GB561109A - An improved process for treating fish livers - Google Patents

Abstract

561,109. Extracting fish liver oils. NATIONAL OIL PRODUCTS CO. Aug. 18, 1942, No. 11595. Convention date, July 26, 1941. [Class 91] Oil is obtained from raw fish livers by extraction at elevated temperatures insufficient to destroy any substantial portion of the vitamin A and below the coagulation point of the protein i.e. about 50-60‹ C. with a mixture of an organic solvent for the oil and a water - miscible lower aliphatic. acid. The latter has a penetrating effect on the liver cells and enhances the release of the oil. Acetic acid is preferred but other acids specified comprise lactic, citric, propionic, and formic. Solid acids dissolve in the juice or water associated with the livers. The solvents specified comprise ethylene dichloride, trichloroethylene, hexane, dichloroethyl ether, ethyl ether, chloroform, acetone, petroleum ether, cyclohexane, and methyl cyclohexane. The proportion of acid in the solvent-acid mixture may range from 2 to 20 per cent by weight, preferably from 5 to 10 per cent. Vitamin A or D- containing fish livers are preferably treated. The livers may be preliminarily treated with the acid before addition of the solvent. The livers are treated in comminuted form. After treatment, the oilsolvent-acid mixture is separated off and any remaining oil removed mechanically or by solvent extraction using the previous solvents, acidified or not. The acid is removed from the liquid by washing with water or by distillation under vacuum, and the solvent is then separated such as by vacuum distillation under an atmosphere of nitrogen. Specification 414,717 is referred to.