GB763474A - Improvements in or relating to the production of fatty acid monoglycerides - Google Patents

Abstract

Fatty acid monoglycerides are produced by reacting with glycerol in the presence of tertiary butyl alcohol and an alkaline catalyst a di- or tri-glyceride of a fatty acid which is substantially insoluble in water, or a mixture of glycerides of said fatty acids, the glycerol being in excess of that required to form the monoglyceride, and separating from the reaction products a product consisting mainly of monoglyceride; any water present in the reaction ingredients being removed before commencing the reaction. Neutral animal or vegetable oils, e.g. tallow or hydrogenated tallow, olive oil, linseed oil, soya bean oil, castor oil, and a mixed blend of oils as used in margarine manufacture, may be used with 50-60 parts by weight of glycerol for every 100 parts by weight of oil. The oil is conveniently dissolved in t-butanol containing hexane and the mixture distilled to remove water. A mixture of mono-, di- and tri-glycerides may be prepared by heating the free fatty acid with glycerol to 200 DEG C. The product, after dissolving in t-butanol and dehydrating by distillation, may be used as starting material. Suitable catalysts are sodium methoxide, sodium t-butoxide, and magnesium alkoxides. The preferred catalyst is sodium or potassium glyceroxide prepared by dissolving alkali metal hydroxide in glycerol and removing water by distillation. The glycerol solution of catalyst may be added to the solution of oil in t-butanol and the mixture allowed to stand for 24 hours. The catalyst is then neutralized, e.g. with citric acid, and the t-butanol recovered by distillation under reduced pressure, water being added in the later stage of the distillation. The residue is allowed to separate into two layers, an upper layer of monoglycerides and a lower layer of aqueous glycerol. In some cases, the monoglyceride may be allowed to crystallize out with out neutralizing the catalyst and the mother liquor after filtering off the monoglyceride may be used for the preparation of fresh monoglyceride. Detailed examples are given of the preparation of glyceryl mono-oleate from olive oil, and glyceryl monostearate from a mixture of mono-, di- and tri-esters produced by heating glycerol and stearic acid.