such, or further treated as by dissolving in ethyl alcohol, saponifying with alcoholic sodium hydroxide in an oxygen free atmosphere, adding water-free calcium chloride in ethyl alcohol to precipitate the soaps, and removing the precipitate by centrifuge or filtration. To remove excess calcium chloride, solid carbon dioxide is added. The precipitate is washed and pet-ether added to dissolve the non-saponifiable constituents. Fat dissolving agents specified include ether, motor spirit or other hydrocarbons or mixtures thereof, whilst soap precipitating agents are halides of the alkaline earth metals or aluminium sulphate. Specification 552,704 is referred to. The Specification as open to inspection under Sect. 91 comprises also this treatment of other green vegetables generally. This subject-matter does not appear in the Specification as accepted.