GB575416A - Process of modifying the molecular structure of oils and fats - Google Patents

Abstract

The fatty acid radicles linked to the glycerine in the fatty glyceride molecules of fats or fatty oils are changed by refluxing the fats or fatty oils with a fatty acid ester of a monohydric alcohol having less than five carbon atoms per molecule or with the alcohol itself, in such a way that only the less volatile fraction of the vaporized esters returns to the reaction zone, the more volatile fraction being removed. Thus, coconut oil may be refluxed with methyl stearate so that methyl esters of C8 and C10 fatty acids are distilled off or palm oil may be refluxed with ethyl oleate so that ethyl palmitate is distilled off. Molecular rearrangement catalysts which assist the transfer of the fatty acid radicles, for instance soaps of zinc, aluminium, magnesium or tin, or alkali metal alkoxides may be present in the reaction zone. Where the alcohol is employed, the fat or fatty oil may first be partially alcoholysed by boiling with the alcohol in presence of an ester interchange catalyst, at least a portion of the glycerin formed may then be removed and finally the residue may be refluxed as described above. Refluxing may be carried out above or below atmospheric pressure and the vapours of a monohydric alcohol may be bubbled through the reaction mixture. Suitable fats or fatty oils comprise one or more of the following: tallow, cottonseed oil, coconut oil, palm oil, palm kernel oil, whale oil or fish oil, while suitable esters of monohydric alcohols are methyl, ethyl, propyl, isopropyl or butyl esters. In examples: (1) coconut oil, methyl esters of soyabean fatty acids and a solution of potassium methoxide in methyl alcohol are refluxed together and methyl esters of fatty acids of 12 or less carbon atoms are distilled off; (2) coconut oil and zinc stearate are refluxed together with methyl alcohol passing through the charge and methyl esters are distilled off. Specifications 249,916, [Class 2 (iii)], and 571,209 are referred to.