Esterification and interesterification

Abstract

A versatile and large group of fatty acid esters are prepared from monohydroxy alcohols (C1 to C22 members), glycols (ethylene and propylene glycols and others), etherglycols (many polyoxyethylene glycols), triols (glycerol and others), tetraols (pentaerythritol and others), polyglycerols, carbohydrate materials (sorbitol, sorbitan, sucrose and others). The two most important direct esterifications of fatty acids are those done with monohydroxy alcohols (methanol, butanol, etc.) and glycerol itself. Esterifications of these materials are carried out with or without the use of catalysts. For edible ester products, the choice of catalyst is determined by (a) rate of reaction promotion permitted by the use of the catalyst; (b) color of product obtained; (c) ease of removal of catalyst; (d) toxicity of catalyst, and perhaps; (e) other factors including promotion of acrolein formation from glycerol, loss by volatilization at high temperatures, inactivation above certain threshold temperatures, and catalyst corrosivity on the materials of construction of the esterifier. In certain instances the last factor may indeed be the paramount one in a particular catalyst choice for a direct esterification. Industrial production of methyl esters is principally by a process of interesterification called methanolysis. Polyols require conditions for complete esterification that are vigorous and severe. The two most important interesterification methods used in the fatty acid industry are the methanolysis of fats and oils for the production of methyl esters and the glycerolysis of fats and oils for the production of three kinds of so‐called “monoglycerides”, namely the 40%, 60% and 90% monoglycerides.

Esterification kinetics of glycerol with fatty acids in the presence of sodium and potassium soaps

“…The formation of a microemulsion during preparation of fatty acid esters in the presence of sodium carboxylate was observed previously [18]. In order to shift the equilibrium constant towards the synthesis of monoacylglycerols azeotropic methods with corresponding solvents [10,11,14] or esterification at reduced pressure were used [19].…”

“…The influence of reaction parameters like temperature [10][11][12][13], molar concentration [13,14], and catalysts [10,11] was mainly investigated for the optimization of monoacylglycerol yield and the rate of the esterification process. Many alkaline catalysts e.g.…”

Physical and chemical properties of randomly interesterified blends of soybean oil and tallow for use as margarine oils

“…One alternative to partial hydrogenation is interesterification of liquid vegetable oils with a hard fat. Interesterification has been used for many years to modify the physical properties of lard to produce a smooth, noncrystalline consistency (14,15). Recently, List and coworkers (16) interesterified soybean oil with completely hydrogenated soybean oil to produce a plastic fat suitable for use in margarines.…”

Interesterificação química e enzimática de misturas de estearina de palma, óleo de coco e óleo de canola para formulação de margarinas com baixa concentração de isômeros trans

“…Desta forma, a interesterificação é uma alternativa à hidrogenação parcial para obter produtos livres de ácidos graxos trans, com aplicações em margarinas e substitutos da manteiga de cacau (LIU; LAMPERT, 1999;SONNTAG, 1982).…”

“…PK has 40-50 % (w/w) of lauric acid, which provides for easy digestion and confers plasticity to the final product (NORIZZAH et al, 2004;SONNTAG, 1982). The health benefits of virgin OO have been attributed to its high content of the monounsaturated fatty acid, oleic acid, and high levels of natural antioxidants, namely tocopherols, providing health benefits (JANSEN;…”