Patent GB-745566-A (GB)
Title: A method of processing fatty triglycerides
IPC: C11C3/06
Filed: 1953-07-31
Abstract: Fatty triglycerides wherein each of the fatty acid radicals contains at least 8 carbon atoms, either pure or in the form of fats and fatty oils, are subjected to concomitant alcoholysis and ester interchange by reacting together such fatty triglycerides, glycerine and an acylated glycerine wherein each acyl radical has from 2 to 6 carbon atoms, in the presence of a basic transesterification catalyst, the proportions of the reactants being such that a product containing acylated glyceryl fatty acid partial ester is obtained.  Naturally occurring fatty triglycerides as found in animal fats such as lard, or vegetable oils such as cottonseed oil, soybean oil, peanut oil, or coconut oil, are particularly suitable.  Mono-, di- or triacyl glycerines or mixtures of two or more such materials may be used, e.g. mono-, di- or triacetins, butyrins, caproins or mixtures thereof. Suitable catalysts include alkali metals, their hydrides, glyceroxides, and hydroxides and bivalent metal hydroxides, e.g. alkaline earth hydroxides, preferably in amounts from 0.001 to 1 per cent, particularly 0.005 to 0.1 per cent by weight based on the total weight of reactants.  The optimum temperature for the process ranges from 180 DEG  to 280 DEG  C., although reaction may be effected at ordinary temperature.  The reaction time varies from 15 minutes to 6 hours.  The glycerine and a polyacylated glycerine may be reacted together prior to the addition of fatty triglyceride.  When an acyl triester of glycerine and glycerine are used in equimolar proportions, preferably each in excess of the amount of fatty triglyceride, the product has an average composition of monoacyl monoglyceride.  The reaction mixture may also contain monoacyl diglycerides and diacyl monoglycerides together with the starting materials.  The latter may be removed by solvent extraction, fractional crystallization of the monoacyl monoglycerides from petrol ether at about 4 DEG  C. or lower, or by vacuum distillation, high vacuum unobstructed path distillation at pressures below 300 microns and at temperatures of 160-185 DEG  C. being most effective.  The products vary from plastic solids of average composition corresponding to monoacyl glyceryl monostearates which form edible coherent films useful as food coatings to liquids which remain fluid at 0 DEG  C. corresponding to monoacyl glyceryl monooleates, useful as food oils and plasticizers.  In examples: (1) glycerine, hydrogenated lard and triacetin are reacted in the presence of strontium hydroxide, unreacted materials are separated on a high vacuum centrifugal still and a film-forming plastic is obtained between 165 DEG  and 185 DEG  C. and below 300m ; (2) hydrogenated lard and calcium hydroxide are added to a pre-reacted mixture of glycerine and triacetin and portions of this mixture are heated for various time periods; (3) to (5) the same reactants as before are heated in various proportions in the presence of calcium hydroxide or sodium hydroxide.ALSO:Fatty triglycerides wherein each of the fatty acid radicals contains at least 8 carbon atoms, either pure or in the form of fats and fatty oils, are subjected to concomitant alcoholysis and ester interchange by reacting together such fatty triglycerides, glycerine and an acylated glycerine wherein each acyl radical has from 2 to 6 carbon atoms, in the presence of a basic transesterification catalyst, the proportions of the reactants being such that a product containing acylated glyceryl fatty acid partial ester is obtained.  Naturally occurring fatty triglycerides as found in animal fats such as lard, or vegetable oils such as cottonseed oil, soyabean oil, peanut oil, or coconut oil, are particularly suitable.  Mono, di or triacyl glycerines or mixtures of two or more such materials may be used, e.g. mono, di or triacetins, butyrins, caproins or mixtures thereof.  Suitable catalysts include alkali metals, their hydrides, glyceroxides, and hydroxides and bivalent metal hydroxides, e.g. alkaline earth hydroxides, preferably in amounts from 0.001 per cent to 1 per cent, particularly 0.005 per cent to 0.1 per cent by weight based on the total weight of reactants.  The optimum temperature for the process ranges from 180 DEG C. to 280 DEG C., although reaction may be effected at ordinary temperature.  The reaction time varies from 15 minutes to 6 hours. The glycerine and a polyacylated glycerine may be reacted together prior to the addition of fatty triglyceride.  When an acyl triester of glycerine and glycerine are used in equimolar proportions, preferably each in excess of the amount of fatty triglyceride, the product has an average composition of monoacyl monoglyceride.  The reaction mixture may also contain monoacyl diglycerides and monoglycerides together with the starting materials.  The latter may be removed by solvent extraction, fractional crystallization of the monacyl monoglycerides from petrol ether at about 4 DEG C. or lower, or by vacuum distillation, high vacuum unobstructed path distillation at pressures below 300 microns and at temperatures of 160 DEG -185 DEG C. being most effective.  The products vary from plastic solids of average composition corresponding to monoacyl glyceryl monostearates which form edible coherent films useful as food coatings to liquids which remain fluid at 0 DEG C. corresponding to monoacyl glyceryl mono-oleates, useful as food oils and plasticizers. In examples (1) glycerine, hydrogenated lard and triacetin are reacted in the presence of strontium hydroxide, unreacted materials are separated on a high vacuum centrifugal still and a film forming plastic is obtained between 165 DEG  and 185 DEG C. and below 300 (2) hydrogenated lard and calcium hydroxide are added to a prereacted mixture of glycerine and triacetin and portions of this mixture are heated for various time periods; (3) to (5) the same reactants as before are heated in various proportions in the presence of calcium hydroxide or sodium hydroxide.