Directed interesterification in glycerides. Reaction in presence of added glycerol

Abstract

Summary Directed interesterification, in which ester‐ester interchange is carried out in triglyceride mixtures with simultaneous crystallization of solid glycerides, has been applied to glyceride mixtures containing free hydroxyl groups. Solid glycerides precipitated from cottonseed oil with added glycerol were principally saturated diglycerides or saturated monoglycerides. The prineipal varables controlling the kind and proportion of solid precipitated during reaction from glycerides of a given original composition are the proportion of free alcohol groups, the time‐temperature schedule for the reaction, and the method of seeding, if any, used to start the crystallization. The method makes it possible to segregate the high‐melting and low‐melting fatty acids of a fat practically completely into separate ester fractions.

Questions begging for answers (Part III) – Interesterification

“…That leaves the anhydrous catalyst inactivation. Quite some time ago, the use of glacial acetic acid was mentioned in this context . It has not been used industrially since the acid is corrosive and its recuperation would be cumbersome.…”

Interesterification, chemical or enzymatic catalysis

“…As discussed in my 2009 Bailey Award Address, the loss caused by the FFA formation can also be avoided by inactivating the catalyst with glacial acetic acid, first reported over 60 years ago . I reported an experiment using 1 wt% of sodium methanolate, which is about twenty times the normal amount.…”

Advances In The Synthesis Of Glycerides Of Fatty Acids

“…Eckey's "directed interesterification" (30a, 48), according to which natural fats can be segregated into saturated and unsaturated triglycerides, has been modified to produce monoglycerides and diglycerides of high purity (49). According to this procedure mixtures of triglycerides and glycerol are subjected in the presence of a highly active catalyst (sodium methoxide) to an interesterification process combined with simultaneous fractional crystallization.…”

“…A. a,a'-Diglycerides Developments in the synthesis of «, «'-diglycerides comprise: (1) the preparation of pure diglycerides with one and two unsaturated acid components by the use of the trityl technique (42,43,44) and by direct acylation of «-monoglycerides (16, 25, 29, 42, 45, 66, 67); (2) the synthesis of saturated diglycerides with the aid of new blocking techniques (10,123,131); and (3) the preparation of simple diglycerides by modified "directed interesterification" (14,15,49) and by the direct acylation of glycerol (27,72,129). The trityl technique and the direct acylation of -monogly ceri des may be used for the preparation of both simple and diacid diglycerides, whereas the modified "directed interesterification" and direct acylation of glycerol produce simple diglycerides only.…”

“…As mentioned in the section on -monoglycerides, the modified "directed interesterification" of fats results in the formation of diglycerides if the reaction is carried out in the presence of suitable proportions of glycerol (14,49). Natural fats containing principally one kind of saturated acid may be used, but better yields and purer products are obtained if mixtures of simple triglycerides and triacetin are interesterified and progressively crystallized (15).…”