GB642977A - Retardation of development of reversion flavor in hydrogenated fats and oils - Google Patents

Abstract

A refined and filtered fatty oil containing combined fatty acids having more than two double bonds in non-conjugated position is contacted with at least one solid material, the group consisting of activated alumina, active aluminium silicate, calcium hydroxide, calcium oxide and zinc oxide and hydrogenated before substantial contact with oxygen whereby the development of reversion flavour is retarded. Activated alumina includes activated bauxite. The amount of solid is at least 0.2 per cent and preferably between 2 and 5 per cent by weight of the oil, and is of 5 to 200 mesh particle size. The temperature should not rise above 60 DEG C. when treatment with the solid is effected. In an example crude soybean oil is refined with caustic soda, decanted, mixed with diatomaceous earth and filtered, bleached and then treated with 5 per cent 80-mesh activated alumina at 27 DEG C. Agitation in a nitrogen atmosphere was carried out for 1 hour followed by filtering as before. Hydrogenation at 180 DEG to 200 DEG C. with a nickel catalyst was promptly effected until the iodine value had dropped to 80, then cooled in hydrogen to 60 DEG C., filtered, bleached and steam deodorized at 200 DEG C. under reduced pressure. In a modification, the refined and bleached soybean oil is dissolved in petroleumether and passed through a tube containing activated alumina. Solvent evaporated and the oil was promptly hydrogenated and deodorized. U.S.A. Specification 2,174,177 is referred to.