Glyceryl stearate, saponification

Fat is boiled with aqueous sodium hydroxide to form soap. The esters are broken down in the presence of water - hydrolysed. This type of reaction is called saponification. The equation given below is that for the saponification of glyceryl stearate (a fat). 

Olive oil is largely glyceryl oleate, and palm oil, glyceryl palmitate. When warmed with solutions of caustic alkalies, these fats are decomposed, yieldmg soaps, hence the term saponification. Thus, for example, with sodium hydroxide, glyceryl stearate yields free glycerine and sodium stearate, which latter is a sodium soap. Thus... 

Soap consists of the sodium and potassium salts of various fatty acids such as oleic, stearic, palmitic, lauric, and myristic acids. The saponification for the formation of soap from aqueous caustic soda and glyceryl stearate is... 

Problem 20.30 (a) How many equivalents of base would be used up by one mole of methyl phthalate, -C6H4(COOCH3)2 What is the saponification equivalent of methyl phthalate (b) What is the relation between saponiheation equivalent and the numto of ester groups per molecule (c) What is the saponification equivalent of glyceryl stearate (tristearoylglyerol) ... 

Soaps Substances formed by saponification. In this reaction, the oil or fat (glyceryl ester) is hydrolysed by aqueous sodium hydroxide to produce the sodium salt of the fatty acid, particularly sodium stearate (from stearic acid). Soap will dissolve grease because of the dual nature of the soap molecule. It has a hydrophobic part (the hydrocarbon chain) and a hydrophilic part (the ionic head) and so will involve itself with both grease and water molecules. However, it forms a scum with hard water by reacting with the Ca2+ (or Mg2+) present. 

Stein and Shapiro (1960) prepared three types of labeled triglycerides. Tritiated triolein was prepared according to Wilzbach (1957). In view of the findings of Nystrom et al. (1959), it may be assumed that tritiation resulted in partial saturation of the double bond and that a mixture of oleate and stearate was obtained. Glyceryl-l-C -trioleate-H has been prepared (Olivecrona, 1962) by esteri ung glycerol-l-C with the H fatty acid obtained after saponification of tritiated triolein. A similar preparation of glyceryl-l-C -tripalmitate-9,10-H has been described by Borgstrom and Jordan (1959). 

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