Improvements in and relating to the prevention of the development of rancidity in vegetable oils

摘要

331,814. Imperial Chemical Industries, Ltd., and Tattersall, H. J. March 7,1929. Fats and fatty oils.-A method of preventing castor oil from becoming rancid, particularly in connection with the manufacture of leather cloth by means of nitrocellulose, consists in treating the oil with peracetic acid, its substitutes or derivatives. The invention is based on the known fact that certain unsaturated compounds react with peracetic acid to form acetoxy glycollic derivatives. For example, trilinolein in the presence of peracetic acid and under suitable conditions forms 11, 111, 1111: 14, 141, 1411-hexahydroxy-10, 101, 10" : 13, 131, 13"-hexacetoxy trilinolein which under the influence of oxidizing agents does not give use to n-caproyl aldehyde, one of the evil-smelling constituents of rancid castor oil. It is found to be unnecessary to convert the whole of the oil into the acetoxyglycollic derivative, and only sufficient peracetic acid is added to attack the trilinolein constituent of the castor oil. This " peracetylated castor oil " may be formed by mixing castor oil, 2170 parts; hydrogen peroxide (100 vols.), 37 parts; glacial acetic acid, 92 parts; and concentrated sulphuric acid, 0.78 part. The treatment is not limited to the treatment of castor oil; it may be applied to any vegetable oil containing unsaturated glycerides, for example, linseed oil or cotton seed oil.