Patent GB-731177-A (GB)
Title: Stabilized monoester compositions and method of making the same
IPC: C11B5/00
Filed: 1952-10-21
Abstract: The invention comprises a mixture of improved stability containing a fatty acid monoester of a polyhydric alcohol, glycine or a salt thereof and phosphoric acid or a salt thereof. The mixture may also contain at least 85 per cent of a fatty material such as a triglyceride.  Diesters or fatty acids may also be present.  Many monoesters are indicated for treatment representative being animal fat esters derived from lard and tallow, vegetable fat esters derived from cottonseed or coconut oils which may be hydrogenated and monoesters made by reacting such acids as stearic and linoleic acid with polyhydric alcohols. Amongst polyhydric alcohols specified are glycerol, ethylene glycol, sorbitol, mannitol and pentaerythritol. The monoesters may be made by conventional ester-interchange processes and details are given of these processes.  The mixture is desirably formed by admixing glycine and phosphoric acid with the monoester at a temperature not substantially lower than 50 DEG  C. and higher than 90 DEG  C. and desirably below 98 DEG  C. and the mixture should be kept at below 120 DEG  C.  Preferably the mixture is prepared at 60-90 DEG  C. and glycine and phosphoric acid added separately, desirably in solution in a solvent such as glycerol.  In the stabilization process salts of glycine and phosphoric acid may be used instead of the free base and acid.  The concentration of phosphoric acid should preferably not be greater than twice that of glycine and ratios of glycine to acid of 4 : 1 to 1 : 2 are desirably used.  The combined weight of glycine and phosphoric acid is desirably from about 0.005 to 0.1 per cent of the weight of monoester.  Various oxidation tests are described in which cottonseed oil monoglyceride, hydrogenated cottonseed oil mono-and diglyceride, peanut oil monoglyceride and lard oil monoglyceride are admixed with glycine and phosphoric acid, it also being shown that the addition of citric acid lessens the antioxidative effect.  In the manufacture of shortening agents the fatty triglyceride is preferably mixed with the stabilized monoester but all ingredients may be used without pre-mixing.  The stabilized monoester is added at elevated temperatures desirably not above 100 DEG  C.  The inhibitory effect on the oxidation of shortenings consisting of partially hydrogenated cottonseed and soybean oils and lard containing cottonseed oil monoglyceride stabilized with glycine and phosphoric acid is illustrated and bleached oleic acid is also stabilized with the same mixture.ALSO:Fats and fatty acids are stabilized against oxidation by the addition of a fatty acid monoester of a polyhydric alcohol, glycine or a salt thereof and phosphoric acid or a salt thereof. Preferably the monoester, glycine and phosphoric acid constituents are mixed together before addition to the fatty material.  Many monoesters are specified, representative being animal fat esters derived from lard and tallow, vegetable fat esters derived from cottonseed or coconut oils which may be p  hydrogenated and monoesters made by reacting such acids as stearic and linoleic acid with polyhydric alcohols.  Amongst polyhydric alcohols specified are glycerol, ethylene glycol, sorbitol, mannitol and pentaerythritol. Representative of fats specified are lard, tallow, cottonseed oil and corn oil and the fats may be hydrogenated.  Representative of fatty acids specified are oleic and linoleic acids.  The fatty materials are preferably admixed with 0.5-5 per cent by weight of monoglyceride which is first stabilized by premixing with glycine and phosphoric acid.  The amount of either glycine or phosphoric acid in the triglyceride-monoglyceride composition is preferably from 0.00005 to 0.02 per cent by weight.  Desirably the mixture is made when the fatty materials are liquid although the temperature should not be raised to more than 120 DEG  C.  Tables illustrate the improvement in stability shown by bleached oleic acid, hydrogenated lard, lard and hydrogenated cottonseed and soybean oils containing such monoesters as cottonseed oil monoglycerides stabilized with glycine and phosphoric acid, comparisons being made with conventional stabilizers such as citric acid and butylated hydroxy anisole.ALSO:Shortenings of improved stability to oxidation contain a fatty acid monoester of a polyhydric alcohol, glycine or a salt thereof and phosphoric acid or a salt thereof.  Many monoesters are specified representative being animal fat esters derived from lard and tallow, vegetable fat esters derived from cottonseed or coconut oils which may be hydrogenated and monoesters made by wasting such acids as stearic and linoleic acid with polyhydric alcohols.  Amongst polyhydric alcohols specified are glycerol, ethylene glycol, sorbitol, wannitol and pentaerythritol. The shortenings may be animal or vegetable, e.g. containing lard or hydrogenated vegetable oils.  Preferably 0.5-5 per cent by weight of monoglyceride based on the weight of fatty torglyceride is used, the monoglyceride first being stabilised by premixing with glycine and phosphoric acid or salts thereof 0.00005-0.02 per cent by weight of glycine or phosphoric acid should preferably be admixed with the triglyceride-monoglyceride composition.  The mixing should be effected at temperatures at which the triglyceride is soft or liquid but not at above 120 DEG C.  Tables are provided illustrating the improvement in stability shown by shortenings of hydrogenated stability and shortening activity shown by shortenings of hydrogenated lard, lard and hydrogenated cottonseed and soybean oils containing such monoesters as cottonseed oil monoglycerides stabilised with glycine and phosphoric acid.