GB515468A - Improvements in or relating to processes of extracting and refining glycerides and products resulting therefrom - Google Patents

Abstract

515,468. Drying-oils ; extracting fatty oils and acids; oil-cake; phosphatides. PITTSBURGH PLATE GLASS CO. March 4, 1938, No. 6808. Convention date, May 22, 1937. [Class 91] [Also in Group IV] Highly unsaturated fractions of glycerides and acids are extracted from crude glyceride oils or materials containing them by treating with furfural at an effective temperature of at least 77‹F. to produce 2 liquid phases. The solvent power of the furfural may be increased by adding phenol or pyridine in a proportion not unduly impairing the selective action. The residual oil -the more saturated fraction-with or without hydrogenation, may be used as food or soap stock. The acid and lecithin content of the extract solution may be reduced by adding thereto water or methyl, ethyl, or other,alcohol. The crude oil may be dissolved in a paraffinic hydrocarbon such as hexane ; on treatment with furfural the glycerides containing conjugate double bonds are dissolved out. Materials subjected to extraction include linseed soya, hempseed, cottonseed, perilla, tung, oiticica and fish oils, and meals or pulps of the seeds, fish, or other oil-source. The extracted meal or pulp is exceptionally rich in phosphatides if the extraction temperature is not too high; the phosphatides may be extracted therefrom by solvents such as petroleum ether, and used as emulsifying and wetting agents, e.g, in paints, drugs, and food products. In examples :-(1) Linseed meal is extracted with 1 or more vol. of furfural, leaving cake retaining most of the phosphatides; the solution of unsaturated and saturated glycerides and fatty acids with colouring matters sterols and some phosphatides is reduced in temperature to 104-106‹F., whereby the phosphatides and highly saturated acids separate and are removed; water is then added to the solution causing separation of the unsaturated glycerides ; the remaining solution is heated to distil off water and furfural, leaving acids, sterols, and colouring matter ; the acids are recovered by vacuum distillation. (2) Fish oil is extracted with a mixture of 3 vols. of furfural and 1 vol. of phenol; water is added to the solution and the mixture cooled to 68‹F. to complete separation of the drying fractions. (3) Soya bean meal is extracted at above 122‹F. with 2 vols. of furfural; water is added to thehot solution to separate lecithin as a sludge. (4) 3 per cent. of phosphatides obtained according to the invention is added to alkalirefined linseed oil to improve its power of wetting titanium oxide or other pigment.