GB974432A - A process for the hydrogenation of phosphatides - Google Patents

Abstract

Phosphatide (i.e. lecithin) material is hydrogenated by a process comprising first contacting a catalyst consisting of one or more of palladium, platinum, and rhodium, preferably dispersed on a carrier, with hydrogen in the absence of said phosphatide material and second contacting said phosphatide material with hydrogen in the presence of the catalyst to promote a decrease in the unsaturation of the phosphatide material. Both the pre-reduction of the catalyst and the hydrogenation of the phosphatide may be performed at 5 to 100 p.s.i.g. being preferably 45 p.s.i.g. and 15 p.s.i.a. respectively, and it is desirable to prevent contact of the catalyst with an oxidizing agent, e.g. air, between the two stages. The phosphatide may be pretreated with an acid, acid anhydride or a solvent comprising an alcohol to inhibit catalyst inactivation and, in general any solvent, or combination of solvents, in which the phosphatide is soluble but which will not inactivate the catalyst may be used for the reaction. It is desirable that such solvents should be removable under vacuum at temperatures lower than 95 DEG C. The phosphatide may also be bleached with an oxidizing agent, e.g. hydrogen peroxide, before or after hydrogenation in order to lighten the colour of the product. It is preferable to conduct the hydrogenation at below 70 DEG C. preferably 25 to 60 DEG C., and to filter off the catalyst at the end of the reaction after the addition of a filter acid. During this filtration the catalyst should be protected from oxygen and, in this connection, it is desirable to saturate the product solution with hydrogen or an inert gas, e.g. nitrogen, prior to filtration. The solvent is removed under reduced pressure and the product may be vacuum steam deodorized. Solutions of base, or aqueous suspensions of bases of limited water solubility, may be added to the product before or after deodorization to raise the aqueous pH to as high as 8.0, after which the water may be removed under vacuum. Numerous examples are given employing as the source of phosphatide commercial soybean lecithin, oil-free soybean phosphatides, alcohol-soluble or insoluble fractions of soybean phosphatides, peanut lecithin and com lecithin. The hydrogenated phosphatides obtained may be used as emulsifiers in the food and pharmaceutical industries (see Division A2).ALSO:Material obtained by the catalytic hydrogenation of phosphatide, e.g. lecithin, (see Division C2) is employed as an emulsifier in food preparations, such as ice-cream, cakes and biscuits.