Hydrolysis of a triglyceride

Figure D1.4.2 Hydrolysis of a triglyceride by lipase or heat to produce free fatty acids.

Saponification Since triglycerides are esters, they undergo the same kinds of reactions as other esters. One important reaction is hydrolysis by aqueous sodium hydroxide, which is a reaction called saponification (see Figure 12.26). Saponification means soap forming, and this is how soaps are synthesized. Hydrolysis of a triglyceride (with hot, aqueous NaOH) gives glycerin and three fatty acids. 

Perhaps the oldest example of ester hydrolysis is the process called saponification. It is the hydrolysis of a triglyceride (fat) with an aqueous base such as sodium hydroxide (NaOH). During the process, glycerol, also commercially named glycerin, is formed, and the fatty acids react with the base, converting them to salts. These salts are called soaps, commonly used in households. 

In addition to de novo synthesis from acetyl CoA, fatty acids can be derived from the enzymatic hydrolysis of triglycerides. The primary form in which fatty acids are stored and transported between cells, triglycerides consist of three fatty acyl chains esterified to glycerol hence they are also called triacylglycerols (see Figure 18-2). Complete hydrolysis of a triglyceride molecule yields three unesterified fatty acid molecules, or free fatty acids (FFAs), and a glycerol molecule. 

Figure 3. Liberation of diglycerides, monoglycerides, and glycerol during hydrolysis of a triglyceride by pancreatic lipase in the presence of sodium taurocholate and calcium ions. Key O, triglyceride 0, diglyceride , monoglyceride X> glycerol. Reproduced, with permission, from Ref. 8. Copyright 1965, Academic Press...

Figure 12 Enzymatic hydrolysis of a triglyceride in combination with migration of the acyl group from the 2- to the 1-position.

Hydrolysis of a triglyceride to glycerol and fatty acids—general reaction (Section 8.4) ... 

An amphoteric amine sulfate surfactant is tested as a catalytic system for the base-catalyzed hydrolysis of a triglyceride. What pH range (<5, 5-8, <8) would you expect to be most appropriate for maximum rate enhancement Explain why. 

Fats and oils are very similar in that both are triesters of glycerol, hence fhe name friglyceride. Hydrolysis of a triglyceride in aqueous base followed by acidificafion gives glycerol and fhree carboxylic acids. Because fhese carboxylic acids can be derived from fafs, fhey are called fatty acids. 

Saponification is the hydrolysis of a triglyceride by a strong base. The products are glycerol and a soap. 

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