| abstract |
Vitamins and sterols are extracted from animal or vegetable fats or oils by saponifying the fats or oils with an aqueous solution of sodium hydroxide of such a concentration that a solid soap containing less than 20 per cent water by weight is obtained, after cooling, subdividing said soap to uniform solid soap particles and extracting the soap particles with a water-miscible aliphatic ketone or water-miscible aliphatic monohydric alcohol in such quantities that the water content of the solution is less than 5 per cent by weight when equilibrium is reached. The water miscible solvent may be acetone, methyl ethyl ketone, methanol, ethanol or isopropanol. The process may be modified in that the saponification is carried out with aqueous sodium hydroxide of such a concentration that a soap containing more than 20 per cent of water by weight is obtained, and the soap so obtained is dried and subdivided to obtain uniform soap particles containing less than 20 per cent water. The aqueous sodium hydroxide solution may contain between 40 and 60 per cent by weight of sodium hydroxide. A saponification catalyst, e.g. 1 per cent by weight of a monohydric alcohol, may be used in the saponification step. Some glycerin is extracted by the solvent and may be recovered by extracting the extracted matter after the removal of the solvent with small quantities of water. One detailed example is given. |