Tallow sucrose esters

The acute toxicity for a number of different compounds in this general class has been studied in a range of animal models. The results summarized in Table 2 reveal that no significant toxic events can be associated specifically through oral ingestion of sugar fatty acid esters. One exception appeared to be the higher dose of lard and tallow sucrose esters administered to the rat, which resulted in death. Also notable is the positive hemolytic result for sucrose monopalmitate when administered intravenously to the rat. Surfac-... 

Lard and tallow sucrose esters Rat 10% for 28 months, no tumors or abnormalities 0.5% for 14 months, no adverse effects 0.5% over two generations, no reproductive effects or neonatal abnormalities 3% No adverse effects, no carcinogenicity over 18 months ... 

Sucrose ester of fatty acid Sucrose cocoate Sucrose tallowate Sodium citrate Propylene glycol Ethanol Water... 

The process originally selected involved transesterification between a triglyceride (fat, e.g., tallow) and sucrose in dimethylformamide (DMF-a mutual solvent) in the presence of a catalyst (potassium carbonate -K2CO3) at a temperature of 90°C. Under these conditions the fatty acid underwent transfer to sucrose giving a complex mixture of mono- and diglycerides and sucrose esters. The reaction is not complete and the product also contains unreacted sucrose and tallow, giving problems in purification and analysis. 

As can be seen, at 125°C there is a dormant period of approximately 6 hours before any significant reaction takes place. This time has been termed the initiation period, the end of which is associated with the reaction mixture incorporating a large amount of gas with concomitant foaming. During this stage an emulsion develops which is followed by the rapid formation of sucrose esters. It is of interest to note that the triglyceride reacts very slowly compared with commercially available tallow. 

The products of our procedure are mixtures of sucrose esters and glycerides, for which an average composition, obtained by using tallow or palm oil as a starting material, is presented in Table I. 

Although data on the toxicology of sucrose esters in humans is less common than in animal models, some studies are reported. A pharmacokinetic study of human volunteers fed 1 g of sucrose tallowate showed no adverse effects, and plasma and urine analyses indicated rapid hydrolysis of the ester in the gastrointestinal tract and almost complete absorption and subsequent excretion of the hydrolysis products. This indicated Kttle tendency for the ester to accumulate in body tissues [79]. 

D.M. Virgo, R. Ashby, H.A. Cummin and P.L.a.F.J.P. Hepworth, Sucrose esters of beef tallow toxicity in dietary administration to beagle dogs for 26 weeks. Unpublished report by Life Science Research, submitted by Tate Lyle Limited, Reading, Berkshire, England. (1979). 

Parrish (1977) reviewed the research and development of lactose ester-type surfactants carried out by Scholnick and his colleagues (Scholnick et al. 1974, 1975 Scholnick and Linfield 1977). Their initial attempts to form lactose esters followed the same transesterification procedures that had been used with sucrose (a fatty acid methyl ester in N,N-dimethylformamide with potassium carbonate as the catalyst). Their successful approach was the reaction of lactose in N-methyl-2-pyrrolidone as the solvent with fatty acid chlorides, resulting in yields of 88 to 95% for esters of lauric, myristic, palmitic, stearic, oleic, and tallow fatty acids. The principal product was the monoester, which is important for detergent use, since diesters and higher esters of lactose are not water soluble. 

Ratio of reactants. Approximately equimolar pro-portions of sucrose and tallow have been used in these studies. However, because the system is heterogeneous, the effect of changing the relative proportions of reactants will be lessened by their mutual insolubility. In practice, the highest conversion of sucrose to esters is obtained with an approximately 40% molar excess of sucrose. 

SCHEME 1 Ryoto sugar ester synthesis is based on transesteriiication of sucrose with a methyl fatty acid ester under conditions in which methanol is continuously removed. The product includes a complex mixture of K-soaps, diesters and mono-/ diglycerides, as well as the sucrose monoester when produced from crude beef tallow. An excess of sucrose is required (3 mol) to enhance the yield of the monoester over higher substituted products. DMF must be recovered for economic operation and because of its toxicity. 

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