Preparation of partial glycerides by direct esterification1

A previously described procedure for the direct esterification of diglycerides without interesterification occurring has been evaluated for the preparation of mono and diglycerides. The esterifications were accomplished withp‐toluenesulfonic acid catalyst and with continuous removal of water of esterification by azeotropic distillation. The effect of such variables as unsaturation, chain length, mode of addition of solvent and reaction temp on the composition and yield of glycerides was observed. Chemical and chromatographic analyses were used to determine the composition of the glycerides and their component fatty acids and to detect the presence of isomeric glycerides. Simple esterification of 1‐monostearin with oleic acid at 80C yielded as much as 72.3% diglycerides, and esterification of glycerol with stearic acid at 100C yielded up to 70.1% monoglycerides, each calculated on a glyceride basis. It is concluded that simple esterification predominates with some intra‐ and interesterification occurring.